PROCESS FOR PRODUCING A SINGLE PHASE IMMERSION COOLING FLUID FROM FISCHER-TROPSCH OIL

Description

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Ser. No. 63/735,637, filed on Dec. 18, 2024, the entirety of which is incorporated herein by reference.

BACKGROUND

Fischer-Tropsch synthesis is known to yield a broad mixture of products including primarily paraffins, and some olefins. The individual compounds of such mixture can contain up to about 200 carbons. Typically, the number of carbons is between about 20 and about 150, with an average number of carbons of about 60. Some Fischer-Tropsch processes yield mixtures enriched with C₅-C₃₀ alkanes containing a significant quantity of olefins and oxygenated compounds, such as alcohols or acids. Trace amounts of sulfur-containing or nitrogen-containing products or aromatic compounds can be also present. Fischer-Tropsch products can be divided into light oils with carbon number 5-16, heavy oils with carbon numbers 7-26, and waxes with carbon numbers 12-100. Fischer-Tropsch liquids are frequently used as a raw material for obtaining various fuel and chemical products, such as, e.g., distillates such as kerosene or diesel fuels, solvents and waxes for food processing among others.

In some existing processes, the Fischer-Tropsch feed is hydrocracked, dewaxed, and separated into one or more product streams. The unconverted oil stream from the separation is recycled to the hydrocracking reaction zone, resulting in it being highly dewaxed due to multiple passes over the dewaxing catalyst. While dewaxing provides better activity, it also results in lower selectivity to distillates.

There is a growing demand for liquid cooling systems in data centers, as they shift away from conventional air-cooling systems. Immersion cooling, where the entire system is immersed in a tank of dielectric fluid, is a powerful solution to address thermal issues in high-density servers. The market need for single-phase immersion cooling is growing. Different fluid options are available, including hydrocarbon liquids, mineral oil, bio-derived fluids, and fluorochemicals.

Therefore, there is a need for novel processes for converting Fischer-Tropsch liquids and waxes into transportation fuels and single-phase immersion cooling fluids.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of one embodiment of a process for converting a Fischer-Tropsch product into a single-phase immersion cooling fluid and aviation fuel.

FIG. 2 is an illustration of another embodiment of a process for converting a Fischer-Tropsch product into a single-phase immersion cooling fluid and aviation fuel.

FIG. 3 is graph of the viscosity as a function of temperature.

FIG. 4 is graph of the flash point as a function of the viscosity.

DESCRIPTION

The present invention meets this need by providing processes for converting Fischer-Tropsch products into a single-phase immersion cooling fluid and optionally aviation fuel. The invention provides a dependable, compatible, efficient, and non-PFAS based fluids for single-phase immersion cooling with a global supply chain. PFAS molecules are Per- and Poly-FluorAlkyl Substances.

Processes for converting Fischer-Tropsch products to synthetic paraffinic kerosene surprisingly can be modified and tailored to co-produce an immersion cooling oil which can be used to generate a fluid with the required properties for single-phase immersion cooling. When the Fischer-Tropsch products are generated from a bio-based feedstock, this fluid option provides a sustainable immersion cooling fluid.

A product stream derived from a Fischer-Tropsch synthesis process is produced comprising normal paraffins. The Fischer-Tropsch product stream is separated to provide a light liquid stream and a waxy stream such that the carbon numbers in the two streams comprise C₁₆₊ normal paraffins. The light liquid stream and the waxy stream are subjected to hydrocracking and/or hydroisomerization to increase the iso-paraffin to n-paraffin ratio.

The resulting stream provides the physical and chemical properties required to meet specific immersion coolant properties. It exhibits an ASTM D 86 T5% equal to or greater than 300° C., or an ASTM D 86 T10% equal to or greater than 300° C., or both. The ASTM D 93 flash point is equal to or greater than 150° C., or equal to or greater than 200° C. The iso-paraffin to normal paraffin mass ratio is equal to or greater than 150, or equal to or greater than 200, or equal to or greater than 250, or equal to or greater than 300, or equal to or greater than 350, or equal to or greater than 400. The pour point utilizing ASTM D97 or equivalent is equal to or less than −25° C., or equal to or less than −30° C.

The aromatic concentration in the resultant product stream can be equal to or less than 0.5 wt %, equal to or less than 0.4 wt %, equal to or less than 0.3 wt %, equal to or less than 0.2 wt %, or equal to or less than 0.1 wt %, such that the coolant stream can be used in services such as food-grade applications and the like.

One aspect of the invention is a process for producing a single-phase immersion cooling fluid from a Fischer-Tropsch product stream. In one embodiments, the process comprises providing the Fischer-Tropsch product stream comprising C₈₊ normal paraffins. The Fischer-Tropsch product stream is hydrocracked in a hydrocracking reaction zone comprising a hydrocracking reactor in the presence of a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked effluent stream comprising C₈₊ normal paraffins and isoparaffins. The hydrocracked effluent stream is separated in a product recovery zone into at least a single-phase immersion cooling fluid stream comprising C₁₈₊ normal paraffins and isoparaffins, the single-phase immersion cooling fluid having a flash point equal to or greater than 150° C. and a pour point equal to or less than −25° C., and a ratio of iso-paraffins to normal paraffin on a weight to weight basis equal to or greater than 60.

In some embodiments, separating the hydrocracked effluent stream into at least the single-phase immersion cooling fluid stream comprises separating the dewaxed effluent stream into at least the single-phase immersion cooling fluid stream, and a renewable diesel stream comprising C₁₈ to C₂₂ normal paraffins and isoparaffins, or a kerosene stream comprising Cs to C₂₀ normal paraffins and isoparaffins, or a naphtha stream comprising C₈₋ normal paraffins and isoparaffins, or a fuel gas stream comprising fuel gas and liquefied petroleum gas, or a hydrogen stream, or combinations thereof.

In some embodiments, the flash point is equal to or greater than 200° C., or the pour point is equal to or less than −30° C., or the ratio of iso-paraffins to normal paraffin on a weight to weight basis equal to or greater than 150, or combinations thereof.

In some embodiments, the single-phase immersion cooling fluid has a ratio of iso-paraffins to normal paraffins on a weight to weight basis equal to or greater than 150.

In some embodiments, the single-phase immersion cooling fluid has a mass ratio of iso-paraffins to normal paraffins on a weight to weight basis equal to or greater than 400.

In some embodiments, the single-phase immersion cooling fluid has an aromatic concentration equal to or less than 0.5 wt %.

In some embodiments, the single-phase immersion cooling fluid has an aromatic concentration equal to or less than 0.1 wt %.

In some embodiments, the process further comprises recycling a portion of the single-phase immersion cooling fluid stream to the hydrocracking reaction zone.

In some embodiments, the hydrocracking catalyst comprises an amorphous acidic component. In some embodiments, the amorphous acidic component comprises amorphous silica-alumina. In some embodiments, wherein the hydrocracking catalyst comprises a noble metal.

In some embodiments, the hydrocracking reaction conditions comprise a temperature in a range of 315° C. to 415° C., or a pressure in a range of 300 to 1000 psig, or both; or the hydrocracking catalyst comprises Y zeolite, beta zeolite, amorphous silica-alumina noble metals, base metals, or combinations thereof; or both.

In some embodiments, the process further comprises passing a hydrogen gas stream to the hydrocracking reaction zone.

In some embodiments, the hydrogen gas stream comprises a recycle hydrogen stream from the product recovery zone.

In some embodiments, separating the hydrocracked effluent stream into at least the single-phase immersion cooling fluid stream comprises separating the dewaxed effluent stream into at least the single-phase immersion cooling fluid stream and a kerosene stream comprising C₈ to C₂₀ normal paraffins and isoparaffins, and further comprising: dewaxing the kerosene stream in a dewaxing reaction zone comprising a dewaxing reactor in the presence of a dewaxing catalyst under dewaxing conditions to form a synthetic paraffinic kerosene stream comprising C₈ to C₂₀ normal paraffins and isoparaffins.

In some embodiments, the dewaxing reaction conditions comprise a temperature in a range of 315° C. to 400° C., or a hydrogen partial pressure in a range of 300 psig to 1000 psig, or both; or the dewaxing catalyst comprises a molecular sieve of AEL or MRE framework with a noble metal; or both.

Another aspect of the invention is a process for producing a single-phase immersion cooling fluid from a Fischer-Tropsch product stream. In one embodiment, the process comprises providing the Fischer-Tropsch product stream comprising C₈₊ normal paraffins. The Fischer-Tropsch product stream is dewaxed in a dewaxing reaction zone comprising a dewaxing reactor in the presence of a dewaxing catalyst under dewaxing conditions to form a dewaxed effluent stream comprising C₈₊ normal paraffins and isoparaffins. The dewaxed effluent stream is separated in a product recovery zone into at least a single-phase immersion cooling fluid stream comprising C₁₈₊ normal paraffins and isoparaffins, the single-phase immersion cooling fluid having a flash point equal to or greater than 150° C. and a pour point equal to or less than −25° C., and a ratio of iso-paraffins to normal paraffin on a weight to weight basis equal to or greater than 60.

In some embodiments, the process further comprises: hydrocracking a portion of the single-phase immersion cooling fluid stream hydrocracking reaction zone comprising a hydrocracking reactor in the presence of a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked effluent stream comprising C₈₊ normal paraffins and isoparaffins; passing the hydrocracked effluent stream to the product recovery zone; and wherein separating the dewaxed effluent stream comprises separating the dewaxed effluent stream and the hydrocracked effluent stream.

In some embodiments, the hydrocracking catalyst comprises an amorphous acidic component. In some embodiments, the amorphous acidic component comprises amorphous silica-alumina.

In some embodiments, the hydrocracking catalyst comprises a noble metal.

In some embodiments, the hydrocracking reaction conditions comprise a temperature in a range of 315° C. to 415° C., or a pressure in a range of 300 to 1000 psig, or both; or the hydrocracking catalyst comprises Y zeolite, beta zeolite, amorphous silica-alumina noble metals, base metals, or combinations thereof; or both.

In some embodiments, the process further comprises passing a hydrogen gas stream to the hydrocracking reaction zone.

In some embodiments, the hydrogen gas stream comprises a recycle hydrogen stream from the product recovery zone.

In some embodiments, providing the Fischer-Tropsch product stream comprises reacting synthesis gas comprising hydrogen and carbon monoxide or carbon dioxide or both in a Fischer-Tropsch reaction zone comprising a Fischer-Tropsch reactor in the presence of a Fischer-Tropsch catalyst under Fischer-Tropsch reaction conditions to form the Fischer-Tropsch product stream.

In some embodiments, the Fischer-Tropsch reaction conditions comprise a temperature in a range of 150° C. to 300° C., or a pressure in a range of 200 to 750 psig, or both; or the Fischer-Tropsch catalyst comprises a Fe-, Co-, Ni-, Ru-based catalyst or combinations thereof; or both.

FIG. 1 illustrates a process 100 for upgrading Fischer-Tropsch oil to synthetic paraffinic kerosene and a single phase immersion coolant. The Fischer-Tropsch product stream 105 comprising C₈₊ normal paraffins is sent to the hydrocracking reaction zone 110 along with a hydrogen recycle stream 115 where the C₈₊ normal paraffins are hydrocracked to C₃ to C₂₀ normal paraffins and isoparaffins.

The hydrocracking reaction zone 110 has multiple beds to manage the temperature rise. The hydrocracking reaction zone 110 comprises one or more hydrocracking reactors, and each hydrocracking reactor can have one or more beds. A single hydrocracking reactor would have more than one bed. If there are two or more hydrocracking reactors, each reactor could have a single bed or multiple beds.

The hydrocracking reaction zone includes a hydrocracking catalyst. Any hydrocracking catalyst suitable for hydrocracking the Fischer-Tropsch feed can be used. The hydrocracking catalyst may comprise an acidic component, including, but not limited to, an amorphous acidic component such as amorphous silica-alumina (ASA). The hydrocracking catalyst may comprise a noble metal. Noble metals include, but are not limited to, Au, Ag, Pt, Pd, Ru, Rh, Pd, Os, and Ir. In another embodiment, the hydrocracking catalyst may comprise base metals. Such base metals include, but are not limited to, Ni, Co, Mo, and W. One suitable hydrocracking catalyst comprises a noble metal and an amorphous silica-alumina acidic component (ASA), which provides high selectivity to synthetic paraffinic kerosene and renewable diesel. In another embodiment, a suitable hydrocracking catalyst comprises a noble metal and crystalline acidic components such as a faujasite-based ultra-stable Y-zeolite and a beta zeolite. Typically, a Fischer-Tropsch product stream does not contain sulfur or nitrogen organic components that significantly affect the noble metal functioning. However, when Fischer-Tropsch products comprise higher concentrations of oxygenates utilizing a hydrocracking catalyst comprising base metal may be advantageous. So, yet in another embodiment a suitable hydrocracking catalyst comprises ASA, a crystalline acidic component and the aforementioned base metals. In some embodiment, the hydrocracking catalyst comprises an acidic component that is only amorphous.

In some embodiments, the hydrocracking reaction conditions comprise a temperature in a range of 315° C. to 415° C., or a pressure in a range of 300 to 1000 psig, or both.

The hydrocracked effluent stream 120 comprises C₃₊ carbon number normal paraffins and isoparaffins.

The hydrocracked effluent stream 120 from the hydrocracking reaction zone 110 and a steam stream 125 are sent to the product recovery zone 130. The product recovery zone 130 comprises one or more fractionation columns. The hydrocracked effluent stream 120 is separated into one or more product streams. For example, the product recovery zone 130 can produce at least a single-phase immersion cooling fluid stream 175 comprising C₁₈₊ normal paraffins and isoparaffins. Additional streams can be produced, including, but not limited to, a hydrogen stream 145, a fuel gas stream 150 comprising fuel gas and liquefied petroleum gas, a naphtha stream 155 comprising C₈₋ normal paraffins, and isoparaffins, and a synthetic paraffinic kerosene stream 135 comprising C₈ to C₂₀ normal and isoparaffins.

The hydrogen stream 145 can be combined with the hydrogen recycle stream 115. The naphtha stream 155 has several potential dispositions. In one embodiment, the naphtha stream is a feed stream to a steam cracking unit that thermally cracks the naphtha stream into light olefins such as ethylene, propylene and the like. In another embodiment, the naphtha stream is blended directly into a gasoline fuel pool since the naphtha is relatively sulfur-free with low concentrations of aromatics. In yet another embodiment, the naphtha can be catalytically reformed into a source of aromatics. In yet a further embodiment, the naphtha can be converted into a synthesis gas comprising carbon monoxide, carbon dioxide, hydrogen and water. The naphtha stream could also be burned as a fuel in the hydrocracking reaction zone 110, dewaxing reaction zone 160, or product recovery zone 130, or in any combination of these zones. Other separations could be performed as known to those of skill in the art.

A portion of the single-phase immersion cooling fluid stream 175 is recycled to the hydrocracking reaction zone 110 and does not go to the dewaxing reaction zone 160. Synthetic paraffinic kerosene stream 135 and the hydrogen recycle stream 115 are sent to the dewaxing reaction zone 160 where a portion of the C₈ to C₂₀ normal paraffins are converted to C₈ to C₂₀ isoparaffins to meet the freeze point specification of SPK. The dewaxing reaction zone 160 comprises one or more dewaxing reactors. Typically, greater than 50% of the normal paraffins are converted to isoparaffins, or greater than 60%, or greater than 70%, or greater than 80%, or greater than 90%.

The dewaxing reaction zone 160 contains a dewaxing catalyst. Any catalyst suitable for dewaxing the hydrocracked Fischer-Tropsch feed can be used. One example of a suitable dewaxing catalyst comprises a noble metal and a molecular sieve comprising 1O-ring, one dimensional channels. Such molecular sieves comprise molecular structures characterized by the International Zeolite Association as AEL, MRE, and the like. Noble metals are described above. The dewaxing catalyst is specific for renewable aviation and diesel applications, as it performs hydroisomerization of n-paraffins to form iso-paraffins to improve cold flow properties such as cloud point, cold filter plugging point, pour point, freeze point and the like. The dewaxing catalyst has very high retention of the synthetic paraffinic kerosene and diesel yield, very little naphtha generation, and it produces good cold flow properties.

The dewaxing reaction conditions include a temperature in the range of 315° C. to 400° C., and a hydrogen partial pressure in a range of 300 psig to 1000 psig.

The dewaxed effluent stream 165 comprises synthetic paraffinic kerosene comprising C₈ to C₂₀ normal paraffins and isoparaffins.

Make up hydrogen stream 170 is combined with hydrogen recycle stream 115.

FIG. 2 illustrates a process 200 for upgrading Fischer-Tropsch oil to sustainable aviation fuel. The Fischer-Tropsch product stream 205 is sent to the dewaxing reaction zone 210 along with a recycle hydrogen stream 215 where a portion of the normal paraffins is converted to isoparaffins.

The dewaxing effluent stream 220 and steam stream 225 are sent to the product recovery zone 230. The product recovery zone 230 comprises one or more fractionation columns.

The dewaxing effluent stream 220 is separated into one or more product streams. For example, the product recovery zone 230 can produce at least a single-phase immersion cooling fluid stream 270 comprising C₁₈₊ normal paraffins and isoparaffins. Additional streams can be produced, including, but not limited to, the recycle hydrogen stream 215, a fuel gas stream 245 comprising fuel gas and liquefied petroleum gas, and a naphtha stream 250 comprising C₈₋ paraffins, and a synthetic paraffinic kerosene stream 235 comprising C₈ to C₂₀ normal paraffins and isoparaffins.

The naphtha stream 250 has several potential dispositions. In one embodiment, the naphtha stream is a feed stream to a steam cracking unit that thermally cracks the naphtha stream into light olefins such as ethylene, propylene and the like. In another embodiment, the naphtha stream is blended directly into a gasoline fuel pool since the naphtha is relatively sulfur-free with low concentrations of aromatics. In yet another embodiment, the naphtha can be catalytically reformed into a source of aromatics. In yet a further embodiment, the naphtha can be converted into a synthesis gas comprising carbon monoxide, carbon dioxide, hydrogen and water. The naphtha stream could also be burned as a fuel in the dewaxing reaction zone 210, product recovery section 230, or hydrocracking reaction zone 255, or in any combination of these zones. Other separations could be performed as known to those of skill in the art.

A portion of the single-phase immersion cooling fluid stream 270 is sent to a hydrocracking reaction zone 255 along with recycle hydrogen stream 215 where the C₁₈₊ paraffins are hydrocracked to C₃ to C₁₈ normal paraffins and isoparaffins.

The hydrocracking reaction zone 255 has multiple beds. The hydrocracking reaction zone 255 comprises one or more hydrocracking reactors, and each hydrocracking reactor can have one or more beds. A single hydrocracking reactor would have more than one bed. If there are two or more hydrocracking reactors, each reactor could have a single bed or multiple beds.

The hydrocracking reaction zone includes a hydrocracking catalyst. Any hydrocracking catalyst suitable for hydrocracking the single-phase immersion cooling fluid stream 270 can be used. Suitable hydrocracking catalysts are described above.

The hydrocracking reaction conditions include a temperature in the range of 315° C. to 415° C., or a pressure in a range of 300 to 1000 psig, or both.

The hydrocracked effluent stream 260 from the hydrocracking reaction zone 255, which comprises C₃₊ normal paraffins and isoparaffins, is sent to the product recovery zone 230 along with the dewaxing effluent stream 220.

Make up hydrogen stream 265 is combined with recycle hydrogen stream 215.

EXAMPLES

FT wax was processed over a hydrocracking and dewaxing catalyst to produce sustainable aviation fuel (SAF) (C₉-C₁₈). Unconverted oil (UCO) is usually recycled back to the reaction zone for complete conversion to SAF product. In this experiment, UCO (C₁₈₊) was collected and fractionated into 4 cuts-C₁₈₋ cut, C₁₈-C₂₀ Cut, C₂₀-C₂₅ cut, and C₂₅-C₃₀ cut. The flash point and boiling point distribution of 3 heavy cuts are shown in Table 1. The viscosity and density of cut 2 and cut 3 are listed in Table 2. Additionally, the viscosity of cuts 2 and 3 as a function of temperature is shown in FIG. 3, and the flash point as a function of viscosity is shown in FIG. 4.

Different blends of these cuts were prepared, and the properties of the blends were analyzed. The results are listed in Table 3. FIG. 4 shows the plot of viscosity against the flash point of the blend which shows a linear trend.

As shown in Table 4, even Cut 2 (C18-C20) meets the OPC requirement of the single phase immersion cooling liquid. Other cuts meet higher flash point at the expense of an increase in the viscosity of the fluid.

Specific Embodiments

While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the preceding description and the appended claims.

A first embodiment of the invention is a process for producing a single-phase immersion cooling fluid from a Fischer-Tropsch product stream comprising providing the Fischer-Tropsch product stream comprising C₈₊ normal paraffins; hydrocracking the Fischer-Tropsch product stream in a hydrocracking reaction zone comprising a hydrocracking reactor in the presence of a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked effluent stream comprising C₈₊ normal paraffins and isoparaffins; separating the hydrocracked effluent stream in a product recovery zone into at least a single-phase immersion cooling fluid stream comprising C₁₈₊ normal paraffins and isoparaffins, the single-phase immersion cooling fluid having a flash point equal to or greater than 150° C. and a pour point equal to or less than-25° C., and a ratio of iso-paraffins to normal paraffin on a weight to weight basis equal to or greater than 60. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein separating the hydrocracked effluent stream into at least the single-phase immersion cooling fluid stream comprises separating the dewaxed effluent stream into at least the single-phase immersion cooling fluid stream, and a renewable diesel stream comprising C₁₈ to C₂₂ normal paraffins and isoparaffins, or a kerosene stream comprising C₈ to C₂₀ normal paraffins and isoparaffins, or a naphtha stream comprising C₈₋ normal paraffins and isoparaffins, or a fuel gas stream comprising fuel gas and liquefied petroleum gas, or a hydrogen stream, or combinations thereof. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the flash point is equal to or greater than 200° C., or the pour point is equal to or less than −30° C., or the ratio of iso-paraffins to normal paraffin on a weight to weight basis equal to or greater than 150, or combinations thereof. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the single-phase immersion cooling fluid has a ratio of iso-paraffins to normal paraffins on a weight to weight basis equal to or greater than 150. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the single-phase immersion cooling fluid has a mass ratio of iso-paraffins to normal paraffins on a weight to weight basis equal to or greater than 400. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the single-phase immersion cooling fluid has an aromatic concentration equal to or less than 0.5 wt %. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the single-phase immersion cooling fluid has an aromatic concentration equal to or less than 0.1 wt %. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising recycling a portion of the single-phase immersion cooling fluid stream to the hydrocracking reaction zone. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the hydrocracking catalyst comprises an amorphous acidic component. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the amorphous acidic component comprises amorphous silica-alumina. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the hydrocracking catalyst comprises a noble metal. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the hydrocracking reaction conditions comprise a temperature in a range of 315° C. to 415° C., or a pressure in a range of 300 to 1000 psig, or both; or the hydrocracking catalyst comprises Y zeolite, beta zeolite, amorphous silica-alumina, noble metals, base metals, or combinations thereof; or both. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising passing a hydrogen gas stream to the hydrocracking reaction zone. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the hydrogen gas stream comprises a recycle hydrogen stream from the product recovery zone. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein separating the hydrocracked effluent stream into at least the single-phase immersion cooling fluid stream comprises separating the dewaxed effluent stream into at least the single-phase immersion cooling fluid stream and a kerosene stream comprising C₈ to C₂₀ normal paraffins and isoparaffins, and further comprising dewaxing the kerosene stream in a dewaxing reaction zone comprising a dewaxing reactor in the presence of a dewaxing catalyst under dewaxing conditions to form a synthetic paraffinic kerosene stream comprising C₈ to C₂₀ normal paraffins and isoparaffins. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the dewaxing reaction conditions comprise a temperature in a range of 315° C. to 400° C., or a hydrogen partial pressure in a range of 300 psig to 1000 psig, or both; or the dewaxing catalyst comprises a molecular sieve of AEL or MRE framework with a noble metal; or both.

A second embodiment of the invention is a process for producing a single-phase immersion cooling fluid from a Fischer-Tropsch product stream comprising providing the Fischer-Tropsch product stream comprising C₈₊ normal paraffins; dewaxing the Fischer-Tropsch product stream in a dewaxing reaction zone comprising a dewaxing reactor in the presence of a dewaxing catalyst under dewaxing conditions to form a dewaxed effluent stream comprising C₈₊ normal paraffins and isoparaffins; separating the dewaxed effluent stream in a product recovery zone into at least a single-phase immersion cooling fluid stream comprising C₁₈₊ normal paraffins and isoparaffins, the single-phase immersion cooling fluid having a flash point equal to or greater than 150° C. and a pour point equal to or less than −25° C., and a ratio of iso-paraffins to normal paraffin on a weight to weight basis equal to or greater than 60. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph further comprising hydrocracking a portion of the single-phase immersion cooling fluid stream hydrocracking reaction zone comprising a hydrocracking reactor in the presence of a hydrocracking catalyst under hydrocracking conditions to form a hydrocracked effluent stream comprising C₈₊ normal paraffins and isoparaffins; and passing the hydrocracked effluent stream to the product recovery zone; wherein separating the dewaxed effluent stream comprises separating the dewaxed effluent stream and the hydrocracked effluent stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the hydrocracking catalyst comprises an amorphous acidic component. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the amorphous acidic component comprises amorphous silica-alumina. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the hydrocracking catalyst comprises a noble metal. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the hydrocracking reaction conditions comprise a temperature in a range of 315° C. to 415° C., or a pressure in a range of 300 to 1000 psig, or both; or the hydrocracking catalyst comprises Y zeolite, beta zeolite, amorphous silica-alumina, noble metals, base metals, or combinations thereof; or both. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph further comprising passing a hydrogen gas stream to the hydrocracking reaction zone. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the hydrogen gas stream comprises a recycle hydrogen stream from the product recovery zone. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein providing the Fischer-Tropsch product stream comprises reacting synthesis gas comprising hydrogen and carbon monoxide or carbon dioxide or both in a Fischer-Tropsch reaction zone comprising a Fischer-Tropsch reactor in the presence of a Fischer-Tropsch catalyst under Fischer-Tropsch reaction conditions to form the Fischer-Tropsch product stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the Fischer-Tropsch reaction conditions comprise a temperature in a range of 150° C. to 300° C., or a pressure in a range of 200 to 750 psig, or both; or the Fischer-Tropsch catalyst comprises a Fe-, Co-, Ni-, Ru-based catalyst or combinations thereof; or both.

Without further elaboration, it is believed that using the preceding description that one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of this invention, without departing from the spirit and scope thereof, to make various changes and modifications of the invention and to adapt it to various usages and conditions. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limiting the remainder of the disclosure in any way whatsoever, and that it is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

In the foregoing, all temperatures are set forth in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.