SYSTEMS AND METHODS FOR APPLYING THERMOLYSIS AND/OR ELECTROLYSIS GAS COMPRESSION TO BLAND/EWING CHEMO-THERMODYNAMIC CYCLES

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part application of U.S. patent application Ser. No. 19/303,034, filed Aug. 18, 2025, which is a continuation-in-part application of U.S. patent application Ser. No. 17/746,848, filed May 17, 2022, which claims priority to, and the benefit of, U.S. Provisional Application No. 63/189,634, filed May 17, 2021, the entire content of each of which is hereby incorporated by reference. U.S. patent application Ser. No. 19/303,034 is also a continuation-in-part application of U.S. patent application Ser. No. 18/197,092, filed on May 14, 2023, which claims priority to, and the benefit of, U.S. Provisional Application No. 63/342,093, filed on May 14, 2022, the entire content of each of which is hereby incorporated by reference. U.S. patent application Ser. No. 19/303,034 is also a continuation-in-part application of U.S. patent application Ser. No. 18/362,951, filed on Jul. 31, 2023, which claims priority to, and the benefit of, U.S. Provisional Application No. 63/393,960, filed Jul. 31, 2022, and U.S. Provisional Application No. 63/439,781, filed Jan. 18, 2023, the entire content of each of which is hereby incorporated by reference. U.S. patent application Ser. No. 19/303,034 is also a continuation-in-part application of U.S. patent application Ser. No. 19/275,589, filed on Jul. 21, 2025, which claims priority to, and the benefit of, U.S. Provisional Application No. 63/674,261, filed on Jul. 22, 2024, the entire content of each of which is hereby incorporated by reference.

This application also incorporates by reference the entire content of U.S. patent application Ser. No. 18/095,463, filed on Jan. 10, 2023, and issued as U.S. Pat. No. 12,352,250, on Jul. 8, 2025.

PRIOR ART

This application is in part related to U.S. Pat. Nos. 4,817,388, 5,179,839, 3,067,594, 3,225,538, and 3,871,179.

BACKGROUND

U.S. Pat. No. 3,067,594 proposed an open-cycle Bland/Ewing chemo-thermodynamic process.

U.S. Pat. No. 3,225,538 proposed a closed-cycle Bland/Ewing chemo-thermodynamic process.

U.S. Pat. No. 3,871,179 proposed the application of the B/E cycle to the classic Stirling cycle.

U.S. Pat. No. 4,817,388, “Engine with Pressurized Valved Cell proposed the concept of an auxiliary “valved cell” for connecting a compressor to an expander via a “transfer valve”.

U.S. Pat. No. 5,179,839, “Alternative Charging Method for Engine with Pressurized Valved Cell”, granted to Joseph B. Bland, proposed an alternative charging method for an auxiliary “valved cell” for connecting a compressor to an expander via a “transfer valve”.

U.S. Pat. No. 12,352,250 proposes:

• • a. A Bland/Ewing (B/E) chemo/thermodynamic cycle termed a B/E Liquid cycle (B/E-L);
  • b. the use of a portion of the B/E-L cycle's exhausted endothermic product as the heat source for vaporizing and/or preheating non-gaseous and/or gaseous reactant/reactant mix and/or assisting in preheating said non-gaseous and/or gaseous product/product mix or a portion of said product/product mix;
  • c. a B/E Combined cycle (B/E-C), where a high temperature heat engine cycle powers lower temperature B/E cycle with the high temperature waste heat of the high temperature heat engine cycle; and
  • d. the use of ducted/valved regeneration as a means of increasing the efficiency of heat transfer for B/E cycles.

U.S. Pat. No. 12,392,261 proposes:

• • a. A Bland/Ewing chemo/thermodynamic cycle termed a Chemo/thermodynamic Closed Combined cycle (CCC) which is composed of
    • i. an Endothermic Chemo/thermodynamic Open cycle (En-C-O), and
    • ii. an Exothermic Chemo/thermodynamic Open cycle (Ex-C-O).
  • b. An Exothermic Reactor Exhaust Compressor (EREC) for permitting otherwise waste CCC heat to convert liquid/frozen working fluids into pressurized vapors and/or gases.
  • c. Various En-C-O and Ex-C-O cycles.
    U.S. Pat. No. 12,352,250

This application is a Continuation In Part of U.S. Pat. No. 19,303,034, which is incorporated by reference in its entirety. U.S. Pat. No. 19,303,034 is a Continuation In Part of U.S. Pat. No. 12,352,250. Figures for U.S. Pat. No. 19,303,034 will be referred to herein by their U.S. Pat. No. 19,303,034 Figure number. Figure element nomenclature for U.S. Pat. No. 19,303,034 will be referred to herein by their U.S. Pat. No. 19,303,034 Figure element nomenclature. U.S. Pat. No. 19,303,034 specification Embodiments will be likewise referred to by their U.S. Pat. No. 19,303,034 Embodiment number. Additional Figures herein will be considered addendums to U.S. Pat. No. 19,303,034 Figures and numbered accordingly. Said additional Figures element nomenclature will likewise be considered addendums to U.S. Pat. No. 19,303,034 and likewise numbered accordingly. Additional Embodiments herein will likewise be considered addendums to U.S. Pat. No. 19,303,034 Embodiments and will likewise be numbered accordingly.

Summarizing U.S. Pat. No. 19,303,034:

The Stirling Cycle as Compared to Existing Stirling Engines

A Stirling cycle involves a strictly ideal series of two isothermal processes separated by two isochoric (i.e., constant volume) processes. That is, for a vapor or gaseous working fluid, from an initial point of lowest pressure and temperature, a Stirling cycle engine posits the use of:

• • (1) An isochoric increase in temperature and concomitant increase in pressure.
  • (2) An isothermal expansion and concomitant decrease in pressure.
  • (3) An isochoric decrease in temperature and concomitant decrease in pressure.
  • (4) An isothermal compression and concomitant increase in pressure, which returns the vapor or gas to the state it started from.

A classic Stirling cycle is clearly described in the specification and drawings of U.S. Pat. No. 3,871,179, FIGS. 1A through 1D. Per those figures, beginning at the position of the upper and lower pistons as shown in FIG. 1A of U.S. Pat. No. 3,871,179, an ideal Stirling cycle engine would seem to require:

• • (1) As shown in the move from FIG. 1A to FIG. 1B, without moving the upper piston, moving the lower piston through its (ideally isothermal) compression stroke;
  • (2) as shown in the move from FIG. 1B to FIG. 1C, moving both pistons simultaneously and at the same rate over an equal distance in order to displace the gases through the cooler/regenerator/heater matrix at constant volume;
  • (3) as shown in the move from FIG. 1C to FIG. 1D, immediately pausing the lower piston while the upper piston undergoes an (ideally isothermal) expansion; and
  • (4) as shown in the move from FIG. 1D to FIG. 1A, cooling the gases at constant volume by movement of both pistons simultaneously and at the same rate over an equal distance in order to displace the gases through the heater/regenerator/cooler matrix at constant volume.

Thus, a classic Stirling cycle would contain sharp “points” where each constant volume process begins and ends and each constant temperature process begins and ends. That is, the cycle would require an essentially impossible scenario to be enacted, where the various pistons are required to instantaneously stop, hold position, and then instantaneously restart in the opposite direction. It would also require both isothermal heating and isothermal cooling.

So-called “Stirling engines” do exist and do produce useful work relatively efficiently. Those practiced in the art of Stirling engine design are highly cognizant of the difference between an ideal “Stirling cycle” and a practical “Stirling engine”. In a Stirling engine, the Stirling cycle's “pointed” processes are essentially “blended” within a single contiguous volume that is essentially shuttled between two or more positive displacement, contiguous but non-synchronous cylinders with pistons or lobes acting upon the contiguous volume. As a result, in a practical Stirling engine, the sharp “points” of the classic Stirling cycle are rounded into curves that are blended into one another, containing no single segment with a true constant volume or constant temperature process. In other words, since halting a piston in mid-movement is extremely difficult if not impossible to accomplish efficiently, constantly reciprocating pistons are used to create an approximation of a Stirling cycle.

The Valved Cell and Closed Cycle Valved Cell Concepts

On Sep. 20, 2000 Joseph B. Bland was awarded a grant from the California Energy Innovation Small Grant (EISG) program for construction of a Closed Cycle Valved Cell (CCVC) testbed. See U.S. patent application Ser. No. 18/362,951, FIG. 7 and FIG. 8 for a photograph and FIG. 9 for a cutaway solid model view of the EISG CCVC testbed. The “EISG CCVC testbed” was constructed and tested under the terms of that program and the results were submitted to the program. The data received indicated that the processes for which it was designed functioned largely as predicted.

The EISG grant was based on the concepts patented in U.S. Pat. No. 4,817,388, “Engine with Pressurized Valved Cell, and U.S. Pat. No. 5,179,839, “Alternative Charging Method for Engine with Pressurized Valved Cell”, both granted to Joseph B. Bland, which proposed the concept of an auxiliary “valved cell” for connecting a compressor to an expander via a “transfer valve”. Over time, it has come to be appreciated that valved cells can be seen as means to connect various kinds of heat engine processes to one another, including, for example, a constant volume displacement regenerator.

The valved cell process described in U.S. Pat. No. 4,817,388 is as follows: “There is, therefore, provided in practice of this invention according to a presently preferred embodiment a method of operating an engine comprising the steps of compressing a gas to a pressure approximately the same as a pressure in the engine, temporarily isolating a mass of the compressed gas, and opening communication between the isolated gas and the engine while the isolated gas is at approximately the same pressure as in the engine for intermittently releasing substantially all of the temporarily isolated mass of gas into the engine for expansion.” U.S. Pat. No. 5,179,839 discloses an alternate means of accomplishing the same result.

As stated in U.S. Pat. Nos. 4,817,388 and 5,179,839, a valved cell is used to present a compressed gas and/or vapor to an expander, and a special kind of intake valve or “transfer valve” is used to connect the valved cell to the expander. The transfer valve is designed to almost instantly connect the valved cell to the expander just following early closure of the expander exhaust valve and the naturally-resulting recompression of remnant gases thus trapped in the cylinder head, such as to at least match the pressure within the recompressed gas with the pressure of the gas within the valved cell. Finally, constant pressure recharging of the valved cell is made to occur just following or just prior to instant closure of the transfer valve following displacement of the contents within the valved cell into the expander, depending on the use of either the charging system of U.S. Pat. No. 4,817,388 or 5,179,839.

In either a Stirling cycle or a Stirling engine, a cyclical positive displacement system with a single contiguous volume is assumed. However, as has been demonstrated in the EISG CCVC testbed, true constant volume (isochoric) displacement heat transfer processes are in fact possible using non-contiguous but synchronized volumes cyclically connected by valves. In the EISG CCVC testbed, the valved cell concept in those patents was used to cyclically connect and disconnect two separate constant volume or isochoric working fluid displacement processes.

The result of this process is a heat engine with true isochoric displacement heat transfer capability as compared to the non-isochoric displacement heat transfer capability found in typical Stirling engines. Careful measurements were made of the prototype engine, verifying that thermal energy was successfully passed isochorically from the exhausting gas to the inflowing gas during the two isochoric processes. Note that a small amount of recompression was used within the expander to “open” the transfer valve at Top Dead Center (TDC), in the manner described within U.S. Pat. Nos. 4,817,388 and 5,179,839. Since the same working fluid was constantly recirculated through the engine, the engine is thus classifiable as a “closed cycle” (CC) heat engine. And since it used a recompression process to aid in opening the transfer valve, the engine is thus classifiable as a “valved cell” (VC) engine. Hence the term CCVC engine.

The EISG CCVC Testbed as a Hybrid Ericsson/Stirling Closed Cycle Heat Engine

An Ericsson cycle, like a Stirling cycle, reuses gases following the expansion process to “preheat” gases prior to the addition of source heat, this theoretically greatly increasing thermal efficiency. In a Stirling cycle, that preheating and source heat addition occurs at constant volume or isochorically, while an Ericsson cycle, that preheating and source heat addition occurs at constant pressure or isobarically. In addition, both cycles propose constant-temperature or isothermal expansion and compression, although neither perfectly accomplishes that. However, because Ericsson cycles occur at constant pressure, it is much easier for them to utilize counter-flow heat exchangers such as those used in the EISG CCVC testbed, since the length of the heat exchangers and the time required for exchanging heat are not as important in constant pressure processes as they are in constant volume processes.

In fact, since a typical existing Stirling engine has a blend of neo-isochoric, neo-isobaric, and neo-isothermal processes, it can be considered a blend of a Stirling cycle and an Ericsson cycle, especially since in both cases pure isochoric heat input and heat removal phases are completely absent.

Thus, in passing through large-volume heat exchangers for heating, recuperating, and cooling, the EISG CCVC testbed can be said to resemble an Ericsson cycle, the main difference being that the heat exchange in the EISG CCVC prototype is done in a “pulsed” pressure manner, not at constant pressure. The EISG CCVC prototype also used a gas compression phase, just as does an Ericsson cycle.

In other words, the EISG CCVC engine is, like the typical existing Stirling engine, classifiable as a hybrid Ericsson/Stirling closed cycle heat engine, since it uses a gas compression phase and heat exchangers, some neo-isobaric and neo-isothermal processes, but also pure isochoric heat input and heat removal phases.

Ducted/Ported and Valved Regeneration

There is an alternative to recuperation called regeneration. In what can be called a “single-stream” regenerator, heat is exchanged to and from a working fluid into and out of what might be envisioned as a “thermal sponge”, which is often a mass of very thin wires, sometimes separated into layers by very thin sheets of perforated thermal insulation, that can very quickly absorb or release thermal energy at varying temperatures from one end to the other of the “sponge”.

Presently, thermal regeneration within Stirling engines uses a “single-stream” regenerator (SSR). Usually, an external heater is attached to the hotter end of an SSR and an external cooler is attached to the colder end. By (A) alternating the working fluid's flow (1) in a direction towards the “hot” end of the sponge during expansion, and (2) in a direction towards the “cold” end of the sponge during compression and (B) cyclically adjusting the volumes of the hot and cold spaces in conjunction with the requirement for expansion or compression, expansion takes place generally in the hotter expander and compression takes place generally in the cooler compressor. The sponge thus is seen as a “preheater” when the working fluid is moved towards the expander, and as a “pre-cooler” when the working fluid is moved towards the compressor. In a classic Stirling cycle or Stirling engine, a single contiguous quantity of working fluid is flowed through a combination cooler/regenerator/heater, first in one direction, as to be heated, and then in the opposite direction, as to be cooled.

A second kind of regenerator is possible that can be called a “dual-stream” regenerator (DSR). When ducts/ports are used, it may be termed a “ducted DSR” (DDSR) and when valves are used it may be termed a “valved DSR” (VDSR). A DDSR is sometimes composed of a thick rotating disc of regenerator material with an outlet duct/port on one side of the rotating disc and an inlet duct/port on the other side of the rotating disc. A first stream of gas or vapor is passed through one duct/port and a second stream is passed through the other duct/port, usually in opposite directions perpendicular to the plane of rotation. These can be used, for example, by a combustion heater exhausting hot combusted fuel and air through the ducted regenerator or a portion of the ducted regenerator, the thermal energy captured within the rotated or rotating regenerator “thermal sponge” material then being used to preheat non-combusted air (and sometimes fuel) entering the combustion heater.

One embodiment of a valved regenerator can create a kind of “valve-switched DSR” (VSDSR). One technique for constructing such a VSDSR is to use regenerators that “switch places” using valves, where two or more regenerators cycle between (a) being charged with thermal energy and (b) giving up that energy. One type of VSDSR was proposed within U.S. patent application Ser. No. 17/746,848, FIG. 6. A more prosaic schematic of a VSDSR is shown in U.S. patent application Ser. No. 18/362,951, FIG. 5a and FIG. 5b, referred to therein as a Synchronized Thermal Regenerator Exchange Pump (STREP). In essence, two or more stationary regenerators “take turns” via switching valves either being charged with thermal energy or having thermal energy removed. Other techniques, such as a rotation-switched DSR (RSDSR), are possible as well, but may still require valves or ports to shut down the flow while the regenerator cores shift, especially in the case of high pressure differentials between heating and cooling working fluids.

A VSDSR operating in syncopation may be used to achieve a more constant flow than a simple VDSR. In U.S. patent application Ser. No. 17/746,848, it was proposed that, rather than a recuperator, the VSDSR shown in FIG. 6 of U.S. patent application Ser. No. 17/746,848 be used for a simple high temperature heat exchange. In that instance, a reactant mix flowing into an endothermic reactor flowed through one regenerator core while a product mix flowing out of the endothermic reactor flowed through a second regenerator core. At intervals, valves “switched” the regenerator core flowing into the reactor and the regenerator core flowing out, thus “using” for a time the store of heat in the core recently charged with product thermal energy to heat up the reactant while the other core was thermally recharged, and thus allowing an essentially constant pressure flow of reactant/reactant mix into the reactor and product/product mix out of the reactor, while simultaneously achieving a highly efficient heat exchange at the minor cost of a small amount of mixing between the reactant and the products.

Sometimes an isobaric flow may be slow enough, and/or the regenerator may be long enough, to permit a small enough intermittent pressure change, thus permitting use of a VDSR or DDSR with a single shared reactor core. An example of a VDSR can be seen as FIG. 1 through FIG. 4 in U.S. patent application Ser. No. 18/362,951. A more prosaic schematic of a simple VDSR is shown in U.S. patent application Ser. No. 18/362,951, FIG. 6a and FIG. 6b.

Advanced Fully-Regenerated Engines

U.S. patent application Ser. No. 17/746,848 states that heat engines are defined as work-generating devices that operate as a result of a temperature difference in their working fluid. The Carnot theorem for maximum theoretical efficiency of a heat engine, mathematically expressed by the equation (Th−Tc)/Th, where Th is the absolute temperature of the hot reservoir or heat source and Tc is the absolute temperature of the cold reservoir or heat sink, specifies limits the thermal efficiency that any heat engine can obtain to the absolute temperature difference between those two thermal reservoirs.

A heat engine cycle does not materially change (Th−Tc)/Th; that is, a heat engine with a given Th and Tc still has the same (Th−Tc)/Th. However, in real world engines, various unavoidable losses, for example friction losses, resistance to flow losses, radiation losses, and so forth, impact and define the percentage of delivered thermal efficiency versus ideal thermal efficiency. Delivered thermal efficiency is defined herein as net work out or Wout(n) divided by total source heat in or Hin(t), or Wout(n)/Hin(t).

Regenerating Heaters and Regenerating Coolers

In theory, either regeneration or counter-flowing separate stream heat exchange (standard heat exchange) can approach a perfect exchange of thermal energy, where the cold working fluid flowing in from the “cold side” can be made to equal the temperature of the hot working fluid flowing in from the “hot side”, and vice versa. In reality, the heat exchange is not perfect for either device. In part, complete heat exchange is a function of the length of the heat exchange device, in part it is a function of the cross section of the heat exchanger's internal passages (smaller passages allow faster heat transfer), in part it is a function of the increase in friction and thus “pumping losses” with any increase in internal volume or decrease in internal passage cross section, in part it is a function, in the case of the recuperator, of the thickness of the internal walls that separate the two flows, thus reducing heat transfer, and in part it is a function of the time the counter-flowing gas streams are given to exchange heat. Given enough volume/length and a slow enough flow rate, and assuming excellent heat insulation, recuperation can come close to regeneration's capability for heat exchange, but for a given degree of heat exchange at a given flow rate for a given internal volume and a given pumping loss over a given length of time, a regenerator is vastly superior to a recuperator.

This difference in flow rate, internal volume, and heat transfer time is particularly meaningful for isochoric processes. Consider the drawings of the ideal Stirling cycle in U.S. Pat. No. 3,871,179, FIGS. 1A through 1D: It is clear that between the two pistons there is a physical space, made up of a heater heat exchanger, a regenerator, and a cooler heat exchanger. If these spaces were not present, and somehow the working gas could be transported directly from one cylinder to the other while still effecting the desired heat transfers, then the volume being transferred from the one piston to the other piston would be exactly equal to the total maximum volume of working fluid in one space or the other. Instead, there is an additional volume in between the two pistons; a kind of “dead space”. The size of that additional volume will determine the amount of thermal energy transferred into and out of the working fluid to elicit a given increase or decrease in pressure and temperature.

That is, for a given isochoric thermal input per stroke, replacing the regenerator with a recuperator in a Stirling cycle will drastically reduce a rise in both pressure and temperature for a given quantity of thermal input. The EISG CCVC testbed, with its very long recuperator and its long heater and cooler heat exchangers, indicated that quite clearly.

In other words, the use of a regenerator rather than a recuperator can improve thermal efficiency in an isochoric process. Note, however, that presently, heat addition and heat removal in Stirling engines still requires the use of heater and cooler heat exchangers, with a regenerator “sandwiched” in between. That added internal volume for the heater and cooler can therefore be seen as a negative for the potential thermal efficiency of isochoric heat input or removal, since increasing the overall volume of the connecting plenum through which the working fluid must be displaced limits a rise in both pressure and temperature for a given isochoric thermal input.

However, as has been shown specifically in FIG. 6 of U.S. patent application Ser. No. 17/746,848, it is possible to construct a valved and/or ported regenerator that can intermittently pass a gas stream through from the hot end of a valved regenerator, switch the valves and/or ports, then intermittently pass a second gas stream from the cold end of a valved regenerator. In the fourth embodiment shown in U.S. patent application Ser. No. 17/746,848, it was proposed that a valved regenerator be used for a simple high temperature heat exchange rather than a recuperator. Note that a ported regenerator can also be used in that instance, especially where the pressure differences between the two streams is small, and in the application proposed in said fourth embodiment, pressure was essentially constant or isobaric for both gas streams. The advantage in said fourth embodiment to a “valve-switching regenerator” operated as a kind of constant pressure heat exchanger feeding into and out of a high temperature environment was that it was likely to increase the efficiency of the heat exchange process over a standard counter-flow heat exchanger.

Note, however, that a valve-switching regenerator can also heat and/or cool a volume of gas being passed through isochorically, although timing and pressure matching are critical, as will be shown. It is therefore proposed that, in addition to situating a regenerator means between a heater and a cooler, as in a present Stirling engine, a valved regenerator heater means and a valved regenerator cooler means be utilized, the intent of said valved heater and cooler means being to replace higher volume and less thermally efficient counter-flowing separate-stream heat exchangers with much lower volume and more thermally efficient valved regenerators, thus increasing the CCVC engine's overall potential (Th−Tc)/Th. Note that this concept may be applied to existing Stirling engines as well to good effect.

a Rankine/Stirling CCVC Engine

In U.S. patent application Ser. No. 17/746,848, the Bland/Ewing chemo-thermodynamic cycle (B/E cycle) disclosed in U.S. Pat. No. 3,225,538 is modified to operate as a kind of B/E Rankine cycle. Applying that concept to the concept proposed by the modified EISG CCVC testbed suggests yet another interesting CCVC embodiment; a kind of combined Rankine/Stirling engine can be created by using the final exhaust from the EISG CCVC testbed to vaporize or partially vaporize a liquid working fluid prior to passing said vaporized working fluid through the modified EISG CCVC testbed. Note that, as in normal steam engines, the exhausted steam can then be cooled to a liquid state, re-pumped to the required pressure as a liquid, and be recycled. That in turn obviates any need for a gaseous compressor, while maintaining thermal efficiency by using otherwise-waste thermal energy for the vaporizer.

(Note: In the system described above under the heading “A CCVC engine with true isochoric waste heat regeneration”, a “compression” is proposed by the so-called displacer/compressor at step “A.d.” above. However, that small compression occurs only until pressures equalize between the exhausting working fluid in the displacer/compressor and the small first displacer, after which the exhaust process can be isobaric. As an alternative, the main engine may, following closure of the small first displacer actuated exhaust valve, be exhausted“explosively” to a lower pressure with the opening of the main engine exhaust valve, thus creating a lower pressure displacer/compressor isobaric exhaust stroke. Then, at the end of the displacer/compressor exhaust stroke, an early closure of the main engine exhaust valve can allow a recompression within the regenerator VDSR, by means of a recompression of remnant gas/vapor by the displacer/compressor into the regenerator VDSR, the expander exhaust SSR, and any connecting manifolds, back to the pressure within the small first displacer just prior to the opening of the small first displacer actuated exhaust valve. Note the similarity of this recompression stroke to the opening of the transfer valve and the recompression stroke that allows a “valved cell” to function efficiently.)

Open Cycle or Semi-Open Cycle CCVC-Based Internal Combustion Engines

One of the most interesting “valved cell” engine capabilities is its ability to operate as an open-cycle engine, thus easily permitting the use of internal combustion as a heat source. For an open cycle based on the EISG CCVC testbed, or Open Cycle Valved Cell (OCVC) isochoric fully regenerating heat engine, the working fluid can be compressed air, the heat input can be the internal combustion of a fuel, and the final exhaust can be vented to the atmosphere.

In a particular instance, the pressurized vapor can be steam. The steam-powered semi-open cycle CCVC engine would be manifested through application of the above-proposed modifications to the EISG CCVC testbed. Just prior to the pressurized steam being taken into the small first displacer, H2 at an equal pressure and temperature may be added, creating H2-enriched steam. Following the displacement of the H2-enriched steam working fluid from a small first displacer through a heat source and into a small second displacer of equal volume, an increase in pressure would be manifested by the isochoric raising of the temperature of the enriched mixture by the addition of otherwise-waste exhaust heat, as shown in the above-proposed modifications to the EISG CCVC testbed. At the beginning of and/or during the following expansion, a valved cell process may then add either preheated and compressed O2 or preheated and compressed H2O2 vapor to the H2-enriched steam, thus adding thermal energy to the CCVC engine by internal combustion. The exhaust of such an engine ideally being pure H2O, said exhaust may then be captured by cooling and condensing, and eventually recycled by electrolysis back into H2 and O2. That is, in a semi-open cycle, the final H2O exhaust can be ultimately recycled back to its original constituents of H2 and O2.

Alternatively, just prior to preheated and pressurized steam being taken into the small first displacer, either O2 or H2O2 at an equal pressure and temperature may be added to the steam, creating either an O2-enriched steam mixture or an H2O2-enriched steam mixture. Following the displacement of the O2-enriched steam or H2O2-enriched steam working fluid from a small first displacer through a heat source and into a small second displacer of equal volume, an increase in pressure would be manifested by the isochoric raising of the temperature of the enriched mixture by the addition of otherwise-waste exhaust heat, as shown in the above-proposed modifications to the EISG CCVC testbed. At the beginning of and/or during the following expansion, a valved cell process may then add compressed and preheated H2 to the O2-enriched or H2O2-enriched steam, thus adding thermal energy to the CCVC engine by internal combustion. Once again, the exhaust of such an engine ideally being pure H2O, said exhaust may then be captured by cooling and condensing and eventually recycled by electrolysis back into H2 and O2. That is, in such a semi-open cycle, the final H2O exhaust can be ultimately recycled back to its original constituents of H2 and O2.

The CCVC Isochoric Engine as a Means of Approaching a True Stirling Cycle Engine

As noted above, a true Stirling cycle requires:

• • (1) An isochoric increase in temperature and concomitant increase in pressure. This can be accomplished with a fully regenerating CCVC heat engine. Alternatively, it may be accomplished with a fully regenerating OCVC heat engine and internal combustion.
  • (2) An isothermal expansion and concomitant decrease in pressure. By using a fuel injector, for example a timed-injection valved cell as was proposed in U.S. Pat. Nos. 4,817,388 and 5,179,839, heat from internal combustion can be added to the working fluid during an expansion stroke and arranged to maintain temperature during said expansion.
  • (3) An isochoric decrease in temperature and concomitant decrease in pressure. This is accomplishable with a fully regenerating CCVC heat engine.
  • (4) An isothermal compression and concomitant increase in pressure, which returns the vapor or gas to the state it started from. There are two possible approaches to achieving an isothermal compression. In the first, a series of compressions and inter-coolings, as in the well-known Ericsson cycle, will essentially “approach” an isothermal compression. In the second, it is possible to (a) exhaust a vaporous working fluid from the engine, cool it to its temperature of condensation, increase it's pressure with a pumping process, and (d) re-vaporize the working fluid. This is, of course, the well-known Rankine cycle. Note that a liquid may be compressed at essentially constant temperature, and that, once vaporized, the vapor can be increased in temperature isochorically. At lower pressures, the “line of vaporization” passing from liquid to vapor approximates an isothermal compression. Assuming otherwise-waste heat is available to supply the energy required for vaporization, there is little impact on such an engine's thermal efficiency.

The Advanced Fully-Regenerated CCVC Heat Engine as Applied to B/E Chemo/Thermodynamic Cycles

A B/E heat engine cycle, by increasing the “endothermic fluid” (product) mol count for the expander to be higher than the “exothermic fluid” (reactant) mol count for the compressor, reduces the work put in by the compressor relative to the work put out by from the expander, known as the heat engine's mechanical efficiency. Since the compressor is usually the biggest part of the engine, that decreases many of the unavoidable losses in heat engines, potentially allowing the Wout(n)/Hin(t) of said heat engines to more closely approach the (Th−Tc)/Th. It is for this reason that it has been proposed in U.S. patent application Ser. No. 18/095,463 that a B/E cycle be separated into at least two half/cycle heat engines. The first heat engine is used to create stored Hin(t) as well as to generate Wout(n). The second heat engine is used to generate work from the release of the stored Hin(t). The overall efficiency is therefore the sum of the two Wout(n) and the two (Hin(t), with the summed quantities then used in the equation Wout(n)/Hin(t).

Semi-Open Cycle CCVC-Based Combined B/E Half-Cycle Heat Engines

U.S. patent application Ser. No. 18/095,463 disclosed the concept of creating a unique full B/E chemo/thermodynamic cycle as disclosed in U.S. Pat. No. 3,225,538 by connecting two semi-open chemo/thermodynamic half-cycles; a semi-open endothermic half-cycle, and a semi-open exothermic half-cycle. The chemo/thermodynamic heat engine cycle analyzed herein is the classic cyclohexane<=>benzene+H2 cycle or C6H12<=>C6H6+3H2 cycle analyzed in U.S. Pat. No. 3,225,538. For the two half-cycles, the endothermic cycle is C6H12=>C6H6+3H2, and the exothermic cycle is C6H12<=C6H6+3H2. Note that in either direction, the exact same amount of thermal energy is stored as is released. However, the endothermic half-cycle occurs at a much higher temperature for a given pressure than the exothermic half-cycle. That is, the endothermic half-cycle requires higher quality heat than the exothermic half-cycle returns.

Both half-cycles have one purpose in common; generate net work out. But for the endothermic half-cycle, a second purpose is to store thermochemical energy, and for the exothermic half-cycle, it's main purpose is to use that stored energy efficiently to generate net work. Note that by far the largest amount of energy used to power the endothermic half-cycle is stored chemically. That in turn means that the largest amount of net work that will be produced independently by the two half-cycles will be produced by the exothermic half-cycle. It also means that maximizing the thermal efficiency of the exothermic half cycle is to maximizing the efficiency of both half-cycles combined.

a Rankine/Stirling Fully-Regenerating CCVC-Based Endothermic Semi-Open Half-Cycle Heat Engine

The C6H12=>C6H6+3H2 endothermic half-cycle has the ability to create a kind of chemical expansion process. Note that C6H12=>C6H6+3H2 literally turns a single molecule into 4 molecules; one molecule of benzene, and 3 molecules of hydrogen gas.

By pressurizing the C6H12 before it is converted into C6H6+3H2, 4 times as many molecules are generated at any given conversion pressure. The same amount of thermal energy is chemically stored, whether the conversion is at low pressure or high pressure. The only requirement is that, as the pressure increases, so does the temperature to feed the conversion. In other words, the C6H12=>C6H6+3H2 endothermic half-cycle may be seen as a kind of chemical H2 pressurization system.

Therefore, the approach being proposed for the endothermic half-cycle is to essentially use the endothermic conversion to produce pressurized H2 gas without a mechanical compressor. For example:

• • 1. Pressurize the liquid C6H12 reactant to some desired pressure.
  • 2. Heat the reactant to the vaporization point.
  • 3. Vaporize the reactant.
  • 4. Raise the pressure of the vaporized reactant slightly with a small amount of compression. The purpose of this, as will be shown, is to increase the temperature at which the eventual vapor product (C6H6) will condense over the temperature at which the C6H12 liquid at the pressure given it in step 1 above will evaporate. C6H12 and C6H6 have temperatures and heats of condensation/vaporization that are very close to one another (at 14.7 psi, C6H12 boils at 343.9 K with a standard heat of vaporization of 380 KJ/kg, while C6H6 boils at 353.2 K with a standard heat of vaporization of 433 KJ/kg). Consequently, condensing slightly higher pressure C6H6 will theoretically supply more than the required heat of vaporization of C6H12, removing the thermal cost of vaporizing the C6H12 from the required source heat in to the proposed process, as will be shown.
  • 5. Preheat the reactant by passing it through a first heat exchanger to the temperature at which the reactant, at the given pressure, will convert the reactant to product in an endothermic catalytic converter.
  • 6. Convert the vaporous C6H12 reactant at constant pressure and temperature into the product C6H6+3H2. Note that, at 100% conversion of C6H12 reactant to C6H6+3H2 product, 1,180 kJ of heat are absorbed chemically per 0.4536 kg (1 pound) of the resulting product. Note for comparison purposes that the vaporization requirement for about 0.45 kg of C6H12 equals (380×0.45=) about 170 kJ, or only about 14% of the required thermal input to create pressurized C6H6+3H2.
  • 7. Exhaust the product from the endothermic reactor and cool the product down with the first heat exchanger to just above the temperature at which the C6H6 will be condense into a liquid. The molar heat capacity of H2 is 28.84 Joules per an increase in temperature of 1 K (mol K). The molar heat capacity of vaporous C6H12 is 105 J/(mol K). The molar heat capacity of C6H6 is 135 J/(mol K). Thus, the molar heat capacity of three mols of H2 plus one mol of vaporous C6H6 equals ((28.84×3)+135=) 221.52 J. That is, the reactant has (135/221.52=) 61% of the heat capacity of the product. Assuming a perfect heat exchange, that will require passing only about 61% of the product through the first heat exchanger to preheat the C6H12 vapor to the temperature of the endothermic catalytic reactor.
  • 8. In a second heat exchanger, cool the 39% portion of C6H6+3H2 down with some process to just above the temperature at which the C6H6 will become a liquid.
  • 9. Recombine the ⅔ and ⅓ streams of C6H6 vapor+3H2 gas.
  • 10. Pass the relatively low temperature C6H6+3H2 product mixture through a fully-regenerating CCVC engine.
  • 11. For the source heat, use the heat separated out in the second heat exchanger. If desired, supply additional source heat to the C6H6+3H2 mixture to superheat it.
  • 12. After the C6H6 vapor and the H2 gas product mix is finally exhausted from the fully-regenerated CCVC engine, cool it down to the point where the C6H6 condenses, thus separating the product into liquid C6H6 and H2 gas.
  • 13. If possible, use any remaining latent heat in the CCVC engine exhaust to further reduce the heat requirements of the CCVC engine, for example, to supply the heat to increase the temperature of the pressurized C6H12 liquid reactant to just below the temperature required for vaporizing it at the given pressure.
  • 14. Based on only the latent heat requirements of the proposed endothermic heat engine, such a fully-regenerated CCVC engine can be expected produce delivered thermal efficiencies in the range of 50% or more.

a Rankine/Stirling Fully-Regenerating CCVC-Based Exothermic Semi-Open Half-Cycle Heat Engine

For a semi-open exothermic half-cycle, the primary purpose is to generate thermal energy to be used in a heat engine operating at maximum efficiency. Per U.S. Pat. No. 3,225,538, FIG. 1, at 1 atmosphere (atm) the conversion of C6H6+3H2 will occur at about 540 K (512 deg F.). That will produce, with negligible work in, 1,180 kJ of heat per 0.4536 kg (1 pound). In addition, in U.S. patent application Ser. No. 18/095,463, it is proposed that a small compressor and negligible work be applied to C6H6 vapor for a similar purpose as that proposed in step 4 above for the endothermic half-cycle engine. That is, it is proposed to supply much of the required heat of vaporization for the C6H6 by the condensation of higher-pressure C6H12. In other words, with such an approach, both the work in to produce heat at 540 K and the heat cost required are negligible compared to the fairly high temperature heat produced.

a Special Use Case Rankine/Stirling CCVC Engine

On the poles of Earth's Moon, special areas exist that never see the light of our Sun. These areas are Permanently Shadowed Regions (PSRs). It is also possible to artificially create shaded areas on the lunar surface that won't seen sunlight which can be called Artificially Shadowed Regions (ASRs). In the depths of some polar craters that never see sunlight, extremely low temperatures approaching 100 Kelvins. The existence of these pools of cold matter constitute a meaningful lunar resource for things like heat engines.

Some potential CCVC working fluids can be found to be extremely useful, thanks to the existence of PSRs and, potentially, of ASRs, and that would be working fluids that are very close to being a volatile vapor at the temperatures there.

One example is CO2. In a PSR, CO2 can be easily converted from a gas to a solid (so-called dry ice). CO2 sublimates into a solid or “boils” to a vapor at 1 atm (14.7 psi) and 195 K (−109 deg F.). A CCVC CO2 working fluid can thus be pressurized to a higher pressure of, for example, 5 atm (73 psi), by essentially placing CO2 in a “pressure cooker” and applying a temperature of, for example 283 K (50 deg F.) to it. That heated, pressurized CO2 can then be fed into a CCVC engine. Between isochoric regenerative waste heat recycling and isochoric heating with a heat source, the CO2 can be easily superheated and super-pressurized to a temperature of 1,000 deg F. (810 K), potentially creating diesel engine-like pressure for expansion in a fully regenerating CCVC heat engine with no compression phase.

Within the confines of a lunar PSR, ASR, or combined PSR and ASR, the exhausting working fluid will still contain enough waste heat to power the Rankine cycle-type vaporization of pressurized solid CO2, likely to a temperature of at least 50 deg F.

The theoretical Carnot thermal efficiency ((Th−Tc)/Th) of a heat engine with a source temperature of 810 K and a theoretical sink temperature of 195 K is ((810−283)/810=) 0.65 or 65%. Coupled with the extremely high delivered thermal efficiency of a compressor-less engine and the very low relative peak temperature, and it's likely that a delivered thermal efficiency could approach 50%. For solar energy, that means possibly 40% of the focused solar power can be converted into electricity, possibly matching if not exceeding the best that a solar-powered Stirling engine has ever achieved.

U.S. Pat. No. 12,352,250 Embodiments

Description—First Embodiment

This is a description of the unmodified EISG CCVC testbed, aka hybrid Ericsson/Stirling closed cycle heat engine. For reference, see paragraph 12 and 13 above and FIG. 1, FIG. 2, and FIG. 3 of the drawings.

The EISG CCVC testbed was designed to be a closed system with a sealed and pre-pressurized working fluid, similar to the standard sealed and pre-pressurized working fluid for Stirling engines. In the EISG CCVC testbed test cases, nitrogen (N2) was used as the working fluid. Pre-pressurization of the testbed was held to about 90 psi, with peak measured pressure of about 190 psi. Peak temperature was about 511 K. Heat energy was supplied by an electric coil heater and an electric cartridge heater physically in contact with the heater heat exchanger. Cooling was supplied by water flowed through coils of copper tubing exterior to and interior to the cooler heat exchanger and exterior to the walls of displacer #1 and the combination displacer #3/compressor.

The piston is a single contiguous, hollow aluminum 2″ diameter tubular piston “rod” with a 2.5″ diameter “pancake” piston on either end. The piston is cyclically driven through a 2.75″ stroke by a prime mover below the engine proper. A ⅜″ diameter titanium rod connects the bottom of the contiguous piston to the prime mover. A 2.5″ outer diameter teflon-and-stainless spring steel seal is mounted in each of the 2.5″ diameter pancake pistons, and a single 2″ inner diameter teflon-and-stainless steel spring seal is mounted in a 2″ diameter tube between displacer cylinder #1 and the displacer cylinder #2. The teflon seals are not lubricated and ride on a vapor-deposited nickel substrate that is coating the single 2″ diameter piston connecting rod and the two 2.5″ diameter cylinders. Excluding manifold and heat exchanger spaces, the four internal spaces of the engine are comprised of the two 2.5″ diameter pancake pistons with piston seals, the 2″ diameter connecting rod, the 2″ diameter cylinder with 2″ diameter rod seal, the two 2.5″ diameter cylinders, and the ⅜″ diameter connecting rod, thus forming the 13.5 cubic inch expander space, the 13.2 cubic inch displacer #3/compressor space, and the 4.86 cubic inch #1 and #2 displacer spaces. The piston is driven by the single converted crankshaft with a 2.75″ throw from a converted single-cylinder four-stroke gasoline prime mover with an oil-lubricated crankcase. The crankshaft is contiguous with a modified single-lobe camshaft, which pushes a cam follower and connecting rod to operate a rocker arm mounted on the expander cylinder head, which opens and closes the poppet-type exhaust valve. The exhaust valve is spring-biased towards closed and opens at or just prior to the upstroke engine's upstroke at BDC and closes just prior to the downstroke at TDC. An arm mounted just below a teflon-and-stainless steel spring seal exhaust valve stem seal extends perpendicularly from the exhaust valve stem. The exhaust valve stem-mounted arm is used to (A) physically close the transfer valve and (B) compress the transfer valve opening spring when the exhaust valve closes as BDC is approached. The reverse poppet-type transfer valve stem has an o-ring seal. The transfer valve stem and o-ring seal are oil-cooled and oil-lubricated with lower pressure oil, as is the exhaust valve stem. The upper portion of the transfer valve head is designed to seal against an upper seat and thus physically protect the transfer valve stem o-ring seal during the passage of the higher pressure hot gases flowing past the transfer valve head and into the expander. The transfer valve head upper seat is also partially oil-cooled, thus providing partial cooling of the transfer valve head. Also, the transfer valve stem is purposefully designed with a slight narrowing in the area where the transfer valve stem contacts the transfer valve o-ring seal during the travel towards opening of the transfer valve, temporarily reducing friction between the stem and the seal for that fractional moment and allowing the transfer valve head to adequately seal against the upper transfer valve head upper seat. Finally, the transfer valve head is provided with a slight physical projection into the expansion chamber, which allows it to operate similarly to that of a steam engine “bash-valve”, thus ensuring that the transfer valve does in fact break free and open at TDC. A second teflon-and-stainless steel spring seal exhaust valve stem seal ensures that the pressurized oil will not contaminate the higher pressure working fluid.

The converted prime mover's connecting rod is stock, but the original piston has been replaced with a titanium “follower” device and “force plates” mounted in the piston cylinder that converts the rotary motion of the crankshaft into linear motion. The ⅜″ diameter titanium rod passes through a teflon-and-stainless steel spring seal at the top of the prime mover that can seal against oil on the one side and substantial pressure on the other. The ⅜″ diameter titanium rod is attached on the lower end to the titanium follower device and on the upper end to the single contiguous piston, which is thus cyclically driven linearly from TDC to BDC.

All “coiled tube heat exchangers” used within the EISG CCVC testbed use lathe-machined multi-spiraled helical ribbing constructed in the manner illustrated and described in U.S. patent application Ser. No. 18/362,951, FIG. 9 and FIG. 10.

Description—Second Embodiment

Modifications to the EISG CCVC testbed, aka hybrid Ericsson/Stirling closed cycle heat engine are herein proposed that will increase the testbed's potential and delivered thermal efficiency. These modifications will leave much of the EISG CCVC testbed unmodified, and may thus be seen both as a practical means for testing the usefulness of the modifications prior to the development of eventual production machinery and as a means for describing and detailing herein the proposed modifications. Changes beyond the First Embodiment labels will therefore be limited, and will be described below. Where no changes are incurred, FIG. 1 and FIG. 3 are referred to for unchanged labeling.

Replacing a Part of the EISG CCVC Testbed Recuperation Process with Regeneration

The existing EISG CCVC testbed uses a device called a “recuperator” to capture otherwise-waste exhaust heat. There is an alternative to recuperation called regeneration. A regenerator is advantaged over a recuperator in its ability to permit an exchange of heat with both a greatly-reduced internal volume and a much faster heat exchange rate. Decreasing internal volume for isochoric heat transfers will increase the theoretical thermal efficiency of a heat engine. A faster heat exchange rate will increase the rpm for delivering power output and thus increase the power output for a given engine mass.

Two basic types of regeneration are presently utilized. The first may be termed “single stream regeneration” (SSR). The second may be termed “dual-stream regeneration” (DSR).

DSR is generally accomplished by either switching the two counter-flowing streams through a single regenerator core, which is accomplished by either ducts/ports, which may be termed a “ducted DSR” or DDSR, or by valves, which may be termed a “valved DSR” or VDSR.

In addition, there is a variant in which may be termed a “valve-switched DSR” (VSDSR) or possibly a “duct/port-switched DSR” (DSDSR). In such a variant, there are at least two and possibly more regenerator cores which are “switched out” by ducts/ports such that one regenerator core or set of regenerator cores is “thermally charged” while the other regenerator core or set of regenerator cores is “thermally depleted”. One design for a possible VSDSR was proposed in U.S. patent application Ser. No. 17/746,848, FIG. 6.

As a means for partially reducing the volume of the present EISG CCVC testbed recuperator and thus increasing the potential thermal efficiency, a kind of combined exhaust heat SSR/cooler is herein proposed.

Replacing the Hybrid Ericsson/Stirling Closed Cycle Heat Engine with a Hybrid Rankine/Stirling Closed Cycle Heat Engine

A unique characteristic of the valved cell process that underlies the EISG CCVC testbed is the ability to connect previously disconnected processes. An Ericsson-like or a Rankine-like process may be integrated with the Stirling-like processes of the EISG CCVC testbed, creating a hybrid Ericsson/Stirling engine that uses constant volume regeneration or a hybrid Rankine/Stirling engine that will increase the net work delivered by the expander. In the case of the proposed modified EISG CCVC testbed, the existing combined displacer/compressor can be converted to a displacer only. That in turn increases delivered thermal efficiency.

Note that the two modifications included in the proposed second embodiment are not mutually exclusive.

Description—Third Embodiment

Modifications to the EISG CCVC testbed are herein proposed that will increase the testbed's potential and delivered thermal efficiency. These modifications will leave much of the EISG CCVC testbed unmodified, and may thus be seen both as a practical means for testing the usefulness of the modifications prior to the development of eventual production machinery and as a means for describing and detailing herein the proposed modifications. Changes beyond the First and Second Embodiment labels will therefore be limited, and will be described below. Where no changes are incurred, FIG. 1, FIG. 3, FIG. 4, FIG. 6, and FIG. 7 are referred to for unchanged labeling.

Replacing the EISG CCVC Testbed Exhaust Heat Exchanger with a VDSR

The existing EISG CCVC testbed uses a recuperator to exchange heat isochorically between the expander exhaust and the displacer #1 (3) to displacer #2 (7) displacement. Even in the proposed Second Embodiment, a recuperator (5) was still show. However, by replacing the recuperator (5) with an SSR/cooler combination (16), as shown in the Second Embodiment, the syncopation between the two isentropic displacement processes found in the existing EISG CCVC testbed is changed dramatically, such that the final exhaust from displacer #3 (17) now occurs out of phase with the displacement process between displacer #1 (3) and displacer #2 (7).

That means it is now possible, as stated above, to tap into the waste heat flowing out of the SSR to directly thermally charge a single regenerator core “valved dual-stream regenerator”, or VDSR heat exchanger, greatly simplifying the process of converting the EISG CCVC prototype to replace the existing recuperator (5) with (a) an exhaust gas regenerator and (b) an isochoric displacement regenerator. That in turn will greatly reduce the “dead space” volumes within the EISG CCVC prototype, further increasing the potential thermal efficiency.

Exhaust Cylinder Displacement Versus Exhaust Compounding.

In replacing the gaseous compression process with the Rankine process, it becomes possible to extend the expansion process a great deal over the standard Stirling expansion process. One means for accomplishing this is via exhaust compound-expansion. For example, the present EISB CCVC testbed expansion chamber, as mentioned above equals 13.5 cubic inches, and the displacer volumes equals the 4.86 cubic inches. Even assuming dead space, that would limit the expansion ratio to 13.5/4.86 or 2.78×.

If the “displacer” were replaced with a 27 cubic inch expander, then the expansion ratio would potentially double to 5.5×, creating significantly more net power output per crank cycle. That would, of course, also significantly lower the post-expansion exhaust pressure. However, with the SSR exhaust system, a great deal of the thermal content “left behind” in the regenerator during the exhaust stroke can be recovered in the following secondary exhaust stroke, allowing for both additional net power out but also a significant amount of waste heat recovery. Finally, the “exhaust resistance” of pumping the expanded and thus lower pressure gases out of the 2nd expander would mean less exhaust work in is required, also aiding the net work out per cycle.

It is also possible for an isochoric displacer #3 (17) to exhaust to a compounding expander as an alternative to changing out displacer #3 (17) for an expander. Again, this is made easier when the modified EISG CCVC testbed uses the proposed modified Rankine process.

Replacing the EISG CCVC Testbed Heater with a VSDSR Heater

The existing EISG CCVC testbed uses a recuperator heater (6) to add source heat to the engine during isochoric heating. It is herein proposed that a “valve-switching dual-stream regenerator (VSDSR) heater be used in the EISG CCVC testbed to replace the existing recuperator heater (6).

Replacing the EISG CCVC Testbed Cooler with a VDSR Cooler

The existing EISG CCVC testbed uses a recuperator cooler (12, 16) to remove heat from the engine during isochoric cooling. It is herein proposed that a “valved dual-stream regenerator (VDSR) cooler be used in the EISG CCVC testbed to replace the existing recuperator cooler (12, 16).

These changes “shorten the paths” of the working fluids between (a) displacer #1 (3) and displacer #2 (7) and (b) the expander (9) and displacer #3 (17) or expander #2 (30), reducing the volume between them and thus increasing the potential isochoric thermal changes in temperature and concomitant pressure.

Description—Fourth Embodiment

Modern Rankine cycles operate at supercritical H2O steam levels to attain decent efficiencies. On the poles of Earth's Moon, special areas called Permanently Shadowed Regions (PSRs) exist that never see sunlight. In the depths of some polar craters that never see sunlight, extremely low temperatures approach 100 K.

One usefulness of Rankine/Stirling CCVC engines may be their ability to operate with very high power density and good efficiency at low temperatures. With careful design, a peak temperature of 810 K (1,000 deg F.) may be sustainable with teflon seals and bearings and no requirement for lubricant or coolant.

Some potential Rankine/Stirling CCVC working fluids can be found to be extremely useful in proximity to PSRs. One example is CO2, which can attain supercritical levels at temperatures of about 300 K (80 deg F.) and about 1,000 psi. A heat engine that can exhaust at a final waste heat of perhaps 100 deg F. can thus easily turn solid CO2 (dry ice) at 1,000 psi into a supercritical gas. Also, at an exhaust pressure of even 1 atm, CO2 gas can be converted back to dry ice at as high a temperature as 195 K (−78 deg C.), which should be attainable in most PSRs.

The theoretical Carnot thermal efficiency ((Th−Tc)/Th) of a heat engine with a source temperature of 810 K (1,000 deg F.) and a theoretical sink temperature of 195 K is ((810−283)/810=) 0.65 or 65%. Coupled with the extremely high delivered thermal efficiency of a compressor-less engine and the very low relative peak temperature, it's likely that a delivered thermal efficiency could approach 50%. For solar energy, that means possibly 40% of the focused solar radiant energy can be converted into electricity, possibly matching if not exceeding the best that a solar-powered Stirling engine has ever achieved.

Description—Fifth Embodiment

Open Cycle CCVC-Based Internal Combustion Engines

Unlike other closed-cycle hot gas engines, a valved cell engine can be open cycle, closed cycle, or even both open and closed cycle. That is because the concept of the valved cell essentially is a means to attach seemingly disparate heat engine processes together. In the original valved cell patents, valved cells were used to connect an externally-pressurized gas to an internally pressurized gas. In essence, converting a closed cycle valved cell (CCVC) to an open cycle valved cell (OCVC) is as simple as taking compressed air into displacer #1, and later exhausting it from displacer #3. Note that even then, all heat can be added from an external heat source in any of the manners proposed above. In fact, some heat can be added that way, and additional heat can be added by injecting fuel into the preheated, pressurized gas, at any of several places. Also, the fuel can be atomized and injected liquid, as is presently done with diesel engines, or it can be vaporized and valved cell-injected gas, as was proposed in the original valved cell patents.

For an open cycle based on the EISG CCVC testbed, or Open Cycle Valved Cell (OCVC) isochoric fully regenerating heat engine, the working fluid can be compressed air, the source heat input can be the internal combustion of a fuel, and the final exhaust can be vented to the atmosphere. Note that a fully regenerating OCVC with isochoric internal combustion can be thought of as a fully regenerating Otto/Stirling hybrid cycle engine, or with isobaric combustion, a fully regenerating Diesel/Stirling hybrid cycle engine, or with isothermal combustion, a fully regenerating Carnot/Stirling hybrid cycle engine.

Semi-Open Cycle CCVC-Based Internal Combustion Engines

Two examples of semi-open CCVC-based internal combustion engines have been suggested.

H2-Enriched Steam Engines

Adding H2 to pressurized steam to create a H2-spiked working fluid that will not in itself combust allows such a working fluid to be taken into displacer #1 in a CCVC engine such as described above that has been converted to an OCVC engine. Following or even during the displacement from displacer #1 to displacer #2, injecting a quantity of O2, as with a valved cell, will literally convert 2 molecules of O2 and a molecule of H2 into 2 molecules of H2O and release heat, probably without even requiring a spark plug or glow plug. The exhaust, barring a few molecules that didn't get converted, is thus more steam than was originally put into the engine, plus work out, plus waste heat. It can be called a semi-closed cycle because the H2O thus created can be broken back down into its H2 and O2 constituents, as by electrolysis, and recycled continually.

O2-Enriched Steam Engines

Alternatively, rather than adding H2 to steam, O2 or even H2O2 could be added to steam. H2 would then be injected following or even during isochoric displacement, once again converting 2 molecules of H2 and 1 of O2 into steam, allowing the eventual breaking of the resulting H2O into separate H2 and O2 gases, as with electrolysis, thus creating a semi-closed cycle.

Description—Sixth and Seventh Embodiment

For the purposes of describing these half-cycles, the chemo/thermodynamic heat engine cycle analyzed herein is the classic reversible cyclohexane: benzene+H2 cycle or C6H12<=>C6H6+3H2 cycle analyzed in U.S. Pat. No. 3,225,538.

As noted earlier, U.S. Pat. No. 3,067,594 proposed an open-cycle Bland/Ewing chemo-thermodynamic process, U.S. Pat. No. 3,225,538 proposed a closed-cycle Bland/Ewing chemo-thermodynamic process, and U.S. Pat. No. 3,871,179 proposed the application of the B/E cycle to the classic Stirling cycle. U.S. patent application Ser. No. 18/095,463 disclosed the concept of creating a unique full B/E chemo/thermodynamic cycle as disclosed in U.S. Pat. No. 3,225,538 by connecting two semi-open chemo/thermodynamic half-cycles; a semi-open endothermic half-cycle, and a semi-open exothermic half-cycle. For the two half-cycles, the endothermic cycle is C6H12=>C6H6+3H2, and the exothermic cycle is C6H12<=C6H6+3H2. Note that in either direction, the exact same amount of thermal energy is stored as is released. However, the endothermic half-cycle occurs at a much higher temperature for a given pressure than the exothermic half-cycle. That is, the endothermic half-cycle requires higher quality heat than the exothermic half-cycle returns.

Both half-cycles have one purpose in common; generate net work out. But for the endothermic half-cycle, a second purpose is to store thermochemical energy, and for the exothermic half-cycle, it's main purpose is to use that stored energy efficiently to generate net work. Note that by far the largest amount of energy used to power the endothermic half-cycle is stored chemically. That in turn means that the largest amount of net work that will be produced by the two half-cycles will be produced by the exothermic half-cycle. It also means that maximizing the thermal efficiency of the exothermic half cycle is what is going to determine just how efficient both half-cycles are combined.

There is one unique result of the C6H12=>C6H6+3H2 endothermic half-cycle that can be seen as beneficial for converting heat into work, and that is this particular endothermic half-cycle's ability to create a kind of chemical expansion process. Note that C6H12=>C6H6+3H2 literally turns a single molecule into 4 molecules; one molecule of benzene, and 3 molecules of hydrogen gas.

In a heat engine, it is useful to find a way to pressurize a gas, and it turns out that, by pressurizing the C6H12 before it is converted into C6H6+3H2, 4 times as many molecules are generated at any given conversion pressure. In other words, one way to look at the C6H12=>C6H6+3H2 endothermic half-cycle is as a kind of chemical H2 pressurization system.

New U.S. Pat. No. 12,352,250 Embodiments

An Alternative Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Heat Engine

A as opposed to raising the pressure of the vaporized reactant with a compressor as described in the Sixth Embodiment of U.S. Pat. No. 19,303,034, an alternative embodiment would use “isochoric displacement heating” to raise the pressure of the vaporized reactant. Isochoric displacement heating is essentially the use of the first regenerative waste exhaust heat displacement process described for the Rankine/Stirling fully-regenerating CCVC-based Bland/Ewing chemo/thermodynamic endothermic semi-open half-cycle heat engine. The purpose of utilizing isochoric displacement heating in this instance is primarily to more efficiently increase pressure and thus the temperature at which the eventual vapor product, in this case C6H6, will condense over and above the lower pressure and thus temperature at which the C6H12 liquid will be evaporated. As noted above, condensing higher pressure C6H6 will theoretically supply more than the required heat of vaporization of C6H12, removing the thermal cost of vaporizing the C6H12 which would otherwise be required to be put into an endothermic B/E Rankine half-cycle embodiment.

This proposed new embodiment also proposes a second alternative to the path taken by the Sixth Embodiment described above. Instead of passing the C6H6 plus H2 mix through a fully-regenerating CCVC engine following the recombining of the approximately ⅔ and ⅓ streams, the higher pressure C6H6 in the recombined streams is first condensed out to supply the heat required for vaporizing liquid C6H12. As a result, the high pressure H2 gas is completely separated from the C6H6 and any remnant C6H12. The high pressure H2 gas may then either be used in some direct process, such as being used to cool the ⅓ stream of C6H6 plus H2 exiting the endothermic catalytic reactor and/or be cooled and stored for later and/or distant use, leaving the ⅓ stream of C6H6 plus H2 to be cooled to thermally power some other useful process; for example, cooled, pressurized H2 can then be superheated and thus super-pressurized by an isochoric displacement process to increase its pressure through the use of thermal energy only. The latent thermal heat of the resulting superheated and super-pressurized H2 may then be transferred to, for example, a secondary heat engine via a heat exchange process, leaving H2 at a high pressure but lower temperature for some following process, for example injection into and internal combustion within in a high pressure diesel engine or a high pressure fuel cell.

This proposed embodiment also proposes a third alternative to the path taken by the Sixth Embodiment described above: Instead of expanding the working fluid, in this case H2, isobarically from a high pressure isobaric external system then adiabatically, it is proposed that the working fluid be expanded purely isobarically. The thermal energy in the working fluid may then be stored in a regenerator system isochorically, that is, at constant volume, somewhat lowering the pressure. The resulting working fluid is then exhausted isobarically into a lower pressure isobaric external system. In that manner, the working fluid retains a measure of its pressure, and reuses its thermal content in a following isochoric regeneration.

Essentially, the work taken out and put in is done isobarically, then in part returned, first isochorically and regeneratively, and second isobarically as work is put in to pump the isochorically-heated and thus higher pressure fluid into the higher pressure isobaric external system, where the working fluid is then heated isobarically, said regenerated heat being taken from the lower pressure isobaric external system.

As regards the issue of exchanging heat regeneratively between the high pressure isobaric external system and the lower pressure isobaric external system, specifically during the proposed combined high pressure C6H6 condensation heat generation process and the lower pressure C6H12 vaporization heat absorption process, a major advantage of regeneration is the very large reduction in internal volume it makes possible when compared to a standard counterflow recuperator for the same amount of heat transfer. It is only the internal volume of the regenerator and its manifolds that will need to be increased or decreased cyclically in pressure by some means, for example, via a pressure change by means of a simple compressor/expander piston attached to the hot end of the regenerator that cyclically increases or decreases the overall volume and thus pressure prior to connection of one or the other of the two fluid flows, or possibly by closing all valves early and allowing steam generation to increase the pressure within the recuperator. On the other hand, since the two streams are designed to remain isobaric, decent heat exchange efficiency should be possible with a standard counterflow recuperator, and the amount of internal volume is less consequential when isobaric working fluids are used. Any advantage for the use of a VDSR or VSDSR over a standard counterflow recuperator will thus need to be determined experimentally.

An Alternative Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Cooling Engine

In this new embodiment, instead of passing the C6H6 plus H2 mix through a fully-regenerating CCVC engine following the recombining of the approximately ⅔ and ⅓ streams, as described in the Sixth Embodiment above, the higher pressure C6H6 in the recombined streams is first condensed out to supply the heat required for vaporizing liquid C6H12, as in the Seventh Embodiment. As a result, the high pressure H2 gas is completely separated from the C6H6 and any remnant C6H12.

The H2 may then be cooled at constant pressure to ambient temperature. It may then be expanded to ambient pressure, producing cold. The chilled H2 may then be either converted into liquid H2 or be “heated” back to ambient temperature at ambient pressure, for example by chilling pressurized gaseous O2 into liquid O2.

Alternatively, prior to final heat exchange and cooling, pressurized H2 can then be reheated and super-pressurized via, for example, a second Isochoric displacement heating process, thus increasing its pressure even more through the isochoric application of thermal energy. The higher pressure H2 may then be expanded to produce work.

Alternatively, rather than expanding the high pressure H2 at that point, the latent thermal heat of the resulting thermally pressurized and reheated H2 may then be transferred, via an isobaric heat exchange process, to a separate external heat engine, creating work out from said separate external heat engine while simultaneously producing cooled ultra-high pressure H2. The H2 may then be finally cooled at constant pressure to ambient temperature, then be expanded to ambient pressure, producing extreme cold. The chilled H2 may then be either converted into liquid H2 or be “heated” back to ambient temperature at ambient pressure, for example by chilling pressurized gaseous O2 into liquid O2. Exhausting isobarically from the isochoric displacement heat input process through a cooler will require work put in, since the constant pressure H2 cooled to ambient temperature will be reduced in volume as it is taken into an expander prior to expansion. However, some or all of this work input can then be recaptured via the following expansion from ambient temperature.

Thermolysis of H2O or H2O2 in Chemo/Thermodynamic Processes

The concept of (1) using a pump to pressurize a liquid chemical compound or reactant, (2) converting it into vapor, (3) either with increased temperature at a given pressure, or increased pressure at a given temperature, or isobarically and isothermally via a catalytic reaction at some given pressure and temperature, endothermically separating the reactant into product, and thus (4) chemically storing the thermal energy contained in the dissociated product, and simultaneously (5) increasing the number of moles of product over the number of moles of reactant available to a following expansion process, then (6) expanding it to produce net work, falls under the purview of newly issued U.S. Pat. No. 12,392,261, granted Aug. 19, 2025 to Joseph Barrett Bland, 7482 Greenhaven Dr, Sacramento, CA. That also applies to thermally splitting liquid H2O into H2 and O2, since pumping high pressure water (reactant) into a system, then increasing the temperature to the point where the resulting pressurized steam thermally dissociates into H2 and O2, is technically possible. Separating the high temperature, high pressure product into separate H2 and O2 streams is also technically possible, as by use of a molecular sieve. Finally, the two gas streams may then be separately expanded to generate net work out, completing a Bland/Ewing/Rankine chemo/thermodynamic endothermic half-cycle. Later and/or distantly, the H2 and O2 product may be reformed back into the H2O reactant, releasing the chemically-stored thermal energy.

The generation of H2O steam that is then dissociated by thermolysis is therefore a valid alternative thermo-chemical approach to creating a fluid suitable for chemo/thermochemical expansion to generate net work, since it will create a 1-to-1.5 chemo/thermodynamic expansion.

Alternatively, H2O2 (hydrogen peroxide) may theoretically be dissociated into H2 and O2 as well, creating a 1-to-2 chemo/thermodynamic expansion. Of course, the H2O2>H2O+O reaction is well-known to be exothermic, but in theory a suitably high pressure, high temperature H2O2 steam reaction can proceed directly to separating the H2 and O2. Note that a silver catalyst is presently used speed up the H2O2>H2O+O reaction, and may potentially serve as a catalyst for an H2O2>H2+O2 reaction at some given temperature and pressure.

Electrolysis of H2O or H2O2 in Chemo/Thermodynamic Processes

There exists a well-known alternative to thermally splitting H2O into H2 and O2, which is splitting by electrolysis. In a paper entitled “Operation of the 25 KW NASA Lewis Research Center Solar Regenerative Fuel Cell Testbed Facility” by Gerald Voecks, it has been demonstrated that liquid H2O may be efficiently pressurized to a very high pressure (approximately 200 atm) by pump, converted into steam, split into pump-pressurized high pressure H2 and O2 via electrolysis, and the resulting high pressure gases are then separated and stored.

The advantage of leaving the H2 and O2 at high pressure is that they can be stored indefinitely in smaller storage tanks. Expanding the gases would thus seem to be contra-indicated, since it requires work to create the electricity to dissociate H2O int H2 and O2. There is, however, the thermochemical expansion to consider, which has increased the potential work of expansion by 1.5×. Looking at the H2 and O2 as potential gaseous expansion material for a heat engine, even assuming losses, it would appear a net thermodynamic advantage may be possible, especially since the H2 and O2, even at low pressure, can still produce very high thermal efficiency in a fuel cell.

It is herein recognized that such an electrolysis of highly pressurized H2O steam is a valid alternative approach to creating a fluid suitable for chemo/thermochemical expansion to generate net work, since it will create a 1-to-1.5 chemo/thermochemical expansion. Alternatively to H2O, H2O2 (hydrogen peroxide) may theoretically be used to create a 1-to-2 chemo/thermodynamic expansion.

Thermal and/or Electric Dissociation of H2O or H2O2 into H2+O2 Capable of being Stored in Liquid Form at Ambient Pressure

Storing H2 Thermochemically in C6H12

Storing of H2 in C6H12 is central to the original idealized Bland/Ewing chemo/thermodynamic cycle. In this proposed embodiment, high pressure H2 generated either thermally or via thermo-electric dissociation is thermochemically stored by passing high pressure, vaporized C6H6 (benzene) product and high pressure H2 product at a desired temperature and thus yield through a catalyst bed, for example activated nickel. The resulting isobaric and isothermal exothermic reaction will generate C6H12 (cyclohexane) and heat, the temperature of the heat being dependent on the pressure of the products. For example, at a 99% yield rate and 200 atm, the product-to-reactant thermochemical reaction will generate heat at approximately 750 K (477 deg C., 890 deg F.). At 1 atm, the reaction will generate heat at approximately 540 K (267 deg C., 512 deg F.). See U.S. Pat. No. 3,225,538, FIG. 1. Note that in both instances the amount of heat produced is exactly the same. Per FIG. 1 in U.S. Pat. No. 3,225,538, the conversion of C6H6+3H2 will produce 1,180 kJ of ˜750K-to-800 K heat per 0.4536 kg (1 pound) of C6H12.

Storing O2 as LOX

Expanding O2 at 100 F (311 K) from 200 atm to 1 atm will theoretically lower the final temperature to 68.43 K. However, before that can happen, O2 will need to change state from a gas to a liquid. That will begin at 90.2 K and 2.63 atm. The heat of condensation/vaporization equals 6.82 kJ. The adiabatic expansion to 90.2 K will produce 4.6 kJ of work. O2 has a molar heat capacity of 29.4 J/K/mol.

Expanding H2 at 100 F (311 K) from 200 atm to 1 atm will theoretically lower the final temperature to 67.53 K. H2 will change state from a gas to a liquid at 20.3 K. H2 has a molar heat capacity of 28.84 J/K/mol.

The total available cooling available in H2 between 311 K and 68 K is thus equal to ((311−68)×28.84=) 7 kJ, or almost exactly what is required to liquify O2 at 90.2 K and 2.63 atm. However, the dissociation of H2O yields 2H2+O2. Therefore, twice the required cooling capacity and thus twice the required H2 is available, since only half a mol of O2 is produced by electrolysis for each mol of H2 produced.

The remaining half a mol of H2 can then be used in a heat engine to produce additional work out. Since no compression work is required, the ambient temperature H2 at 200 atm can become the working fluid for a fully-regenerated CCVC heat engine. Following that, the H2 can be stored thermo-chemically, as in a “benzene battery”, the benzene battery's exothermic heat of which can then be used to preheat the thermal carrier fluid exiting the valved regenerator heater of the fully-regenerating CCVC engine prior to the thermal carrier fluid being heated to a final temperature by a heat source, thus utilizing that exothermic heat at the overall thermal efficiency of the fully-regenerated CCVC heat engine. Delivered thermal efficiency of the captured source heat on the order of 50% is expected.

Using the H2O Critical Point to Supply the Heat of Vaporization for H2O Reactant Thermolysis

Converting 1 gram of H2O at 1 atm and 100 deg C. (373.15 K) from liquid to vapor will require 2.26 kJ. Since 1 mol of H2O equals 18.015 grams, the total required vaporization energy equals 40.71 kJ. The specific heat capacity of water is about 75.4 J/mol/K and the isobaric specific heat capacity of steam is equal to about 33.5 J/mol/K. Assuming H2O stored at Standard Temperature and Pressure (STP) of 273.15 K and 1 atm, 1 mol of H2O raised to 373.15 K will require ((373−273)×75.4=) 7.54 kJ. At 373.15 K and 1 atm, 40.71 kJ would need to be added to convert the preheated H2O liquid to steam.

At a pressure of about 217 atm (22 MPa, 3,200 psi), and a temperature of 647 K (374 deg C., 705 deg F.), H2O is at its critical point. Assuming, therefore, only the specific heat capacity of liquid water is required to that point, the total required thermal input would equal (647−273)×75.4=) 28.2 kJ.

Assuming thermolysis occurs at a temperature of 2,270 K (2,000 deg C., 3,625 deg F.), an additional ((2270−647)×33.5=) 54.4 kJ of latent heat would be required to raise the pressurized steam to that temperature.

Assuming a 100% conversion at that temperature and pressure, the specific heat capacity of O2 would equal that of one half of a mol, or (29.4/2=) 14.7 J/mol/K. The specific heat capacity of 1 mol of H2 equals 28.8 J/mol/K. The specific heat capacity of 1 mol of H2 plus 0.5 moles of O2 thus produced would equal (28.8+14.7=) 43.5 J/mol/K, for a total between 2,270 K and 647 K of (1623×43.5=) 70.6 kJ, or an excess of latent heat within the product over that required of (70.6-54.4=) 16.2 kJ. That is, with perfect thermal regeneration, 16.2 kJ of thermal energy is potentially available.

As proposed in U.S. patent application Ser. No. 19/303,034, following thermolysis, the product can be divided into two streams, ideally one of H2 and one of O2, as, for example, passing the product through a molecular sieve at peak temperature. Note that the O2 can be “kept” with any remnant H2O steam in this process. This is especially practical with H2 being one of the molecular products, since it is a much smaller molecule than either H2O or O2. Thus, with 100% thermolysis, the H2 stream would possess 28.8 J/mol/K of latent heat at 2,270 K, equal to ((2270−647)×28.8=) 46.7 kJ, and the O2 would possess (70.6−46.7=) 23.9 KJ/mol/K of latent heat.

In a perfect regeneration, the O2 by itself could supply (23.9/54.4=) 44% of the thermal requirement to preheat the H2O steam from 647 K to 2,270 K. The 16.2 kJ of H2 latent heat not used would equal (16.2/46.7=) about 0.35 moles of H2, and could be separated at a temperature of 2,270 K and 214 atm. Per U.S. patent application Ser. No. 19/303,034, the H2 could then be cooled regeneratively to 647 K, thus making available high grade heat, for example to a heat engine.

Between the temperature range marked by the critical temperature of 647 K and 273 K, the separated H2 stream and the main H2 stream having been reunited, the remaining H2+0.5 O2 product latent heat would equal about (647−273)×43.5=) 16.3 kJ, or an excess of latent heat within the product over that required for preheating of (16.3−7.54=) 8.76 kJ. The H2 portion of the latent heat would equal ((647−273)×28.8=) 10.8 kJ, and the O2 portion of the latent heat would thus equal (16.3−10.8=) 5.5 kJ.

Recall that 28.2 kJ was required to preheat 1 mol of H2O to its critical point at a temperature of 647 K and a pressure of 214 atm. Thus, the potentially available 8.76 kJ would equal sufficient thermal energy to preheat (8.76/28.2=) about 0.31 moles of H2O liquid to that pressure and temperature.

Recall that 54.4 kJ of thermal energy was required to heat 1 mol of H2O from 647 K to 2,270 K. The latent heat available in the previous reaction of the 0.35 moles of H2 regenerated between 2,270 K and 647 K equaled 16.2 kJ. That equals (16.2/54.4=) 30% or almost exactly the thermal heat required to raise 0.31 moles of H2O vapor at 647 K to 2,270 K.

Thus the thermolysis of H2O reactant at 2,270 K into 1H2+0.5 O2 product will (1) thermo-chemically store about 285.8 KJ/mol and (2) produce sufficient additional latent heat in the product to theoretically increase the potential yield of said product by about 30%. Alternatively, the vaporized H2O reactant at 2,270 K and 213 atm could be expanded to produce work. An adiabatic expansion from 213 atm to 1 atm would drop the temperature from 2,270 K to 619 K and produce 13 kJ of work. Note, however, that 691 K is still very hot.

Thus, the thermal exhaust from the first heat engine can power a second heat engine. If the second heat engine were a much lower pressure steam engine of, for example, 10 atm, an expansion to 1 atm would drop the temperature to 354 K and produce an additional 7 kJ of work, for a total of 20 kJ. It will also produce 1 mol of H2 at 204 atm, 0.5 mol of O2 at 204 atm, and about 8.76 kJ of high grade heat.

It is anticipated that it may be necessary to use an EREC to over-compress the vaporous H2O reactant at its critical temperature, thus ensuring that slightly higher pressure H2+0.5 O2 (plus remnant H2O vapor) product will have a sufficiently higher temperature to both supply energy to the lower pressure reactant above its critical temperature and below its critical temperature.

It is also anticipated that the yield of H2+0.5 O2 will be substantially less than 100%. However, in that instance, the remnant H2O reactant, having exactly the same liquid and vaporous heat capacity of the source reactant, can, in a perfect regeneration, supply exactly the thermal requirements for preheating necessary to elevate the necessary fraction of H2O reactant to the temperature required for dissociation. In short, assuming a minimum dissociation of possibly as little as 25%, the remnant 8.76 kJ of high grade heat per mol of H2 passed through the system can potentially supply sufficient make-up thermal energy to drive the system, thus only requiring the addition of high grade thermal energy in the system that is equal to the thermal energy stored in the product, thus converting the source energy perfectly into thermo-chemically stored energy.

Using the H2O2 Critical Point to Supply the Heat of Vaporization for H2O2 Reactant Thermolysis

At one atm and 423.3 K (150.2 deg C., 302.4 deg F.), H2O2 begins to boil. However, it is highly likely to undergo potentially explosive thermal decomposition if heated at this pressure to this temperature, since H2O2 is potentially highly exothermic, and has a heat of decomposition of 2.83 kJ/gram, or (2.83×34.1=) 96.5 KJ/mol.

The energy required to convert H2O2 at 1 atm and 423.3 K from liquid to vapor is estimated at 1.26 KJ/gram. Since the molar mass is 34.01 grams, the vaporization energy equals (1.26×34.01=) 42.9 KJ/mol. The specific heat capacity of H2O2 liquid is about 89.3 J/mol/K, and the isobaric specific heat capacity of H2O2 steam is equal to about 43.1 J/mol/K.

Assuming H2O2 stored at Standard Temperature and Pressure (STP) of 273.15 K and 1 atm, 1 mol of H2O2 raised to 423.3 K will require (423−273)×89.3=) 13.4 kJ. (At that temperature, 42.9 kJ would need to be added to convert the hot H2O2 liquid to steam, for a total of (13.4+42.9=) 56.3 kJ).

At a pressure of about 204 atm (20.7 MPa, 3,002 psi), and a temperature of 730 K (457 deg C., 854.6 deg F.), H2O2 is at its critical point. Assuming, therefore, only the specific heat capacity of liquid H2O2 is required to that point, the total required thermal input would equal (730−273)×89.3=) 40.8 kJ.

Assuming H2O2 thermolysis occurs at a temperature of 2,270 K (2,000 deg C., 3,625 deg F.), an additional ((2270−730)×43.1=) 66.4 kJ of latent heat would be required to raise the pressurized steam to that temperature.

Assuming a 100% conversion at that temperature and pressure, the specific heat capacity of H2+O2 thus produced would equal (28.8+29.4=) 58.2 J/mol/K, for a total between 2,270 K and 730 K of (1540×58.2=) 89.6 kJ, or an excess of latent heat within the product over that required of (89.6−66.4=) 23.2 kJ. That is, with perfect thermal regeneration, 23.2 kJ of thermal energy is potentially available.

As proposed above for H2O and in U.S. patent application Ser. No. 19/303,034, following thermolysis, the product can be divided into two streams, ideally one of H2 and one of O2, as, for example, passing the product through a molecular sieve at peak temperature, as noted above. Thus, with 100% thermolysis, the H2 stream would possess 28.8 J/mol/K of latent heat at 2,270 K, equal to (2270-730)×28.8=) 44.35 kJ, and the O2 would possess (89.6-44.35=) 45.25 kJ of latent heat.

In a perfect regeneration, the O2 by itself could supply (45.25/66.4=) 68% or 45.15 kJ of the thermal requirement to preheat the H2O steam from 730 K to 2,270 K, leaving (66.4-45.15=) 21.25 kJ of H2 latent heat not used.

Between the temperature range marked by the critical temperature of 730 K and 273 K, the separated H2 stream and the main H2 stream having been reunited, the remaining latent heats of the H2+O2 product of 58.2 J/mol/K would equal about (730−273)×58.2=) 26.6 kJ, or remaining required thermal energy for preheating of H2O2 reactant minus latent heat within the product of (40.8−26.6=) 14.2 kJ. This can be supplied by the 21.25 kJ of H2 latent heat not used in the thermal regeneration from 2,270 K to 730 K, leaving (21.25−14.2=) 7.05 of H2 latent heat not used. That would equal (7.05/44.35)=) about 0.16 moles of H2 that could be separated at a temperature of 2,270 K and 214 atm. Per U.S. patent application Ser. No. 19/303,034, the 0.16 moles of H2 could then be cooled regeneratively to 273 K, thus making available ((2,270−730)×28.8×0.16=) 7.1 kJ of high grade heat, for example to a heat engine.

Thus the 100% thermolysis of H2O2 reactant at 2,270 K into H2+O2 product will (1) thermo-chemically release about 96.5 kJ/mol in the dissociation of 0.5 mol of O2 from 1 mol of H2O2, and simultaneously store about 285.8 KJ/mol in the dissociation of H2O into 1 mol of H2 plus 0.5 moles of O2, for a net H2O2 dissociation into 1 mol of H2 and one mol of O2 thermal requirement of (285.8-96.5=) 189.3 kJ. It will also produce 1 mol of H2 at 204 atm, 1 mol of O2 at 204 atm, and about 7.1 kJ of high grade heat.

It is anticipated that it may be necessary to use an EREC to over-compress the vaporous H2O2 reactant at its critical temperature, thus ensuring that slightly higher pressure H2+O2 (plus remnant H2O vapor) product will have a sufficiently higher temperature to both supply energy to the lower pressure reactant above its critical temperature and below its critical temperature.

It is also anticipated that the yield of H2+O2 will be substantially less than 100%. However, in that instance, the remnant H2O, having exactly the same liquid and vaporous heat capacity, can, in a perfect regeneration, supply exactly the thermal requirements for preheating necessary to elevate the H2O reactant to the temperature required for dissociation. In short, assuming a minimum of possibly as little as 25%, the remnant high grade heat of 7.1 kJ per mol of H2 passed through the system can potentially supply sufficient make-up thermal energy to drive the system, thus only requiring the addition of high grade thermal energy in the system that is equal to the thermal energy stored in the product, thus converting the source energy perfectly into thermo-chemically stored energy.

Using a Combination of Electrolysis and Thermolysis

It is anticipated that it is possible that a combination of both electrolysis and thermolysis will yield better overall thermal efficiency than either on their own,

SUMMARY

This application proposes several new embodiments of a fully-regenerated isochorically-heated Closed Cycle Valved Cell (CCVC) heat engine. It further proposes further applications to Bland/Ewing (B/E) chemo/thermodynamic half-cycles. Additionally, this application proposes new processes for improving the usefulness of thermolysis and electrolysis, especially in relation to but not limited to using those processes for the dissociation of H2O and H2O2 at high pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be illustrated in greater detail by description in connection with specific examples of the practice of it and by reference to the accompanying drawings, in which:

FIG. 1 is partially cutaway and partially transparent solid model of the existing EISG CCVC testbed. FIG. 1 shows the EISG CCVC testbed at Top Dead Center (TDC). The numbers under the boxed labels represent information found within corresponding boxed labels within FIG. 3

FIG. 2 is similar to FIG. 1 and shows the EISG CCVC testbed at Bottom Dead Center (BDC).

FIG. 3 is a schematic of the processes that occur within the EISG CCVC testbed. The numbers under the boxed labels represent the various means employed with the EISG CCVC testbed. The prime mover can be seen as the standard crankcase and single-cycle camshaft below the engine in FIG. 1, FIG. 2, and elsewhere in other figures.

FIG. 4 is a proposed modified version of the EISG CCVC testbed. FIG. 4 shows the EISG CCVC testbed at Top Dead Center (TDC). The numbers under the boxed labels represent additional information found within corresponding boxed labels within FIG. 6 and FIG. 7.

FIG. 5 is similar to FIG. 4 and shows the modified EISG CCVC testbed at Bottom Dead Center (BDC).

FIG. 6 is a schematic of the processes that occur within a modified version of the EISG CCVC testbed. The numbers under the boxed labels represent the various means employed within a modified version of the EISG CCVC testbed.

FIG. 7 is a schematic of the processes that occur within another modified version of the EISG CCVC testbed. The numbers under the boxed labels represent the various means employed within another modified version of the EISG CCVC testbed.

FIG. 8 is another proposed modified version of the EISG CCVC testbed. FIG. 8 shows the EISG CCVC testbed at Top Dead Center (TDC). The numbers under the boxed labels represent additional information found within corresponding boxed labels within FIG. 12, FIG. 13, and FIG. 14.

FIG. 9 is a rotated closeup of the modified EISG CCVC testbed shown in FIG. 8.

FIG. 10 is similar to FIG. 8 and shows the modified EISG CCVC testbed at Bottom Dead Center (BDC).

FIG. 11 is a rotated closeup of the modified EISG CCVC testbed shown in FIG. 10.

FIG. 12 is a schematic of the processes that occur within another modified version of the EISG CCVC testbed. The numbers under the boxed labels represent the various means employed within a modified version of the EISG CCVC testbed.

FIG. 13 is a schematic of the processes that occur within another modified version of the EISG CCVC testbed. The numbers under the boxed labels represent the various means employed within a modified version of the EISG CCVC testbed.

FIG. 14 is a schematic of the processes that occur within another modified version of the EISG CCVC testbed. The numbers under the boxed labels represent the various means employed within a modified version of the EISG CCVC testbed.

FIG. 15 is a schematic of a process that occurs within a modified version of the EISG CCVC testbed. The numbers under the boxed labels represent the various means employed within a modified version of the EISG CCVC testbed. Reference to the boxed labels in FIG. 15 is made to the boxed labels in U.S. Pat. No. 19,303,034, “Applying open cycle and closed cycle valved cell heat engines to Bland/Ewing chemo-thermodynamic cycles”, FIG. 1 through FIG. 14. Additionally, special reference is made to FIG. 14 of U.S. Pat. No. 19,303,034 where additions and differences are indicated by the use of boxed labels with heavy dashed borders.

FIG. 16 is modification of the partially cutaway and partially transparent solid model of the modified EISG CCVC testbed illustrated in U.S. Pat. No. 19,303,034, FIG. 8, indicating where elements shown in FIG. 8 are slightly modified within FIG. 16. The boxed labels in FIG. 16 refer to the matching boxed labels in U.S. Pat. No. 19,303,034, FIG. 8, as modified by FIG. 15.

DETAILED DESCRIPTION

Description—Eighth Embodiment

An Alternative Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Heat Engine

As described above and as shown in FIG. 15, as opposed to raising the pressure of the vaporized reactant with a compressor as described in the Sixth Embodiment of U.S. Pat. No. 19,303,034 and above for the Rankine/Stirling fully-regenerating CCVC-based Bland/Ewing (B/E) chemo/thermodynamic endothermic half-cycle, an alternative embodiment would use “isochoric displacement heating” to raise the pressure of the vaporized reactant. Isochoric displacement heating is essentially the use of the first regenerative waste exhaust heat displacement process described for the Rankine/Stirling fully-regenerating CCVC-based Bland/Ewing chemo/thermodynamic endothermic semi-open half-cycle heat engine. The purpose of utilizing isochoric displacement heating in this instance is primarily to more efficiently increase pressure and thus the temperature at which the eventual vapor product, in this case C6H6, will condense over and above the lower pressure and thus temperature at which the C6H12 liquid will be evaporated. As noted above, condensing higher pressure C6H6 will theoretically supply more than the required heat of vaporization of C6H12, removing the thermal cost of vaporizing the C6H12 which would otherwise be required to be put into an endothermic B/E Rankine half-cycle embodiment.

Operation—Eighth Embodiment

An Alternative Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Heat Engine

Steps

• • 1. Medium pressure liquid C6H12 reactant enters the cold end of a counter-flow combined-function heat exchanger (boxed label 43 in FIG. 15), which essentially comprises a higher pressure C6H6 condenser, a lower pressure C6H12 vaporizer, and an H2 gas separator. The heat exchanger (43) heats and vaporizes the lower pressure reactant with the higher pressure condensing and cooling vaporous C6H6 and gaseous H2 product. Since the reactant and the product are not at the same pressure, and some mixing of the two streams can be tolerated, either a standard counter-flow heat exchanger or a “valve-shifted dual-stream” regenerator (VSDSR) may be used. A following cooler (not shown) will probably be required to fully separate the C6H6 liquid, any remnant C6H12 liquid, and H2 gas products.
  • 2. At TDC, the SSR actuated exhaust valve (boxed label 44 in FIG. 15), the displacer #2 intake check valve (boxed label 45 in FIG. 15), and the main engine exhaust valve (32) are all closed, completely isolating the VDSR heat exchanger (24). In addition, the displacer #1 intake check valve (2), the displacer #2 exhaust check valve (boxed label 46 in FIG. 15), and the expander exhaust valve (boxed label 47 in FIG. 15) are closed, and the high pressure isobaric expander intake/transfer valve (transfer valve) (boxed label 48 in FIG. 15) has just opened.
  • 3. At the beginning of the move from TDC to BDC, hot, high pressure H2 gas begins to flow isobarically from a high pressure isobaric external system, past the transfer valve (48), and into the expander (9).
  • 4. Simultaneously, at the beginning of the move from TDC to BDC, displacer #1 (3) begins expanding high pressure remnant C6H12 reactant vapor captured at the close of the displacer #1 exhaust check valve (4).
  • 5. Shortly following the beginning of the move from TDC to BDC, pressure within displacer #1 drops sufficiently for medium pressure vaporous C6H12 reactant to begin passing through the displacer #1 intake check valve (2), for example by C6H12 reactant vapor pressure from the heat exchanger (43) overcoming the spring pressure bias towards closed of the displacer #1 intake check valve (2), thus flowing medium pressure vaporous C6H12 reactant into displacer #1 (3).
  • 6. Simultaneously, at the beginning of the move from TDC to BDC, the main engine exhaust valve (32) is opened, connecting the VDSR heat exchanger (24) and its manifolds to a medium pressure external system. Since the pressure in the VDSR heat exchanger (24) will be at the maximum internal pressure point of the engine, decompression down to the medium pressure regime of the external isobaric system will occur through the main engine exhaust valve (32). Note that the work “lost” through this “pressure blowdown” will be minimized to the degree that the volume of the VDSR heat exchanger (24) and its connecting manifolds is minimized.
  • 7. Simultaneously, at the beginning of the move from TDC to BDC, displacer #2 (7) begins to exhaust its contents.
  • 8. Simultaneously, at the beginning of the move from TDC to BDC, the displacer #2 exhaust check valve (46), which is biased towards closed, for example, by a spring, will sense the raising pressure within displacer #2 (7) and open access to the high pressure isobaric external system.
  • 9. Simultaneously, at the beginning of the move from TDC to BDC, displacer #3/compressor (13) begins re-pressurizing medium pressure H2 gas.
  • 10. Simultaneously, at the beginning of the move from TDC to BDC, medium pressure H2 gas being exhausted from displacer #3/compressor (13) begins re-entering exhaust SSR (28) via the exhaust check valve (ECV) #4 (39, FIG. 14), bypassing the VDSR cooler (35, FIG. 14), for example by higher pressure H2 gas exiting displacer #3/compressor (13) overcoming ECV #4 (39, FIG. 14) spring pressure.
  • 11. Slightly following the main engine exhaust valve (32) opening to the external medium pressure system, thus equalizing pressure, the SSR actuated exhaust valve (44) is opened, connecting the hot end of the (medium pressure) exhaust SSR (28) to the hot end of the (medium pressure) VDSR heat exchanger (24). Otherwise-waste heat stored in the exhaust SSR (28) is thus recaptured in the medium pressure H2 gas isobarically exhausting through the exhaust SSR (28), and deposited in the VDSR heat exchanger (24), with the cooled H2 then exhausting into the medium pressure external system, thus “charging” the VDSR heat exchanger (24) with thermal energy.
  • 12. As BDC begins to be approached, the SSR actuated exhaust valve (44) is closed, thus causing the medium pressure H2 gas captured between the displacer #3/compressor (13), the (closed) expander exhaust valve (boxed label 47 in FIG. 15), and the (closed) SSR actuated exhaust valve (44) to begin increasing in pressure, eventually approximately equaling the high pressure within the expander (9) just prior to opening of the expander exhaust valve (47).
  • 13. Slightly before BDC, the expander exhaust valve (47) begins opening. Simultaneously, both the transfer valve (48) and the main engine exhaust valve (32) begin to close, briefly connecting all spaces within the engine at the pressure of the medium pressure external isobaric system.
  • 14. By BDC, the expander exhaust valve (47) is open, the transfer valve (48) and the main engine exhaust valve (32) are closed, and isobaric flow through-out the engine briefly stops.
  • 15. Following BDC, as the engine begins moving towards TDC, the displacer #1 exhaust check valve (4) automatically opens as, for example, gas pressure within displacer #1 (3) overcomes displacer #1 exhaust check valve (4) spring pressure.
  • 16. Simultaneously, as displacer #2 (7) begins moving towards TDC, pressure drops inside displacer #2 (7).
  • 17. Simultaneously, at the beginning of the move from BDC to TDC, the displacer #2 exhaust check valve (46), which is biased towards closed, for example, by a spring, will sense the lowering pressure and close access to the high pressure isobaric external system.
  • 18. At the beginning of the move from BDC to TDC, displacer #1 (3) begins displacing medium pressure C6H12 vaporous reactant past displacer #1 exhaust check valve (4) and into the cold end of the VDSR heat exchanger (24).
  • 19. Simultaneously, at the beginning of the move from BDC to TDC, displacer #2 (7) begins expanding remnant medium pressure H2, dropping the internal pressure and opening the displacer #2 intake check valve (45), for example by overcoming spring pressure with H2 isochorically flowing out of displacer #1 (3), flowing from the cold end to the hot end of the VDSR heat exchanger (24), flowing past displacer intake check valve #2 (43), and flowing into displacer #2 (7).
  • 20. Simultaneously, at the beginning of the move from BDC to TDC, the expander begins isochorically to exhaust pas the expander exhaust valve (45), through the exhaust SSR (28), through the VDSR cooler system (see FIG. 14), and into displacer #3/compressor.
  • 21. As TDC is approached, the expander exhaust valve (45) is closed, capturing remnant H2 within the expander (9). By TDC, the captured remnant H2 in the expander (9) is recompressed to at least match the pressure on the inlet side of the high pressure isobaric expander intake/transfer valve (boxed label 46 in FIG. 15). Consequently, the transfer valve (46) is free to open, for example by spring pressure applying a bias towards open.
  • 22. Considering the high pressure isobaric external system, on the side of the displacer #2 exhaust check valve (44) opposite displacer #2, the high pressure preheated C6H12 vapor exhaust is passed through the C6H12/C6H6+H2 recuperator (or VDSR or VSDSR regenerator) (boxed label 47 in FIG. 15), where the inflowing C6H12 vapor is preheated to the temperature of the high pressure, high temperature endothermic catalytic reactor (boxed label 48 in FIG. 15) by the outflowing C6H+H2 product mix.
  • 23. The high temperature, high pressure C6H12 reactant is then passed through the endothermic reactor (47) receiving thermal energy from a primary source of heat input (source heat in) (27), where it is converted, in this case via a catalyst bed, into C6H6+H2 (plus remnant C6H12) product.
  • 24. The C6H6+H2 product is then separated into two streams, as noted above, the first of which, as has been shown, is used to preheat with latent heat the inflowing C6H12 reactant in the C6H12/C6H6+H2 recuperator (47), and second of which is passed into the H2/C6H6+H2 recuperator (or VDSR or VSDSR regenerator) (boxed label 49 in FIG. 15) and is used to heat with latent heat inflowing high pressure H2 gas, which, as will be made clear below, constitutes the working fluid for the high pressure isobaric external system.
  • 25. Following the cooling, in the C6H12/C6H6+H2 recuperator (47) and the H2/C6H6+H2 recuperator (49), of the two C6H6+H2 product streams exiting the endothermic reactor (47), the two streams are rejoined.
  • 26. The reconstituted C6H6+H2 product stream is then passed through the (high pressure) C6H6 condenser, (medium pressure) C6H12 vaporizer, and (high pressure) H2 separator heat exchanger (41). A valve-switching dual stream regenerator (VSDSR) that alternately flows a liquid in on the cold side and its vapor out on the hot side in one regenerator while a second regenerator is flowing a vapor/gas mix in on the hot side and a liquid-saturated gas out on the cold side, then switches, should be possible, especially since some mixing of the two streams is allowable.
  • 27. The separated high pressure liquid and gas products (in this case, C6H6 and H2) then take different paths. The high pressure liquid C6H6 is passed through a hydraulic motor (boxed label 50 in FIG. 15), which both reduces the pressure of the liquid C6H6 and, since the liquid C6H6 goes back into the medium pressure C6H6/C6H12 liquid storage tank with separator piston (boxed label 51 in FIG. 15) that the C6H12 is being removed from (with a separator piston, for example with a roll sock seal, separating the two liquids), the hydraulic C6H6 motor (50) serves also to pump out the liquid C6H12 into the heat exchanger (41).
  • 28. Meanwhile, the separated high pressure H2 gas that was generated by the endothermic reactor (48) also can take two different paths. Generally, it will be passed back through the H2/C6H6+H2 recuperator (49) and from there be sent to the engine's transfer valve (46). However, recall that, after passing through the engine, the H2 is lowered in pressure by the displacer #3/compressor (13) system, eventually being exhausted through the main engine exhaust valve (32). It is then cooled with an H2 cooler (boxed label 52 in FIG. 15) to remove any liquid, such as remnant C6H12 vapor picked up during the VDSR heat exchanger (24) process, and stored in a medium pressure H2 storage tank system (boxed label 53 in FIG. 15). As a result, if an excess of H2 is produced by the endothermic reactor (48), an alternative path for high pressure H2 exiting the heat exchanger (41) is to also be stored in the medium pressure H2 storage tank system (53). But it is also arranged that H2 stored in the medium pressure H2 storage tank system (53) can be sent to the H2/C6H6+H2 recuperator (49). Consequently, a pneumatic H2 motor/compressor (54) is arranged to either add H2 to the medium pressure H2 storage tank system (53) and generate work out as a motor or take H2 from it and compress it as a compressor.

Description—Ninth Embodiment

An Alternative Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Cooling Engine

Instead of passing the C6H6 plus H2 mix through a fully-regenerating CCVC engine following the recombining of the approximately ⅔ and ⅓ streams, as described in the Sixth Embodiment above, the higher pressure C6H6 in the recombined streams is first condensed out to supply the heat required for vaporizing liquid C6H12, as in the Seventh Embodiment. As a result, the high pressure H2 gas is completely separated from the C6H6 and any remnant C6H12.

The H2 may then be cooled at constant pressure to ambient temperature. It may then be expanded to ambient pressure, producing cold. The chilled H2 may then be either converted into liquid H2 or be “heated” back to ambient temperature at ambient pressure, for example by chilling pressurized gaseous O2 into liquid O2.

Description—Tenth Embodiment

Using a Second Isochoric Displacement Process to Enhance a Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Heat Engine

Alternatively to the Ninth Embodiment above, prior to final heat exchange and cooling, pressurized H2 can then be reheated and super-pressurized via, for example, a second Isochoric displacement heating process, thus increasing its pressure even more through the isochoric application of thermal energy, for example by using the thermal content of the ⅓ stream of C6H6 plus H2 exiting the endothermic catalytic reactor. The higher pressure H2 may then be expanded to produce work.

Description—Eleventh Embodiment

Using a Second Isochoric Displacement Process to Enhance a Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Cooling Engine

Alternatively to the Tenth Embodiment above, rather than expanding the high pressure H2 at that point, the latent thermal heat of the resulting thermally pressurized and reheated H2 may then be transferred, via an isobaric heat exchange process, to a separate external heat engine, creating work out from said separate external heat engine while simultaneously producing cooled ultra-high pressure H2. The H2 may then be finally cooled at constant pressure to ambient temperature, then be expanded to ambient pressure, producing even more extreme cold. The chilled H2 may then be either converted into liquid H2 or be “heated” back to ambient temperature at ambient pressure, for example by chilling pressurized gaseous O2 into liquid O2.

Description—Twelfth Embodiment

An Alternative Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Expansion Engine

The concept of using a pump to pressurize a liquid chemical compound or reactant, convert it into vapor, thermally separating it and thus (1) chemically storing the thermal energy contained in the dissociated chemical compound or product and (2) increasing the number of moles of product over the number of moles of reactant available to a following expansion process, then expanding it, falls under the purview of newly issued U.S. Pat. No. 12,392,261, granted Aug. 19, 2025. That also applies to thermally splitting liquid H2O into H2 and O2, since pumping high pressure water (reactant) into a system, then increasing the temperature to the point where the resulting pressurized steam thermally dissociates into H2 and O2, is technically possible. Separating the product into separate H2 and O2 streams is also technically possible, as by using a molecular sieve. Finally, the two gas streams may be separately expanded to generate net work out.

Generating pressurized H2O steam from pressurized H2O liquid that will then be thermo-chemically dissociated is a valid alternative approach to creating a fluid suitable for chemo/thermochemical expansion to generate net work, since it will create a 1-to-1.5 chemo/thermochemical expansion. Alternatively, H2O2 (hydrogen peroxide) may be used as well, creating a 1-to-2 chemo/thermodynamic expansion, since the reaction yields H2 and O2. Other compounds can similarly be used.

There exists a well-known alternative to thermally splitting H2O into H2 and O2, which is splitting by electrolysis. In a paper entitled “Operation of the 25 KW NASA Lewis Research Center Solar Regenerative Fuel Cell Testbed Facility” by Gerald Voecks, it has been demonstrated that liquid H2O may be efficiently pressurized to a very high pressure (approximately 200 atm) by pump, split into pump-pressurized high pressure H2 and O2 via electrolysis, and the resulting high pressure gases are then separated and stored. It is herein recognized that such an electrolysis of highly pressurized H2O is a valid alternative approach to creating a fluid suitable for chemo/thermochemical expansion to generate net work, since it will create a 1-to-1.5 chemo/thermochemical expansion. Alternatively, H2O2 (hydrogen peroxide) may be used to create a 1-to-2 chemo/thermodynamic expansion.

The advantage of generating the H2 and O2 at high pressure is that they can be stored indefinitely in smaller storage tanks. Expanding the gases would thus seem to be contra-indicated, since it requires work to create the electricity to dissociate H2O int H2 and O2. There is, however, the thermochemical expansion to consider, which has increased the potential work of expansion by 1.5×. Looking at the H2 and O2 as potential gaseous expansion material for a heat engine, even assuming losses, it would appear a net advantage may be possible, especially since the H2 and O2, even at lower pressure (<1 MPa or about 10 atm), can still produce very high thermal efficiency in a fuel cell.

Description—Thirteenth Embodiment

An Alternative Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Cooling Engine

An alternative storage approach exists to that disclosed in the Gerald Voecks paper referenced above, which takes into account the chemo/thermodynamic concepts disclosed herein, and forms the essence of the embodiment proposed herein. By expanding the H2 product constituent from ambient temperature, additional work out may be created, while the H2 may simultaneously be greatly reduced in temperature below ambient. The cold thus produced is then usable to assist in the liquefaction of the high pressure O2 produced by electrolysis. Liquefaction of O2 is advantaged over storage as a pressurized gas in that the tank itself can be far less massive for liquid O2, since the pressure may equal ambient. It is also far easier to maintain liquid O2 against inevitable boil-off losses than liquid H2. The H2 then, at whatever remnant pressure, may be alternatively “stored” by combining with C6H6 to produce C6H12, which, like liquid O2, is also able to be stored at both ambient pressure and ambient temperature. In addition, since the resulting exothermic release of heat from the storage of H2 in the form of C6H12 has been found to essentially equal the thermochemical production of earlier-captured thermal energy, as has been proposed above as a Bland/Ewing half-cycle, that released thermal energy can be used to create net work, which in turn can be used to create electricity (which in turn can be used to convert high pressure water vapor into H2 and O2).

The H2 thus “captured” in C6H12 results in the completion of a Bland/Ewing exothermic chemo/thermodynamic half-cycle, thus making available for use the second matching endothermic Bland/Ewing chemo/thermodynamic half-cycle, as is proposed herein, the two half-cycles thus jointly creating a full Bland/Ewing chemo/thermodynamic cycle, a process that is covered by U.S. Pat. No. 12,352,250, granted Jul. 8, 2025 to Joseph Barrett Bland, 7482 Greenhaven Dr, Sacramento, CA.

Finally, the H2 released by a full Bland/Ewing work-producing cycle as described herein, when combined with O2 (for example, using liquid O2 created by expansion of cooled H2 following the high pressure, high temperature electrolysis of H2O in the process described above, of for example using O2 available in Earth's atmosphere), create a “Benzene Battery” chemo/thermodynamic full cycle, which is covered by U.S. patent application Ser. No. 18/197,092, filed May 14, 2023.

Description—Fourteenth Embodiment

An Alternative Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Expansion Engine

As an alternative embodiment, the high pressure H2 (at ˜200 atm, per the quoted Voecks paper), may be considered “feed stock” for a B/E Benzene Battery, as proposed in U.S. patent application Ser. No. 18/197,092. Liquid benzene (C6H6) may be pressurized to ˜200 atm, vaporized and preheated to the exothermic catalytic reaction temperature of ˜750K-to-800K per FIG. 1 in US Patent 3,225, 538, mixed with similarly preheated H2 at 200 atm created by high pressure electrolysis, and then converted into cyclohexane (C6H6). Per FIG. 1 in U.S. Pat. No. 3,225,538, the conversion of C6H6+3H2 will produce 1,180 kJ of ˜750K-to-800 K heat per 0.4536 kg (1 pound) of C6H12. That would convert approximately 16.17 mols of H2. At a mass of 2.02 g/mol, that would equal about 0.0327 kg of H2. For comparison purposes, the high heat of combustion for H2 is about 141,800 KJ/kg. Thus, the high heat of combustion of 0.0327 kg of H2 or 4,637 kJ equals (4637/1180=) 3.93 times the thermal energy generated by the exothermic creation of one pound of C6H12.

Per the above, that energy could be used to power a heat engine with a source temperature of at least 750-800 K. With superheating, for example by the use of concentrated solar energy, a fully-regenerating CCVC-based heat engine, real-world thermal efficiency in excess of 50% is possible, suggesting that on the order of a 10-12% increase in the production of electricity and thus of H2 generation for a given base solar input is made possible by “releasing” the potential stored energy of a B/E exothermic C6H6 heat engine half-cycle with this alternative embodiment of a Rankine/Stirling fully-regenerating CCVC-based Bland/Ewing chemo/thermodynamic endothermic semi-open half-cycle expansion engine. For the full cyclohexane/benzene B/E chemo/thermodynamic cycle, or C6H12+Hin+Wout<=>C6H6+3H2+Hout+Wout, overall efficiency may also equal in excess of 50%.

Description—Fifteenth Embodiment

Thermolysis of H2O or H2O2 in Chemo/Thermodynamic Processes

The generation of H2O and/or H2O2 steam that is then dissociated by thermolysis is herein proposed as a valid means of creating a fluid suitable for chemo/thermochemical expansion, since it will create a 1-to-1.5 chemo/thermodynamic expansion.

Description—Sixteenth Embodiment

Electrolysis of H2O or H2O2 in Chemo/Thermodynamic Processes

The dissociation of liquid or vaporous H2O and/or H2O2 by electrolysis is herein proposed as a valid means of creating a fluid suitable for chemo/thermochemical expansion, since it will create a 1-to-1.5 chemo/thermodynamic expansion.

Description—Seventeenth Embodiment

a Combination of Thermolysis and Electrolysis of H2O or H2O2 in Chemo/Thermodynamic Processes

The generation of H2O and/or H2O2 steam that is then dissociated by a combination of thermolysis and electrolysis is herein proposed as a valid means of creating a fluid suitable for chemo/thermochemical expansion, since it will create a 1-to-1.5 chemo/thermodynamic expansion.

Description—Eighteenth Embodiment

The Use of a Cyclical Carrier Fluid Such as C6H12 as a Means for Storing Both H2 and O2 in Liquid Form

It is proposed that a cyclical carrier fluid such as C6H12 be used in conjunction with highly pressurized H2O, H2O2, or other H2-containing compounds that can be converted into their constituent elements by thermolysis and/or electrolysis. The separated high pressure H2 and O2 would be cooled to ambient temperature and then expanded to reduce their temperature. In the case of O2, expansion would be required to stop at the point of liquifaction. In the case of H2, since the temperature required for liquifaction is exceedingly low, expansion can continue to a much colder temperature than the O2. Consequently, sufficient latent cold is available in the H2 to more than supply the reduction in temperature of the O2 for the purpose of the O2's liquefaction.

The high pressure H2, being warmed by the cooling of the O2, would then be used as the working fluid in a heat engine to create work, eventually being exhausted at a pressure and temperature designed to maximize its passing through a fuel cell and creating electricity. The O2, being liquid, could likewise be passed through a heat engine to create work, eventually being exhausted at a pressure and temperature designed to maximize its passing through a fuel cell and creating electricity.

Description—Nineteenth Embodiment

Thermolysis of H2O or H2O2 Reactant with Thermal Regeneration of the Product of Thermolysis as a Means of Efficiently Preheating the Reactant

A kind of regenerator is possible that can be called a “dual-stream” regenerator (DSR). When ducts/ports are used, it may be termed a “ducted DSR” (DDSR) and when valves are used it may be termed a “valved DSR” (VDSR). One embodiment of a VDSR can create a kind of “valve-switched DSR” (VSDSR), where two or more regenerators cycle between (a) being charged with thermal energy and (b) giving up that energy.

It is herein proposed that one or the other of these various forms of DSRs be used to greatly increase the efficiency of thermolysis by taking advantage of the difference in latent heat capacity between the reactant and, following dissociation, the and the product. By making it less important that the dissociation be complete, regeneration, which is highly efficient, allows multiple passes of reactant through a given system to achieve a given amount of conversion.

It is further proposed that concentrated solar energy be used almost exclusively as the source of energy for this type of thermolysis. Concentrated solar energy is highly advantaged as a heat source because it is already environmentally omnipresent and thus environmentally low impact, because it is low in production cost, and because thermolysis of H2O and H2O2 requires exceedingly high temperatures.

Description—Twentieth Embodiment

An Lunar PSR-Based Rankine/Stirling Fully-Regenerating CCVC-Based Bland/Ewing Chemo/Thermodynamic Endothermic Semi-Open Half-Cycle Cooling Engine

In a lunar Permanently Shadowed Region (PSR) such as those at the lunar poles, “ambient temperature” can be extremely low, possibly approaching 100 K, but can be assumed to approximate 150-200 K on average. O2 has a critical point/condensation temperature at about 50 atm of about 150 K, and that temperature can be assumed to be somewhat higher at 200 atm. Therefore, the expansion of 200 atm H2 can be seen to easily be capable of liquifying O2 in that environment. Liquid H2 itself needs to be cooled to approximately 20 K at about 1 atm. However, rapidly quenched H2, such as from adiabatic expansion to below the liquefaction temperature, will essentially “boil off” H2 due to heat released as orthohydrogen converts to its “spin isomer” parahydrogen. If liquid H2 is desired, catalysts can aid in the conversion to parahydrogen at various temperatures. However, for the use case proposed above, the boiling points of both orthohydrogen and parahydrogen are nearly equal, so “boiled-off H2” can still serve as a meaningful “liquifier” for many gases, including O2.