Biodegradable cooling fluids via direct immersion

Abstract

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

Description

[Technical field]

[0001] The present invention relates to the use of readily biodegradable isoparaffinic fluids as cooling fluids via direct immersion, particularly for data centers. The present invention also relates to a cooling system and method via direct immersion in a readily biodegradable isoparaffinic cooling fluid. [Background technology]

[0002] Data storage is completely expanded. Many aspects of our daily life (smart devices, homes, cities, and driverless vehicles) depend on data centers, especially those with a large number of computers and a large number of servers. These centers are expensive in terms of energy consumption.

[0003] Many techniques can be used to cool the electronic devices (e.g., processors, memory, networking devices, and other heat-generating devices) contained in a data center. For example, forced convection can be established by providing a flow of cooling air above these devices. Fans located in the vicinity of the devices, in the data processing server room, and / or in ducts in fluid communication with the air surrounding the electronic devices can force a flow of cooling air within the data center.

[0004] Recently, cooling systems that involve immersion in a cooling liquid have been developed.

[0005] Single-phase direct immersion liquid cooling means that the coolant does not change phase during the cooling process (heat dissipation) of the data center equipment.

[0006] Direct single-phase immersion coolants have been developed. They are typically fluorocarbon compounds. These compounds are potent greenhouse gases that can affect the ozone layer (global warming potential).

[0007] A further problem which the present invention seeks to solve is the health and comfort of the operator using the coolant.

[0008] WO 2022 / 038313 discloses bio-based fluids and their use as single-phase direct immersion coolants. This document does not disclose fluids as claimed herein, particularly those having an aromatic content of less than 100 ppm. High aromatic content, as disclosed in this document, creates irritation problems for those handling the fluid.

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

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

[0011] In one embodiment, the hydrocarbon fluid to total weight of the hydrocarbon fluid is - at least 95% by weight of isoparaffins, and / or - maximum 5% by weight of normal paraffins, and / or - max. 1% by weight of naphthenes, and / or - Aromatics less than 50 ppm by weight Includes.

[0012] In one embodiment, the hydrocarbon fluid comprises a flash point according to standard ASTM D93 of 110 ° C or more, preferably 120 ° C or more and even 140 ° C or more, and / or - kinematic viscosity at 40°C of less than 5 cSt, preferably less than 4 cSt has.

[0013] In one embodiment, the hydrocarbon fluid comprises - initial and final boiling points in the range of 200 to 400°C, preferably 240 to 350°C, more preferably 250 to 340°C, and / or - the difference between the final boiling point and the initial boiling point in the range of 10°C to 80°C, preferably 20°C to 50°C has.

[0014] In one embodiment, the hydrocarbon fluid to total weight of the hydrocarbon fluid is - 30-60% by weight of C15 isoparaffins and 30-60% by weight of C16 isoparaffins, or - 5-15% by weight of C15 isoparaffins, 30-60% by weight of C16 isoparaffins, 10-30% by weight of C17 isoparaffins, and 10-30% by weight of C18 isoparaffins, or - 10-30% by weight of C17 isoparaffin and 60-90% by weight of C18 isoparaffin Includes.

[0015] In one embodiment, the composition comprises 100% by weight of cooling fluid.

[0016] In another embodiment, the composition further comprises from 0.01 to 20% by weight, relative to the total weight of the composition, of an additive, preferably selected from among antioxidants, flame retardants and mixtures thereof.

[0017] In another embodiment, the composition is flame retardant-free.

[0018] The present invention also relates to a cooling system via direct immersion, - a bathtub containing a composition comprising 80-100% 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 of at least 60%; - at least one item of equipment that is cooled and partially or completely immersed in the composition; Equipped with.

[0019] In one embodiment of the cooling system, the items of equipment being cooled are equipment in a data center.

[0020] In one embodiment of the cooling system, the hydrocarbon fluid includes one or more of the following characteristics: - Hydrocarbon fluids by weight of the total hydrocarbon fluids at least 95% by weight of isoparaffins, and / or Maximum 5% by weight of normal paraffin, and / or Maximum 1% by weight of naphthenes, and / or Aromatics less than 50 ppm by weight Contains; and / or the hydrocarbon fluid is a flash point according to standard ASTM D93 of 110 ° C or more, preferably 120 ° C or more and even 140 ° C or more, and / or Kinematic viscosity at 40°C of 5 cSt or less, preferably 4 cSt or less having; and / or the hydrocarbon fluid is an initial boiling point and a final boiling point within the range of 200 to 400° C., preferably 240 to 350° C., more preferably 250 to 340° C., and / or The difference between the final boiling point and the initial boiling point is in the range of 10°C to 80°C, preferably 20°C to 50°C. having; and / or the hydrocarbon fluids relative to the total weight of the hydrocarbon fluids 30-60% by weight of C15 isoparaffins and 30-60% by weight of C16 isoparaffins, or 5-15% by weight of C15 isoparaffins, 30-60% by weight of C16 isoparaffins, 10-30% by weight of C17 isoparaffins, and 10-30% by weight of C18 isoparaffins, or 10-30% by weight of C17 isoparaffin and 60-90% by weight of C18 isoparaffin Includes.

[0021] In one embodiment of the cooling system, the composition comprises 100% cooling fluid by weight.

[0022] In one embodiment of the cooling system, the composition further comprises 0.01 to 20% by weight, based on the total weight of the composition, of an additive, preferably selected from among antioxidants, flame retardants and mixtures thereof.

[0023] A further subject of the present invention is a method for cooling via direct immersion, comprising a step of fully or partially immersing at least one item of equipment to be cooled in a composition comprising 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, of not less than 60% by weight of carbon atoms.

[0024] In one embodiment of the cooling method, the items of equipment being cooled are equipment in a data center.

[0025] In one embodiment of the cooling method, the items of equipment being cooled are equipment in a data center.

[0026] In one embodiment of the cooling method, the hydrocarbon fluid has one or more of the following characteristics: - Hydrocarbon fluids by weight of the total hydrocarbon fluids, at least 95% by weight of isoparaffins, and / or Maximum 5% by weight of normal paraffin, and / or Maximum 1% by weight of naphthenes, and / or Aromatics less than 50 ppm by weight Contains; and / or the hydrocarbon fluid is a flash point according to standard ASTM D93 of 110 ° C or more, preferably 120 ° C or more and even 140 ° C or more, and / or Kinematic viscosity at 40°C of 5 cSt or less, preferably 4 cSt or less having; and / or the hydrocarbon fluid is an initial boiling point and a final boiling point within the range of 200 to 400° C., preferably 240 to 350° C., more preferably 250 to 340° C., and / or The difference between the final boiling point and the initial boiling point is in the range of 10°C to 80°C, preferably 20°C to 50°C. having; and / or the hydrocarbon fluids relative to the total weight of the hydrocarbon fluids 30-60% by weight of C15 isoparaffins and 30-60% by weight of C16 isoparaffins, or 5-15% by weight of C15 isoparaffins, 30-60% by weight of C16 isoparaffins, 10-30% by weight of C17 isoparaffins, and 10-30% by weight of C18 isoparaffins, or 10-30% by weight of C17 isoparaffin and 60-90% by weight of C18 isoparaffin Includes.

[0027] In one embodiment of the cooling method, the composition comprises 100% by weight of cooling fluid.

[0028] In one embodiment of the cooling method, the composition further comprises 0.01 to 20% by weight, based on the total weight of the composition, of an additive, preferably selected from among antioxidants and flame retardants, and mixtures thereof.

[0029] The present invention provides refrigeration fluids with excellent resistance to aging, in particular the hydrocarbon fluids defined in the present invention have improved life spans compared to prior art fluids, especially compared to fluids having a higher aromatics content.

[0030] The use as a cooling fluid via immersion provides for a long-term use of the same fluid, possibly reaching up to 5 or even 10 years. As a result, it is advantageous that the fluid remains very stable over time, in other words, that the fluid does not degrade over time.

[0031] Thus, the inventors have discovered that the hydrocarbon fluids defined in the present invention are particularly stable to ageing, in particular due to their low aromatic content of less than 100 ppm.

[0032] Thus, the inventors have found that the hydrocarbon fluids defined in the present invention are much less irritating than prior art fluids, and that this mildness is achieved in particular by the low aromatic content. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] The present invention relates to the use as a cooling fluid via direct immersion of a composition comprising 80-100% 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.

[0034] A further subject of the present invention is a cooling system via direct immersion, comprising: - a bathtub containing a composition comprising 80-100% 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; - At least one item of equipment that is cooled and partially or completely immersed in a hydrocarbon fluid; The cooling system includes:

[0035] Finally, a further subject of the present invention is a method for cooling via direct immersion, comprising a step of fully or partially immersing at least one item of equipment to be cooled in a composition comprising 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.

[0036] As a preliminary remark, it is pointed out that in the specification and in the claims that follow, the expression "between" should be interpreted as including the cited limitations.

[0037] In the sense of the present invention, the term "paraffins" includes isoparaffins and n-paraffins.

[0038] In the sense of the present invention, the term "isoparaffin" denotes an acyclic branched alkane.

[0039] In the sense of the present invention, the term "n-paraffin" denotes acyclic straight-chain alkanes.

[0040] In the sense of the present invention, the term "naphthene" denotes a (non-aromatic) cyclic alkane.

[0041] Composition: In the present invention, the composition contains 80 to 100% by weight of the hydrocarbon fluid, based on the total weight of the composition.

[0042] In one embodiment, the composition comprises 100% by weight of a hydrocarbon fluid. In this embodiment, a hydrocarbon fluid is used as the cooling fluid.

[0043] In another embodiment, the composition further comprises 0.01 to 20 wt. % of an additive selected from among antioxidants, flame retardants, and mixtures thereof, based on the total weight of the composition.

[0044] In one embodiment, the composition comprises, based on the total weight of the composition: - 85 to 99.99% by weight, preferably 90 to 99.5% by weight, more preferably 95 to 99% by weight of a hydrocarbon fluid, - 0.01 to 15% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight of additives Includes.

[0045] In one embodiment, the composition further comprises, based on the total weight of the composition: - at least 97% by weight, preferably at least 98% by weight, of a hydrocarbon fluid, - optionally 0.01 to 3% by weight, preferably 0.05 to 2% by weight, of antioxidant(s); and further consisting of the above.

[0046] In one embodiment, the composition comprises, based on the total weight of the composition: - 85 to 99.99% by weight, preferably 90 to 99.5% by weight, more preferably 95 to 99% by weight of a hydrocarbon fluid, - 0.01 to 15% by weight, preferably 0.5 to 10% by weight, more preferably 1 to 5% by weight of additives Including, The composition does not contain a flame retardant.

[0047] Hydrocarbon fluids: The hydrocarbon fluid used in the present invention has a content of isoparaffins of at least 90% by weight, preferably at least 95% by weight, more preferably at least 98% by weight, based on the total weight of the hydrocarbon fluid.

[0048] The hydrocarbon fluid used in the present invention has a normal paraffin content of 10 wt.% or less, preferably 5 wt.% or less, more preferably 2 wt.% or less, based on the total weight of the hydrocarbon fluid.

[0049] Preferably, the hydrocarbon fluid used in the present invention has a weight ratio of isoparaffins to normal paraffins of at least 12:1, preferably at least 15:1, more preferably at least 19:1.

[0050] In one embodiment, the hydrocarbon fluid used in the present invention has a weight content of isoparaffins in the range of 90-100% and a weight content of 0-10%, preferably 95-100% isoparaffins and 0-5% normal paraffins, more preferably 98-100% isoparaffins and 0-2% normal paraffins, based on the total weight of the hydrocarbon fluid.

[0051] Preferably, the hydrocarbon fluid used in the present invention has a weight content of naphthenic compounds of less than 1%, preferably less than 0.5%, more preferably less than 100 ppm, based on the total weight of the hydrocarbon fluid.

[0052] In a preferred embodiment, the hydrocarbon fluid used in the present invention has a weight content of isoparaffins in the range of 90 to 100%, a weight content of normal paraffins in the range of 0 to 10%, and a weight content of naphthenes of 1% or less, based on the total weight of the hydrocarbon fluid.

[0053] More preferably, the hydrocarbon fluid used in the present invention has a weight content of isoparaffins in the range of 95 to 100%, a weight content of normal paraffins in the range of 0 to 5%, and a weight content of naphthenes of 0.5% or less, based on the total weight of the hydrocarbon fluid.

[0054] More preferably, the hydrocarbon fluid used in the present invention has, based on the total weight of the hydrocarbon fluid, an isoparaffin weight content in the range of 98% to 100%, a normal paraffin weight content in the range of 0 to 2%, and a naphthene weight content of 100 ppm or less.

[0055] The isoparaffin, normal paraffin and naphthene content can be determined by any method known to those skilled in the art, such as gas chromatography.

[0056] The hydrocarbon fluids used in the present invention contain less than 100 ppm by weight of aromatics, preferably less than 50 ppm by weight of aromatics, more preferably less than 20 ppm by weight of aromatics based on the total weight of the hydrocarbon fluid.

[0057] The aromatic content can be determined by any method known to one of skill in the art, for example, UV spectroscopy.

[0058] In a preferred embodiment, the hydrocarbon fluid used in the present invention has a weight content of isoparaffins in the range of 90-100%, a weight content of normal paraffins in the range of 0-10%, a weight content of naphthenes of 1% or less, and a weight content of aromatic compounds of 100 ppm or less. More preferably, the hydrocarbon fluid used in the present invention has a weight content of isoparaffins in the range of 95-100%, a weight content of normal paraffins of 0-5%, a weight content of naphthenes of 0.5% or less, and a weight content of aromatic compounds of 50 ppm or less. Even more preferably, the hydrocarbon fluid used in the present invention has a weight content of isoparaffins in the range of 95-100%, a weight content of normal paraffins of 0-5%, and a weight content of aromatic compounds of 100 ppm or less. More preferably, the hydrocarbon fluid used in the present invention has a weight content of isoparaffins in the range of 98% to 100%, a weight content of normal paraffins of 0 to 2%, a weight content of naphthenes of 100 ppm or less, and a weight content of aromatic compounds of 100 ppm or less.

[0059] The hydrocarbon fluids used in the present invention also preferably have an extremely low content by weight of sulfur-containing compounds, typically less than 5 ppm, preferably less than 3 ppm, more preferably less than 0.5 ppm, levels too low to be detected by conventional low sulfur content analytical equipment.

[0060] The hydrocarbon fluids used in the present invention also preferably have a flash point, according to standard ASTM D93, of at least 110° C., preferably at least 120° C., more preferably at least 140° C. A high flash point, typically above 110° C., overcomes safety issues, particularly during storage or transportation, and reduces the flammability of the hydrocarbon fluid.

[0061] The hydrocarbon fluids used in the present invention also preferably have a vapor pressure at 20°C of 0.01 kPa or less.

[0062] In one embodiment, the hydrocarbon fluids used in the present invention also preferably have a flash point of 110° C. or more and a vapor pressure of 0.01 kPa or less at 20° C. according to standard ASTM D93.

[0063] More preferably, the hydrocarbon fluids used in the present invention have a flash point of 120°C or greater and a vapor pressure at 20°C of 0.01 kPa or less.

[0064] More preferably, the hydrocarbon fluids used in the present invention have a flash point of 140°C or greater and a vapor pressure at 20°C of 0.01 kPa or less.

[0065] The hydrocarbon fluids used in the present invention further preferably have a kinematic viscosity at 40° C., measured according to standard ASTM D445, of less than or equal to 5 cSt, preferably less than or equal to 4 cSt.

[0066] Preferably, the hydrocarbon fluid used in the present invention has an initial and final boiling point within the range of 200-400°C, preferably 240-350°C, more preferably 250-340°C.

[0067] The boiling point can be determined according to standard ASTM D86.

[0068] Preferably, the difference between the final boiling point and the initial boiling point is in the range of 10°C to 80°C, preferably 20°C to 50°C.

[0069] In one particularly preferred embodiment, the hydrocarbon fluid used in the present invention contains at least 95 wt.% isoparaffins and less than 100 ppm aromatics by weight, and has initial and final boiling points within the range of 200-400°C.

[0070] In one particularly preferred embodiment, the hydrocarbon fluid used in the present invention contains at least 95 wt.% isoparaffins and less than 100 ppm aromatics by weight, and has initial and final boiling points within the range of 250-340°C.

[0071] In one particularly preferred embodiment, the hydrocarbon fluid used in the present invention contains at least 95% by weight isoparaffins and less than 100 ppm by weight aromatics, has initial and final boiling points within the range of 200 to 400°C, and the difference between the final and initial boiling points is in the range of 10°C to 80°C.

[0072] In one particularly preferred embodiment, the hydrocarbon fluid used in the present invention contains at least 95 wt. % isoparaffins and less than 100 ppm aromatics by weight, has initial and final boiling points within the range of 250-340°C, and the difference between the final and initial boiling points is in the range of 10°C to 80°C.

[0073] In one particularly preferred embodiment, the hydrocarbon fluid used in the present invention contains at least 95 wt. % isoparaffins and less than 100 ppm aromatics by weight, has initial and final boiling points within the range of 250-340°C, and the difference between the final and initial boiling points is in the range of 20°C to 50°C.

[0074] In one embodiment, the hydrocarbon fluid used in the present invention comprises, based on the total weight of the hydrocarbon fluid, - 20-80% by weight of C15 isoparaffins and 20-80% by weight of C16 isoparaffins (the fluid optionally being isoparaffins having 14 or fewer carbon atoms and / or having 17 or more carbon atoms); or - 3-20% by weight of C15 isoparaffins, 20-70% by weight of C16 isoparaffins, 5-40% by weight of C17 isoparaffins, and 5-40% by weight of C18 isoparaffins (the fluid optionally containing isoparaffins having 14 or fewer carbon atoms and / or isoparaffins having 19 or more carbon atoms); or - 5-40 wt. % C17 isoparaffins and 60-95 wt. % C18 isoparaffins (the fluid optionally contains isoparaffins having 16 or fewer carbon atoms and / or isoparaffins having 19 or more carbon atoms). Includes.

[0075] In one particular embodiment, the hydrocarbon fluid used in the present invention comprises, based on the total weight of the hydrocarbon fluid: - 30-60% by weight of C15 isoparaffins and 30-60% by weight of C16 isoparaffins (the fluid optionally being isoparaffins having 14 or fewer carbon atoms and / or having 17 or more carbon atoms); or - 5-15% by weight of C15 isoparaffins, 30-60% by weight of C16 isoparaffins, 10-30% by weight of C17 isoparaffins, and 10-30% by weight of C18 isoparaffins (the fluid optionally containing isoparaffins having 14 or fewer carbon atoms and / or isoparaffins having 19 or more carbon atoms); or - 10-30 wt. % C17 isoparaffins and 60-90 wt. % C18 isoparaffins (the fluid optionally contains isoparaffins having 16 or fewer carbon atoms and / or isoparaffins having 19 or more carbon atoms). Includes.

[0076] The expression "CX isoparaffin" refers to an isoparaffin having X carbon atoms.

[0077] In one embodiment, the hydrocarbon fluid used in the present invention has a biogenic carbon content of at least 90% by weight, preferably at least 95% by weight, more preferably at least 97% by weight, based on the total weight of carbon atoms in the hydrocarbon fluid.

[0078] Biogenic carbon content can be determined according to the 2020 standard ASTM D6866.

[0079] In one embodiment, the hydrocarbon fluid used in the present invention comprises 5-15 wt.% C15 isoparaffins, 30-60 wt.% C16 isoparaffins, 10-30 wt.% C17 isoparaffins, and 10-30 wt.% C18 isoparaffins and has an aromatics content of less than 100 ppm by weight based on the total weight of the hydrocarbon fluid.

[0080] In one embodiment, the hydrocarbon fluid used in the present invention has initial and final boiling points in the range of 240-300°C, contains 5-15 wt% C15 isoparaffins, 30-60 wt% C16 isoparaffins, 10-30 wt% C17 isoparaffins, and 10-30 wt% C18 isoparaffins, and has an aromatics content of less than 100 ppm by weight based on the total weight of the hydrocarbon fluid.

[0081] In one embodiment, the hydrocarbon fluid used in the present invention comprises 10-30 wt.% C17 isoparaffins and 60-90 wt.% C18 isoparaffins and has an aromatics content of less than 100 ppm by weight based on the total weight of the hydrocarbon fluid.

[0082] In one embodiment, the hydrocarbon fluid used in the present invention has initial and final boiling points in the range of 260-340°C, contains 10-30 wt% C17 isoparaffins and 60-90 wt% C18 isoparaffins, and has an aromatics content of less than 100 ppm by weight based on the total weight of the hydrocarbon fluid.

[0083] In one embodiment, the hydrocarbon fluid used in the present invention comprises 5-15 wt.% C15 isoparaffins, 30-60 wt.% C16 isoparaffins, 10-30 wt.% C17 isoparaffins, and 10-30 wt.% C18 isoparaffins, and has an aromatics content of less than 100 ppm by weight based on the total weight of the hydrocarbon fluid, and the fluid has a biogenic carbon content of at least 95 wt.% based on the total weight of carbon atoms in the hydrocarbon fluid.

[0084] In one embodiment, the hydrocarbon fluid used in the present invention has initial and final boiling points in the range of 240-300°C, contains 5-15 wt% C15 isoparaffins, 30-60 wt% C16 isoparaffins, 10-30 wt% C17 isoparaffins, and 10-30 wt% C18 isoparaffins, has an aromatics content of less than 100 ppm by weight based on the total weight of the hydrocarbon fluid, and the fluid has a biogenic carbon content of at least 95 wt% based on the total weight of carbon atoms in the hydrocarbon fluid.

[0085] In one embodiment, the hydrocarbon fluid used in the present invention comprises 10-30 wt.% C17 isoparaffins and 60-90 wt.% C18 isoparaffins and has an aromatics content of less than 100 ppm by weight based on the total weight of the hydrocarbon fluid, and the fluid has a biogenic carbon content of at least 95 wt.% based on the total weight of carbon atoms in the hydrocarbon fluid.

[0086] In one embodiment, the hydrocarbon fluid used in the present invention has initial and final boiling points in the range of 260-340°C, contains 10-30 wt% C17 isoparaffins and 60-90 wt% C18 isoparaffins, has an aromatics content of less than 100 ppm by weight based on the total weight of the hydrocarbon fluid, and the fluid has a biogenic carbon content of at least 95 wt% based on the total weight of carbon atoms in the hydrocarbon fluid.

[0087] In one embodiment, the hydrocarbon fluid used in the present invention comprises 5-15 wt.% C15 isoparaffins, 30-60 wt.% C16 isoparaffins, 10-30 wt.% C17 isoparaffins, and 10-30 wt.% C18 isoparaffins, and has an aromatics content of less than 50 ppm by weight based on the total weight of the hydrocarbon fluid, and the fluid has a biogenic carbon content of at least 90 wt.% based on the total weight of carbon atoms in the hydrocarbon fluid.

[0088] In one embodiment, the hydrocarbon fluid used in the present invention comprises 10-30 wt.% C17 isoparaffins and 60-90 wt.% C18 isoparaffins and has an aromatics content of less than 50 ppm by weight based on the total weight of the hydrocarbon fluid, and the fluid has a biogenic carbon content of at least 90 wt.% based on the total weight of carbon atoms in the hydrocarbon fluid.

[0089] The hydrocarbon fluids used in the present invention have a 28 day biodegradability of at least 60% as measured according to standard OECD 301 B. Thus, typically, the hydrocarbon fluids of the present invention can be said to be readily biodegradable.

[0090] In contrast, a product is said to be "essentially biodegradable" if it has a 28-day biodegradability in the range of 20-60% according to standard OECD 301, e.g. standard OECD 301B.

[0091] In one embodiment, the hydrocarbon fluids used in the present invention have a 28 day biodegradability of at least 70%, preferably at least 80%, measured according to standard OECD 301B.

[0092] Preferably, the hydrocarbon fluids used in the present invention have a 28 day biodegradability of at least 60% measured according to standard OECD 306. Standard OECD 306 is more restrictive than standard OECD 301B.

[0093] 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 and final boiling point within the range of 200-400°C, and said hydrocarbon fluid has a 28-day biodegradability of at least 60% measured according to standard OECD 301B.

[0094] 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 and final boiling point within the range of 250-340°C, and said hydrocarbon fluid has a 28-day biodegradability of at least 60% measured according to standard OECD 301B.

[0095] 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 and final boiling point in the range of 250-340°C, the difference between the final and initial boiling points being in the range of 20°C to 50°C, and said hydrocarbon fluid has a 28-day biodegradability of at least 60%, measured according to standard OECD 301B.

[0096] In one embodiment, the hydrocarbon fluid used in the present invention comprises 5-15% by weight of C15 isoparaffins, 30-60% by weight of C16 isoparaffins, 10-30% by weight of C17 isoparaffins and 10-30% by weight of C18 isoparaffins, has an aromatics content of less than 100 ppm by weight relative to the total weight of the hydrocarbon fluid, and said hydrocarbon fluid has a 28-day biodegradability of at least 60% measured according to standard OECD 301B.

[0097] In one embodiment, the hydrocarbon fluid used in the present invention comprises 10-30% by weight of C17 isoparaffins and 60-90% by weight of C18 isoparaffins, has an aromatics content of less than 100 ppm by weight 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.

[0098] 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 and final boiling point in the range of 200-400°C, and said hydrocarbon fluid has a 28-day biodegradability according to standard OECD 301B of at least 60%.

[0099] 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 and final boiling point within the range of 250-340°C, and said hydrocarbon fluid has a 28-day biodegradability of at least 60% measured according to standard OECD 301B.

[0100] 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 and final boiling point in the range of 250-340°C, the difference between the final and initial boiling points being in the range of 20°C to 50°C, and said hydrocarbon fluid has a 28-day biodegradability of at least 60%, measured according to standard OECD 301B.

[0101] In one embodiment, the hydrocarbon fluid used in the present invention comprises 5-15% by weight of C15 isoparaffins, 30-60% by weight of C16 isoparaffins, 10-30% by weight of C17 isoparaffins and 10-30% by weight of C18 isoparaffins, has an aromatics content of less than 50 ppm by weight relative to the total weight of the hydrocarbon fluid, and said hydrocarbon fluid has a 28-day biodegradability of at least 60% measured according to standard OECD 301B.

[0102] In one embodiment, the hydrocarbon fluid used in the present invention comprises 10-30% by weight of C17 isoparaffins and 60-90% by weight of C18 isoparaffins, has an aromatics content of less than 50 ppm by weight 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.

[0103] Method for obtaining a hydrocarbon fluid: The hydrocarbon fluids used in the present invention can be obtained as follows: The hydrocarbon fluids used in the present invention are typically hydrocarbon fractions derived from the conversion of biomass.

[0104] By derived from the conversion of biomass it is meant a hydrocarbon fraction produced from a bio-based feedstock, which may be selected from among vegetable oils, animal fats, fish oils and mixtures thereof.

[0105] Preferably, the bio-based hydrocarbon fraction is obtained by a process comprising the steps of hydrodeoxygenation (HDO) and isomerization (ISO). The hydrodeoxygenation step (HDO) results in the decomposition of the structure of the biological ester or triglyceride components, the removal of oxygenated phosphorus- and sulfur-containing compounds, and the hydrogenation of the olefinic bonds. The product resulting from the hydrodeoxygenation reaction is then isomerized. The hydrodeoxygenation and isomerization steps can preferably be followed by a fractionation step. Advantageously, the fraction of interest is subjected to a hydrotreating step, followed by distillation to obtain the desired specifications of the hydrocarbon fluid of the present invention.

[0106] This HDO / ISO process is carried out on crude biofeed, also called biomass or bio-based raw material, selected from the group formed by vegetable oils, animal fats, fish oils and mixtures thereof. Suitable bio-based raw materials are, for example, rapeseed oil, canola oil, tallow, sunflower oil, soybean oil, hemp oil, olive oil, flax oil, mustard oil, palm oil, groundnut oil, castor oil, coconut oil, animal fats such as tallow, recycled food fats, raw materials from genetic engineering, and biological raw materials produced from microorganisms such as algae and bacteria. Condensation products, esters and other derivatives obtained from crude biological materials can also be used as raw materials.

[0107] Preferably, the bio-based feedstock is an ester or triglyceride derivative. This material is first subjected to a hydrodeoxygenation step (HDO) to break down the constituent ester or triglyceride structures and remove oxygenated phosphorus and sulfur-containing compounds with simultaneous hydrogenation of the olefinic bonds. This 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 paraffins.

[0108] In the HDO process, hydrogen and the bio-based feedstock are passed simultaneously or countercurrently through a catalytic hydrodeoxygenation bed. In the HDO process, the pressure and temperature are between 20 bar and 150 bar, and between 200° C. and 500° C., respectively. Known conventional hydrodeoxygenation catalysts are used in this process. Optionally, the bio-based feedstock can be subjected to a pre-hydrogenation under mild conditions to prevent secondary reactions of the double bonds before the HDO process. After the hydrodeoxygenation process, the product resulting from the reaction is subjected to an isomerization process (ISO), whereby a mixture of hydrogen, products and optionally n-paraffins is passed simultaneously or countercurrently through an isomerization catalyst bed. In the ISO process, the pressure and temperature are between 20 bar and 150 bar, and between 200° C. and 500° C., respectively. Known conventional isomerization catalysts are used in this process.

[0109] Additional secondary processes may also be performed (eg, intermediate mixing, entrapment or other similar processes).

[0110] The product obtained from the HDO / ISO process can be optionally fractionated to obtain the fraction of interest.

[0111] 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 operated in countercurrent. Patent application EP1728844 describes a process for producing hydrocarbon compounds from a mixture of compounds of vegetable 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 producing a hydrocarbon mixture that can be used as diesel or in a diesel oil composition by hydrodeoxygenation of a biomixture, optionally containing free fatty acids, for example fatty acid esters, in a mixture with vegetable oils, for example sunflower oil, rapeseed oil, canola oil, palm oil or pine oil, followed by hydroisomerization over a specific catalyst. Patent application EP2368967 describes the process and the products obtained with this process.

[0112] Advantageously, the biobased feedstock contains less than 15 ppm, preferably less than 8 ppm, more preferably less than 5 ppm, even more preferably less than 1 ppm sulfur according to standard EN ISO 20846. Ideally, the feed is sulfur-free as the biobased feedstock.

[0113] The deoxygenated and isomerized feed resulting from the HDO / ISO process is then optionally fractionated and then hydrogenated to obtain the desired boiling range.

[0114] Preferably, the hydrogenation process is a catalytic hydrogenation process of a bio-based, deoxygenated and isomerized feed (or fraction) at a temperature of 80-180° C. and a pressure of 50-160 bar.

[0115] The hydrogen used in the hydrogenation unit is typically high purity hydrogen, meaning hydrogen having a purity greater than, for example, 99%, even though other grades may also be used.

[0116] The hydrogenation step is carried out using a catalyst. Standard hydrogenation catalysts may be solid or supported and may include the following metals: nickel, platinum, palladium, rhenium, rhodium, nickel tungstate, nickel-molybdenum, molybdenum, cobalt-molybdenum. The support may be silica, alumina, silica-alumina, or a zeolite.

[0117] One preferred catalyst is preferably 100 to 200 m 2 The hydrogenation conditions are typically: nickel on an alumina support with a specific surface area ranging from 0.1 to 1000000 / g; or a solid nickel catalyst. - pressure: 50-160 bar, preferably 80-150 bar, more preferably 90-120 bar; - temperature: 80-180°C, preferably 120-160°C, more preferably 150-160°C; - Liquid hourly space velocity (LHSV): 0.2-5 hr-1, preferably 0.4-3 hr-1, more preferably 0.5-0.8 hr-1; - Hydrotreating rate: Compliant with the above conditions and possibly ranging up to 200Nm3 / tonne of feed to be treated.

[0118] The temperature in the reactor is typically between 150-160°C at a pressure of about 100 bar, the liquid hourly space velocity is about 0.6 hr-1, and the process rate is adjusted depending on the quality of the feed being processed and the parameters of the first hydrogenation reactor.

[0119] The hydrogenation can be carried out in one or more reactors in series. The reactors can contain one or more catalyst beds. The catalyst beds are generally fixed catalyst beds.

[0120] The hydrogenation process preferably comprises two or three reactors, preferably three reactors, and is preferably carried out in three reactors in series.

[0121] The first reactor allows for the capture of sulfur-containing compounds and the hydrogenation of essentially all unsaturated compounds up to about 90% by weight of the aromatic compounds. The product resulting from the first reactor is substantially free of sulfur compounds. In the second stage, i.e., the second reactor, the hydrogenation of aromatics continues, so that up to 99% by weight of the aromatics are hydrogenated.

[0122] The third stage in the third reactor is a finishing stage in which an aromatics content of less than 100 ppm, preferably less than 50 ppm, more preferably less than 20 ppm is obtained.

[0123] It is possible to use reactors containing two, three or more catalyst beds. The catalysts can be used in different or essentially equal amounts in each reactor. For example, for three reactors, the amounts as a function of weight can 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.

[0124] Instead of three hydrogenation reactors it is also possible to use one or two hydrogenation reactors.

[0125] It is also possible that the first reactor can be a twin reactor, which is used alternately. This mode of operation makes it possible in particular to facilitate the loading and unloading of the catalyst: if the first reactor contains a first saturated catalyst (substantially all the sulfur is trapped on and / or in the catalyst), it often has to be changed.

[0126] A single reactor containing two, three or more catalyst beds can also be used.

[0127] To control the temperature and hydrothermal balance of each reaction, it may be necessary to insert a recycle system or quench boxes between reactors to cool the effluent from one reactor to another or from one catalyst bed to another. In a preferred embodiment, there is no cooling or quench intermediate.

[0128] In one embodiment, the products resulting from the process and / or the separated gases are at least partially recycled in the feed system of the hydrogenation reactor. This dilution contributes to keeping the exothermicity of the reaction within controlled limits, especially in the first stage. Recycling also allows for the exchange of heat prior to the reaction and therefore better control over the temperature.

[0129] The effluent from the hydrogenation unit contains mainly hydrogenation products and hydrogen. Flash separators are used to separate the gas phase effluent, mainly residual hydrogen, from the liquid phase, mainly the hydrogenated hydrocarbon fraction. The process can be carried out using three flash separators, one at high pressure, one at medium pressure, and one at low pressure, very close to atmospheric pressure.

[0130] The gaseous hydrogen collected at the top of the flash separator can be recycled to the feed system of the hydrogenation unit or at different levels within the hydrogenation unit between the reactors.

[0131] In one embodiment, the final product is separated at atmospheric pressure. It is then fed directly to a vacuum fractionation unit. Preferably, fractionation is carried out at a pressure between 10 and 50 mbar, more preferably at about 30 mbar.

[0132] Fractionation can be carried out such that various hydrocarbon fluids can be removed simultaneously from the fractionation column and their boiling points can be predetermined.

[0133] Thus, by adapting the feed through its initial and final boiling point, the hydrogenation reactor, the separator and the fractionation unit can be directly connected without the need to use intermediate tanks. This integration of hydrogenation and fractionation allows for a reduction in the number of items of equipment and an optimized heat integration associated with energy savings.

[0134] Thus, in one embodiment of the present invention, the hydrocarbon fluid used in the present invention is obtained by a process comprising a catalytic hydrogenation step of hydrodeoxygenated and hydroisomerized biomass, said hydrogenation step being carried out at a temperature in the range of 80-180°C and a pressure in the range of 50-160 bar, preferably at a temperature in the range of 120-160°C and a pressure in the range of 80-150 bar, more preferably at a temperature in the range of 150-160°C and a pressure in the range of 90-120 bar.

[0135] In one particular embodiment, the hydrocarbon fluid used in the present invention is - a step of hydrodeoxygenation of the biomass followed by a step of hydroisomerization to obtain a hydrodeoxygenated and hydroisomerized biomass, - a catalytic hydrogenation step of the hydrodeoxygenated and hydroisomerized biomass, said hydrogenation step being carried out at a temperature in the range of 80-180°C and a pressure in the range of 50-160 bar, preferably at a temperature in the range of 120-160°C and a pressure in the range of 80-150 bar, more preferably at a temperature in the range of 150-160°C and a pressure in the range of 90-120 bar.

[0136] The biomass is preferably selected from among vegetable oils, animal fats, fish oils and mixtures thereof.

[0137] The hydrocarbon fluids used in the present invention ideally result from the processing of bio-based feedstocks. The term "biogenic carbon" or "bio-based carbon" indicates that the carbon is of natural origin and derived from living materials as described below. Bio-based carbon content, biogenic carbon content and bio-material content are expressions that indicate the same value. Materials from renewable sources or bio-materials are organic materials whose carbon is derived from atmospheric CO2 recently fixed (at the human scale) via photosynthesis. Bio-materials (100% bio-based carbon) are organic materials with a carbon content of 100% or more. -12 Higher, typically around 1.2x10 -12 of 14 C / 12 C isotope ratio, but the ratio in fossil materials is 0. Isotopes formed in the atmosphere 14 C is integrated by photosynthesis on time scales of several decades or less. 14 The half-life of C is 5730 years. Therefore, materials derived from photosynthesis, i.e. plants in general, are necessarily 14 It has the highest content of C isotope.

[0138] Additives In one embodiment, the composition used as a cooling fluid includes, in addition to the hydrocarbon fluid, one or more additives.

[0139] Among the additives which may be used there may be mentioned antioxidants, flame retardants and mixtures thereof.

[0140] In one embodiment, the composition includes at least one flame retardant additive. The flame retardant additive can be selected from halogenated compounds, phosphorus compounds, metal hydroxides, and mixtures thereof.

[0141] In one embodiment, the flame retardant additive satisfies formula (I): RF-L-RH(I) During the ceremony, RF is a hydrocarbon radical having in particular 1 to 22, preferably 1 to 20 and more preferably 1 to 16 carbon atoms, RH is a hydrocarbon radical having in particular 1 to 22, preferably 1 to 20 and more preferably 1 to 16 carbon atoms, - L is a linker selected from the following group: -CH2-, -CH=CH-, -O-, -S- or -PO4-, RF and / or RH may also contain at least one element, preferably selected from among the elements of the halogen class, such as fluorine, bromine and / or chlorine.

[0142] In one embodiment, the composition does not include perfluorooctyl bromide.

[0143] When used in the composition, the flame retardant(s) preferably comprises from 0.01 to 20% by weight of the composition, preferably from 1 to 10% by weight of the composition.

[0144] In one embodiment, the composition comprises at least one antioxidant additive.Antioxidant additives generally allow the delayed decomposition of the composition during use.This decomposition can be specifically interpreted as the formation of deposits, the presence of sludge, or an increase in the viscosity of the composition.

[0145] The antioxidant additives act, in particular, as radical inhibitors or hydroperoxide decomposers. Among the antioxidants routinely used, mention may be made of phenol-type antioxidant additives, amine-type antioxidant additives, and sulfur-phosphorus antioxidant additives. Some of these antioxidant additives, such as those containing sulfur and phosphorus, may generate ash. The phenol-based antioxidant additives may be ashless or in the form of neutral or basic metal salts. The antioxidant additives are, in particular, sterically hindered phenols, esters of sterically hindered phenols, and sterically hindered phenols containing thioether bridges, diphenylamines, esters of sterically hindered phenols, and esters of sterically hindered phenols containing thioether bridges, diphenylamines, ... diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenylamines, diphenyl 12 The amine may be selected from among alkyl substituted diphenylamines, alkyl substituted diphenylamines, and mixtures thereof.

[0146] In one embodiment, the sterically hindered phenol has at least one C-C vicinal carbon to the carbon atom bearing the alcohol functional group. 10 It is selected from among compounds containing a phenol group substituted with an alkyl group, preferably a C1-C6 alkyl group, preferably a C4 alkyl group, preferably a tert-butyl group.

[0147] Amine compounds are another class of antioxidant additives that can be optionally used in combination with the phenolic antioxidant additives. Examples of amine compounds are aromatic amines, such as those of the formula NR 4 R 5 R 6 wherein R 4 is an optionally substituted aliphatic or aromatic group; R 5 is an optionally substituted aromatic group, R 6 is a hydrogen atom, an alkyl group, an aryl group or a group of the formula R 7 S(O)zR 8 where R 7 is an alkylene or alkenylene group, R 8 is an alkyl group, an alkenyl group, or an aryl group, and z is 0, 1, or 2.

[0148] Sulfurized alkylphenols or their alkali or alkaline earth metal salts can also be used as antioxidant additives.

[0149] Another class of antioxidant additives includes copper-containing compounds such as copper thio- or dithio-phosphates, salts of copper and carboxylic acids, copper dithiocarbamates, sulfonates, phenates, and acetylacetonates. Copper I and II salts, and salts of succinic acid or anhydride can also be used.

[0150] When used in the composition, the antioxidant(s) preferably comprise from 0.01 to 3% by weight of the composition, preferably from 0.05 to 2% by weight of the composition.

[0151] Uses of the Hydrocarbon Fluid or Composition: The hydrocarbon fluid or composition is used as a cooling fluid via direct immersion, particularly via direct immersion of data center equipment.

[0152] Preferably, the cooling is via single-phase direct immersion, in other words, the hydrocarbon fluid (or composition) typically does not undergo a phase change during the cooling process.

[0153] An example of equipment in a data center is a server, specifically a computer that contains a microprocessor.

[0154] In one embodiment, the present invention relates to the use as a cooling fluid via direct immersion of a composition comprising 80-100% by weight of a hydrocarbon fluid relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of a hydrocarbon fluid comprising at least 90% by weight of isoparaffins relative to the total weight of the hydrocarbon fluid and less than 50 ppm by weight of aromatics, said hydrocarbon fluid having a 28 day biodegradability measured according to standard OECD 301B of 60% or more, said hydrocarbon fluid having an initial and final boiling point within the range of 200-400°C, preferably 240-350°C, more preferably 250-340°C.

[0155] In one embodiment, the present invention relates to the use as a cooling fluid via direct immersion of a composition comprising 95-100% by weight of a hydrocarbon fluid relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of a hydrocarbon fluid comprising at least 90% by weight of isoparaffins relative to the total weight of the hydrocarbon fluid and less than 100 ppm by weight of aromatics, said hydrocarbon fluid having a 28 day biodegradability measured according to standard OECD 301B of 60% or more, said hydrocarbon fluid having an initial and final boiling point within the range of 200-400°C, preferably 240-350°C, more preferably 250-340°C.

[0156] In one embodiment, the present invention relates to the use as a cooling fluid via direct immersion of a composition comprising 98-100% by weight of a hydrocarbon fluid relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of a hydrocarbon fluid comprising at least 90% by weight of isoparaffins relative to the total weight of the hydrocarbon fluid and less than 100 ppm by weight of aromatics, said hydrocarbon fluid having a 28 day biodegradability measured according to standard OECD 301B of 60% or more, said hydrocarbon fluid having an initial and final boiling point within the range of 200-400°C, preferably 240-350°C, more preferably 250-340°C.

[0157] In one embodiment, the invention relates to the use as a cooling fluid via direct immersion of items of equipment in a data center of a composition comprising 80-100% by weight of a hydrocarbon fluid relative to the total weight of the composition, said hydrocarbon fluid comprising at least 90% by weight of a hydrocarbon fluid comprising at least 90% by weight of isoparaffins relative to the total weight of the hydrocarbon fluid and less than 50 ppm by weight of aromatics, said hydrocarbon fluid having a 28 day biodegradability of at least 60% measured according to standard OECD 301B.

[0158] Cooling System A further subject of the present invention is a system for cooling at least one item of equipment via direct immersion, comprising: a bathtub comprising the composition defined in the present invention, - at least one item of said equipment is partially or completely immersed in the composition;

[0159] Immersion may be full immersion where the entire volume of the item of equipment is immersed in the hydrocarbon fluid.

[0160] Immersion may be partial if the entire volume of the item of equipment is not immersed in the hydrocarbon fluid, but only a portion of it.

[0161] Preferably, the items of equipment being cooled are equipment in a data center, such as servers or computers.

[0162] The composition comprising the hydrocarbon fluid may be static or may be circulating within the cooling system.

[0163] The cooling system may further comprise a heat exchange system in which cooling liquid heated by the equipment in the bath is cooled before being returned to the bath.

[0164] In one embodiment, the hydrocarbon fluid or composition can then be placed in circulation between a bath containing at least one item of equipment to be cooled and the heat exchange system.

[0165] The heat exchange system can be connected to a water or air circuit, the water or air allowing cooling of the hydrocarbon fluid or composition before it is returned to the bath, ensuring its cooling function.

[0166] Circulation of the cooling fluid may be achieved by a pump system.

[0167] The heat recovered from the composition comprising the hydrocarbon fluid during heat exchange can optionally be recovered and used, for example, to heat a building.

[0168] Cooling method A further subject of the present invention is a method for cooling at least one item of equipment via direct immersion, comprising a step of completely or partially immersing said at least one item of equipment in a composition as defined in the present invention.

[0169] Typically, the composition is placed in a bath and the item of equipment is fully or partially immersed in the composition within the bath.

[0170] Preferably, the items of equipment being cooled are equipment in a data center, such as servers or computers.

[0171] The cooling method of the present invention can be implemented in the cooling system of the present invention.

[0172] The cooling method of the present invention may further comprise a step of cooling the composition heated by immersion of the equipment in the bath. This step of cooling the composition may be carried out by a heat exchanger and a water or air circuit outside the bath. In one embodiment, after the step of cooling the composition, the method of the present invention may further comprise a step of recovering heat originating from the composition, which is optionally used, for example, to heat a building. EXAMPLES

[0173] In the remainder of the specification, examples are given to illustrate the invention and are not intended to limit its scope in any way.

[0174] According to the method described in this invention, three hydrocarbon streams were prepared by HDO / ISO of biomass followed by a hydrogenation step.

[0175] Table 1 summarizes the physicochemical properties of the hydrocarbon fluids. [Table 1]

[0176] The following standards and methods were used to measure the above properties: - Flash point EN ISO 2719; - Density at 15°C: EN ISO 1185; - Pour point: EN ISO 3016; - Viscosity at 40°C: EN ISO 3104; - Boiling point: ASTM D86; - Biodegradability: OECD 301B method; - Pour point: ASTM D5950.

[0177] The specific heat was measured using a DSC calorimeter (DSC NETZSCH 204 Phoenix) 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.

[0178] The thermal conductivity was determined in the following manner.

[0179] A device was used that consisted of two aluminum tubes, an inner and an outer one. The fluid to be measured was placed in the annular space between the two tubes. Pulsed energy (Dirac type) was applied to the inner tube and the temperature was measured in the outer tube to obtain a thermogram.

[0180] Knowing the thermal diffusivity, density and specific heat of the two layers of the two aluminum tubes as a function of temperature, and knowing the density and specific heat of the fluid being analyzed, it is possible to deduce the thermal conductivity of the fluid as a function of temperature.

[0181] First, the instrument is calibrated at different temperatures using a reference sample, SERIOLA 1510 (heat transfer fluid). Different thermal properties were previously measured separately.

[0182] The sample (the 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.

[0183] For each temperature measurement, the procedure is as follows: The sample is stabilized at a given temperature A light flash is applied to the inner surface of the inner tube and the temperature rise on the outer surface of the outer tube is recorded over time.

[0184] Thermal conductivity can be calculated based on the average value of at least three measurements at each given temperature.

[0185] Tests were carried out to compare the oxidative stability properties of the fluids of the present invention with those of fluids according to WO 2022 / 038313.

[0186] The fluids tested were: - Fluid 3 of Table 1, - Fluid CC1 obtained by HDO / ISO of biomass having a boiling range of 190-310 °C, an isoparaffin content of 95% by weight and an aromatics content of 600 ppm, as described in WO 2022 / 038313.

[0187] Applying standard ASTM D2272, tests were carried out on compositions containing 99.5% by weight of a fluid (either Fluid 3 or Fluid CC1) and 0.5% by weight of BHT as antioxidant (RPVOT test).

[0188] The results are as follows: - fluid 3=465 minutes, - Fluid CC1=315 minutes.

[0189] These results demonstrate that the fluids of the present invention exhibit much better oxidative stability than the prior art fluids.

[0190] In summary, hydrocarbon fluids exhibit excellent thermal properties and have a very low aromatics content, which means that they are particularly advantageous for cooling equipment in data centers via direct immersion. The very low aromatics content improves aging and provides better resistance to aging, which is most useful in this type of application where the same fluid can be used for 5 or even 10 years, and reduces or even eliminates the aggressiveness of the fluid, thereby improving operator safety of the fluid.

Claims

1. 1. Use of a composition comprising 80-100% by weight of a hydrocarbon fluid relative to the total weight of the composition as a cooling fluid via direct immersion, 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 said hydrocarbon fluid, said hydrocarbon fluid having a 28 day biodegradability measured according to standard OECD 301B of 60% or more.

2. 10. The use of claim 1, wherein the composition is used as a cooling fluid via direct immersion of items of equipment in a data center.

3. The hydrocarbon fluid comprises, based on a total weight of the hydrocarbon fluid: at least 95% by weight of isoparaffins, and / or - maximum 5% by weight of normal paraffins, and / or max. 1% by weight of naphthenes, and / or - less than 50 ppm by weight of aromatics 3. The use according to claim 1 or 2, comprising:

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

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

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

7. 7. Use according to any of the preceding claims, wherein the composition further comprises from 0.01 to 20% by weight, relative to the total weight of the composition, of an additive, preferably chosen among antioxidants, flame retardants and mixtures thereof, preferably among antioxidants.

8. 1. A cooling system via direct immersion, comprising: a bathtub comprising a composition comprising 80-100% 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 said hydrocarbon fluid, said hydrocarbon fluid having a 28-day biodegradability measured according to standard OECD 301B of at least 60%; at least one item of equipment that is cooled and partially or completely immersed in said composition; A cooling system comprising:

9. The cooling system of claim 8 , wherein the item of equipment being cooled is equipment in a data center.

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

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

12. 1. A method for cooling via direct immersion, comprising the step of fully or partially immersing at least one item of equipment to be cooled in a composition comprising 80-100% 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 said hydrocarbon fluid, said hydrocarbon fluid having a 28 day biodegradability measured according to standard OECD 301B of 60% or more by weight of total carbon atoms.

13. The method of cooling of claim 12 , wherein the item of 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 a composition as defined in claim 6 or claim 7.

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