Biodegradable cooling fluids by direct immersion

Abstract

The invention relates to the use of a composition as a cooling fluid by direct immersion, said composition comprising from 80% to 100% by weight, relative to the total weight of the composition, of a hydrocarbon fluid comprising at least 90% by weight, relative to the total weight of the hydrocarbon fluid, of isoparaffins and less than 100 ppm by weight of aromatics, the hydrocarbon fluid has a 28-day biodegradability higher than or equal to 60% as measured according to the OECD 301B standard.

Description

Technical Field

[0001] The present invention relates to the use of readily biodegradable isoparaffinic fluids as cooling fluids by direct immersion, in particular for data centers. The present invention also relates to cooling systems and cooling methods by direct immersion in readily biodegradable isoparaffinic cooling fluids. Background Art

[0002] Data storage is expanding across the board. Many aspects of our daily lives (smart devices, homes, cities, and driverless vehicles) rely on data centers, which consist of large numbers of computers and servers. These centers are costly in terms of energy consumption.

[0003] Many techniques can be used to cool the electronic equipment (such as processors, memory, network equipment and other heat-generating equipment) contained in a data center. For example, strong convection can be set by providing a flow of cooling air over these devices. Fans located near the equipment, fans located in the data processing server room, and / or fans located in ducts in fluid communication with air surrounding the electronic equipment may force a continuous flow of cooling air into the data center.

[0004] More recently, cooling systems by immersion in a cooling fluid have been developed.

[0005] Fluid cooling by single-phase direct immersion means that the cooling fluid does not undergo a phase change during the equipment cooling process (heat dissipation) in the data center.

[0006] Cooling fluids by direct single-phase immersion have been developed. They are usually fluorocarbons. These compounds are powerful greenhouse gases and may have an impact on the ozone layer (potential global warming).

[0007] Another problem addressed by the present invention is the health and comfort of operators using cooling fluids.

[0008] Document WO2022 / 038313 discloses a bio-based fluid and its use as a cooling fluid by single-phase direct immersion. The document does not disclose the fluid claimed in the present application, especially a fluid having an aromatic content of less than 100 ppm. The high content of aromatics disclosed in this document may cause irritation problems to people handling the fluid.

[0009] It is an object of the present invention to provide a bio-based, readily biodegradable hydrocarbon fluid as a cooling fluid for data centers by direct single-phase immersion that has a longer life than prior art fluids and provides improved safety for operators. Summary of the invention

[0010] The present invention relates to the use of a composition as a cooling fluid by direct immersion, the composition comprising 80% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, the hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid having a 28-day biodegradability measured according to the OECD 301B standard higher than or equal to 60%.

[0011] In one embodiment, the hydrocarbon fluid comprises, relative to the total weight of the hydrocarbon fluid:

[0012] - at least 95% by weight of isoparaffins, and / or

[0013] - up to 5% by weight of n-paraffins, and / or

[0014] - up to 1% by weight of cycloalkanes, and / or

[0015] - Less than 50 ppm by weight of aromatics.

[0016] In one embodiment, the hydrocarbon fluid has:

[0017] a flash point higher than or equal to 110° C., preferably higher than or equal to 120° C., even higher than or equal to 140° C., according to ASTM D93; and / or

[0018] - a kinematic viscosity at 40°C lower than or equal to 5 cSt, preferably lower than or equal to 4 cSt.

[0019] In one embodiment, the hydrocarbon fluid has:

[0020] - an initial boiling point and a final boiling point in the range of -200°C to 400°C, preferably 240°C to 350°C, more preferably 250°C to 340°C; and / or

[0021] The difference range between the final boiling point and the initial boiling point is -10°C to 80°C, preferably 20°C to 50°C.

[0022] In one embodiment, the hydrocarbon fluid comprises, relative to the total weight of the hydrocarbon fluid:

[0023] - 30% to 60% by weight of C15 isoparaffins and 30% to 60% by weight of C16 isoparaffins; or

[0024] - 5 to 15% by weight of C15 isoparaffins, 30 to 60% by weight of C16 isoparaffins, 10 to 30% by weight of C17 isoparaffins and 10 to 30% by weight of C18 isoparaffins; or

[0025] - 10 to 30% by weight of C17 isoparaffins and 60 to 90% by weight of C18 isoparaffins.

[0026] In one embodiment, the composition comprises 100% by weight of cooling fluid.

[0027] In another embodiment, the composition further comprises 0.01 wt% to 20 wt% of an additive, relative to the total weight of the composition, the additive being preferably selected from antioxidants, flame retardants and mixtures thereof.

[0028] In another embodiment, the composition is free of flame retardants.

[0029] The invention also relates to a cooling system by direct immersion, comprising:

[0030] - a bath comprising a composition comprising from 80% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, said hydrocarbon fluid having a 28-day biodegradability measured according to the OECD 301B standard higher than or equal to 60%,

[0031] - At least one device to be cooled partially or completely immersed in said composition.

[0032] In one embodiment of the cooling system, the equipment to be cooled is equipment in a data center.

[0033] In one embodiment of the cooling system, the hydrocarbon fluid comprises one or more of the following characteristics:

[0034] - Relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid comprises:

[0035] o at least 95% by weight of isoparaffins, and / or

[0036] o up to 5% by weight of n-paraffins, and / or

[0037] o up to 1% by weight of cycloalkanes, and / or

[0038] o Less than 50 ppm by weight of aromatics;

[0039] - and / or the hydrocarbon fluid has:

[0040] o a flash point higher than or equal to 110°C, preferably higher than or equal to 120°C, even higher than or equal to 140°C, according to ASTM D93; and / or

[0041] o a kinematic viscosity at 40°C lower than or equal to 5 cSt, preferably lower than or equal to 4 cSt;

[0042] - and / or the hydrocarbon fluid has:

[0043] o an initial boiling point and a final boiling point in the range of 200°C to 400°C, preferably 240°C to 350°C, more preferably 250°C to 340°C; and / or

[0044] o the difference between the final boiling point and the initial boiling point ranges from 10°C to 80°C, preferably from 20°C to 50°C;

[0045] - and or, relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid comprises:

[0046] o 30 wt% to 60 wt% C15 isoparaffins and 30 wt% to 60 wt% C16 isoparaffins; or

[0047] o 5 wt% to 15 wt% C15 isoparaffins, 30 wt% to 60 wt% C16 isoparaffins, 10 wt% to 30 wt% C17 isoparaffins, and 10 wt% to 30 wt% C18 isoparaffins; or

[0048] o 10 to 30 wt% C17 isoparaffins and 60 to 90 wt% C18 isoparaffins.

[0049] In one embodiment of the cooling system, the composition comprises 100% by weight of cooling fluid.

[0050] In one embodiment of the cooling system, the composition further comprises 0.01 to 20 wt % of an additive, relative to the total weight of the composition, the additive being preferably selected from antioxidants, flame retardants and mixtures thereof.

[0051] A further subject of the invention is a cooling method by direct immersion comprising a step of completely or partially immersing at least one device to be cooled in a composition comprising from 80% to 100% by weight of a hydrocarbon fluid, relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics, relative to the total weight of the hydrocarbon fluid, said hydrocarbon fluid having a 28-day biodegradability, measured according to standard OECD 301B, greater than or equal to 60% relative to the total weight of carbon atoms.

[0052] In one embodiment of the cooling method, the equipment to be cooled is equipment in a data center.

[0053] In one embodiment of the cooling method, the equipment to be cooled is equipment in a data center.

[0054] In one embodiment of the cooling method, the hydrocarbon fluid has one or more of the following characteristics:

[0055] - Relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid comprises:

[0056] o at least 95% by weight of isoparaffins, and / or

[0057] o up to 5% by weight of n-paraffins, and / or

[0058] o up to 1% by weight of cycloalkanes, and / or

[0059] o Less than 50 ppm by weight of aromatics;

[0060] - and / or, the hydrocarbon fluid has:

[0061] o a flash point higher than or equal to 110°C, preferably higher than or equal to 120°C, even higher than or equal to 140°C, according to ASTM D93; and / or

[0062] o a kinematic viscosity at 40°C lower than or equal to 5 cSt, preferably lower than or equal to 4 cSt;

[0063] - and / or, the hydrocarbon fluid has:

[0064] o an initial boiling point and a final boiling point in the range of 200°C to 400°C, preferably 240°C to 350°C, more preferably 250°C to 340°C; and / or

[0065] o the difference between the final boiling point and the initial boiling point ranges from 10°C to 80°C, preferably from 20°C to 50°C;

[0066] - and or, relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid comprises:

[0067] o 30 wt% to 60 wt% C15 isoparaffins and 30 wt% to 60 wt% C16 isoparaffins; or

[0068] o 5 wt% to 15 wt% C15 isoparaffins, 30 wt% to 60 wt% C16 isoparaffins, 10 wt% to 30 wt% C17 isoparaffins, and 10 wt% to 30 wt% C18 isoparaffins; or

[0069] o 10 to 30 wt% C17 isoparaffins and 60 to 90 wt% C18 isoparaffins.

[0070] In one embodiment of the cooling method, the composition comprises 100% by weight of the cooling fluid.

[0071] In one embodiment of the cooling method, the composition further comprises 0.01 to 20 wt % of an additive, relative to the total weight of the composition, the additive being preferably selected from antioxidants, flame retardants and mixtures thereof.

[0072] The present invention allows to provide a cooling fluid having excellent resistance to aging. In particular, the hydrocarbon fluid defined in the present invention has an improved lifetime compared to prior art fluids, in particular compared to fluids having a higher aromatic content.

[0073] By using it as a cooling fluid under immersion, the use time of the same fluid can be extended, possibly up to 5 years, or even 10 years. It is therefore advantageous that the fluid remains highly stable over time, in other words, does not degrade over time.

[0074] The inventors have thus found that the hydrocarbon fluids defined in the present invention are particularly stable against aging, this stability being due in particular to the low aromatics content of less than 100 ppm.

[0075] The inventors have therefore found that the hydrocarbon fluids defined in the present invention are less irritating than the fluids of the prior art, this low irritation being achieved in particular by the low content of aromatic hydrocarbons. DETAILED DESCRIPTION

[0076] The present invention relates to the use of a composition as a cooling fluid by direct immersion, the composition comprising 80% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, the hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid having a 28-day biodegradability of at least 60% measured according to the OECD 301B standard.

[0077] A further subject of the invention is a cooling system by direct immersion, comprising:

[0078] a bath comprising a composition comprising from 80% to 100% by weight of a hydrocarbon fluid, relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics, relative to the total weight of the hydrocarbon fluid, said hydrocarbon fluid having a 28-day biodegradability measured according to the OECD 301B standard of at least 60%,

[0079] - At least one device to be cooled partially or completely immersed in said composition.

[0080] Finally, a further subject of the invention is a cooling method by direct immersion comprising a step of completely or partially immersing at least one device to be cooled in a composition comprising from 80% to 100% by weight of a hydrocarbon fluid, relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics, relative to the total weight of the hydrocarbon fluid, said hydrocarbon fluid having a 28-day biodegradability of at least 60%, measured according to standard OECD 301B.

[0081] As a preliminary remark, it is pointed out that, in the description and in the following claims, the expression "between" should be interpreted as including the cited limitations.

[0082] In the meaning of the present invention, the term "paraffins" includes isoparaffins and normal paraffins.

[0083] In the meaning of the present invention, the term "isoparaffins" denote non-cyclic branched alkanes.

[0084] In the meaning of the present invention, the term "n-paraffins" denote non-cyclic straight-chain alkanes.

[0085] In the meaning of the present invention, the term "cycloalkanes" denotes (non-aromatic) cycloalkanes.

[0086] Composition

[0087] In the present invention, the composition comprises 80 wt% to 100 wt% of the hydrocarbon fluid relative to the total weight of the composition.

[0088] In one embodiment, the composition comprises 100 wt% hydrocarbon fluid. In this embodiment, the hydrocarbon fluid is used as cooling fluid.

[0089] In another embodiment, the composition further comprises 0.01 wt % to 20 wt % of an additive selected from an antioxidant, a flame retardant and a mixture thereof, relative to the total weight of the composition.

[0090] In one embodiment, the composition comprises, relative to the total weight of the composition:

[0091] - 85% to 99.99% by weight, preferably 90% to 99.5% by weight, more preferably 95% to 99% by weight of hydrocarbon fluids,

[0092] - 0.01 to 15% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, of additives.

[0093] In one embodiment, the composition comprises, or even consists of, relative to the total weight of the composition:

[0094] at least 97% by weight, preferably at least 98% by weight, of hydrocarbon fluids,

[0095] - Optionally 0.01 to 3% by weight, preferably 0.05 to 2% by weight, of an antioxidant.

[0096] In one embodiment, the composition comprises, relative to the total weight of the composition:

[0097] - 85% to 99.99% by weight, preferably 90% to 99.5% by weight, more preferably 95% to 99% by weight of hydrocarbon fluids,

[0098] 0.01 to 15% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight, of additives,

[0099] The composition contains no flame retardants.

[0100] Hydrocarbon Fluids

[0101] The isoparaffin content of the hydrocarbon fluid used in the present invention is at least 90% by weight, preferably at least 95% by weight, more preferably at least 98% by weight, relative to the total weight of the hydrocarbon fluid.

[0102] The content of normal paraffins in the hydrocarbon fluid used in the present invention is less than or equal to 10 wt %, preferably less than or equal to 5 wt %, more preferably less than or greater than 2 wt %, relative to the total weight of the hydrocarbon fluid.

[0103] Preferably, the hydrocarbon fluid used in the present invention has a weight ratio of iso-paraffins to normal-paraffins of at least 12:1, preferably at least 15:1, more preferably at least 19:1.

[0104] In one embodiment, the hydrocarbon fluid used in the present invention has a weight content of 90% to 100% of isoparaffins and a weight content of 0% to 10% of normal paraffins, preferably 95% to 100% of isoparaffins and 0% to 5% of normal paraffins, more preferably 98% to 100% of isoparaffins and 0% to 2% of normal paraffins, relative to the total weight of the hydrocarbon fluid.

[0105] Preferably, the hydrocarbon fluid used in the present invention has a cycloalkyl compound content of less than or equal to 1% by weight, preferably less than or equal to 0.5% by weight, more preferably less than or greater than 100 ppm, relative to the total weight of the hydrocarbon fluid.

[0106] In a preferred embodiment, the hydrocarbon fluid used in the present invention has a weight content of 90% to 100% of isoparaffins, a weight content of 0% to 10% of normal paraffins and a weight content of less than or equal to 1% of cycloparaffins, relative to the total weight of the hydrocarbon fluid.

[0107] More preferably, the hydrocarbon fluid used in the present invention has a weight content of 95% to 100% isoparaffins, a weight content of 0% to 5% normal paraffins and a weight content of less than or equal to 0.5% cycloparaffins, relative to the total weight of the hydrocarbon fluid.

[0108] Further preferably, the hydrocarbon fluid used in the present invention has an isoparaffin content of 98% to 100% by weight, a normal paraffin content of 0% to 2% by weight and a cycloparaffin content of less than or equal to 100 ppm by weight, relative to the total weight of the hydrocarbon fluid.

[0109] The content of isoparaffins, normal paraffins and cycloparaffins can be determined by any method known to those skilled in the art, such as gas chromatography.

[0110] The hydrocarbon fluid used in the present invention contains less than 100 ppm by weight of aromatic hydrocarbons, preferably less than 50 ppm by weight of aromatic hydrocarbons, more preferably less than 20 ppm by weight of aromatic hydrocarbons, relative to the total weight of the hydrocarbon fluid.

[0111] The aromatic content can be determined by any method known to those skilled in the art, for example by UV spectroscopy.

[0112] In a preferred embodiment, the hydrocarbon fluid used in the present invention has a weight content of 90% to 100% of isoparaffins, a weight content of 0% to 10% of normal paraffins, a weight content of less than or equal to 1% of cycloparaffins, and a weight content of less than or equal to 100ppm of aromatic compounds. More preferably, the hydrocarbon fluid used in the present invention has a weight content of 95% to 100% of isoparaffins, a weight content of 0% to 5% of normal paraffins, a weight content of less than or equal to 0.5% of cycloparaffins, and a weight content of less than or equal to 50ppm of aromatic compounds. More preferably, the hydrocarbon fluid used in the present invention has a weight content of 95% to 100% of isoparaffins, a weight content of 0% to 5% of normal paraffins, and a weight content of less than or equal to 100ppm of aromatic compounds. Further preferably, the hydrocarbon fluid used in the present invention has an isoparaffin content of 98% to 100% by weight, a normal paraffin content of 0% to 2% by weight, a cycloparaffin content of less than or equal to 100 ppm by weight, and an aromatic compound content of less than or equal to 100 ppm by weight.

[0113] The hydrocarbon fluids used in the present invention also preferably have very low weight contents of sulfur-containing compounds, typically less than or equal to 5 ppm, preferably less than or equal to 3 ppm, more preferably less than or greater than 0.5 ppm, a level too low for detection by conventional low sulfur content analyzers.

[0114] According to the ASTM D93 standard, the hydrocarbon fluid used in the present invention also preferably has a flash point higher than or equal to 110° C., preferably higher than or equal to 120° C., more preferably higher than or equal to 140° C. A high flash point, usually higher than 110° C., can particularly overcome safety issues during storage or transportation, ensuring that the flammability of the hydrocarbon fluid is low.

[0115] The vapor pressure of the hydrocarbon fluid used in the present invention at 20° C. is also preferably lower than or equal to 0.01 kPa.

[0116] In one embodiment, the hydrocarbon fluid used in the present invention also preferably has a flash point higher than or equal to 110° C. and a vapor pressure lower than or equal to 0.01 kPa at 20° C. according to ASTM D93 standard.

[0117] More preferably, the hydrocarbon fluid used in the present invention has a flash point higher than or equal to 120° C. and a vapor pressure lower than or equal to 0.01 kPa at 20° C.

[0118] More preferably, the hydrocarbon fluid used in the present invention has a flash point higher than or equal to 140° C. and a vapor pressure lower than or equal to 0.01 kPa at 20° C.

[0119] Furthermore, the hydrocarbon fluid used in the present invention preferably has a kinematic viscosity at 40° C. lower than or equal to 5 cSt, preferably lower than or equal to 4 cSt, as measured according to the ASTM D445 standard.

[0120] Preferably, the initial boiling point and the final boiling point of the hydrocarbon fluid used in the present invention are in the range of 200°C to 400°C, preferably 240°C to 350°C, more preferably 250°C to 340°C.

[0121] The boiling point can be determined according to ASTM D86 standard.

[0122] Preferably, the difference between the final boiling point and the initial boiling point ranges from 10°C to 80°C, preferably from 20°C to 50°C.

[0123] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95 wt% of isoparaffins and less than 100 ppm by weight of aromatics, and has an initial boiling point and a final boiling point in the range of 200°C to 400°C.

[0124] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95 wt% of isoparaffins and less than 100 ppm by weight of aromatics, and has an initial boiling point and a final boiling point in the range of 250°C to 340°C.

[0125] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 100 ppm by weight of aromatic hydrocarbons, and has an initial boiling point and a final boiling point in the range of 200°C to 400°C, and the difference between the final boiling point and the initial boiling point in the range of 10°C to 80°C.

[0126] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 100 ppm by weight of aromatic hydrocarbons, and has an initial boiling point and a final boiling point in the range of 250°C to 340°C, and the difference between the final boiling point and the initial boiling point in the range of 10°C to 80°C.

[0127] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 100 ppm by weight of aromatic hydrocarbons, and has an initial boiling point and a final boiling point in the range of 250°C to 340°C, and the difference between the final boiling point and the initial boiling point in the range of 20°C to 50°C.

[0128] In one embodiment, the hydrocarbon fluid used in the present invention comprises, relative to the total weight of the hydrocarbon fluid:

[0129] - 20% to 80% by weight of C15 isoparaffins and 20% to 80% by weight of C16 isoparaffins, the fluid may contain isoparaffins having 14 or fewer carbon atoms, and / or isoparaffins having 17 or more carbon atoms; or

[0130] - 3 wt% to 20 wt% C15 isoparaffins, 20 wt% to 70 wt% C16 isoparaffins, 5 wt% to 40 wt% C17 isoparaffins and 5 wt% to 40 wt% C18 isoparaffins, the fluid optionally comprising isoparaffins having 14 or fewer carbon atoms, and / or isoparaffins having 19 or more carbon atoms; or

[0131] - 5 to 40% by weight of C17 isoparaffins and 60 to 95% by weight of C18 isoparaffins, the fluid optionally comprising isoparaffins having 16 or fewer carbon atoms and / or isoparaffins having 19 or more carbon atoms.

[0132] In a particular embodiment, the hydrocarbon fluid used in the present invention comprises, relative to the total weight of the hydrocarbon fluid:

[0133] - 30% to 60% by weight of C15 isoparaffins and 30% to 60% by weight of C16 isoparaffins, the fluid may contain isoparaffins having 14 or fewer carbon atoms, and / or isoparaffins having 17 or more carbon atoms; or

[0134] - 5 to 15% by weight of C15 isoparaffins, 30 to 60% by weight of C16 isoparaffins, 10 to 30% by weight of C17 isoparaffins and 10 to 30% by weight of C18 isoparaffins, the fluid optionally comprising isoparaffins having 14 or fewer carbon atoms and / or isoparaffins having 19 or more carbon atoms; or

[0135] - 10 to 30% by weight of C17 isoparaffins and 60 to 90% by weight of C18 isoparaffins, the fluid optionally comprising isoparaffins having 16 or fewer carbon atoms and / or isoparaffins having 19 or more carbon atoms.

[0136] The expression "CX isoparaffin" denotes an isoparaffin having X carbon atoms.

[0137] In one embodiment, the hydrocarbon fluid used in the present invention has a biocarbon content of at least 90 wt%, preferably at least 95 wt%, more preferably at least 97 wt%, relative to the total weight of carbon atoms in the hydrocarbon fluid.

[0138] Biochar content can be measured according to the 2020 ASTM D6866 standard.

[0139] In one embodiment, the hydrocarbon fluid used in the present invention comprises 5 to 15 wt. % of C15 isoparaffins, 30 to 60 wt. % of C16 isoparaffins, 10 to 30 wt. % of C17 isoparaffins and 10 to 30 wt. % of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, and has an aromatic content of less than 100 ppm by weight.

[0140] In one embodiment, the initial boiling point and the final boiling point of the hydrocarbon fluid used in the present invention are in the range of 240°C to 300°C, and the hydrocarbon fluid used in the present invention contains 5% to 15% by weight of C15 isoparaffins, 30% to 60% by weight of C16 isoparaffins, 10% to 30% by weight of C17 isoparaffins and 10% to 30% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, and has an aromatic content of less than 100 ppm by weight.

[0141] In one embodiment, the hydrocarbon fluid used in the present invention comprises 10 to 30 wt% of C17 isoparaffins and 60 to 90 wt% of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, and has an aromatic content of less than 100 ppm by weight.

[0142] In one embodiment, the hydrocarbon fluid used in the present invention has an initial boiling point and a final boiling point in the range of 260°C to 340°C, relative to the total weight of the hydrocarbon fluid, contains 10% to 30% by weight of C17 isoparaffins and 60% to 90% by weight of C18 isoparaffins, and has an aromatic content of less than 100 ppm by weight.

[0143] In one embodiment, the hydrocarbon fluid used in the present invention comprises from 5% to 15% by weight of C15 isoparaffins, from 30% to 60% by weight of C16 isoparaffins, from 10% to 30% by weight of C17 isoparaffins and from 10% to 30% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, has an aromatics content of less than 100 ppm by weight, and the biogenic carbon content of the fluid is at least 95% by weight relative to the total weight of carbon atoms in the hydrocarbon fluid.

[0144] In one embodiment, the initial boiling point and the final boiling point of the hydrocarbon fluid used in the present invention are in the range of 240°C to 300°C, and the hydrocarbon fluid used in the present invention contains 5% to 15% by weight of C15 isoparaffins, 30% to 60% by weight of C16 isoparaffins, 10% to 30% by weight of C17 isoparaffins and 10% to 30% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, has an aromatic content of less than 100 ppm by weight, and the biogenic carbon content of the fluid is at least 95% by weight relative to the total weight of carbon atoms in the hydrocarbon fluid.

[0145] In one embodiment, the hydrocarbon fluid used in the present invention comprises from 10% to 30% by weight of C17 isoparaffins and from 60% to 90% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, has an aromatics content of less than 100 ppm by weight, and the biogenic carbon content of the fluid is at least 95% by weight relative to the total weight of carbon atoms in the hydrocarbon fluid.

[0146] In one embodiment, the initial boiling point and the final boiling point of the hydrocarbon fluid used in the present invention are in the range of 260°C to 340°C, and the hydrocarbon fluid used in the present invention contains 10% to 30% by weight of C17 isoparaffins and 60% to 90% by weight of C18 isoparaffins relative to the total weight of the hydrocarbon fluid, has an aromatic content of less than 100 ppm by weight, and the biocarbon content of the fluid is at least 95% by weight relative to the total weight of carbon atoms in the hydrocarbon fluid.

[0147] In one embodiment, the hydrocarbon fluid used in the present invention comprises from 5% to 15% by weight of C15 isoparaffins, from 30% to 60% by weight of C16 isoparaffins, from 10% to 30% by weight of C17 isoparaffins and from 10% to 30% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, has an aromatics content of less than 50 ppm by weight, and the biogenic carbon content of the fluid is at least 90% by weight relative to the total weight of carbon atoms in the hydrocarbon fluid.

[0148] In one embodiment, the hydrocarbon fluid used in the present invention comprises from 10% to 30% by weight of C17 isoparaffins and from 60% to 90% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, has an aromatics content of less than 50 ppm by weight, and the biogenic carbon content of the fluid is at least 90% by weight relative to the total weight of carbon atoms in the hydrocarbon fluid.

[0149] The hydrocarbon fluids used in the present invention have a 28-day biodegradability of at least 60%, measured according to standard OECD 301 B. Thus, in general, the hydrocarbon fluids of the present invention can be said to be readily biodegradable.

[0150] In contrast, according to standard OECD 301, for example standard OECD 301B, a product would be called "inherently biodegradable" if its biodegradability within 28 days is between 20% and less than 60%.

[0151] In one embodiment, the hydrocarbon fluid used in the present invention has a 28-day biodegradability measured according to standard OECD 301B of at least 70%, preferably at least 80%.

[0152] Preferably, the hydrocarbon fluid used in the present invention has a 28-day biodegradability of at least 60%, measured according to standard OECD 306. Standard OECD 306 is more restrictive than standard OECD 301B.

[0153] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 100 ppm by weight of aromatics, has an initial boiling point and a final boiling point in the range of 200°C to 400°C, and has a 28-day biodegradability of at least 60% measured according to standard OECD 301B.

[0154] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 100 ppm by weight of aromatics, has an initial boiling point and a final boiling point in the range of 250°C to 340°C, and has a 28-day biodegradability of at least 60% measured according to standard OECD 301B.

[0155] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 100 ppm by weight of aromatics, has an initial boiling point and a final boiling point in the range of 250°C to 340°C, the difference between the final boiling point and the initial boiling point in the range of 20°C to 50°C, and the hydrocarbon fluid has a 28-day biodegradability measured according to standard OECD 301B of at least 60%.

[0156] In one embodiment, the hydrocarbon fluid used in the present invention comprises from 5% to 15% by weight of C15 isoparaffins, from 30% to 60% by weight of C16 isoparaffins, from 10% to 30% by weight of C17 isoparaffins and from 10% to 30% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, with an aromatics content of less than 100 ppm by weight, the hydrocarbon fluid having a 28-day biodegradability measured according to standard OECD 301B of at least 60%.

[0157] In one embodiment, the hydrocarbon fluid used in the present invention comprises from 10% to 30% by weight of C17 isoparaffins and from 60% to 90% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, with an aromatic content of less than 100 ppm by weight, the hydrocarbon fluid having a 28-day biodegradability measured according to standard OECD 301B of at least 60%.

[0158] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 50 ppm by weight of aromatics, has an initial boiling point and a final boiling point in the range of 200°C to 400°C, and has a 28-day biodegradability of at least 60% measured according to standard OECD 301B.

[0159] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 50 ppm by weight of aromatics, has an initial boiling point and a final boiling point in the range of 250°C to 340°C, and has a 28-day biodegradability of at least 60% as measured according to standard OECD 301B.

[0160] In a particularly preferred embodiment, the hydrocarbon fluid used in the present invention comprises at least 95% by weight of isoparaffins and less than 50 ppm by weight of aromatics, has an initial boiling point and a final boiling point in the range of 250°C to 340°C, the difference between the final boiling point and the initial boiling point in the range of 20°C to 50°C, and the hydrocarbon fluid has a 28-day biodegradability measured according to standard OECD 301B of at least 60%.

[0161] In one embodiment, the hydrocarbon fluid used in the present invention comprises 5 to 15% by weight of C15 isoparaffins, 30 to 60% by weight of C16 isoparaffins, 10 to 30% by weight of C17 isoparaffins and 10 to 30% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, has an aromatics content of less than 50 ppm by weight, and the hydrocarbon fluid has a 28-day biodegradability measured according to standard OECD 301B of at least 60%.

[0162] In one embodiment, the hydrocarbon fluid used in the present invention comprises from 10% to 30% by weight of C17 isoparaffins and from 60% to 90% by weight of C18 isoparaffins, relative to the total weight of the hydrocarbon fluid, with an aromatic content of less than 50 ppm by weight, the hydrocarbon fluid having a 28-day biodegradability measured according to standard OECD 301B of at least 60%.

[0163] Methods for obtaining hydrocarbon fluids:

[0164] The hydrocarbon fluid used in the present invention can be obtained in the following manner: The hydrocarbon fluid used in the present invention is a hydrocarbon fraction generally derived from biomass conversion.

[0165] Derived from biomass conversion, it refers to hydrocarbon fractions produced from bio-based raw materials. The bio-based raw materials can be selected from vegetable oils, animal fats, fish oils and mixtures thereof.

[0166] Preferably, the biomass hydrocarbon fraction is obtained by a process comprising a hydrodeoxygenation (HDO) and an isomerization (ISO) step. The hydrodeoxygenation step (HDO) results in a structural decomposition of the bio-ester or triglyceride component to remove oxygen-containing, phosphorus-containing and sulfur-containing compounds and hydrogenate olefin bonds. The product produced by the hydrodeoxygenation reaction is then isomerized. Preferably, a fractionation step is performed after the hydrodeoxygenation and isomerization steps. Advantageously, the fraction of interest is subjected to a hydrotreating step and then distilled to obtain the specifications of the hydrocarbon fluid required by the present invention.

[0167] The HDO / ISO process is implemented on a crude biofeed, also known as biomass or bio-based raw materials, selected from vegetable oils, animal fats, fish oils and mixtures thereof. Suitable bio-based raw materials are for example rapeseed oil, rapeseed oil, tall oil, sunflower oil, soybean oil, linseed oil, olive oil, linseed oil, mustard oil, palm oil, peanut oil, castor oil, coconut oil, animal fats such as tallow, recycled food fats, raw materials from genetic engineering sources, and bio-based raw materials produced by microorganisms such as algae and bacteria. Condensation products, esters and other derivatives obtained from crude biomaterials can also serve as raw materials.

[0168] Preferably, the bio-based feedstock is an ester or triglyceride derivative. The material first undergoes a hydrodeoxygenation step (HDO) to decompose the structures that make up the esters or triglycerides and remove oxygen-, phosphorus- and sulfur-containing compounds while hydrogenating the olefinic bonds. The hydrodeoxygenation step (HDO) of the bio-based feedstock is followed by isomerization of the resulting product, resulting in branching of the hydrocarbon chains and improvement of the low temperature properties of the alkanes.

[0169] In the HDO step, hydrogen and bio-based feedstock are passed through a catalytic hydrodeoxygenation bed simultaneously or in countercurrent. In the HDO step, the pressure and temperature are 20 bar to 150 bar and 200° C. to 500° C., respectively. Known conventional hydrodeoxygenation catalysts are used in this step. Optionally, the bio-based feedstock can be pre-hydrogenated under mild conditions to prevent secondary reactions of double bonds before the HDO step. After the hydrodeoxygenation step, the product produced by the reaction is subjected to an isomerization step (ISO), wherein hydrogen, product and an optional normal paraffin mixture are passed through an isomerization catalytic bed simultaneously or in countercurrent. In the ISO step, the pressure and temperature are 20 bar to 150 bar and 200° C. to 500° C., respectively. Known conventional isomerization catalysts are used in this step.

[0170] Additional secondary processes (such as intermediate mixing, capture or other similar processes) may also be implemented.

[0171] The product produced by the HDO / ISO step may optionally be fractionated to obtain fractions of interest.

[0172] Various HDO / ISO processes are described in the literature. Application WO2014 / 033762 describes a process comprising a prehydrogenation step, a hydrodeoxygenation step (HDO) and an isomerization step in countercurrent operation. Patent application EP1728844 describes a process for producing hydrocarbon compounds from a mixture of compounds of plant and animal origin. The process comprises a pretreatment step of the mixture to remove contaminants, such as alkali metal salts, followed by a hydrodeoxygenation step (HDO) and an isomerization step. Patent application EP2084245 describes a process for preparing a hydrocarbon mixture that can be used as diesel or a diesel composition by hydrodeoxygenating a biomixture containing fatty acid esters and then hydroisomerizing them over a specific catalyst, the fatty acid esters being optionally in a mixture with free fatty acids, for example vegetable oils such as sunflower oil, rapeseed oil, palm oil or pine oil. Patent application EP2368967 describes the process and the products obtained therefrom.

[0173] Advantageously, the bio-based feedstock contains less than 15 ppm of sulphur, preferably less than 8 ppm, more preferably less than 5 ppm, further preferably less than 1 ppm, according to standard EN ISO 20846. Ideally, the feedstock comprises no sulphur as bio-based feedstock.

[0174] The deoxygenated and isomerized feed produced by the HDO / ISO process is then hydrogenated, optionally after fractionation, to obtain the desired boiling range.

[0175] Preferably, the hydrogenation step is a step of catalytic hydrogenation of the bio-based, deoxygenated and isomerized feed (or fraction) at a temperature of 80°C to 180°C and a pressure of 50 bar to 160 bar.

[0176] The hydrogen used in hydrogenation units is usually high purity hydrogen. High purity refers to hydrogen with a purity greater than 99%, although other grades of hydrogen may also be used.

[0177] The hydrogenation step is carried out over a catalyst. Standard hydrogenation catalysts can be solid or supported and can contain the following metals: nickel, platinum, palladium, rhenium, rhodium, nickel tungstate, nickel molybdenum, molybdenum, cobalt molybdenum. The support can be silica, alumina, silica-alumina or a zeolite.

[0178] A preferred catalyst is nickel on an alumina support, preferably with a specific surface area of ​​100 m 2 / g to 200m 2 / g catalyst, or solid nickel catalyst. The hydrogenation conditions are generally as follows:

[0179] - pressure: 50 to 160 bar, preferably 80 to 150 bar, more preferably 90 to 120 bar;

[0180] - Temperature: 80°C to 180°C, preferably 120°C to 160°C, more preferably 150°C to 160°C;

[0181] - Liquid Hourly Space Velocity (LHSV): 0.2 hr-1 to 5 hr-1, preferably 0.4 hr-1 to 3 hr-1, more preferably 0.5 hr-1 to 0.8 hr-1;

[0182] - Hydrogen treatment rate: adapted to the above conditions, may be up to 200 Nm3 / ton of feed to be treated.

[0183] The temperature in the reactor is generally between 150°C and 160°C, the pressure is about 100 bar, and the liquid hourly space velocity is about 0.6 hr-1, the treatment rate being adjusted according to the quality of the feed to be treated and the parameters of the first hydrogenation reactor.

[0184] The hydrogenation can be carried out in one or more reactors connected in series. The reactor may include one or more catalyst beds. The catalyst bed is usually a fixed catalyst bed.

[0185] The hydrogenation process preferably comprises two or three reactors, preferably three reactors, and is preferably carried out in three reactors connected in series.

[0186] The first reactor allows the capture of sulfur compounds and hydrogenation of substantially all unsaturated compounds, making aromatic compounds up to about 90% by weight. The product obtained by the first reactor is substantially free of sulfur compounds. In the second stage, i.e. in the second reactor, the hydrogenation of aromatics continues so that up to 99% by weight of aromatics are hydrogenated.

[0187] The third stage in the third reactor is the final stage and allows obtaining an aromatics content of less than 100 ppm, preferably less than 50 ppm, more preferably less than 20 ppm.

[0188] Reactors comprising two, three or more catalytic beds may be used. The catalyst may be used in different amounts or substantially equal amounts in each reactor; for example, for three reactors, the amount as a function of weight may be 0.05-0.5 / 0.10-0.70 / 0.25-0.85, preferably 0.07-0.25 / 0.15-0.35 / 0.4-0.78, more preferably 0.10-0.20 / 0.20-0.32 / 0.48-0.70.

[0189] It is also possible to use one or two hydrogenation reactors instead of three.

[0190] The first reactor may also be a dual reactor used alternately. This mode of operation is particularly convenient for loading and unloading of the catalyst: when the first reactor contains a first saturated catalyst (substantially all the sulfur is trapped on and / or in the catalyst), it has to be changed frequently.

[0191] It is also possible to use a single reactor equipped with two, three or more catalytic beds.

[0192] It may be necessary to insert a quench box in the circulation system or between the reactors to cool the effluent from one or the other reactor or from one catalyst bed to another catalyst bed, so as to control the temperature and hydrothermal balance of each reaction. In a preferred embodiment, there is no cooling or quenching of the intermediates.

[0193] In one embodiment, the products and / or separated gases produced by the process are at least partially recycled in the feed system of the hydrogenation reactor. This dilution helps to keep the exothermicity of the reaction within controlled ranges, particularly in the first stage. Recovery further allows heat exchange to be performed before the reaction, thereby better controlling the temperature.

[0194] The effluent from the hydrogenation unit contains mainly hydrogenation products and hydrogen. A flash separator is used to separate the gas phase effluent (mainly residual hydrogen) from the liquid phase (mainly hydrogenated hydrocarbon fraction). The process can be carried out using three flash separators, one high pressure, one medium pressure, and one low pressure very close to atmospheric pressure.

[0195] The gaseous hydrogen collected at the top of the flash separator can be recycled back to the feed system of the hydrogenation unit, or recycled at different levels in the hydrogenation unit between reactors.

[0196] In one embodiment, the final product is separated at atmospheric pressure. It is then directly sent to a vacuum fractionation apparatus. Preferably, the fractionation is carried out at a pressure of 10 mbar to 50 mbar, more preferably at about 30 mbar.

[0197] Fractionation can be performed so that various hydrocarbon fluids can be extracted from the fractionation column simultaneously and their boiling point temperatures can be predetermined.

[0198] By adjusting the initial and final boiling points of the feed, the hydrogenation reactor, separator and fractionation unit can be directly connected without the use of intermediate tanks. This integration of hydrogenation and fractionation allows for optimized heat integration, reduced equipment count and energy savings.

[0199] Therefore, in one embodiment of the present invention, the hydrocarbon fluid used in the present invention is obtained by a process comprising subjecting the hydrodeoxygenated and hydroisomerized biomass to a catalytic hydrogenation step, the hydrogenation step being carried out at a temperature of 80°C to 180°C and a pressure of 50 bar to 160 bar, preferably at a temperature of 120°C to 160°C and a pressure of 80 bar to 150 bar, more preferably at a temperature of 150°C to 160°C and a pressure of 90 bar to 120 bar.

[0200] In a particular embodiment, the hydrocarbon fluid used in the present invention is obtained by the following process, which comprises:

[0201] - a hydrodeoxygenation step of the biomass followed by a hydroisomerization step in order to obtain a hydrodeoxygenated and hydroisomerized biomass,

[0202] - a catalytic hydrogenation step of the hydrodeoxygenated and hydroisomerized biomass, the hydrogenation step being carried out at a temperature of 80 to 180°C and a pressure of 50 to 160 bar, preferably at a temperature of 120 to 160°C and a pressure of 80 to 150 bar, more preferably at a temperature of 150 to 160°C and a pressure of 90 to 120 bar,

[0203] The biomass is preferably selected from the group consisting of vegetable oils, animal fats, fish oils and mixtures thereof.

[0204] The hydrocarbon fluids used in the present invention are ideally derived from the processing of bio-based feedstocks. The term "biochar" or "bio-based carbon" means that the carbon is of natural origin, derived from biological material as shown below. Bio-based carbon content, bio-carbon content and bio-material content are expressions indicating the same value. Material from renewable resources or bio-material is an organic material in which the carbon comes from atmospheric carbon dioxide that has been recently fixed (in the human range) by photosynthesis. Bio-material (carbon 100% bio-based) 14 C / 12 C isotope ratio is higher than 10 -12 , typically about 1.2 x 10 -12 , while the ratio of fossil materials is zero. Isotopes formed in the atmosphere 14 C is integrated via photosynthesis on time scales not exceeding a few decades. 14 The half-life of C is 5730 years. Therefore, the materials produced by photosynthesis, that is, plants in general, must have the greatest 14 C isotope content.

[0205] additive

[0206] In one embodiment, the composition as a cooling fluid includes one or more additives in addition to the hydrocarbon fluid.

[0207] Among the additives that can be used, mention may be made of antioxidants, flame retardants and mixtures thereof.

[0208] In one embodiment, the composition includes at least one flame retardant additive. The flame retardant additive may be selected from the group consisting of halogenated compounds, phosphorus compounds, metal hydroxides, and mixtures thereof.

[0209] In one embodiment, the flame retardant additive satisfies formula (I):

[0210] RF-L-RH(I)

[0211] in:

[0212] - RF is a hydrocarbon group, in particular a hydrocarbon group having 1 to 22, preferably 1 to 20, more preferably 1 to 16 carbon atoms,

[0213] - RH is a hydrocarbon group, in particular a hydrocarbon group having 1 to 22, preferably 1 to 20, more preferably 1 to 16 carbon atoms, and

[0214] -L is a linker selected from the following groups: -CH2-, -CH=CH-, -O-, S- or -PO4-,

[0215] RF and / or RH may further include at least one element selected from the halogen group of elements, such as, preferably, fluorine, bromine and / or chlorine.

[0216] In one embodiment, the composition is free of perfluorooctyl bromide.

[0217] If used in the composition, the flame retardant is preferably present in an amount of from 0.01 wt % to 20 wt % by weight of the composition, preferably from 1 wt % to 10 wt % by weight of the composition.

[0218] In one embodiment, the composition comprises at least one antioxidant additive. Antioxidant additives generally allow the composition to delay degradation during use. This degradation can be manifested in particular by the formation of deposits, the appearance of sludge or an increase in the viscosity of the composition.

[0219] The antioxidant additives act in particular as free radical inhibitors or hydroperoxide decomposers. Among the conventionally used antioxidants, mention may be made of phenolic antioxidant additives, aminic antioxidant additives, sulfur-phosphorus antioxidant additives. Some of these antioxidant additives, such as those containing sulfur and phosphorus, produce ash. Phenolic antioxidant additives may be ashless or in the form of neutral or basic metal salts. The antioxidant additive may be selected in particular from hindered phenols, esters of hindered phenols and hindered phenols containing thioether bridges, diphenylamine, esters of hindered phenols separated by at least one C1-C 12 Alkyl-substituted diphenylamines and mixtures thereof.

[0220] In one embodiment, the sterically hindered phenols are selected from compounds comprising a phenolic group in which at least one carbon atom ortho to the carbon atom carrying the alcohol function is replaced by at least one C1-C 10 Alkyl, preferably C1-C6 alkyl, preferably C4 alkyl, preferably tert-butyl substituted.

[0221] Amine compounds are another class of antioxidant additives that can be used, optionally in combination with phenolic antioxidant additives. Examples of amine compounds are aromatic amines, such as those of the formula NR 4 R 5 R 6 Aromatic amines, where R 4 is an optionally substituted aliphatic or aryl group, R 5 is an optionally substituted aryl group, R 6 is a hydrogen atom, an alkyl group, an aryl group or a group of formula R 7 S(O) 8 , where R 7 is an alkylene or alkenylene group, R 8 is alkyl, alkenyl or aryl, and z is 0, 1 or 2.

[0222] Sulfurized alkylphenols or their alkali or alkaline earth metal salts may also be used as antioxidant additives.

[0223] Another class of antioxidant additives includes copper-containing compounds such as copper thio- or dithiophosphates, copper salts with carboxylic acids, copper dithiocarbamates, sulfonates, phenates, and acetylacetonates. Copper I and II salts, salts of succinic acid or anhydride may also be used.

[0224] If used in the composition, the antioxidant preferably comprises from 0.01 wt % to 3 wt % by weight of the composition, preferably from 0.05 wt % to 2 wt % by weight of the composition.

[0225] Uses of hydrocarbon fluids or compositions:

[0226] The hydrocarbon fluid or composition is used as a cooling fluid by direct immersion, particularly by direct immersion of equipment in a data center.

[0227] Preferably, the cooling is by single-phase direct immersion cooling. In other words, generally the hydrocarbon fluid (or composition) does not undergo a phase change during the cooling process.

[0228] Examples of equipment in a data center are servers, particularly computers that include microprocessors.

[0229] In one embodiment, the present invention relates to the use of a composition as a cooling fluid by direct immersion, the composition comprising 80% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, the hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 50 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid having a 28-day biodegradability measured according to the OECD 301B standard higher than or equal to 60%, the initial boiling point and the final boiling point of the hydrocarbon fluid being in the range of 200°C to 400°C, preferably 240°C to 350°C, more preferably 250°C to 340°C.

[0230] In one embodiment, the present invention relates to the use of a composition as a cooling fluid by direct immersion, the composition comprising 95% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, the hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid having a 28-day biodegradability measured according to the OECD 301B standard of higher than or equal to 60%, the initial boiling point and the final boiling point of the hydrocarbon fluid being in the range of 200°C to 400°C, preferably 240°C to 350°C, more preferably 250°C to 340°C.

[0231] In one embodiment, the present invention relates to the use of a composition as a cooling fluid by direct immersion, the composition comprising 98% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, the hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid having a 28-day biodegradability measured according to the OECD 301B standard of higher than or equal to 60%, the initial boiling point and the final boiling point of the hydrocarbon fluid being in the range of 200°C to 400°C, preferably 240°C to 350°C, more preferably 250°C to 340°C.

[0232] In one embodiment, the present invention relates to the use of a composition as a cooling fluid by direct immersion, the composition comprising from 80% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, the hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 50 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid having a 28-day biodegradability measured according to the OECD 301B standard higher than or equal to 60%.

[0233] Cooling system

[0234] Another subject of the invention is a system for cooling at least one device by direct immersion, comprising:

[0235] - a bath comprising a composition as defined in the invention,

[0236] - said at least one device to be cooled being partially or completely immersed in said composition.

[0237] The submersion may be total submersion if the total volume of the equipment is submerged in the hydrocarbon fluid.

[0238] The submersion may be partial if not the entire volume of the device is submerged in the hydrocarbon fluid, but only a portion thereof.

[0239] Preferably, the equipment to be cooled is equipment in a data center, such as a server or a computer.

[0240] The composition comprising a hydrocarbon fluid may be static or circulated within a cooling system.

[0241] The cooling system may also include a heat exchange system in which the cooling liquid heated by the device in the bath is cooled before returning to the bath.

[0242] In one embodiment, the hydrocarbon fluid or composition may then be placed in circulation between a bath comprising at least one device to be cooled and a heat exchange system.

[0243] The heat exchange system may be connected to a water or air circuit which allows cooling of the hydrocarbon fluid or composition before it returns to the bath, ensuring its cooling function.

[0244] The cooling fluid may be circulated by a pumping system.

[0245] The heat recovered from the composition comprising hydrocarbon fluid during the heat exchange is optionally recovered and used, for example, for heating a building.

[0246] Cooling method

[0247] Another subject of the present invention is a method for cooling at least one device by direct immersion, comprising a step of completely or partially immersing said at least one device in a composition as defined in the present invention.

[0248] Typically, the composition is placed in a bath and the device is fully or partially immersed in the composition of the bath.

[0249] Preferably, the equipment to be cooled is equipment in a data center, such as a server or an 0850 computer.

[0250] The cooling method of the present invention can be implemented in the refrigeration system of the present invention.

[0251] The cooling method of the present invention may also include the step of cooling the composition, which is heated by immersing the device in a bath. The cooling step of the composition may be implemented by a heat exchanger and a water or air loop outside the bath. In one embodiment, after the cooling step of the composition, the method of the present invention may also include the step of recovering the heat from the composition, the heat recovered being optionally used for, for example, heating a building.

[0252] Example

[0253] In the remainder of the specification, examples are given to illustrate the present invention, and these examples do not limit the scope of the present invention in any way.

[0254] According to the process described in the present invention, three hydrocarbon fluids are produced by HDO / ISO of biomass after the hydrogenation step.

[0255] Table 1 Collection of physicochemical properties of hydrocarbon fluids.

[0256] [Table 1]

[0257]

[0258]

[0259] The following standards and methods are used to measure the above properties: - Flash point EN ISO 2719;

[0260] Density at -15°C: EN ISO 1185;

[0261] -Pour point: EN ISO 3016;

[0262] -Viscosity at 40°C: EN ISO 3104; -Boiling point: ASTM D86;

[0263] -Biodegradability: OECD 301B method;

[0264] - Pour point: ASTM D5950.

[0265] The specific heat is measured according to the standards ISO 113587, ASTM E1269, ASTM E968, ASTM E793, ASTM D3895, ASTM D3417, ASTM D3418, DIN 51004, DIN 51007 and DIN 53765 using a DSC calorimeter (DSC Netzsch 204 Phoenix).

[0266] Thermal conductivity is determined by the following method:

[0267] A device consisting of two aluminum tubes, an inner and an outer tube, was used. The fluid to be measured is located in the annular space between the two tubes. Pulse energy (Dirac type) is applied to the inner tube and the temperature is measured on the outer tube, allowing the thermogram to be obtained.

[0268] Knowing the thermal diffusivity, density and specific heat of the two-layer aluminum tube as a function of temperature, and knowing the density and specific heat of the fluid to be analyzed, the thermal conductivity of the fluid as a function of temperature can be derived from this.

[0269] The device was first calibrated using a reference sample of Seriola 1510 (heat transfer fluid) at different temperatures. The different thermal properties were previously measured separately.

[0270] The sample (fluid to be measured) is mixed and loaded (using a syringe) into the annular space between the two tubes. The loaded device is then placed in a temperature controlled chamber.

[0271] For each temperature measurement, the procedure is as follows. The sample is stabilized at a given temperature. A flash is applied to the inner surface of the inner tube and the increase in temperature of the outer surface of the outer tube is recorded over time.

[0272] The thermal conductivity can be calculated from the average of at least 3 measurements at each given temperature.

[0273] Tests were carried out to compare the oxidation stability of the fluid of the invention with that of a fluid according to document WO 2022 / 038313.

[0274] The fluids tested were as follows:

[0275] - Fluid 3 in Table 1,

[0276] - As described in document WO2022 / 038313, the biomass fluid CC1 obtained by HDO / ISO has a boiling point range of 190°C to 310°C, an isoparaffin content of 95% by weight, and an aromatic content of 600 ppm.

[0277] According to standard ASTM D2272 (RPVOT test), a composition comprising 99.5% by weight of a fluid (ie fluid 3 or fluid CC1) and 0.5% by weight of BHT as antioxidant was tested.

[0278] The results are as follows:

[0279] Fluid 3 = 465 minutes,

[0280] Fluid CC1 = 315 minutes.

[0281] These results indicate that the fluids of the present invention exhibit better oxidative stability than prior art fluids.

[0282] In summary, hydrocarbon fluids show excellent thermal properties and very low aromatic content, which means it is particularly beneficial for cooling equipment in data centers by direct immersion. The very low aromatic content improves aging, provides better resistance to aging, which is most useful for such applications where the same fluid can be used for 5 or even 10 years, and reduces or even eliminates fluid irritation, thereby improving fluid operator safety.

Claims

1. Use of a composition as a cooling fluid by direct immersion, said composition comprising from 80% to 100% by weight of a hydrocarbon fluid relative to the total weight of said composition, said hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, said hydrocarbon fluid having a 28-day biodegradability higher than or equal to 60% measured according to the OECD 301B standard.

2. The use according to claim 1, wherein The composition is used as a cooling fluid by directly immersing a piece of equipment in a data center.

3. The use according to claim 1 or 2, wherein Relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid comprises: - at least 95% by weight of isoparaffins, and / or - up to 5% by weight of n-paraffins, and / or - up to 1% by weight of cycloalkanes, and / or - Less than 50 ppm by weight of aromatics.

4. The use according to any one of claims 1 to 3, wherein the hydrocarbon fluid has: a flash point higher than or equal to 110° C., preferably higher than or equal to 120° C., even higher than or equal to 140° C., according to ASTM D93; and / or - a kinematic viscosity at 40°C lower than or equal to 5 cSt, preferably lower than or equal to 4 cSt; and / or - an initial boiling point and a final boiling point in the range of 200°C to 400°C, preferably 240°C to 350°C, more preferably 250°C to 340°C; and / or The difference range between the final boiling point and the initial boiling point is -10°C to 80°C, preferably 20°C to 50°C.

5. The use according to any one of claims 1 to 4, wherein Relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid comprises: - 30% to 60% by weight of C15 isoparaffins and 30% to 60% by weight of C16 isoparaffins; or - 5 to 15% by weight of C15 isoparaffins, 30 to 60% by weight of C16 isoparaffins, 10 to 30% by weight of C17 isoparaffins and 10 to 30% by weight of C18 isoparaffins; or - 10 to 30% by weight of C17 isoparaffins and 60 to 90% by weight of C18 isoparaffins.

6. The use according to any one of claims 1 to 5, wherein The composition comprises 100% by weight of cooling fluid.

7. The use according to any one of claims 1 to 6, wherein The composition further comprises from 0.01% to 20% by weight of an additive, relative to the total weight of the composition, preferably chosen from antioxidants, flame retardants and mixtures thereof, preferably chosen from antioxidants.

8. A cooling system by direct immersion, comprising: - a bath comprising a composition comprising from 80% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, said hydrocarbon fluid having a 28-day biodegradability measured according to the OECD 301B standard higher than or equal to 60%, - at least one device to be cooled partially or completely immersed in said composition.

9. The cooling system according to claim 8, wherein: The equipment to be cooled is equipment in a data center.

10. The cooling system according to claim 8 or 9, wherein: The hydrocarbon fluid is as defined in any one of claims 3 to 5.

11. The cooling system according to any one of claims 8 to 10, wherein: The composition is as defined in claim 6 or claim 7.

12. A cooling method by direct immersion, comprising a step of completely or partially immersing at least one device to be cooled in a composition comprising from 80% to 100% by weight of a hydrocarbon fluid relative to the total weight of the composition, the hydrocarbon fluid comprising at least 90% by weight of isoparaffins and less than 100 ppm by weight of aromatics relative to the total weight of the hydrocarbon fluid, the hydrocarbon fluid having a 28-day biodegradability measured according to standard OECD 301B, greater than or equal to 60% relative to the total weight of carbon atoms.

13. The cooling method according to claim 12, wherein: The equipment to be cooled is equipment in a data center.

14. The cooling method according to claim 12 or 13, wherein: The hydrocarbon fluid is as defined in any one of claims 3 to 5.

15. The cooling method according to any one of claims 12 to 14, wherein: The composition is as defined in claim 6 or claim 7.

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