TEMPERATURE CONTROL FOR ACID CONDENSATION

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and incorporates by reference U.S. Provisional Application No. 63/662,782, filed Jun. 21, 2024.

BACKGROUND

Bioreforming processes can produce aromatic hydrocarbons and other useful compounds from biomass feedstocks, including cellulose, hemicellulose, and lignin. For instance, cellulose and hemicellulose can be used as feedstock for various bioreforming processes, including aqueous phase reforming (APR) and hydrodeoxygenation (HDO)—catalytic reforming processes that, when integrated with hydrogenation, can convert cellulose and hemicellulose into an array of products, including hydrogen, liquid fuels, aromatics, kerosene, diesel fuel, lubricants, and fuel oils, among others. In addition, catalytic acid condensation (AC) can be used to convert oxygenates (e.g., generated by HDO) or other compounds into hydrocarbons.

APR and HDO methods and techniques are described in U.S. Pat. Nos. 6,699,457; 6,964,757; 6,964,758; and 7,618,612 (all to Cortright et al., entitled “Low-Temperature Hydrogen Production from Oxygenated Hydrocarbons”); U.S. Pat. No. 6,953,873 (to Cortright et al., entitled “Low-Temperature Hydrocarbon Production from Oxygenated Hydrocarbons”); and U.S. Pat. Nos. 7,767,867; 7,989,664; and 8,198,486 (all to Cortright, entitled “Methods and Systems for Generating Polyols”), all of which are incorporated herein by reference. Various other APR and HDO methods and techniques are also described in U.S. Pat. Nos. 8,053,615; 8,017,818; 7,977,517; 8,362,307; 8,367,882; and 8,455,705 (all to Cortright and Blommel, entitled “Synthesis of Liquid Fuels and Chemicals from Oxygenated Hydrocarbons”); U.S. Pat. No. 8,231,857 (to Cortright, and entitled “Catalysts and Methods for Reforming Oxygenated Compounds”); U.S. Pat. No. 8,350,108 (to Cortright et al., entitled “Synthesis of Liquid Fuels from Biomass”); and International Patent Application No. PCT/US2008/056330 (to Cortright and Blommel, entitled “Synthesis of Liquid Fuels and Chemicals from Oxygenated Hydrocarbons” and published as WO2008109877A1), all of which are incorporated herein by reference.

SUMMARY OF THE INVENTION

Some aspects of the present disclosure provide a method for production a C₄₊ product stream. A first inlet stream can be provided to an acid condensation (AC) reactor train, including providing the first inlet stream at a first inlet temperature to a first AC reactor. The first inlet stream can be reacted in the presence of a first condensation catalyst in the first AC reactor to produce a first AC effluent stream. The first AC effluent stream can be cooled to a second inlet temperature (e.g., that is substantially equal to the first inlet temperature). The cooled first AC effluent stream can be provided to a second AC reactor as a second inlet stream. The second inlet stream can be reacted in the presence of a second condensation catalyst in the second AC reactor to produce a second AC effluent stream.

Providing the first inlet stream at the first inlet temperature can include heating the first inlet stream with the first AC effluent stream.

Providing the first inlet stream at the first inlet temperature can include heating the first inlet stream with the second AC effluent stream.

Providing the first inlet stream at the first inlet temperature can include cooling the first AC effluent stream.

The first AC effluent stream and the first inlet stream can be provided to a first heat exchanger to heat the first inlet stream and cool the first AC effluent stream.

Reacting the first inlet stream in the first AC reactor can produce the first AC effluent stream with the first AC effluent stream having a higher temperature than the first inlet temperature.

Reacting the second inlet stream in the second AC reactor can produce the second AC effluent stream with the second AC effluent stream having a temperature substantially equal to the second inlet stream.

The first condensation catalyst can have the same formulation as the second condensation catalyst.

The first AC reactor and the second AC reactor can be configured to selectively operate as a lead reactor and a lag rector, or as a lag reactor and a lead reactor, respectively.

The first inlet stream can be provided at the first inlet temperature to the second AC reactor as the lead reactor. The first inlet stream can be reacted in the presence of a first condensation catalyst in the second AC reactor to produce the first AC effluent stream. The first AC effluent stream from the second AC reactor can be cooled to the second inlet temperature. The cooled first AC effluent stream from the second AC reactor can be provided as a second inlet stream to the first AC reactor as the lag reactor. The second inlet stream can be reacted in the presence of a second condensation catalyst in the first AC reactor to produce the second AC effluent stream.

The first inlet stream provided to the AC reactor train can be an outlet stream from an upstream hydrodeoxygenation (HDO) reactor train.

Some aspects of the present disclosure provide a system for producing a C₄₊ product stream. An acid condensation (AC) reactor train can include a first AC reactor, a second AC reactor, and a third AC reactor configured for interchangeable operation as a lead AC reactor, a lag AC reactor, and a regenerating AC reactor. A first heat exchanger can include a first side and a second side, the first and second sides arranged for heat exchange between a first-side stream and a second-side stream without mixing the first-side stream with the second-side stream. The lag AC reactor can be configured to receive, as an inlet stream, an effluent stream from the lead AC reactor. The first heat exchange can be configured to receive an inlet stream for the lead AC reactor through the first side as the first-side stream and to receive the effluent stream from the lead AC reactor through the second side as the second-side stream, to heat the first-side stream to an inlet temperature for the lead AC reactor and cool the second-side stream to an inlet temperature for the lag AC reactor.

The inlet temperature for the lead AC reactor can be substantially equal to the inlet temperature for the lag AC reactor.

A second heat exchanger can include a first side and a second side, the first and second sides of the second heat exchanger arranged for heat exchange between a first-side stream and a second-side stream of the second heat exchanger without mixing the first-side stream with the second-side stream of the second heat exchanger. The second heat exchanger can be configured to receive an effluent stream from the lag AC reactor through the first side as the first-side stream of the second heat exchanger and to receive an effluent flow from an upstream hydrodeoxygenation (HDO) reactor train through the second side as the second-side stream of the second heat exchanger, to heat the second-side stream of the second heat exchanger and cool the first-side stream of the second heat exchanger. The heated second-side stream of the second heat exchanger can be provided as the first-side stream of the first heat exchanger to be heated to the inlet temperature for the lead AC reactor.

The lag AC reactor can produce an AC effluent stream having a temperature substantially equal to the inlet temperature for the lag AC reactor.

Some aspects of the present disclosure provide a method for producing a C₄₊ product stream. A first inlet stream can be provided to a lead acid condensation (AC) reactor of an AC reactor train at a first inlet temperature. The first inlet stream can be reacted in the presence of a first condensation catalyst in the lead AC reactor to produce a first AC effluent stream. The first AC effluent stream can be cooled with the first inlet stream, to cool the first AC effluent stream to a second inlet temperature. The cooled first AC effluent stream can be provided to a lag AC reactor as a second inlet stream. The second inlet stream can be reacted in the presence of a second condensation catalyst in the lag AC reactor to produce a second AC effluent stream.

The first inlet temperature can be substantially equal to the second inlet temperature.

The first inlet stream can be heated with the second AC effluent stream.

Reacting the second inlet stream in the second AC reactor can produce the second AC effluent stream with the second AC effluent stream having a temperature substantially equal to the second inlet stream.

Reacting the first inlet stream in the first AC reactor can produce the first AC effluent stream with the first AC effluent stream having a higher temperature than the first inlet temperature.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows an example system for providing a feed stream to an AC reaction train.

FIG. 2 shows an example AC reactor train according to an example of the disclosed technology.

FIG. 3 shows another example AC reactor train.

FIGS. 4 and 5 show experimental data from example implementations using the AC reactor trains of FIGS. 2 and 3.

DETAILED DESCRIPTION

The present disclosure relates to processes and systems for AC reactions, including as can be implemented downstream of HDO reactions. In one aspect, the present disclosure provides improved temperature control for inlet streams for AC reactors, including as can improve C₄₊ yields and reduce coking.

Generally, the technology disclosed herein can be used to improve AC processing for a wide range of feed streams. As an example context, FIG. 1 illustrates a system for AC processing of HDO products, with the relevant HDO reactions being implemented for a feed stream from an upstream hydrogenation reactor system (not shown). The particular system of FIG. 1 should not be viewed as limiting however, as a wide variety of systems can be implemented to provide a feed stream to an AC reactor system (e.g., as variously disclosed in U.S. Pat. Nos. 6,699,457; 6,964,757; 6,964,758; 7,618,612; 6,953,873; 7,767,867; 7,989,664; 6,953,873; 7,767,867; 7,989,664; 8,198,486; 8,053,615; 8,017,818; 7,977,517; 8,362,307; 8,367,882; 8,455,705 8,231,857; and 8,350,108; in International Patent Publication WO2008109877A1; or as otherwise known in the art).

In the example of FIG. 1, a feed stream including products from hydrogenation reaction (HYD) is introduced to a hydrodeoxygenation (HDO) reactor 100 for catalytic HDO reactions to produce an intermediate stream 110. The intermediate stream 110 is then separated into a light stream 120 (e.g., a first oxygenate stream) and a heavy residual stream 130. In some cases, although not shown in FIG. 1, the heavy residual stream 130 can be fed into an upgrading reactor along with H₂, to produce an intermediate upgraded stream (e.g., a second oxygenate stream). For example, such an upgrading reactor can be included in the same vessel as the HDO reactor (e.g., as shown) or can be provided separately (not shown). Once produced, as applicable, the intermediate upgraded stream can be combined with the light stream 120 (e.g., can be combined with a heavy fraction of the light stream 120, after further separation of the light stream 120) to form an upgraded oxygenate stream as an HDO product stream 140. The HDO product stream 140 can then be provided to a set of AC reactors 150 for catalytic AC reactions (e.g., after vaporization in a feed vaporizer 160). In the illustrated example, two AC reactors are provided, configured to interchangeably operate as lead and lag reactors 150A, 150B. In other examples, other arrangements are possible, including with more than two AC reactors as further discussed below.

In some examples, the heavy residual stream 130 can be first separated into heavy and light fractions, with the light fraction being provided to the set of AC reactors 150 in combination with the light stream 120 and the heavy fraction first undergoing further HDO reactions. In some examples, the heavy residual stream 130, or a fraction thereof, may not be combined with the light stream 120 before the light stream 120 is provided to the AC reactor(s) 150.

HDO Catalyst and HDO Reaction

The term “hydrodeoxygenation catalyst” (HDO catalyst) refers to a catalyst that catalyzes a process that removes oxygen from oxygen-containing compounds in the presence of hydrogen. Suitable HDO catalysts and processes include, for example, those described in WO 2014/152370 and WO/2023/064565, all of which are incorporated herein by reference.

In some embodiments, the HDO catalyst is composed of a heterogeneous catalyst having one or more materials capable of catalyzing a reaction between hydrogen and a feedstock solution to remove one or more of the oxygen atoms from the feedstock solution to produce one or more oxygenate. In some embodiments, the HDO catalyst is composed of one or more metal adhered to a support and may include, without limitation, Cu, Re, Fe, Ru, Ir, Co, Rh, Pt, Pd, Ni, W, Os, Mo, Ag, Au, alloys and combinations thereof. The HDO catalyst may include these elements alone or in combination with one or more promoters, such as Mn, Cr, Mo, W, V, Nb, Ta, Ti, Zr, Y, La, Sc, Zn, Cd, Ag, Au, Sn, Ge, P, Al, Ga, In, Tl, and combinations thereof. In some embodiments, the HDO catalyst includes Pt, Ru, Cu, Re, Co, Fe, Ni, W or Mo. In some embodiments, the HDO catalyst includes Fe or Re and at least one transition metal selected from Ir, Ni, Pd, P, Rh, and Ru. In some embodiments, the HDO catalyst includes Fe, Re and at least Cu or one Group VIIIB transition metal. In some embodiments, the metal of the HDO catalyst comprises Pd, W, Mo, Ni, Pt, Ru, or a combination thereof. In some embodiments, the HDO catalyst comprises a promoter. As an example, the promoter of the deoxygenation catalyst can comprise Sn, W, or a combination thereof. The support may include a nitride, carbon, silica, alumina, zirconia, titania, vanadia, ceria, zinc oxide, chromia, boron nitride, heteropolyacids, kieselguhr, hydroxyapatite, or a mixture thereof. In some embodiments, the support comprises zirconia.

The aqueous feed stream is reacted with hydrogen in the presence of the HDO catalyst at temperatures, pressures, and weight hourly space velocities effective to produce the desired oxygenate products. The specific oxygenates produced will depend on various factors, including the feedstock solution, reaction temperature, reaction pressure, water concentration, hydrogen concentration, the reactivity of the catalyst, and the flow rate of the feedstock solution as it affects the space velocity (the mass/volume of reactant per unit of catalyst per unit of time), gas hourly space velocity (GHSV), and weight hourly space velocity (WHSV). For example, an increase in flow rate, and thereby a reduction of the feed stream exposure to the HDO catalyst over time, will limit the extent of the reactions that may occur, thereby causing increased yield for higher level di-and tri-oxygenates, with a reduction in ketone, alcohol, and cyclic ether yields.

In general, the reaction may include a temperature gradient to allow partial deoxygenation of the oxygenated hydrocarbon at temperatures below the caramelization point of a feedstock, from which the aqueous feed stream is generated. Including a temperature gradient helps prevent the oxygenated hydrocarbons in the feed stream from condensing (e.g., caramelizing) on the catalyst and creating a substantial pressure drop across the reactor, which can lead to inoperability of the reactor. The caramelization point, and therefore the required temperature gradient, will vary depending on the feedstock. In one embodiment, the temperature gradient is from about 170° C. to 300° C. or between about 200° C. to 290° C. In another embodiment, a temperature gradient is not employed.

Operating pressures up to about 2000 psig can be used to help maintain the carbon backbone, minimize the amount of light organic acids and ketones that are formed, and increasing the product selectivity towards alcohols. By increasing operating pressures, the thermodynamics of the reaction favors alcohols to ketones and organic acids, thereby shifting the product selectivity, maintaining the carbon backbone, and improving product yields. Light organic acids are particularly undesirable products as they are highly corrosive. Producing fewer light organic acids provides more flexibility with regards to materials of construction of a reactor system because corrosion is less of an issue.

The reaction temperature and pressures are preferably selected to maintain at least a portion of a feedstock, from which the aqueous feed stream is generated, in the liquid phase at the reactor inlet. It is recognized, however, that temperature and pressure conditions may also be selected to more favorably produce the desired products in the vapor-phase. In general, the reaction should be conducted at process conditions wherein the thermodynamics of the proposed reaction are favorable. For instance, the minimum pressure required to maintain a portion of the feedstock in the liquid phase will likely vary with the reaction temperature. As temperatures increase, higher pressures will generally be required to maintain the feedstock in the liquid phase, if desired. Pressures above that required to maintain the feedstock in the liquid phase (i.e., vapor-phase) are also suitable operating conditions.

In condensed phase liquid reactions, the pressure within the reactor must be sufficient to maintain the reactants in the condensed liquid phase at the reactor inlet. For liquid phase reactions, the reaction temperature should be greater than about 100° C., or 120° C., or 150° C., or 180° C., or 200° C., and less than about 300° C., or 290° C., or 270° C., or 250° C., or 220° C. The reaction pressure should be greater than about 70 psig, or 145 psig, or 300 psig, or 500 psig, or 750 psig, or 1050 psig, and less than about 2000 psig, or 1950 psig, or 1900 psig, or 1800 psig. In one embodiment, the reaction temperature is between about 120° C. and 300° C., or between about 200° C. and 300° C., or between about 270° C. and 290° C., and the reaction pressure is between about 145 and 1950 psig, or between about 1000 and 1900 psig, or between about 1050 and 1800 psig.

For vapor phase reactions, the reaction should be carried out at a temperature where the vapor pressure of the oxygenated hydrocarbon is at least about 0.1 atm, preferably higher (e.g., 350 psi), and the thermodynamics of the reaction are favorable. This temperature will vary depending upon the specific oxygenated hydrocarbon compound used, but is generally greater than about 100° C., or 120° C., or 250° C., and less than about 600° C., or 500° C., or 400° C. for vapor phase reactions. In one embodiment, the reaction temperature is between about 120° C. and about 500° C., or between about 250° C. and about 400° C.

In general, the HDO reaction should be conducted under conditions where the residence time of the aqueous feed stream over the catalyst is appropriate to generate the desired products. For example, the WHSV for the reaction may be at least 0.01 gram of oxygenated hydrocarbon per gram of catalyst per hour (g/g-hr). In some embodiments, the WHSV for the HDO reaction is 0.01 to about 40.0 g/g-hr, such as about 0.05 to about 40.0, about 1.0 to about 40.0, about 5.0 to about 40.0, or about 1.0 to about 20.0 g/g-hr. The WHSV can be, for example, about 0.05, 0.1, 0.25, 0.5, 0.75, 1.0, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, 5.0, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30, 35, or 40 g/g-hr.

In some embodiments, the amount of hydrogen fed to the HDO reaction ranges from 0-2400%, 5-2400%, 10-2400%, 15-2400%, 20-2400%, 25-2400%, 30-2400%, 35-2400%, 40-2400%, 45-2400%, 50-2400%, 55-2400%, 60-2400%, 65-2400%, 70-2400%, 75-2400%, 80-2400%, 85-2400%, 90-2400%, 95-2400%, 98-2400%, 100-2400%, 200-2400%, 300-2400%, 400-2400%, 500-2400%, 600-2400%, 700-2400%, 800-2400%, 900-2400%, 1000-2400%, 1100-2400%, or 1150-2400%, or 1200-2400%, or 1300-2400%, or 1400-2400%, or 1500-2400%, or 1600-2400%, or 1700-2400%, or 1800-2400%, or 1900-2400%, or 2000-2400%, or 2100-2400%, or 2200-2400%, or 2300-2400%, based on the total number of moles of the oxygenated hydrocarbon(s) in the feedstock, including all intervals between. The hydrogen may be external hydrogen or recycled hydrogen. The term “external H₂” refers to hydrogen that does not originate from the feedstock solution but is added to the reactor system from an external source. The term “recycled H₂” refers to unconsumed hydrogen, which is collected and then recycled back into the reactor system for further use.

AC Catalyst and AC Reactions

In some examples, reacting the HDO product stream 140 (or another product stream) in the presence of a condensation catalyst (i.e., in the AC reactor(s) 150) can produce a C₄₊ compound. The C₄₊ compound can include a member selected from the group consisting of C₄₊ alcohol, C₄₊ ketone, C₄₊ alkane, C₄₊ alkene, C₅₊ cycloalkane, C₅₊ cycloalkene, aryl, fused aryl, and a mixture thereof. In one exemplary embodiment, the C₄₊ alkane comprises a branched or straight chain C_4-30 alkane, or a branched or straight chain C_4-9, C_7-14, C_12-24 alkane, or a mixture thereof. In another exemplary embodiment, the C₄₊ alkene comprises a branched or straight chain C_4-30 alkene, or a branched or straight chain C_4-9, C_7-14, C_12-24 alkene, or a mixture thereof. In another exemplary embodiment, the C₅₊ cycloalkane comprises a mono-substituted or multi-substituted C₅₊ cycloalkane, and at least one substituted group is a branched C₃₊ alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₁₊ alkylene, a phenyl, or a combination thereof, or a branched C_3-12 alkyl, a straight chain C_1-12 alkyl, a branched C_3-12 alkylene, a straight chain C_1-12 alkylene, a phenyl, or a combination thereof, or a branched C_3-4 alkyl, a straight chain C_1-4 alkyl, a branched C_3-4 alkylene, straight chain C_1-4 alkylene, a phenyl, or a combination thereof. In another exemplary embodiment, the C₅₊ cycloalkene comprises a mono-substituted or multi-substituted C₅₊ cycloalkene, and at least one substituted group is a branched C₃₊ alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₂₊ alkylene, a phenyl, or a combination thereof, or a branched C_3-12 alkyl, a straight chain C_1-12 alkyl, a branched C_3-12 alkylene, a straight chain C_2-12 alkylene, a phenyl, or a combination thereof, or a branched C_3-4 alkyl, a straight chain C_1-4 alkyl, a branched C_3-4 alkylene, straight chain C_2-4 alkylene, a phenyl, or a combination thereof. In another exemplary embodiment, the aryl comprises an unsubstituted aryl, or a mono-substituted or multi-substituted aryl, and at least one substituted group is a branched C₃₊ alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₂₊ alkylene, a phenyl, or a combination thereof, or a branched C_3-12 alkyl, a straight chain C_1-12 alkyl, a branched C_3-12 alkylene, a straight chain C_2-12 alkylene, a phenyl, or a combination thereof, or a branched C_3-4 alkyl, a straight chain C_1-4 alkyl, a branched C_3-4 alkylene, a straight chain C_2-4 alkylene, a phenyl, or a combination thereof. In another exemplary embodiment, the fused aryl comprises an unsubstituted fused aryl, or a mono-substituted or multi-substituted fused aryl, and at least one substituted group is a branched C₃₊ alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₂₊ alkylene, a phenyl, or a combination thereof, or a branched C_3-4 alkyl, a straight chain C_1-4 alkyl, a branched C_3-4 alkylene, a straight chain C_2-4 alkylene, a phenyl, or a combination thereof. In another exemplary embodiment, the C₄₊ alcohol comprises a compound according to the formula R¹ —OH, wherein R¹ is a branched C₄₊ alkyl, straight chain C₄₊ alkyl, a branched C₄₊ alkylene, a straight chain C₄₊ alkylene, a substituted C₅₊ cycloalkane, an unsubstituted C₅₊ cycloalkane, a substituted C₅₊ cycloalkene, an unsubstituted C₅₊ cycloalkene, an aryl, a phenyl, or a combination thereof.

In another exemplary embodiment of method of making the C₄₊ compound, the C₄₊ ketone comprises a compound according to the formula

wherein R³ and R⁴ are independently a branched C₃₊0 alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₂₊ alkylene, a substituted C₅₊ cycloalkane, an unsubstituted C₅₊ cycloalkane, a substituted C₅₊ cycloalkene, an unsubstituted C₅₊ cycloalkene, an aryl, a phenyl, or a combination thereof. Examples of desirable C₄₊ ketones include, without limitation, butanone, pentanone, hexanone, heptanone, octanone, nonanone, decanone, undecanone, dodecanone, tridecanone, tetradecanone, pentadecanone, hexadecanone, heptyldecanone, octyldecanone, nonyldecanone, eicosanone, uneicosanone, doeicosanone, trieicosanone, tetraeicosanone, or isomers thereof.

The condensation catalyst is generally a catalyst capable of forming longer chain compounds by linking two molecules (e.g., oxygen containing species or other functionalized compounds, including olefins) through a new carbon-carbon bond, and converting the resulting compound to a hydrocarbon, alcohol, or ketone. In some embodiments, the condensation catalyst is an acid condensation catalyst. The condensation catalyst may include, without limitation, carbides, nitrides, zirconia, alumina, silica, aluminosilicates, phosphates, zeolites (e.g., ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35 and ZSM-48), titanium oxides, zinc oxides, vanadium oxides, lanthanum oxides, yttrium oxides, scandium oxides, magnesium oxides, cerium oxides, barium oxides, calcium oxides, hydroxides, heteropolyacids, inorganic acids, acid modified resins, base modified resins, and combinations thereof. The condensation catalyst may include the above alone or in combination with a modifier, such as Ce, La, Y, Sc, P, B, Bi, Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, and combinations thereof. The condensation catalyst may also include a metal, such as Cu, Ag, Au, Pt, Ni, Fe, Co, Ru, Zn, Cd, Ga, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys and combinations thereof, to provide a metal functionality.

The condensation catalyst may be self-supporting (i.e., the catalyst does not need another material to serve as a support) or may require a separate support suitable for suspending the catalyst in the reactant stream. One particularly beneficial support is silica, especially silica having a high surface area (greater than 100 square meters per gram), obtained by sol-gel synthesis, precipitation or fuming. In other embodiments, particularly when the condensation catalyst is a powder, the catalyst system may include a binder to assist in forming the catalyst into a desirable catalyst shape. Applicable forming processes include extrusion, pelletization, oil dropping, or other known processes. Zinc oxide, alumina, and a peptizing agent may also be mixed together and extruded to produce a formed material. After drying, this material is calcined at a temperature appropriate for formation of the catalytically active phase, which usually requires temperatures in excess of 450° C.

The condensation catalyst may include one or more zeolite structures comprising cage-like structures of silica-alumina. Zeolites are crystalline microporous materials with well-defined pore structures. Zeolites contain active sites, usually acid sites, which can be generated in the zeolite framework. The strength and concentration of the active sites can be tailored for particular applications. Examples of suitable zeolites for condensing secondary alcohols and alkanes may comprise aluminosilicates, optionally modified with cations, such as Ga, In, Zn, Mo, and mixtures of such cations, as described, for example, in U.S. Pat. No. 3,702,886, which is incorporated herein by reference. As recognized in the art, the structure of the particular zeolite or zeolites may be altered to provide different amounts of various hydrocarbon species in the product mixture. Depending on the structure of the zeolite catalyst, the product mixture may contain various amounts of aromatic and cyclic hydrocarbons.

Examples of suitable zeolite catalysts include ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35 and ZSM-48. Zeolite ZSM-5, and the conventional preparation thereof, is described in U.S. Pat. No. 3,702,886; Re. 29,948 (highly siliceous ZSM-5); U.S. Pat. Nos. 4,100,262 and 4,139,600, all incorporated herein by reference. Zeolite ZSM-11, and the conventional preparation thereof, is described in U.S. Pat. No. 3,709,979, which is also incorporated herein by reference. Zeolite ZSM-12, and the conventional preparation thereof, is described in U.S. Pat. No. 3,832,449, incorporated herein by reference. Zeolite ZSM-23, and the conventional preparation thereof, is described in U.S. Pat. No. 4,076,842, incorporated herein by reference. Zeolite ZSM-35, and the conventional preparation thereof, is described in U.S. Pat. No. 4,016,245, incorporated herein by reference. Another preparation of ZSM-35 is described in U.S. Pat. No. 4,107,195, the disclosure of which is incorporated herein by reference. ZSM-48, and the conventional preparation thereof, is taught by U.S. Pat. No. 4,375,573, incorporated herein by reference. Other examples of zeolite catalysts are described in U.S. Pat. No. 5,019,663 and U.S. Pat. No. 7,022,888, also incorporated herein by reference. An exemplary condensation catalyst is a ZSM-5 zeolite modified with Cu, Pd, Ag, Pt, Ru, Re, Ni, Sn, or combinations thereof.

As described in U.S. Pat. No. 7,022,888, which is incorporated herein by reference, the condensation catalyst may be a bifunctional pentasil zeolite catalyst including at least one metallic element from the group of Cu, Ag, Au, Pt, Ni, Fe, Co, Ru, Zn, Cd, In, Rh, Pd, Ir, Re, Mn, Cr, Mo, W, Sn, Os, alloys and combinations thereof, or a modifier from the group of In, Zn, Fe, Mo, Au, Ag, Y, Sc, Ni, P, Ta, lanthanides, and combinations thereof. The zeolite may have strong acidic sites, and may be used with reactant streams containing an oxygenated hydrocarbon at a temperature of below 580° C. The bifunctional pentasil zeolite may have ZSM-5, ZSM-8 or ZSM-11 type crystal structure consisting of a large number of 5-membered oxygen-rings (i.e., pentasil rings). In one embodiment the zeolite will have a ZSM-5 type structure.

Alternatively, solid acid catalysts such as alumina modified with phosphates, chloride, silica, and other acidic oxides may be used. Also, sulfated zirconia, phosphated zirconia, titania zirconia, or tungstated zirconia may provide the necessary acidity. Re and Pt/Re catalysts are also useful for promoting condensation of oxygenates to C₅₊ hydrocarbons and/or C₅₊ mono-oxygenates. The Re is sufficiently acidic to promote acid-catalyzed condensation. In certain embodiments, acidity may also be added to activated carbon by the addition of either sulfates or phosphates.

The specific C₄₊ compounds produced will depend on various factors, including, without limitation, the type of oxygenated compounds in the reactant stream, condensation temperature, condensation pressure, the reactivity of the catalyst, and the flow rate of the reactant stream as it affects the space velocity, GHSV, LHSV, and WHSV. In certain embodiments, the reactant stream is contacted with the condensation catalyst at a WHSV that is appropriate to produce the desired hydrocarbon products. In one embodiment the WHSV is at least 0.1 grams of volatile (C₂₊O_1-3) oxygenates in the reactant stream per gram catalyst per hour. In another embodiment the WHSV is between 0.1 to 10.0 g/g hr, including a WHSV of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 g/g hr, and increments between.

In certain embodiments the condensation reaction is carried out at a temperature and pressure at which the thermodynamics of the proposed reaction are favorable. For volatile C₂₊O_1-3 oxygenates the reaction may be carried out at a temperature where the vapor pressure of the volatile oxygenates is at least 0.1 atm (and preferably a good deal higher). The condensation temperature will vary depending upon the specific composition of the oxygenated compounds. The condensation temperature will generally be greater than 80° C., or 100° C., or 125° C., or 150° C., or 175° C., or 200° C., or 225° C., or 250° C., and less than 500° C., or 450° C., or 425° C., or 375° C., or 325° C., or 275° C. For example, the condensation temperature may be between 80° C. to 500° C., or between 125° C. to 450° C., or between 250° C. to 425° C. The condensation pressure will generally be greater than 0 psig, or 10 psig, or 100 psig, or 200 psig, and less than 2000 psig, or 1800 psig or, or 1600 psig, or 1500 psig, or 1400 psig, or 1300 psig, or 1200 psig, or 1100 psig, or 1000 psig, or 900 psig, or 700 psig. For example, the condensation pressure may be greater than 0.1 atm, or between 0 and 1500 psig, or between 0 and 1200 psig.

C₄₊ alkanes and C₄₊ alkenes produced from acid condensation can have from 4 to 30 carbon atoms (C₄₊ alkanes and C₄₊ alkenes) and may be branched or straight chained alkanes or alkenes. The C₄₊ alkanes and C₄₊ alkenes may also include fractions of C_4-9, C_7-14, C_12-24 alkanes and alkenes, respectively, with the C_4-9 fraction directed to gasoline, the C_7-16 fraction directed to jet fuels, and the C_11-24 fraction directed to diesel fuel and other industrial applications, such as chemicals. Examples of various C₄₊ alkanes and C₄₊ alkenes include, without limitation, butane, butene, pentane, pentene, 2-methylbutane, hexane, hexene, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, heptane, heptene, octane, octene, 2,2,4,-trimethylpentane, 2,3-dimethyl hexane, 2,3,4-trimethylpentane, 2,3-dimethylpentane, nonane, nonene, decane, decene, undecane, undecene, dodecane, dodecene, tridecane, tridecene, tetradecane, tetradecene, pentadecane, pentadecene, hexadecane, hexadecene, heptyldecane, heptyldecene, octyldecane, octyldecene, nonyldecane, nonyldecene, eicosane, eicosene, uneicosane, uneicosene, doeicosane, doeicosene, trieicosane, trieicosene, tetraeicosane, tetraeicosene, and isomers thereof.

C₅₊ cycloalkanes and C₅₊ cycloalkenes produced from acid condensation can have from 5 to 30 carbon atoms and may be unsubstituted, mono-substituted or multi-substituted. In the case of mono-substituted and multi-substituted compounds, the substituted group may include a branched C₃₊ alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₂₊ alkylene, a phenyl or a combination thereof. By way of example, at least one of the substituted groups include a branched C_3-12 alkyl, a straight chain C_1-12 alkyl, a branched C_3-12 alkylene, a straight chain C_1-12 alkylene, a straight chain C_2-12 alkylene, a phenyl or a combination thereof. By way of further example, at least one of the substituted groups include a branched C_3-4 alkyl, a straight chain C_1-4 alkyl, a branched C_1-4 alkylene, straight chain C_1-4 alkylene, straight chain C_2-4 alkylene, a phenyl or a combination thereof. Examples of desirable C₅₊ cycloalkanes and C₅₊ cycloalkenes include, without limitation, cyclopentane, cyclopentene, cyclohexane, cyclohexene, methyl-cyclopentane, methyl-cyclopentene, ethyl-cyclopentane, ethyl-cyclopentene, ethyl-cyclohexane, ethyl-cyclohexene, propyl-cyclohexane, butyl-cyclopentane, butyl-cyclohexane, pentyl-cyclopentane, pentyl-cyclohexane, hexyl-cyclopentane, hexyl-cyclohexane, and isomers thereof.

Aryls will generally consist of an aromatic hydrocarbon in either an unsubstituted (phenyl), mono-substituted or multi-substituted form. In the case of mono-substituted and multi-substituted compounds, the substituted group may include a branched C₃₊ alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₂₊ alkylene, a phenyl or a combination thereof. By way of example, at least one of the substituted groups include a branched C₃₊ alkyl, a straight chain C_1-12 alkyl, a branched C_3-12 alkylene, a straight chain C_2-12 alkylene, a phenyl or a combination thereof. By way of further example, at least one of the substituted groups include a branched C_3-4 alkyl, a straight chain C_1-4 alkyl, a branched C_3-4 alkylene, straight chain C_2-4 alkylene, a phenyl or a combination thereof. Examples of various aryls include, without limitation, benzene, toluene, xylene (dimethylbenzene), ethyl benzene, para xylene, meta xylene, ortho xylene, C₉₊ aromatics, butyl benzene, pentyl benzene, hexyl benzene, heptyl benzene, octyl benzene, nonyl benzene, decyl benzene, undecyl benzene, and isomers thereof.

Fused aryls will generally consist of bicyclic and polycyclic aromatic hydrocarbons, in either an unsubstituted, mono-substituted, or multi-substituted form. In the case of mono-substituted and multi-substituted compounds, the substituted group may include a branched C₃₊ alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₂₊ alkylene, a phenyl or a combination thereof. By way of example, at least one of the substituted groups include a branched C_3-4 alkyl, a straight chain C_1-4 alkyl, a branched C_3-4 alkylene, straight chain C_2-4 alkylene, a phenyl or a combination thereof. Examples of various fused aryls include, without limitation, naphthalene, anthracene, and isomers thereof.

Polycyclic compounds will generally consist of bicyclic and polycyclic hydrocarbons, in either an unsubstituted, mono-substituted, or multi-substituted form. Although polycyclic compounds generally include fused aryls, as used herein the polycyclic compounds generally have at least one saturated or partially saturated ring. In the case of mono-substituted and multi-substituted compounds, the substituted group may include a branched C₃₊ alkyl, a straight chain C₁₊ alkyl, a branched C₃₊ alkylene, a straight chain C₂₊ alkylene, a phenyl or a combination thereof. By way of example, at least one of the substituted groups include a branched C_3-4 alkyl, a straight chain C_1-4 alkyl, a branched C_3-4 alkylene, straight chain C_2-4 alkylene, a phenyl or a combination thereof. Examples of various fused aryls include, without limitation, tetrahydronaphthalene and decahydronaphthalene, and isomers thereof.

The C₄₊ alcohols may also be cyclic, branched or straight chained, and have from 4 to 30 carbon atoms. In general, the C₄₊ alcohols may be a compound according to the formula R¹ —OH, wherein R¹ is a member selected from a branched C₄₊ alkyl, straight chain C₄₊ alkyl, a branched C₄₊ alkylene, a straight chain C₄₊ alkylene, a substituted C₅₊ cycloalkane, an unsubstituted C₅₊ cycloalkane, a substituted C₅₊ cycloalkene, an unsubstituted C₅₊ cycloalkene, an aryl, a phenyl or combinations thereof. Examples of desirable C₄₊ alcohols include, without limitation, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptyldecanol, octyldecanol, nonyldecanol, eicosanol, uneicosanol, doeicosanol, trieicosanol, tetraeicosanol, or isomers thereof.

In some embodiments, a condensation product stream comprising C₄₊ compounds can be fractionated into various product streams, such as gasoline, jet fuel (kerosene), diesel fuel, and aromatics. For example, the condensation product stream may be passed through a three-phase separator to separate the condensation product stream into an acid condensation gas stream, an organic stream, and an aqueous stream. The organic stream and aqueous stream can be separated by density difference, while the acid condensation gas stream comprising uncondensed gases can be recycled to the acid condensation reactor to generate additional C₄₊ compounds. In some embodiments, a gas transport device, such as a blower or compressor, can be configured in the acid condensation gas stream to control the recycle pressure. In some embodiments, an optional purge stream may also be used to control the pressure of the recycle loop in the acid condensation gas stream. In some embodiments, the aqueous stream is discarded from the process, or further processed in downstream process units.

In some embodiments, the organics stream is fractionated in a distillation column to separate the organic stream into a light product stream and a heavy product stream. In some embodiments, the distillation unit is configured to remove co-boiling contaminants for benzene, toluene, or a combination thereof.

In some embodiments, the distillation column is configured to generate a heavy stream that is free or substantially free of co-boiling non-aromatic contaminants for benzene. The distillation column may remove co-boiling nonaromatic contaminants for benzene by fractionating the organic stream into a C₆₋ stream comprising benzene, co-boiling non-aromatic contaminants for benzene, and lighter products through the light product stream. The distillation column may further fractionate the organic stream into a heavy product stream comprising C₇₊ compounds.

In some embodiments, the distillation column is configured to generate a heavy stream that is free or substantially free of co-boiling nonaromatic contaminants for toluene. The distillation column may remove co-boiling nonaromatic contaminants for toluene by fractionating the organic stream into a C₇₋ or C₈₋ stream comprising toluene, co-boiling nonaromatic contaminants for toluene, and lighter products through the light product stream. The distillation column may further fractionate the organic stream into a heavy product stream comprising C₈₊ or C₉₊ compounds.

In some embodiments, the heavy product stream is fractionated in a distillation column to separate the heavy product stream comprising C₇₊ compounds, C₈₊ compounds, or C₉₊ compounds into the mixed aromatic feed stream and a heavy product stream. In some embodiments, the distillation column is configured to fractionate the heavy product stream 140 into a mixed aromatic feed stream 16 comprising C₇₊ compounds and a heavy product feed stream comprising C₁₁₊ compounds. In some embodiments, the mixed aromatic feed stream comprises C₇₊ compounds, or C₈₊ compounds, or C₉₊ compounds, or C_7-10 compounds, or C_8-10 compounds, or C_9-10 compounds.

In some embodiments, the heavy stream may be further separated for use as kerosene (e.g., C_11-14 as jet fuel use), diesel fuel use (e.g., C_12-24), and lubricants or fuel oils (e.g., C₂₅₊). Alternatively, the heavy stream may be cracked to produce addition fractions for use in gasoline, kerosene, aromatics, and/or diesel fractions.

Control of AC Reaction Train

As noted above, a set (or train) of AC reactors may generally include more than one reactor, with a first reactor functioning as a lead reactor and a second reactor functioning as a lag reactor. Correspondingly, an initial feed stream (e.g., from a vaporizer downstream of an HDO reactor) can be provided first to the lead reactor for AC reactions (e.g., the reactor 150A). The effluent (or outlet) stream from the lead reactor can then be provided to the lag reactor (e.g., the reactor 150B) for further AC reactions, including to react unconverted species from the lead reactor effluent (e.g., oxygenates and olefins).

Generally, the AC reactions are exothermic and the effluent stream from a given AC reactor is thus expected to be at a higher temperature than the inlet stream. Correspondingly, without modification, an inlet stream for a lag AC reactor would be expected to be at a higher temperature than an inlet stream for a corresponding lead AC reactor. It has been discovered, however, that elevated inlet temperatures for the lag AC reactor can result in dealkylation of branched aromatic compounds, and corresponding break down of the compounds into benzene and light alkanes (e.g., via removal of methyl and ethyl groups from xylenes, toluene, tri-methyl benzene, ethyl benzene, etc., or removal of propyl groups from propyl benzene). Both of these products may be undesirable for production of fuels, including due to regulatory limits on levels of benzene in gasoline and the high volatility of the light alkanes, which may prevent their inclusion in liquid products (e.g., for blending to provide renewable gasoline or other renewable fuels).

Accordingly, aspects of the disclosed technology can include controlling the operation of an AC reaction train to reduce the temperature of the effluent of a lead AC reactor before the effluent stream is provided as an inlet stream to a lag AC reactor. In particular, for example, heat exchangers (of various known forms) can be arranged relative to relevant inlet and effluent streams—or otherwise—to reduce the temperature of a lead AC reactor effluent stream (or other stream) so that a corresponding temperature of an inlet stream for a lag AC reactor is equal to or substantially equal to the temperature of an inlet stream for the lead AC reactor (i.e., within 3% of, within 2% of, or within 1% of).

EXAMPLES

FIG. 2 illustrates an example configuration of an AC reaction train according to an example implementation of the disclosed technology (e.g., as an implementation of the AC reactors 150). In particular, a set of three AC reactors D, E, F are provided, along with flow control equipment (e.g., of generally known type) that can selectively route inlet and effluent flows to interchangeably operate the reactors D, E, F in any combination of lead, lag, and regenerating operation (i.e., with the latter to remove coke laid down during time on process). In the illustrated example, and as further discussed below, the reactor D is operating as a lead reactor, the reactor E is operating as a lag reactor, and the reactor F is being regenerated, although other configurations are possible.

In the illustrated example operating state, an AC feed stream 201 from a feed vaporizer (not shown in FIG. 2) is provided as an inlet stream that passes through a first heat exchanger A and is heated by an effluent stream 208 from the lag AC reactor E. The heated feed stream 202 then passes through a second heat exchanger B to be heated by effluent stream 206 from the lead AC reactor D. In some cases, including during startup, supplemental heating can also be provided by a process (e.g., electric) heater C. The resulting heated stream 204 is then provided as a feed stream to the lead AC reactor D, where exothermic reactions occur.

After reactions in the lead reactor D, an effluent stream 205 is provided as (or with) the effluent stream 206 through the second heat exchanger B, where it is cooled by heat exchange with the feed stream 202. The resulting cooled stream 207 then passes as an inlet stream to the lag AC reactor E, for clean-up reactions to convert olefins and oxygenates from the lead AC reactor D. These reactions may not result in a significant exotherm, so the effluent stream 208 from the lag AC reactor E may be at a temperature substantially equal to the temperature of the cooled inlet stream 207 at the inlet to the lag AC reactor E. As noted above, the effluent stream 208 then passes through the first heat exchanger A, where it is cooled against the AC feed stream 201.

In an example process, the AC reaction train illustrated in FIG. 2 can be operated so that the various streams have temperatures as listed below. In particular, it can be seen that the cooled inlet stream 207 can be at a temperature that is substantially equal to the temperature of the heated inlet stream 204, and thus the inlet streams for the lag and lead AC reactors, respectively, can also have substantially equal temperatures.

For completeness, other streams illustrated in FIG. 2 include an AC regeneration inlet stream 210 and an AC regeneration outlet stream 211, as well as an effluent stream 209 from the heat exchanger A.

FIG. 3 illustrates another example configuration of an AC reaction train, similar to the configuration of FIG. 2 but without heat exchange between the effluent/inlet stream of the lead/lag AC reactor and the inlet stream of the lead AC reactor. Thus, for example, the heated feed stream 202 passes to the lead AC reactor D without passing through a heat exchanger to be heated by the effluent stream 205 from the lead AC reactor D. Correspondingly, the feed stream 202 does not cool the effluent stream 205 before it is provided as the inlet stream 207 to the lag AC reactor E (although the heater C may still be used in some cases). As a result, the temperature of the inlet stream 207 for the lag reactor E may be substantially equal to the temperature of the effluent stream 205 of the lead reactor D, rather than being substantially equal to the temperature of the inlet stream 204 of the lead reactor D. Correspondingly, significantly more de-alkylation reactions can occur, which strip alkyl groups from branched aromatics and create significant amounts of benzene and light alkanes.

In an example process, the AC reaction train illustrated in FIG. 3 can be operated so that the various streams have temperatures as listed below. In particular, it can be seen that the temperature of the inlet stream 207 for the lag AC reactor E is significantly elevated above, not substantially equal to, the temperature of the inlet stream 204 for the lead AC reactor D.

In testing, a laboratory scale 90-day stability run was undertaken for a sequence of hydrogenation, HDO, and AC reactions, with the product from each reaction step going directly to the next, i.e., HYD→HDO→AC. In particular, the effect of running the inlet of AC Lag Reactor at a substantially equal temperature as the inlet to the AC Lead Reactor was investigated by introducing heat exchange between the product and feed streams of the lead AC reactor, to lower the inlet temperature of the lag AC reactor to be substantially equal to the inlet temperature of the lead AC reactor.

As illustrated in the graph of FIG. 4, operation with cooling of the inlet stream of the lag AC reactor increased the yield of C₄₊ and C₅₊ liquid products by approximately 3%. Further, as illustrated in the graph of FIG. 5, the concentration of benzene in the crude product was reduced from 3.5 wt % to 2.0 wt %, which is believed to result from less de-alkylation of aromatics. As noted above, due to potentially low limits on the level of benzene in gasoline, reducing the benzene concentration may have significant benefits (e.g., may allow higher blend ratios for production of renewable gasoline).

Thus, examples of the disclosed technology can provide improved processes and systems for AC reactions, In particular, through improved temperature control at inlets of AC reactors, some examples can provide improved C₄₊ yields or reduced coking of AC catalysts.

Unless otherwise specifically indicated, ordinal numbers are used herein for convenience of reference, based generally on the order in which particular components are presented in the relevant part of the disclosure. In this regard, for example, designations such as “first,” “second,” etc., generally indicate only the order in which a thus-labeled component is introduced for discussion and generally do not indicate or require a particular spatial, functional, temporal, or structural primacy or order. Relatedly, similar or identical components may be referred to with different ordinal numbers in different contexts.

Unless otherwise specified or limited, the terms “about” and “approximately,” as used herein with respect to a reference value, refer to variations from the reference value of ±20% or less (e.g., ±15, +10%, ±5%, etc.), inclusive of the endpoints of the range.