Cooling liquid for direct immersion in single-phase liquids

Abstract

Use of a renewable paraffinic composition for single-phase direct liquid immersion cooling, comprising at least 80 wt-% paraffins in the C16 to C19 range. A single-phase direct liquid immersion cooling system and method for single-phase direct liquid immersion cooling are also disclosed.

Description

[Technical Field]

[0001] This disclosure generally relates to single-phase liquid direct immersion cooling. This disclosure is not limited to, but also relates to the use of renewable paraffinic compositions for single-phase liquid direct immersion cooling. [Background technology]

[0002] This section provides useful background information and does not assume that any technology described herein is representative of the prior art.

[0003] In recent years, an unprecedented amount of data has been created, much of which is stored in data centers housing computer systems and related components. Traditionally, these computer systems have been cooled using air cooling or air circulation. Approximately 40% of the energy consumption of data centers is due to air-cooled electronic equipment, and the carbon footprint of data centers is estimated to be larger than that of the aviation industry.

[0004] In recent years, liquid cooling has begun to be used as an alternative to air cooling in data centers. It is estimated that replacing air cooling with liquid cooling can lead to significant reductions in both cost and energy consumption. Furthermore, liquid cooling is thought to be able to support a larger power load per rack compared to air cooling.

[0005] The main liquid cooling options are two-phase liquid cooling and single-phase liquid cooling.

[0006] In two-phase liquid cooling, the cooling liquid has a boiling point below or at the operating temperature, so the liquid evaporates, thereby maintaining its temperature at its boiling point. The resulting gas phase is cooled by the liquid and returned to the cooling liquid.

[0007] In single-phase liquid cooling, the coolant does not undergo a phase change. Single-phase cooling can be either single-phase direct cooling or single-phase indirect cooling. In single-phase indirect cooling, the coolant does not come into contact with any computer system or related components, whereas in single-phase liquid direct cooling (often referred to as single-phase liquid direct immersion cooling), the computer hardware is directly immersed in the coolant, and therefore the coolant comes into contact with the hardware.

[0008] Single-phase direct liquid cooling is simpler and less expensive than two-phase or indirect liquid cooling. However, the cooling liquid's impact on computer hardware can be significant. Many uncertainties and concerns exist regarding the effects of the cooling liquid on computer hardware, hindering the widespread adoption of single-phase direct liquid cooling systems in data centers.

[0009] However, several cooling liquids have been proposed for single-phase direct cooling. These liquids are mainly perfluorocarbon liquids, such as those sold under brands like 3M® Fluorinert® and 3M® Novec®, for example, 3M® Fluorinert® FC-40, FC-72, and FC-770. These liquids have several desirable properties, such as inertness and stability. However, several drawbacks have also been identified. For example, fluorocarbon compounds are very potent greenhouse gases and are known to persist in nature. Therefore, the disposal of these liquids, and components immersed in them, can pose challenges. Furthermore, these fluorine compounds form hydrogen fluoride (HF) upon combustion, which poses a real danger, for example, in the case of a fire in a data center facility. [Overview of the Initiative]

[0010] It is an object to solve or mitigate at least some of the problems associated with conventional single-phase liquid direct cooling. In particular, the object is to provide a more environmentally sustainable and climate-friendly single-phase liquid direct immersion cooling.

[0011] The appended claims define the scope of protection.

[0012] In a first aspect, there is provided the use of a renewable paraffin-based composition for single-phase liquid direct immersion cooling, comprising paraffin in the range of C16 - C19 of at least 80 wt-% based on the total weight of the renewable paraffin composition.

[0013] In a second aspect, a tank comprising a renewable paraffin-based composition comprising paraffin in the range of C16 - C19 of at least 80 wt-% based on the total weight of the renewable paraffin composition, and an object to be immersion-cooled in the renewable paraffin composition is provided with a single-phase liquid direct immersion cooling system.

[0014] In a third aspect, providing a tank comprising a renewable paraffin-based composition comprising paraffin in the range of C16 - C19 of at least 80 wt-% based on the total weight of the renewable paraffin composition, and immersing an object to be cooled in the renewable paraffin composition is provided with a method for single-phase liquid direct immersion cooling.

[0015] Some exemplary embodiments will be described with reference to the accompanying drawings.

Brief Description of the Drawings

[0016] [Figure 1] FIG. 1 is a schematic diagram of a single-phase liquid direct immersion cooling system according to an exemplary embodiment. [Figure 2a]Figure 2a) shows a schematic diagram of the test setup for Example 2 and a photograph of the test setup for Example 2 in use, respectively. [Figure 2b] Figure 2b) shows a schematic diagram of the test setup for Example 2 and a photograph of the test setup for Example 2 in use, respectively. [Figure 3a] Figure 3a) shows photographs of the motherboard piece before and after immersion in test T1. [Figure 3b] Figure 3b) shows photographs of the motherboard piece before and after immersion in test T1, respectively. [Figure 3c] Figure 3c) shows photographs of the motherboard piece before and after immersion in test T2. [Figure 3d] Figure 3d) shows photographs of the motherboard piece before and after immersion in test T2. [Figure 3e] Figure 3e) shows photographs of the motherboard piece before and after immersion in test T3. [Figure 3f] Figure 3f) shows photographs of the motherboard piece before and after immersion in test T3. [Figure 3g] Figure 3g) shows photographs of the motherboard piece before and after immersion in test T4, respectively. [Figure 3h] Figure 3h) shows photographs of the motherboard piece before and after immersion in test T4, respectively. [Figure 3i] Figure 3i) shows photographs of the motherboard piece before and after immersion in test T5, respectively. [Figure 3j] Figure 3j) shows photographs of the motherboard piece before and after immersion in test T5, respectively. [Figure 3k] Figure 3k) shows photographs of the motherboard piece before and after immersion in test T6. [Figure 3l]Figure 3l) shows photographs of the motherboard piece before and after immersion in test T6. [Figure 4a] Figure 4a) shows photographs of the RAM boards before and after immersion in P2 and FC-40, respectively. [Figure 4b] Figure 4b) shows photographs of the RAM boards before and after immersion in P2 and FC-40, respectively. [Figure 4c] Figure 4c) shows photographs of the RAM boards before and after immersion in P2 and FC-40, respectively. [Figure 4d] Figure 4d) shows photographs of the RAM boards before and after immersion in P2 and FC-40, respectively. [Figure 5] Figure 5 shows the distillation curves for P2 and FC-40. [Figure 6a] Figure 6a) shows the viscosity coefficients of P2, FC-40, and S5X as functions of temperature within the temperature range of 15°C to 50°C. The solid line represents the simulated value, and the dots represent the measured value. [Figure 6b] Figure 6b) shows the densities of P2, FC-40, and S5X as functions of temperature within the temperature range of 15°C to 50°C, with solid lines representing simulated values ​​and dots representing measured values. [Figure 6c] Figure 6c) shows the specific heat capacity (mass heat capacity) of P2, FC-40, and S5X as a function of temperature within the temperature range of 15°C to 50°C. The solid line represents the simulated value, and the dots represent the measured value. [Figure 6d] Figure 6d) shows the thermal conductivity of P2, FC-40, and S5X as a function of temperature within the temperature range of 15°C to 50°C. The solid line represents the simulated value, and the dots represent the measured value. [Figure 7] Figure 7 is a schematic diagram of the flow sheet used in the data center cooling simulation of Example 4. [Modes for carrying out the invention]

[0017] Alkanes and paraffins are generally known to be synonymous and interchangeable. In the context of this disclosure, paraffins or paraffins(plural) mean isoparaffins and / or n-paraffins. Isoparaffins (i-paraffins) are branched, open-chain paraffins, while normal paraffins (n-paraffins) are unbranched, straight-chain paraffins. In other words, in this specification, the terms paraffins or paraffins(plural) refer to acyclic paraffins.

[0018] In one embodiment, the isoparaffin has one or more C1-C9, typically C1-C2, alkyl side chains. Preferably, the side chains are methyl side chains, and the isoparaffin is mono-, di-, tri- and / or tetra-methyl substituted.

[0019] In the context of this disclosure, the boiling point range covers the temperature interval from the initial boiling point (IBP), defined as the temperature at which the first drop of the distillation product is obtained, to the final boiling point (FBP), at which the compound with the highest boiling point evaporates.

[0020] The EN ISO 3405:2011 and ASTM D86:2015 standards, “Standard test method for distillation of petroleum products at atmospheric pressure,” and the ASTM D7345:2017 standard, “Standard test method for distillation of petroleum products at atmospheric pressure (micro-distillation method),” describe a distillation method for measuring the boiling point distribution of liquid fuel products having a boiling point range of 0°C to 400°C (ASTM D7345: 20°C to 400°C). Using ASTM D86 or ASTM D7345, the boiling point is measured in 25 vol-% distillation. The boiling point may also be shown in 88% distillation. This method is suitable for measuring the boiling point distribution of the renewable paraffinic compositions of this disclosure.

[0021] All standards referred to herein are the latest revisions available unless otherwise noted.

[0022] As used herein, “hydrotreatment” means a catalytic process of an organic material by means of any molecular hydrogen. Preferably, the hydrogenation is the removal of oxygen from an oxygen-containing organic compound as water, i.e., deoxygenation (HDO). Additionally / alternatively, the hydrogenation may be the removal of sulfur from a sulfur-containing organic compound as hydrogen sulfide (H2S), i.e., desulfurization (HDS), the removal of nitrogen from a nitrogen-containing organic compound as ammonia (NH3), i.e., denitrification (HDN), and / or the removal of a halogen, for example, the removal of chlorine from a chlorine-containing organic compound as hydrochloric acid (HCl), i.e., dechlorination (HDCl).

[0023] For example, the term "hydrogenated deoxygenation (HDO)" of triglycerides or other fatty acid derivatives or fatty acids, in the context of this disclosure, means, for example, the removal of oxygen as water, such as oxygen from a carboxyl group, by means of molecular oxygen, in the presence of a catalyst.

[0024] In the context of this disclosure, the term "deoxygenation" means the removal of oxygen from organic molecules, such as fatty acid derivatives, alcohols, ketones, aldehydes, and / or ethers, by any of the means described above, or by decarboxylation or decarbonylation.

[0025] This disclosure provides the use of a recyclable paraffin-based composition as a cooling liquid for single-phase liquid direct immersion cooling (in single-phase liquid direct immersion cooling), or for single-phase liquid direct immersion cooling (in single-phase liquid direct immersion cooling), comprising at least 80 wt-% paraffin in the C16-C19 range, based on the total weight of the recyclable paraffin composition. The recyclable paraffin-based composition is maintained in liquid form over a wide temperature range and may therefore also be referred to as a recyclable paraffin-based liquid.

[0026] Surprisingly, it has been found that renewable paraffin-based compositions containing at least 80 wt-% paraffin in the C16-C19 carbon range are particularly suitable for single-phase liquid direct immersion cooling. At least 80 wt-% paraffin in the C16-C19 range simultaneously imparts a high flash point and low kinematic viscosity to the renewable paraffin-based composition, which cannot be achieved by compositions primarily containing lighter and / or heavier paraffin. The high flash point improves safety, and the low kinematic viscosity facilitates the cooling liquid's circulation through all parts of the object being cooled, reaching even its very small cavities (essentially all outer surfaces of the object being cooled), thus improving heat exchange between the object being cooled and the cooling liquid. When the cooling liquid can reach essentially all outer surfaces of the object being cooled, including very small cavities, the formation of localized hot spots is reduced, and even if localized hot spots do appear, rapid cooling of those hot spots is possible. A further advantage of containing a high amount of paraffin in the C16-C19 range is that such a cooling liquid is stable, non-toxic, non-corrosive, and does not form CO and CO2 when burned, for example in the event of a fire in operating equipment. CO and CO2 are far less dangerous than HF formed when conventional fluorocarbon liquids are burned. Furthermore, C16-C19 paraffin is classified as readily biodegradable according to OECD Test Guideline 301F, which is advantageous over conventional fluorocarbon liquids, for example, which are virtually non-biodegradable. In addition, the renewable paraffin-based composition of the present invention has a relatively low density, which facilitates the circulation or pumping of the renewable paraffin-based composition in the cooling system, which is advantageous for reducing power consumption, for example. Furthermore, the relatively low density reduces the weight of the tank containing the renewable paraffin-based composition, which facilitates stacking of immersion cooling tanks on top of each other, for example.The relatively low density is also advantageous in embodiments where the cooling liquid is not circulated through a heat exchange unit, but the immersion tank is configured to contain a sufficient amount of renewable paraffinic composition to enable cooling without circulation through a heat exchange unit. Surprisingly, renewable paraffinic compositions containing at least 80 wt-% paraffin in the C16-C19 carbon range have been found to have beneficial thermal conductivity and thermal absorption properties and are therefore particularly suitable for single-phase liquid direct immersion cooling. Beneficial thermal conductivity, as used herein, means rapid thermal conduction, and beneficial thermal conductivity properties are indicated, for example, by high thermal conductivity and / or high thermal diffusivity. Cooling liquids with beneficial thermal absorption properties can absorb more heat without the cooling liquid temperature rising too much, and beneficial thermal absorption properties are indicated, for example, by high volumetric heat capacity and / or mass heat capacity.

[0027] In one embodiment, the renewable paraffin-based composition contains 90 wt-% or more, preferably 95 wt-% or more, and more preferably 98 wt-% or more of paraffin in the C16-C19 range, based on the total weight of the renewable paraffin-based composition. The aforementioned advantages associated with the high amount of C16-C19 paraffin are particularly pronounced for these compositions. Furthermore, renewable paraffin-based compositions containing 90 wt-% or more of paraffin in the C16-C19 range are particularly stable, especially when compared to compositions containing significant amounts of olefins, such as ester-based or glyceride-based compositions. The high content of acyclic paraffin also ensures a low oxygen content in the renewable paraffin-based composition. Significant oxygen content in single-phase liquid direct immersion quenching solutions can lead to increased acidity and sludge formation, which can be detrimental to the immersed object and / or single-phase liquid cooling systems, and sludge formation can hinder efficient heat exchange, especially if the sludge accumulates or forms on the immersed object being cooled.

[0028] In one embodiment, the use of a recyclable paraffin-based composition involves circulating the recyclable paraffin-based composition through a heat exchange unit. The heat exchange unit is not particularly limited and can be any heat exchange unit suitable for cooling the recyclable paraffin-based composition. Preferably, the heat exchange unit is configured to cool the recyclable paraffin-based composition.

[0029] In one embodiment, the use of a renewable paraffin-based composition is for single-phase liquid direct immersion cooling of electronic hardware, preferably computer hardware, more preferably servers, or for single-phase liquid direct immersion cooling of fuel cells. In single-phase liquid direct immersion cooling of electronic hardware, the renewable paraffin-based composition is in direct contact with the electronic hardware immersed therein. Similarly, in single-phase liquid direct immersion cooling of fuel cells, the fuel cell or fuel cell stack is directly immersed in the renewable paraffin-based composition. Fuel cells are an environmentally friendly energy source, and the present invention provides the use of an environmentally friendly coolant for single-phase liquid direct immersion cooling of fuel cells.

[0030] Remarkably, the renewable paraffin-based compositions of the present invention are compatible with electronic hardware, particularly high-precision computer hardware such as servers. Computer hardware often includes a variety of materials and components, including, for example, epoxy resins, polyvinyl chloride and / or other plastics, fiberglass, various metals such as steel and aluminum, copper wiring, printed circuit boards, transistors, capacitors, resistors, microprocessors, motherboards, RAM boards and / or marking dyes. Remarkably, as shown in the examples, direct immersion of computer hardware in the renewable paraffin-based compositions of the present invention has been found not to cause leaching of the computer hardware or any other effects or harm. The examples demonstrate that after immersion in the renewable paraffin-based compositions of the present invention, the computer hardware functions normally without failure. Furthermore, the dielectric properties of the paraffin in the renewable paraffin-based compositions are excellent and comparable to those required for single-phase liquid direct immersion cooling of electronic hardware.

[0031] As used herein, electronic devices or hardware and electrical devices are not synonymous. A key difference between electronic and electrical is that electronic refers to decision-making (processing) capabilities, while electrical simply refers to the conversion of electrical energy from one form to another, or the transmission of electrical energy. For example, an electrical circuit may simply use electricity to power a device or machine, whereas an electronic circuit may interpret signals or commands and perform tasks as appropriate. Therefore, electrical devices can be considered passive, while electronic devices can be considered active. These differences in function and performance are naturally reflected in the structure of electronic and electrical devices.

[0032] Typically, electrical equipment is simple and robust in structure, has few or no moving parts, and is often physically larger than electronic equipment. Electronic hardware or devices, on the other hand, are typically very complex systems consisting of numerous small parts made of various materials. Compared to electronic equipment, which tends to operate at relatively low voltages (often DC), electrical equipment typically operates at considerably higher voltages (often AC).

[0033] The typically small size of electronic device components presents a cooling challenge. For example, microprocessors can contain circuit lines that are just a few micrometers thick, and electronic devices can contain wiring that is even nanometer-sized. It is crucial to ensure that all the tiny components of hardware are properly cooled without any damage. Insufficient cooling can even damage delicate electronic components, especially as components become smaller. The trend of the number of transistors in high-density integrated circuits doubling approximately every two years (Moore's Law) continues, while electronic devices are becoming increasingly smaller. Therefore, cooling electronic devices is becoming more difficult, and improved solutions are needed.

[0034] Due to the difference between electrical equipment and electronic equipment, different considerations must be taken when considering direct contact between a liquid and simple electrical equipment compared to when considering direct contact between a liquid and electronic hardware. For example, thermal properties such as heat absorption capacity (mass heat capacity, volumetric heat capacity) and thermal conductivity (thermal conductivity, thermal diffusivity), as well as density, viscosity, and (electrical) conductivity, can be considered important properties of the cooling liquid used in single-phase direct immersion cooling of electronic hardware.

[0035] For example, the operating temperature of single-phase liquid direct immersion cooling for electronic hardware such as computer hardware like servers is typically between room temperature (approximately 20°C) and approximately 65°C. However, under heavy load, the temperature of a computer server can reach approximately 90°C. In ASICS-based cryptographic mining equipment, the temperature can rise to approximately 75°C.

[0036] In one embodiment, the operating temperature of the single-phase liquid direct immersion cooling is within the temperature range of 15°C to 90°C, preferably 15°C to 75°C, and more preferably 20°C to 65°C. These temperatures are particularly advantageous for single-phase liquid direct immersion cooling of computer hardware such as servers, or other electronic hardware.

[0037] Renewable paraffinic compositions, primarily containing paraffins in the C16-C19 range, have a beneficial evaporation profile, meaning they do not essentially evaporate at the aforementioned operating temperatures. This enhances the safety of single-phase liquid direct immersion cooling and allows the use of immersion cooling systems where the coolant liquid is in direct contact with the ambient air. However, renewable paraffinic compositions can also be used in sealed cooling systems.

[0038] In one embodiment, the renewable paraffin composition contains less than 2 wt-% of C15 and lighter paraffins, based on the total weight of the renewable paraffin composition. A low amount of C15 and lighter paraffins is preferable because it provides the renewable paraffin composition with a high flash point. It also provides the renewable paraffin composition with particularly good thermal conductivity and thermal absorption properties.

[0039] In one embodiment, the renewable paraffin-based composition, as measured according to ENISO2719:2016, has a flash point of at least 125°C, preferably at least 135°C, more preferably at least 140°C, and even more preferably at least 145°C. As mentioned above, the operating temperature of single-phase liquid direct immersion cooling of computer hardware such as servers is generally between room temperature and about 65°C, and can rise to about 75°C for ASICS-based crypto mining devices. Under heavy load, the server temperature can reach about 90°C. A high flash point, for example, a flash point of at least 125°C, ensures the safe use of renewable paraffin-based compositions for single-phase liquid direct immersion cooling of computer hardware, for example.

[0040] In one embodiment, the renewable paraffin-based composition was measured at 20°C according to ASTM D7896-19 to 1.60 MJ / (m³). 3 K) ~ 1.90 MJ / (m 3 It has a volumetric specific heat (volume heat capacity) within the range of K). In one embodiment, the renewable paraffin-based composition has a thermal conductivity in the range of 0.11 W / (m·K) to 0.15 W / (m·K), as measured according to ASTM D7896-19 at 20°C. In one embodiment, the renewable paraffin-based composition has a thermal conductivity of 0.06 mm, as measured according to ASTM D7896-19 at 20°C. 2 / s~0.09mm 2 It has a thermal diffusivity in the range of / s. Preferably, the recyclable paraffin-based composition is measured at 20°C according to ASTM D7896-19 and has a thermal diffusivity of 1.60 MJ / (m³). 3 K) ~ 1.90 MJ / (m 3 Volumetric specific heat in the range of K), thermal conductivity in the range of 0.11 W / (m·K) to 0.15 W / (m·K) measured at 20°C according to ASTM D7896-19, and 0.06 mm 2 / s~0.09mm 2It has a thermal diffusivity in the range of 0.06 mm 2 / s to 0.09 mm 2 / s. These properties reflect the performance in single-phase liquid direct immersion cooling of electronic device hardware. High thermal conductivity and high thermal diffusivity enable rapid heat transfer from the immersed object to the cooling liquid. High volumetric specific heat allows the coolant liquid to absorb more heat while increasing the temperature of the coolant liquid less compared to coolant liquids with low volumetric specific heat. In certain embodiments, the renewable paraffinic composition contains less than 2 wt-% of C15 and lighter paraffins based on the total weight of the renewable paraffin composition, and has a flash point of at least 125 °C, preferably at least 135 °C, more preferably at least 140 °C, even more preferably at least 145 °C, measured in accordance with EN ISO 2719:2016, and / or a volumetric specific heat in the range of 1.60 MJ / (m 3 K) to 1.90 MJ / (m 3 K) measured in accordance with ASTM D7896-19 at 20 °C, a thermal conductivity in the range of 0.11 W / (m·K) to 0.15 W / (m·K) measured in accordance with ASTM D7896-19 at 220 °C, and a thermal diffusivity in the range of 0.06 mm 2 / s to 0.09 mm 2 / s. 3 K) to 1.90 MJ / (m 3 K) range of volumetric specific heat, a thermal conductivity in the range of 0.11 W / (m·K) to 0.15 W / (m·K) measured in accordance with ASTM D7896-19 at 220 °C, and a thermal diffusivity in the range of 0.06 mm 2 / s to 0.09 mm 2 / s measured in accordance with ASTM D7896-19 at 20 °C. 2 / s to 0.09 mm 2 / s range of thermal diffusivity.

[0041] In certain embodiments, the renewable paraffinic composition contains paraffins in the range of C16 - C19 of 95 wt-% or more, preferably 98 wt-% or more, based on the total weight of the renewable paraffin composition, and has a flash point of at least 125 °C, preferably at least 135 °C, more preferably at least 140 °C, even more preferably at least 145 °C, measured in accordance with EN ISO 2719:2016, and / or a volumetric specific heat in the range of 1.60 MJ / (m 3 K) to 1.90 MJ / (m 3 K) measured in accordance with ASTM D7896-19 at 20 °C 3 K) to 1.90 MJ / (m 3Volumetric specific heat within the range of K), thermal conductivity in the range of 0.11 W / (m·K) to 0.15 W / (m·K) measured at 220°C according to ASTM D7896-19, and 0.06 mm² measured at 20°C according to ASTM D7896-19. 2 / s~0.09mm 2 It has a thermal diffusivity in the range of / s.

[0042] In one embodiment, the renewable paraffinic composition contains less than 5 wt-%, preferably less than 2 wt-% of C20 and heavier paraffins, based on the total weight of the renewable paraffinic composition. Without being bound by any theory, it is thought that impurities tend to accumulate in heavier (C20 and heavier) hydrocarbon fractions, and therefore, renewable paraffinic compositions containing very small amounts of C20 and heavier paraffins, or having a minimal amount of C20 and heavier paraffins (optionally reduced to substantially 0 wt-%), may contain smaller amounts of impurities that contribute to particularly low (electrical) conductivity, such as less than 1 pS / m at 22°C, such as metallic impurities. Lower amounts of C20 and heavier paraffins result in lower density and kinematic viscosity of the renewable paraffinic composition compared to compositions containing larger amounts of C20 and heavier paraffins.

[0043] Preferably, the renewable paraffin-based composition contains up to 5 ppm by weight of metal, based on the total weight of the renewable paraffin composition.

[0044] Preferably, the water content of the renewable paraffin-based composition is less than 50 ppm by weight, based on the total weight of the renewable paraffin-based composition. The renewable paraffin-based composition of this disclosure has high water repellency. Low water content and high water repellency are beneficial when the renewable paraffin-based composition is used as a coolant liquid in single-phase liquid direct immersion cooling of electronic hardware, as electronic hardware is susceptible to moisture.

[0045] In one embodiment, the renewable paraffin-based composition is measured according to EN ISO 12185 and has a yield of 700-850 kg / m³ at 20°C. 3 Preferably 760-800 kg / m 3 More preferably 770-790 kg / m 3 It has a density within a certain range. These densities are significantly lower than those of conventional fluorocarbon liquids. In other words, a certain volume of the renewable paraffin-based composition in these embodiments has a significantly lower weight or mass than the same volume of conventional fluorocarbon coolant liquid. The advantage of this is that the coolant liquid tanks of the renewable paraffin-based composition in these embodiments can be easily stacked on top of each other (vertically) without requiring expensive and particularly tough materials in the floor or building where the tanks and / or laminated structure and / or laminate are located; for example, two or three tanks can be stacked on top of each other. Stacking the tanks on top of each other saves floor space and allows more objects to be cooled within a given (floor) area. A further advantage of single-phase liquid direct immersion cooling of renewable paraffin-based compositions with relatively low density is, as mentioned above, easier circulation of the coolant liquid.

[0046] In one embodiment, the renewable paraffin-based composition contains less than 5 wt-%, more preferably less than 2 wt-%, of C20 and heavier paraffins, based on the total weight of the renewable paraffin composition, and weighs 850 kg / m³ at 20°C, as measured according to EN ISO 12185. 3 Preferably 800 kg / m 3 More preferably, 790 kg / m 3 It has the following density:

[0047] In one embodiment, the renewable paraffin-based composition contains 90 wt-% or more, preferably 95 wt-% or more, and more preferably 98 wt-% or more of paraffin in the C16-C19 range, based on the total weight of the renewable paraffin composition, and weighs 700-850 kg / m³ at 20°C, as measured according to EN ISO 12185. 3 Preferably 760-800 kg / m 3 More preferably 770-790 kg / m 3 It has a density of .

[0048] In one embodiment, the recyclable paraffin-based composition has a boiling point range of about 270°C to about 325°C, preferably about 275°C to about 320°C, and more preferably about 280°C to about 300°C, as measured according to EN ISO 3405:2011. For example, as measured according to EN ISO 3405:2011, the initial boiling point IBP of the recyclable paraffin-based composition may be about 275°C, preferably about 280°C, and the final boiling point FBP may be about 320°C, preferably about 300°C. In one embodiment, the recyclable paraffin-based composition has a NOACK150 value of 9 wt-% or less, preferably 8.5 wt-% or less, as measured according to ASTM D5800-15aB.

[0049] Renewable paraffinic compositions having high IBP temperature values ​​(e.g., 275°C or higher) and / or low NOACK150 values ​​(e.g., 9 wt-% or lower) contain little to no volatile compounds and at most very low VOC content. This is advantageous compared to conventional perfluorocarbon liquids, which are relatively volatile and can evaporate almost completely during NOACK testing. In other words, the advantage of high IBP temperature and / or low NOACK150 values ​​is that, at operating temperatures such as those mentioned above, there is little to no evaporation of the renewable paraffinic composition. This enhances the safety of single-phase liquid direct immersion cooling, for example in relation to maintenance, and enables the use of single-phase liquid direct immersion cooling systems in which the cooling liquid is in direct contact with the ambient air.

[0050] In one embodiment, the renewable paraffin-based composition comprises 95 wt% or more, preferably 98 wt% or more, of paraffin in the C16-C19 range, based on the total weight of the renewable paraffin-based composition, wherein the initial boiling point IBP of the renewable paraffin-based composition is about 275°C, preferably about 280°C, and the final boiling point FBP is about 320°C, preferably about 300°C, as measured according to EN ISO3405:2011. In one embodiment, the renewable paraffin-based composition comprises 95 wt% or more, preferably 98 wt% or more, of paraffin in the C16-C19 range, based on the total weight of the renewable paraffin-based composition, and the renewable paraffin-based composition has a NOACK150 value of 9 wt-% or less, preferably 8.5 wt-% or less, as measured according to ASTMD5800-15aB.

[0051] In one embodiment, the renewable paraffin-based composition contains less than 10 wt-% olefin, preferably less than 5 wt-% olefin, more preferably less than 2 wt-% olefin, based on the total weight of the renewable paraffin-based composition, and even more preferably the renewable paraffin-based composition is substantially olefin-free. The low olefin content improves the stability of the renewable paraffin-based composition. The low olefin content is also advantageous for ensuring the dielectric behavior of the renewable paraffin-based composition.

[0052] In one embodiment, the recyclable paraffinic composition contains 5 wt-% or less, preferably 2 wt-% or less, of naphthenes based on the total weight of the recyclable paraffinic composition, and more preferably the recyclable paraffinic composition is substantially naphthene-free. Naphthenes in the cooling liquid, particularly a few wt% of naphthenes, can cause the formation of sludge or precipitates (e.g., microcrystalline wax), which can be particularly detrimental to the performance of the immersed object, as well as to single-phase liquid direct immersion cooling systems or their components, such as pumps. Sludge or precipitates can also hinder efficient heat exchange, especially if the precipitate adheres to the object being cooled.

[0053] In one embodiment, the renewable paraffinic composition contains at least 99 wt-% hydrocarbons based on the total weight of the renewable paraffinic composition. In another embodiment, the renewable paraffinic composition contains more than 90 wt-% paraffin, preferably at least 95 wt-% and more preferably at least 98 wt-% paraffin, based on the total weight of the renewable paraffinic composition. A high paraffin content is preferable to improve the stability of the renewable paraffinic composition, particularly when compared to, for example, ester-based or glyceride-based compositions, but also when compared to compositions containing a significant amount of olefins. A high paraffin content also ensures a low oxygen content in the renewable paraffinic composition. A significant oxygen content in the liquid during direct immersion cooling can lead to an increased acid value and sludge formation, as described above. Furthermore, renewable paraffinic compositions with high paraffin content, such as exceeding 90 wt-%, may be classified as readily biodegradable according to OECD Test Guideline 301 F.

[0054] In one embodiment, the renewable paraffin-based composition contains more than 90 wt%, preferably at least 95 wt%, more preferably at least 98 wt%, of paraffin on a basis of the total weight of the renewable paraffin-based composition, and up to 10 wt% of C16 paraffin, e.g., 2 wt% to 10 wt% of C16 paraffin, preferably up to 6 wt% of C16 paraffin, e.g., 2 wt% to 6 wt% of C16 paraffin. The relatively small amount of C16 paraffin in the renewable paraffin-based composition further improves, i.e., raises, the flash point of the renewable paraffin-based composition compared to a high C16-C18 paraffin content in the composition. It also improves, i.e., raises, the thermal conductivity, thermal diffusivity, and volumetric specific heat of the renewable paraffin-based composition.

[0055] In one embodiment, the renewable paraffin-based composition contains, on a basis of the total weight of the renewable paraffin composition, more than 90 wt-%, preferably at least 95 wt-%, more preferably at least 98 wt-%, of paraffin, and up to 2 wt-%, of C19 paraffin, e.g., 1 wt-% to 2 wt-%, of C19 paraffin. The relatively small amount of C19 paraffin in the renewable paraffin-based composition further reduces the density and kinematic viscosity of the composition when the C16-C19 paraffin content in the composition is high.

[0056] In one embodiment, the renewable paraffin-based composition comprises, on a basis of the total weight of the renewable paraffin composition, more than 90 wt-%, preferably at least 95 wt-%, more preferably at least 98 wt-%, of paraffin, and more than 37 wt-%, and optionally less than 42 wt-%, of C17 paraffin. Such a renewable paraffin-based composition functions well as a cooling liquid for single-phase liquid direct immersion cooling, providing a favorable combination of high flash point, low density, and low kinematic viscosity. Such a renewable paraffin-based composition also provides good thermal conductivity and thermal absorption properties.

[0057] In one embodiment, the renewable paraffin-based composition comprises, on a basis of the total weight of the renewable paraffin composition, more than 90 wt-%, preferably at least 95 wt-%, more preferably at least 98 wt-%, of paraffin, and more than 45 wt-%, preferably more than 48 wt-%, more preferably more than 50 wt-%, and optionally less than 57 wt-%, of C18 paraffin. Such a renewable paraffin-based composition functions well as a cooling liquid for single-phase liquid direct immersion cooling, providing a favorable combination of high flash point, low density, and low kinematic viscosity. Such a renewable paraffin-based composition also provides good thermal conductivity and thermal absorption properties.

[0058] In one embodiment, the renewable paraffin-based composition contains more than 90 wt-% and optionally less than 95 wt-% C17-C18 paraffin. This gives the renewable paraffin-based composition a favorable combination of a high flash point, even at 140°C, low density, and low kinematic viscosity, which provides improved fluidity. Such a renewable paraffin-based composition also provides good thermal conductivity and thermal absorption properties.

[0059] In one embodiment, the renewable paraffin-based composition contains more than 90 wt-% and optionally less than 95 wt-% of C17-C18 paraffins, where the ratio of C18 i-paraffins to C18 n-paraffins is greater than 40, for example between 42 and 47, based on the weights of C18 n-paraffins and C18 i-paraffins in the renewable paraffin-based composition. This composition exhibits good performance in single-phase liquid direct immersion cooling. The high share of C17-C18 paraffins provides renewable paraffinic compositions with a favorable combination of a high flash point, low density, and reduced kinematic viscosity, which is at least 140°C, even 145°C, while the high weight ratio of C18 i-paraffins to C18 n-paraffins provides even lower kinematic viscosity and therefore better fluidity. This combination ensures particularly efficient heat conduction and improved safety in subsequent use. Increasing the ratio of C18 i-paraffins to C18 n-paraffins provides renewable paraffinic compositions that are more fluid while retaining the high volumetric heat capacity, thermal conductivity, and thermal diffusivity to which C17-C18 paraffins contribute.

[0060] In one preferred embodiment, the renewable paraffin-based composition contains, on a basis of the total weight of the composition, more than 90 wt-% of paraffins in the C17-C18 range (where the ratio of the amount of C18 i-paraffins to the amount of C18 n-paraffins is greater than 40, based on the weights of C18 n-paraffins and C18 i-paraffins in the renewable paraffin-based composition), as well as more than 45 wt-%, preferably more than 48 wt-%, and more preferably more than 50 wt-% of C18 paraffins, based on the total weight of the renewable paraffin-based composition. Such a renewable paraffin-based composition functions well as a cooling liquid for single-phase liquid direct immersion cooling and has good thermal conductivity and thermal absorption properties.

[0061] In one embodiment, the ratio of the amount of C17 i-paraffin to the amount of C17 n-paraffin is greater than 20 and preferably less than 30, based on the weights of C17 n-paraffin and C17 i-paraffin in the recyclable paraffin-based composition. Such a recyclable paraffin-based composition has particularly good fluidity and low kinematic viscosity while having good thermal conductivity and thermal absorption properties, and functions well as a cooling liquid for single-phase liquid direct immersion cooling.

[0062] In one embodiment, the renewable paraffin-based composition comprises, on a basis of the total weight of the renewable paraffin composition, 3-4 wt-% of C16 isoparaffin, 35-40 wt-% of C17 isoparaffin, 50-55 wt-% of C18i-paraffin, 1-3 wt-% of C19 isoparaffin, 0.1-1 wt-% of C16n-paraffin, 0.5-2 wt-% of C17n-paraffin, 0.5-2 wt-% of C18n-paraffin, and 0.01-1 wt-% of C19n-paraffin. Such a renewable paraffin-based composition functions well as a cooling liquid for single-phase liquid direct immersion cooling and has good thermal conductivity and thermal absorption properties.

[0063] In one embodiment, the renewable paraffin composition contains less than 1 wt-% of compounds, preferably less than 0.5 wt-% of aromatic compounds, based on the total weight of the renewable paraffin composition. The low aromatic compound content improves safety by reducing the health risks associated with aromatic compounds and contributes to lowering density, as aromatic compounds tend to have a higher density than paraffin.

[0064] In one embodiment, the regenerative paraffin-based composition was measured according to EN ISO 3104 at 40°C and yielded 15 mm 2 Less than / s, preferably 10 mm 2 Less than / s, more preferably 5mm 2 It has a kinematic viscosity of less than / s. Typically, renewable paraffin-based compositions have a viscosity of 1 mm 2Larger than / s, for example, 1.5mm 2 Greater than / s, or 2mm 2 It has a kinematic viscosity greater than / s (measured according to EN ISO3104 at 40°C). Low kinematic viscosity indicates better fluidity in recyclable paraffinic compositions. Better fluidity ensures that essentially all outer surfaces of the object being cooled, including very small cavities, can be in contact with the coolant liquid, ensuring more efficient heat conduction and reducing the risk of localized hot spots in recyclable paraffinic compositions. Low kinematic viscosity also facilitates the circulation of the coolant liquid in the cooling system.

[0065] In one embodiment, the recyclable paraffin-based composition has an (electrical) conductivity of less than 1 pS / m at 22°C, as measured according to ISO 6297:1997. Low (electrical) conductivity is advantageous, in particular, when using the recyclable paraffin-based composition for immersion cooling of electronic hardware such as computer hardware.

[0066] In one embodiment, the recyclable paraffin composition contains more than 60 wt-%, preferably more than 70 wt-%, more preferably more than 80 wt-%, even more preferably more than 90 wt-%, and most preferably more than 95 wt-%, of isoparaffin on a basis of the total weight of the recyclable paraffin composition. A high isoparaffin content, such as 80 wt-%, reduces the kinematic viscosity of the recyclable paraffin composition and improves its fluidity. The reduction in kinematic viscosity is particularly noticeable at low temperatures. The improved fluidity ensures that the cooling can reach essentially all outer surfaces of the object being cooled, even very small cavities, and can improve heat transfer efficiency. It also reduces the risk of localized hot spots, thereby improving the lifespan and safety of the recyclable paraffin composition. More efficient cooling also allows for tighter packing of the object being cooled in the immersion tank and / or can reduce the cooling rate. A high isoparaffin content also improves the low-temperature performance of the renewable paraffin-based composition, including improved fluidity at low temperatures. In one embodiment, the renewable paraffin-based composition contains more than 90 wt-% and less than 98 wt-% isoparaffin, based on the total weight of the renewable paraffin composition. This translates to good performance over a wide temperature range, particularly in terms of reduced kinematic viscosity and improved fluidity.

[0067] In one embodiment, the recyclable paraffinic composition comprises more than 90 wt-%, preferably at least 95 wt-%, more preferably at least 98 wt-%, of paraffin and more than 60 wt-%, preferably more than 70 wt-%, more preferably more than 80 wt-%, even more preferably more than 90 wt-%, and most preferably more than 95 wt-%, of isoparaffin.

[0068] In one embodiment, the isoparaffin is a methyl-substituted isoparaffin.

[0069] In one embodiment, the recyclable paraffin-based composition has a cloud point of less than -15°C, preferably less than -20°C, more preferably less than -25°C, and even more preferably less than -30°C, as measured according to ASTM D7689:2017. The low cloud point temperature ensures that paraffin crystals do not precipitate when the recyclable paraffin-based composition is cooled efficiently and rapidly, which allows for the use of a filterless pump, for example, in a single-phase liquid direct immersion cooling system.

[0070] In one embodiment, the recyclable paraffin-based composition has a pour point below -45°C, preferably below -50°C, more preferably below -55°C, even more preferably below -60°C, and most preferably below -65°C, as measured according to ASTM D5950:2014. A low pour point facilitates pumping of the recyclable paraffin-based composition, for example, in relation to efficient and rapid cooling.

[0071] Good low-temperature operability, i.e., a low cloud point such as below -15°C and / or a low pour point such as below -45°C, allows the use of regenerative paraffinic compositions together with highly efficient heat exchangers that rapidly cool the coolant liquid. For example, solidification on the surface of a highly efficient heat exchanger can be avoided. A highly efficient heat exchange unit allows for the formation of a particularly compact system for cooling. Low-temperature operability may be improved by appropriate additives. However, if the regenerative paraffinic composition has a low cloud point and / or a low pour point, the use of additives to improve low-temperature operability is not necessary.

[0072] Furthermore, a recyclable paraffin-based composition with good low-temperature operability will maintain its fluidity even at low outdoor temperatures, such as below -15°C. This good low-temperature operability allows for cooling of the recyclable paraffin-based composition, for example, by passing it through piping installed outdoors. In addition, the good low-temperature properties prevent the formation of precipitates at low outdoor temperatures.

[0073] The advantages of single-phase cooling compared to two-phase cooling are that, while two-phase cooling maintains the coolant temperature at its boiling point, single-phase cooling operates over a wider temperature range and allows the operating temperature to be set to a desired level. Coolants that maintain their liquid form over a wide temperature range are beneficial in that they allow for the selection of a desired operating temperature or temperature range from a broader range.

[0074] In one embodiment, the recyclable paraffin-based composition comprises more than 80 wt-%, preferably more than 90 wt-%, and more preferably more than 95 wt-%, of isoparaffin, and has a cloud point of less than -15°C, preferably less than -20°C, more preferably less than -25°C, and even more preferably less than -30°C, as measured according to ASTMD7689:2017, and / or a pour point of less than -45°C, preferably less than -50°C, more preferably less than -60°C, as measured according to ASTMD5950:2014, and even more preferably less than -65°C.

[0075] Preferably, the recyclable paraffin-based composition has a surface tension of less than 40 mN / m, preferably less than 35 mN / m, as measured according to ASTM D971M, and more preferably less than 30 mN / m.

[0076] Preferably, the recyclable paraffin-based composition is measured at 55°C according to ASTM D1169-19a and yields 1.0 × 10⁻⁶. 14 Ωcm~10×10 15 It has an electrical resistivity within the range of Ωcm. Renewable paraffin-based compositions have a negative correlation between electrical resistivity and temperature, meaning that electrical resistivity decreases with increasing temperature. The electrical resistivity of renewable paraffin-based compositions remains relatively high even at high temperatures that may occur during use.

[0077] Preferably, the recyclable paraffin-based composition has a specific heat capacity (mass heat capacity) in the range of 1.5 kJ / (kgK) to 3.0 kJ / (kgK), as measured at 40°C according to ASTM E1269-11(2018).

[0078] Preferably, the recyclable paraffin-based composition has a breakdown voltage of at least 60kV, preferably at least 65kV, more preferably at least 70kV, as measured at 20°C according to IEC60156:2018, and it may be less than 80kV or 75kV or less.

[0079] Surface tension, (electrical) resistivity, mass heat capacity and / or volumetric heat capacity, and breakdown voltage reflect the performance of renewable paraffinic compositions as coolants in single-phase liquid direct immersion cooling of electronic equipment.

[0080] In one embodiment, the renewable paraffinic composition may include one or more additives selected from, for example, antioxidants, metal passivators, pour point depressants, additives that reduce gasification tendency, and / or any other commonly used additives. However, none of these described additives are necessary for the renewable paraffinic composition to function adequately as a cooling liquid for single-phase liquid direct immersion cooling, but they may be used, alone or in combination with other additives, to further enhance certain or more properties of the renewable paraffinic composition.

[0081] Preferably, the renewable paraffin-based composition is classified as readily biodegradable according to OECD Test Guideline 301 F. The paraffin in the renewable paraffin-based composition of the present invention is readily biodegradable, which facilitates the disposal of the renewable paraffin-based composition after it has served as a coolant for single-phase liquid direct immersion cooling. Disposal of parts immersed in the renewable paraffin-based composition is also easy. This is a clear advantage over conventional perfluorocarbon-based coolants, which are virtually very persistent and therefore require special care and preparation when disposed of, including any objects immersed in the conventional perfluorocarbon-based coolant.

[0082] Optionally, after the renewable paraffin composition has functioned as a coolant for single-phase liquid direct immersion cooling, the used renewable paraffin composition may be provided as feedstock for a refinery. The used renewable paraffin composition may be supplied to the refinery as is, or it may be pre-treated before being supplied to the refinery. Thus, the used renewable paraffin composition may be treated, for example, as diesel fuel or chemicals, which enables a value-added use of the renewable paraffin that functioned as a coolant for single-phase liquid direct immersion cooling.

[0083] In one embodiment, a renewable paraffinic composition may be obtained by a method comprising: hydrogenating and optionally isomerizing a renewable feed stock to obtain a renewable paraffinic feed; and subjecting the obtained renewable paraffinic feed to at least one separation or fractionation process to recover a renewable paraffinic composition containing at least 80 wt-% of paraffins in the C16-C19 carbon range, based on the total weight of the renewable paraffinic composition. After hydrogenation and without isomerization, the renewable paraffinic feed mainly consists of n-paraffins. After hydrogenation and isomerization, the renewable paraffinic feed mainly consists of n-paraffins and isoparaffins, with the degree of isomerization depending on the isomerization treatment.

[0084] Any known separation or fractionation method, or any combination of any known separation and / or fractionation method, that is suitable for recovering a recyclable paraffinic composition from a recyclable paraffinic feed as described in the embodiments described above may be used.

[0085] In one embodiment, the separation or fractionation process includes distillation, preferably fractional distillation, of a recyclable paraffin-based feed. Distillation is also beneficial in that it contributes to the removal of impurities such as residual water, metals, and / or oxidizing agents. Significant amounts of such impurities can be harmful if sensitive computer hardware comes into direct contact with them. In one embodiment, the separation or fractionation process includes two or more separation or fractionation steps.

[0086] In one embodiment, the separation or fractionation process includes recovering from the separation or fractionation a recyclable paraffinic composition having a boiling point range of about 270°C to about 325°C, preferably about 275°C to about 320°C, and more preferably about 280°C to about 300°C, as measured in accordance with EN ISO3405:2011.

[0087] Preferably, the separation or fractionation is selected so that the majority of paraffins in the C16-C19 range, particularly isoparaffins in the C16-C19 range, remain in the recovered composition. The separation process may be selected to obtain a recyclable paraffinic composition having a predetermined distribution of carbon atoms, n-paraffins, and i-paraffins. By selecting the separation or fractionation in this way, it is possible to control the viscosity and density of the recovered hydrocarbon composition. In addition, since impurities are typically concentrated at the bottom of the heavier hydrocarbon column, the amount of impurities can be reduced, which can further lower the electrical conductivity of the recyclable paraffinic composition.

[0088] Typically, renewable paraffinic feeds obtained by hydrogenation and optionally isomerization of renewable (biogenetic) feedstocks have a carbon number distribution in the range of C8-C22 or C10-C20, preferably C15-C18, and a boiling point range of 140°C-340°C, preferably 180°C-320°C. Selection of renewable feedstocks with favorable properties, such as selecting a renewable feedstock containing a large amount of compounds with carbon chain lengths longer than or equal to C16, can be used to increase the yield of renewable paraffinic compositions.

[0089] Most renewable feedstocks contain materials with a high oxygen content. In some embodiments, the renewable feedstock comprises fatty acids, or fatty acid derivatives such as triglycerides, or combinations thereof. Hydrogenation removes oxygen from the renewable feedstock, preferably as water, i.e., by hydrodeoxygenation (HDO). Optionally, the production of renewable paraffinic feed may include other deoxygenation treatments (multiple deoxygenation treatments) in addition to hydrogenation. Such deoxygenation treatments are not particularly limited, and any suitable deoxygenation treatment may be performed. Suitable treatments include catalytic cracking (CC), decarboxylation, and / or decarbonylation.

[0090] In one preferred embodiment, the hydrogenation treatment is hydrogenation deoxygenation. Thus, in one embodiment, obtaining a regenerative paraffinic feed involves hydrogenation deoxygenation and optional isomerization of the regenerative feedstock. Reaction conditions and catalysts suitable for hydrogenation deoxygenation of the regenerative feedstock and for the optional isomerization of the resulting n-paraffin are known. An example of such a process is shown in International Publication No. 2015 / 101837 A2, paragraphs

[0032] to

[0037] . Furthermore, for example, Finnish Patent No. 100248, Examples 1 to 3, shows an example of hydrogenation deoxygenation and isomerization of a regenerative feedstock.

[0091] Hydrogenation deoxygenation is preferably carried out at a pressure selected from the range of 2 to 15 MPa, preferably 3 to 10 MPa, and at a temperature selected from the range of 200 to 500°C, preferably 280 to 400°C. Hydrogenation deoxygenation can be carried out in the presence of a known hydrogenation deoxygenation catalyst containing metals (multiple metals) of Group VIII and / or Group VIB of the periodic table. The catalyst may be supported on any conventional support such as alumina, silica, zirconia, titania, amorphous carbon, molecular sieves, or a combination thereof. Preferably, the hydrogenation deoxygenation catalyst is a supported Pd, Pt, Ni, or NiW catalyst, or a supported Mo-containing catalyst such as a NiMo or CoMo catalyst, with the support being alumina and / or silica, or a combination of these catalysts. Typically, NiMo / Al2O3 and / or CoMo / Al2O3 catalysts are used.

[0092] HDO is preferably carried out in the presence of hydrogen gas and a NiMo sulfide catalyst or a CoMo sulfide catalyst. HDO is performed under a hydrogen pressure selected from the range of 1 to 20 MPa, at a temperature selected from the range of 200°C to 400°C, and for 0.2 hours. -1 ~10h -1This can be carried out at a liquid space velocity selected from the range. When a sulfidation catalyst is used, the sulfidation state of the catalyst can be maintained during the HDO process by adding sulfur to the gas phase or by using a feedstock in which sulfur-containing mineral oil is mixed with a regenerative feedstock. The sulfur content of the total feedstock subjected to hydrodeoxygenation may be, for example, in the range of 50 wppm (ppm by weight) to 20,000 wppm, preferably in the range of 100 wppm to 1,000 wppm.

[0093] The effective conditions required for hydrogenation deoxygenation may reduce the oxygen content of the feedstock to less than 1 wt-%, for example, less than 0.5 wt-% or less than 0.2 wt-%. Optionally, these conditions may be selected to result in partial hydrogenation deoxygenation equivalent to at least 40 wt-%, at least 50 wt-%, or at least 75 wt-% deoxygenation.

[0094] In general, renewable paraffin-based feeds can be produced from renewable feed stocks using any known method. Specific examples of methods for producing renewable paraffin-based feeds are described in European Patent Application Publication 1741768, paragraphs

[0038] to

[0070] , particularly paragraphs

[0056] to

[0070] , and Examples 1 to 6. Other methods may also be used, specifically other Biomass-To-Liquid (BTL) methods such as biomass gasification followed by the Fischer-Tropsch process.

[0095] The preparation of a renewable paraffin-based feed may optionally include a step of hydrogenating the carbon chain after hydrogenation. Thus, the chain length of the formed paraffin can be adjusted, and the product distribution of the manufactured renewable paraffin-based feed can be indirectly controlled.

[0096] The isomerization treatment is not particularly limited, and any suitable isomerization treatment may be used. However, catalytic isomerization is preferred. The isomerization treatment is preferably carried out at a temperature selected from the range of 200 to 500°C, preferably 280 to 400°C, for example 300 to 350°C, and at a pressure selected from the range of 1 to 15 MPa, preferably 3 to 10 MPa. The isomerization treatment may be carried out in the presence of a known isomerization catalyst, for example, a catalyst comprising molecular sieves and / or a metal and support selected from Group VIII of the periodic table. Preferably, the isomerization catalyst is a catalyst comprising SAPO-11 or SAPO-41 or ZSM-22 or ZSM-23 or ferrielite, and Pt, Pd or Ni, and Al2O3 or SiO2. Typical isomerization catalysts include, for example, Pt / SAPO-11 / Al2O3, Pt / ZSM-22 / Al2O3, Pt / ZSM-23 / Al2O3, and / or Pt / SAPO-11 / SiO2. The catalysts may be used alone or in combination. Catalyst deactivation can be reduced by the presence of hydrogen molecules during the isomerization process. In one preferred embodiment, the isomerization catalyst is a noble metal bifunctional catalyst such as Pt-SAPO and / or Pt-ZSM catalysts, which are used in combination with hydrogen.

[0097] At least linear paraffins from the hydrogenation process may be subjected to any isomerization process, or the hydrogenated renewable feedstock as a whole may be subjected to any isomerization process. The isomerization process is a process that primarily functions to isomerize the paraffins obtained from the hydrogenation process. That is, while most thermal or catalytic conversions (e.g., HDO) result in small percentages of isomerization (usually less than 5 wt-%), the isomerization process, which may be optionally included in the production of renewable paraffinic feed, is a process that leads to a significant increase in isoparaffin content. The isomerization process may include further intermediate steps, such as purification and / or fractionation.

[0098] In embodiments where both the hydrogenation deoxygenation and isomerization steps are applied, these may be carried out simultaneously or sequentially. In one embodiment, producing a regenerative paraffin-based feed involves performing hydrogenation deoxygenation and hydrogen isomerization in a single step on the same catalyst bed by using a mixture of a single catalyst for this combined process, such as NiW or a Pt catalyst such as Pt / SAPO, with a Mo catalyst supported on a support, such as NiMo supported on alumina.

[0099] In one embodiment, producing a regenerative paraffin-based feed involves hydrogenation and deoxygenation in the presence of hydrogen gas and a hydrogenation and deoxygenation catalyst, such as CoMo, NiMo, NiW, or CoNiMo, supported on a carrier such as an alumina carrier, a zeolite carrier, or a mixed carrier, preferably optionally a NiMO catalyst supported on an alumina carrier, and performing the process at a temperature in the range of 250 to 400°C, a pressure in the range of 2 to 8 MPa, for 0.5 to 3 hours. -1 The hydrogenation deoxygenation reaction is carried out at a WHSV (weight space velocity, i.e., mass flow rate / catalyst mass) in the range of 350-900 nl / l and an H2 / renewable feedstock ratio; optionally, the hydrogenated renewable feedstock is subjected to an isomerization step in the presence of hydrogen and an isomerization catalyst, preferably a noble metal bifunctional catalyst such as Pt-SAPO or Pt-ZSM catalyst or NiW; and at a temperature of 250-400°C, a pressure of 1-6 MPa, and for 0.5-3 hours. -1 The process includes carrying out the isomerization reaction at a WHSV in the range of 100 to 800 nl / l and an H2 / oil ratio of 100 to 800 nl / l. Preferably, in embodiments in which the hydrogenation deoxygenation step and the isomerization step are carried out sequentially, the hydrogenation deoxygenation step is carried out prior to the isomerization step.

[0100] The yield of renewable paraffinic compositions can be increased by selecting process conditions for the manufacturing process of renewable paraffinic feeds.

[0101] As used herein, renewable raw materials mean materials and products that can be obtained, derived from, or originate from plants and / or animals, and include materials and products that can be obtained, derived from, or originate from fungi and / or algae. As used herein, renewable raw materials may also include genetically modified renewable raw materials. Renewable raw materials may also be referred to as biological raw materials or bio-derived raw materials.

[0102] In the context of this disclosure, fossil or mineral raw materials mean naturally occurring, non-renewable compositions such as crude oil, petroleum oil / gas, shale oil / gas, natural gas, or coal deposits, and combinations thereof, including any hydrocarbon-rich deposits that can be utilized from above-ground or underground sources. The terms fossil or mineral may also mean recycled materials derived from non-renewable resources.

[0103] Renewable or bio-derived carbon atoms contain a greater number of unstable radiocarbons compared to fossil-derived carbon atoms. 14 It contains a C atom. Therefore, 12 C and 14By analyzing the ratio of 13C isotopes, it is possible to distinguish between carbon compounds derived from renewable or biological sources and those derived from fossil fuels. Therefore, specific ratios of these isotopes can be used as "tags" to identify renewable carbon compounds and distinguish them from non-renewable carbon compounds. Isotope ratios do not change during chemical reactions. Examples of appropriate methods for analyzing the carbon content from biological or renewable sources include DIN 51637 (2014), ASTM D6866 (2020), and EN 16640 (2017). As used herein, the carbon content from biological or renewable sources is expressed as the biogenic carbon content, meaning the amount of biogenic carbon in the material, as a weight percentage of the total carbon (TC) in the material (in accordance with ASTM D6866 (2020) or EN 16640 (2017)). Biological feedstock or raw material (biological raw material) typically refers to material containing only biogenic carbon.

[0104] Typically, hydrocarbons made from 100% palm oil have a biocarbon content of approximately 100 wt-%. Typically, hydrogenated animal fats have a biocarbon content of approximately 100 wt-%. Typically, fossil crude oil-based mineral oils have a biocarbon content of approximately 0 wt-%.

[0105] In the context of this disclosure, renewable feedstocks refer to biological feedstock components, typically containing lipids (e.g., fatty acids or glycerides), including oils and / or fats, such as renewable oils and / or fats, e.g., plant oils / fats, wood oils / fats, vegetable oils / fats, animal oils / fats, fish oils / fats and algal oils / fats, or oils / fats from other microbial processes, e.g., genetically modified algal oils / fats, genetically modified oils / fats from other microbial processes, and genetically modified vegetable oils / fats. Components or derivatives of such materials, e.g., alkyl esters (typically C1-C5 alkyl esters, e.g., methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl esters) or olefins, etc., may also be used. Renewable feedstocks have a bio-derived carbon content of about 100 wt-% based on the total weight (TC) of carbon in the renewable feedstock, as measured according to ASTM D6866 (2020) or EN 16640 (2017). In one embodiment, the renewable paraffinic composition contains recycled fossil material up to about 49 wt-% of the total weight of the renewable paraffinic composition. In another embodiment, the renewable paraffinic composition contains hydrocarbons derived from waste plastics, particularly paraffins, preferably in the C16-C19 range. The waste plastics may be considered either recycled fossil material or recycled renewable material, depending on the origin of the waste plastics.

[0106] The oils and / or fats of renewable feedstock typically include C10-C24 fatty acids and their derivatives, including fatty acid esters, glycerides, i.e., glycerol esters of fatty acids. Glycerides may include monoglycerides, diglycerides, and triglycerides in particular.

[0107] The oils and / or fats in renewable feedstock may include single types of oils, single types of fats, mixtures of various oils, mixtures of various fats, mixtures of oils and fats, fatty acids, glycerol, and / or mixtures of the foregoing. Optionally, renewable feedstock may also include recyclable waste and / or recyclable residues, such as used edible oils, free fatty acids, palm oil by-products or process by-streams, sludge, by-streams from vegetable oil processing, or combinations thereof.

[0108] Renewable paraffinic compositions are compositions derived primarily from renewable raw materials. In one embodiment, as measured according to ASTM D6866(2020) or EN 16640(2017), the bio-based carbon content of a renewable paraffinic composition is more than 50 wt-%, preferably at least 70 wt-%, more preferably at least 80 wt-%, even more preferably at least 90 wt-%, and most preferably at least 99 wt-%, based on the total weight of carbon in the renewable paraffinic composition. This reflects the origin of the renewable paraffinic composition.

[0109] The disclosure also provides a single-phase liquid direct immersion cooling system comprising a tank containing a renewable paraffin-based composition comprising at least 80 wt-% of paraffins in the C16-C19 carbon number range, based on the total weight of the renewable paraffin composition, and an object to be immersed and cooled in the renewable paraffin composition.

[0110] The renewable paraffin-based composition contained in the tank may be the renewable paraffin-based composition described in relation to the first embodiment. In one embodiment, the tank does not contain any liquid other than the renewable paraffin-based composition.

[0111] In one embodiment, a single-phase liquid direct immersion cooling system comprises a heat exchange unit; and means for circulating a regenerative paraffinic composition through the heat exchange unit. The means for circulating the regenerative paraffinic composition may be configured to circulate the regenerative paraffinic composition through the heat exchange unit continuously, intermittently, at intervals, or in combination thereof.

[0112] Alternatively, in embodiments where the recyclable paraffinic composition is not circulated through the heat exchange unit, the tank is configured to contain an amount of recyclable paraffinic composition sufficient to allow cooling without circulating the recyclable paraffinic composition through the heat exchange unit. Typically, such a tank contains a fairly large amount of recyclable paraffinic composition.

[0113] In one embodiment, the circulation of the regenerative paraffinic composition through the heat exchange unit is carried out by natural convection. Natural convection means that the regenerative paraffinic composition is circulated without a pump or mixing means. Optionally, natural convection may be amplified in some embodiments by a mixer such as a stirrer or pump.

[0114] In one embodiment, the heat exchange unit is configured to cool a regenerative paraffinic composition circulated through it. In another embodiment, the single-phase liquid direct immersion cooling system is configured to maintain the temperature of the regenerative paraffinic composition contained in the tank within a temperature range of 15°C to 90°C, preferably 15°C to 75°C, and more preferably 20°C to 65°C.

[0115] In one embodiment, the heat exchange unit and the means for circulating the regenerative paraffin-based composition through the heat exchange unit are configured to maintain the temperature of the regenerative paraffin-based composition contained in the tank within a temperature range of 15°C to 90°C, preferably 15°C to 75°C, and more preferably 20°C to 65°C.

[0116] In one embodiment, two or more objects to be cooled are immersed in a recyclable paraffin-based composition.

[0117] The object or multiple objects to be cooled may be partially or completely immersed in a recyclable paraffin-based composition. In one embodiment, if the object is heated unevenly, only a portion or part of the object being heated will be immersed in the recyclable paraffin-based composition.

[0118] In one embodiment, the object or multiple objects to be cooled are electronic hardware, preferably computer hardware, more preferably a server or multiple servers, or the object or multiple objects to be cooled are a fuel cell or multiple fuel cells. In one embodiment, the tank includes a rack or multiple racks that hold multiple servers.

[0119] The heat exchange unit is not particularly limited and may be any heat exchange unit or heat exchange means suitable for cooling a renewable paraffin-based composition. The heat exchange unit may be an external heat exchange unit or a heat exchange unit integrated into a tank. Examples of suitable heat exchange units include, for example, a heat sink such as a metal heat sink, underground piping, piping located outdoors, or a heat exchange unit equipped with a water cooling tower.

[0120] In one embodiment, the heat exchange unit comprises a heat exchanger connected to a water cooling tower, where means for circulating a regenerative paraffin-based composition through the heat exchange unit are configured to bring the regenerative paraffin-based composition into contact with the heat exchanger.

[0121] The means for circulating the recyclable paraffin-based composition through the heat exchange unit are not particularly limited, and any means suitable for circulating the recyclable paraffin-based composition through the heat exchange unit may be used. In one embodiment, the means for circulating the recyclable paraffin-based composition through the heat exchange unit include piping and, optionally, a pump or a number of pumps. The piping may be arranged so that the recyclable paraffin-based composition is moved by gravity.

[0122] In one embodiment, a single-phase liquid direct immersion cooling system comprises two or more tanks, each containing a recyclable paraffin-based composition and one or more objects to be immersed and cooled in the recyclable paraffin-based composition. The tanks may be stacked on top of each other and / or arranged adjacent to each other.

[0123] In one embodiment of the system comprising two or more tanks, means for circulating a regenerative paraffinic composition through heat exchange units are configured to circulate the regenerative paraffinic composition from each tank through the heat exchange units. In another embodiment of the system comprising two or more tanks, the system comprises two or more heat exchange units and means for circulating a regenerative paraffinic composition through the two or more heat exchange units. Means for circulating a regenerative paraffinic composition through two or more heat exchange units may be configured to circulate a regenerative paraffinic composition from a predetermined tank or a predetermined number of tanks through a predetermined heat exchanger or through a predetermined number of heat exchangers. In one embodiment, each tank comprises its own dedicated heat exchange unit.

[0124] The tank or a group of tanks may be a so-called open tank in which the recyclable paraffin-based composition is in direct contact with air, or a tank in which the recyclable paraffin-based composition is not in contact with air. The tank or a group of tanks may be covered, for example, with a lid or cover, so that air remains between the recyclable paraffin-based composition and the cover, or so that there is no space or air between the recyclable paraffin-based composition and the cover. Alternatively, the tank may be in direct contact with its surroundings, and the single-phase direct liquid immersion cooling system forms an open system. In one embodiment, the single-phase direct liquid immersion cooling system may be sealed from its environment, i.e., the single-phase direct liquid immersion cooling system may be configured so that it is not in contact with ambient air inside the system.

[0125] Figure 1 is a schematic diagram showing a single-phase liquid direct immersion cooling system 100 according to an exemplary embodiment. In the embodiment of Figure 1, the single-phase liquid direct immersion cooling system comprises a tank 110 of a recyclable paraffin-based composition, i.e., a container filled to a predetermined level with the recyclable paraffin-based composition. A rack 120 containing multiple servers is immersed in the recyclable paraffin-based composition. In the embodiment of Figure 1, the single-phase liquid direct immersion cooling system 100 further comprises a heat exchange unit 130 comprising a heat exchanger 140 connected to a water cooling tower 150, and a water pump 160 configured to deliver hot water from the heat exchanger 140 to the water cooling tower 150 and cold water from the water cooling tower 150 to the heat exchanger 140. The single-phase liquid direct immersion cooling system 100 of Figure 1 also comprises a pump 170 configured to deliver warm recyclable paraffin-based composition from the tank 110 to the heat exchanger 140 and cold recyclable paraffin-based composition from the heat exchanger 140 to the tank 110. A pump 170, configured to deliver the regenerative paraffinic composition from tank 110, includes a filter configured to filter the warm regenerative paraffinic composition before it passes through heat exchanger 140. Arrows in Figure 1 indicate the pathways of the regenerative paraffinic composition and water within the single-phase liquid direct immersion cooling system 100. These pathways may be formed, for example, by pipes.

[0126] The disclosure also provides a vessel containing a renewable paraffin-based composition comprising at least 80 wt-% paraffin in the C16-C19 range, based on the total weight of the renewable paraffin composition; and a method for single-phase liquid direct immersion cooling, comprising immersing an object to be cooled in the renewable paraffin composition.

[0127] The renewable paraffin-based composition contained in the tank may be the renewable paraffin-based composition described in relation to the first embodiment. In one embodiment, the tank does not contain any liquid other than the renewable paraffin-based composition.

[0128] In one embodiment, the method includes circulating a recyclable paraffin-based composition through a heat exchange unit. Circulation of the recyclable paraffin-based composition through the heat exchange unit can be carried out continuously, at intervals, intermittently, or a combination thereof.

[0129] In one embodiment, circulating a regenerative paraffin-based composition through a heat exchange unit includes cooling the regenerative paraffin-based composition within the heat exchange unit.

[0130] In one embodiment, the method includes maintaining the temperature of the regenerative paraffin-based composition contained in the tank within a temperature range of 15°C to 90°C, preferably 15°C to 75°C, more preferably 20°C to 65°C, by circulating the regenerative paraffin-based composition, preferably through a heat exchange unit.

[0131] In one embodiment, circulating a regenerative paraffin-based composition through a heat exchange unit includes guiding the regenerative paraffin-based composition from a tank to a heat exchange unit and from the heat exchange unit to a tank via pipes or piping. In another embodiment, circulating a regenerative paraffin-based composition through a heat exchange unit includes pumping the regenerative paraffin-based composition from a tank to a heat exchange unit and from the heat exchange unit to a tank.

[0132] In one embodiment, the method includes immersing two or more objects to be cooled in a recyclable paraffin-based composition. The objects to be cooled or multiple objects may be immersed at least partially or completely in the recyclable paraffin-based composition. The objects to be cooled or multiple objects immersed in the recyclable paraffin-based composition may be any objects or multiple objects described in relation to the first or second aspect, such as electronic hardware, preferably computer hardware, more preferably a server or multiple servers, or a rack holding a server or multiple servers, or a fuel cell or multiple fuel cells.

[0133] In one embodiment, the method includes providing a plurality of tanks containing a recyclable paraffinic composition, immersing an object or a plurality of objects to be cooled in the recyclable paraffinic composition in each tank, and circulating the recyclable paraffinic composition through a heat exchange unit or through two or more heat exchange units. The recyclable paraffinic composition in a given tank or a given plurality of tanks may be circulated through a given heat exchange unit or a given plurality of heat exchange units. In one embodiment, the recyclable paraffinic composition is circulated from each tank to a heat exchange unit dedicated to that tank.

[0134] The highly efficient cooling solutions described herein can increase data output without temperature being a limiting factor. Sometimes it is desirable to keep data output constant, in which case the solutions of the present invention can provide a reduced operating temperature. Often, it is preferable to increase data output and raise the operating temperature while utilizing excess heat, such as in district heating. The solutions of the present invention support both operating modes. [Examples]

[0135] Example 1: Renewable paraffin-based composition The carbon number distribution, as well as the physical and chemical properties, of two examples of renewable paraffinic compositions (referred to as compositions P1 and P2) are shown below.

[0136] Table 1 summarizes the carbon number distribution of composition P1, and Table 2 summarizes the physical and chemical properties of composition P1. Table 3 summarizes the carbon number distribution of composition P2, and Table 4 summarizes the physical and chemical properties of composition P2.

[0137] Exemplary composition P1 was prepared by hydrogenation deoxygenation and isomerization of a renewable feedstock, as described above. Therefore, the biogenic carbon content of P1 was 100% (ASTM D6866(2020) or EN 16640(2017)). Following the isomerization step, a distillation step was performed to recover a hydrocarbon composition having an initial boiling point (IBP) of 275.4°C and a final boiling point (FBP) of 321.0°C. The carbon number distribution of composition P1 is shown in Table 1. Composition P1 contained 96.05% i-paraffins and 3.95% n-paraffins. 95.71 wt-% of the total paraffins were in the C16–C19 range. The amount of C15 and lighter paraffins was 0.69 wt-%, and the amount of C20 and heavier paraffins was 3.59 wt-%. The biodegradability of composition P1 was evaluated according to OECD Test Guideline 301F, and it was found that the composition is readily biodegradable.

[0138] [Table 1]

[0139] [Table 2] TIFF0007839782000003.tif222122 TIFF0007839782000004.tif111125

[0140] An exemplary composition P2 was prepared by distillation of composition P1 to recover a hydrocarbon composition having an initial boiling point (IBP) of 283.5°C and a final boiling point (FBP) of 298.5°C. The carbon number distribution of composition P2 is shown in Table 3. The biogenic carbon content of P2 was also 100% (ASTM D6866(2020) or EN 16640(2017)). The carbon number distribution of composition P2 is shown in Table 3. Composition P2 contained 96.75% i-paraffin and 3.25% n-paraffin. 99.08 wt-% of the total paraffin was in the range of C16-C19. Based on the weights of C18i-paraffin and C18n-paraffin in composition P2, the ratio of the amount of C18i-paraffin to the amount of C18n-paraffin is 45.52. Composition P2 contained 0.31 wt-% of C15 and lighter paraffins, and 0.62 wt-% of C20 and heavier paraffins. Furthermore, composition P2 contained more than 37 wt-% of C17 paraffins.

[0141] Table 4 summarizes the physical and chemical properties of composition P2. As can be seen from Table 4, composition P2 contains very little or no metal, which enhances its dielectric behavior. As can be seen from Table 4, the (electrical) conductivity of composition P2 was less than 1 pS / m. In other words, composition P2 is very suitable for use as a coolant for single-phase liquid direct immersion cooling of electronic hardware, such as computer hardware. The biodegradability of composition P2 was evaluated according to OECD Test Guideline 301F, and it was found that the composition is readily biodegradable.

[0142] [Table 3]

[0143] [Table 4] TIFF0007839782000007.tif235126 TIFF0007839782000008.tif114125

[0144] [Table 5]

[0145] Example 2: Immersion Test The effects of immersion liquids (cooling liquids) on computer hardware were investigated.

[0146] A computer motherboard was cut into pieces, and the pieces were partially immersed in the renewable paraffinic composition P2(P2) of Example 1 and the renewable paraffinic composition corresponding to Fluorinert® FC-40, commercially available from 3M®, at various temperatures, as shown in Table 5.

[0147] [Table 6]

[0148] Figure 2a) is a schematic diagram of the test setup 200. Immersion liquid 210 was poured into a flange pot 220, and a cut portion of the motherboard 230 was partially immersed in the liquid 210 by being suspended from the top of the flange pot using a wire or thread 240. A water condenser 250 was connected to the lid of the flange pot. The flange pot 220 was placed in an oil bath 260 on a hot plate 270, and the oil bath was stirred with a magnetic stirrer. The temperatures of the immersion liquid 210 and the oil bath 260 were monitored with thermometers 280 and 290, respectively. Figure 2b) shows a photograph of the test setup in use.

[0149] In tests T1, T2, T4, and T5, the temperature was kept constant at either 20°C or 50°C, and the immersion time was approximately 24 hours. In tests T3 and T6, the temperature cycled through room temperature to 50°C, 50°C to 85°C, and 85°C to room temperature during immersion. In tests T3 and T6, the immersion time at room temperature was approximately 4 hours, at 50°C approximately 24 hours, at 85°C approximately 23 hours, and again at room temperature approximately 3 hours. After the predetermined immersion time was completed, the motherboard pieces were removed from the immersion solution and flange pot and dried with pressurized air. The motherboard pieces were then left to dry in the air overnight.

[0150] After drying overnight, the motherboard pieces were characterized by measuring their mass, circuit resistance, and capacitance before and after immersion. The characteristics are shown in Table 6 below. Circuit resistance was measured using the same unit design (plug pins) before and after immersion, and the value obtained after three consistent measurements was recorded.

[0151] [Table 7]

[0152] Furthermore, the motherboard pieces before and after immersion were visually inspected, and their thickness was measured before and after immersion to assess the possibility of expansion. Photographs of the motherboard pieces before and after immersion are shown in Figures 3a) to 3l). Figures 3a) and 3b) show the motherboard pieces before and after immersion by T1, respectively. Figures 3c) and 3d) show the motherboard pieces before and after immersion by T2, respectively. Figures 3e) and 3f) show the motherboard pieces before and after immersion by T3, respectively. Figures 3g) and 3h) show the motherboard pieces before and after immersion by T4, respectively. Figures 3i) and 3j) show the motherboard pieces before and after immersion by T5, respectively. Figures 3k) and 3bl) show the motherboard pieces before and after immersion by T6, respectively.

[0153] In each of T1-T6, immersion did not cause any peeling or swelling, and the lettering on the motherboard pieces did not fade during immersion. Furthermore, after the motherboard pieces were dried overnight, only a very small amount of immersion liquid residue was observed on the motherboard pieces. Also, in each of T1-T6, as can be seen from Table 6, immersion did not have a significant effect on the mass, circuit resistance, or capacitance of the motherboard pieces. The change in circuit resistance was essentially negligible, indicating that the coolant did not adhere to the pins and that no metal leached into the coolant. Surprisingly, immersion in P2 had no effect on the motherboard pieces, and P2 performed comparably to the commercially available coolant FC-40 for single-phase direct liquid immersion cooling.

[0154] The properties of the cooling fluids T1 to T6 were evaluated by measuring their density and refractive index before and after immersion. The results are shown in Table 7 below. The cooling fluids were also visually inspected before and after immersion.

[0155] [Table 8]

[0156] The densities of P2 and FC-40 were unaffected in any of the tests T1-T4. While changes in density can indicate significant changes in the composition of the cooling liquid, this was not observed in any of the tests T1-T6. P2 has a significantly lower density than FC-40, which is advantageous in terms of the energy required to circulate the liquid. The lower density also reduces the weight of the immersion tank, which is advantageous, for example, when tanks are stacked on top of each other. Furthermore, due to its lower density, P2 exerts less buoyancy on objects immersed in it compared to FC-40. This is particularly beneficial in single-phase direct immersion cooling of very light objects or objects with shapes that are highly susceptible to buoyancy. Additionally, the refractive index of P2 remained unchanged. The refractive index of FC-40 could not be measured as it was outside the measurement range. While not intended to impose any particular theory, it appears that the refractive index of FC-40 is too low to measure. Because refractive index measurement is highly sensitive, it can therefore be used to monitor changes such as dissolution or decomposition in the cooling liquid. The advantage of being able to measure the refractive index is that it allows for easy online and real-time monitoring of changes in the cooling liquid, and enables easy and rapid identification of the need to change the immersion liquid or adjust and maintain a single-phase liquid direct immersion cooling system. Both P2 and FC-40 are clear liquids, and their appearance did not change during either of the T1-T3 and T4-T6 tests, respectively.

[0157] Therefore, it can be concluded that no dissolution of the motherboard fragments was observed. P2 did not dissolve any delicate structures or markings on the motherboard fragments and was compatible with the computer hardware as well as commercially available single-phase liquid direct immersion cooling fluid FC-40. Elemental analysis of the cooling fluid was performed after each of T1-T6 to confirm that there was no leaching during immersion. Fresh, unused P2 and FC-40 were used as reference. The results of the elemental analysis are shown in Table 9 below.

[0158] [Table 9] TIFF0007839782000014.tif26162

[0159] As can be seen from Table 9, there was almost no leaching of material into the cooling liquid. For P2, an increase in sodium and silicon from the glass reaction vessel was expected, but there was no trace of leaching from any motherboard pieces during immersion. As can be seen from Table 9, immersion caused almost no change in the elemental composition of FC-40.

[0160] Figure 5 shows the distillation curves for P2 and FC-40, respectively. The black curve represents P2, and the gray curve represents FC-40. As can be seen from Figure 4, P2 boils at a higher temperature than FC-40, and the boiling point range of P2 is significantly narrower than that of FC-40. Therefore, P2 contains fewer volatile compounds than FC-40 and can maintain the liquid phase at higher operating temperatures. This improves the safety of P2 and allows its use in single-phase liquid direct immersion cooling systems that are open to the ambient. Since FC-40 is a source of greenhouse gases, measures must be taken to prevent its release into the ambient from single-phase liquid direct immersion cooling systems. Compared to FC-40, P2 offers a more sustainable, environmentally friendly, and climate-friendly alternative overall. Unlike FC-40, P2 can be obtained from renewable feedstock, does not emit greenhouse gases, is not inherently sustainable, but is instead classified as readily biodegradable according to OECD Test Guideline 301 F, and, after serving as a coolant for single-phase liquid direct immersion cooling, is expected to have value-added applications in refineries.

[0161] Example 3: Usefulness of computer hardware after immersion The RAM board was removed from a desktop computer and immersed in P2 at 50°C for 83 hours. The test setup described in relation to Example 2 and shown in Figures 2a) and 2b) was used. The oil bath agitation was set to 250 rpm.

[0162] Photographs of the RAM board before immersion are shown in Figures 4a) and 4c), and after immersion in Figures 4b) and 4d). Visual inspection of the RAM board before and after immersion concluded that the RAM board showed no visual changes, and no significant residue of P2 was found on the board after drying. The RAM board was reinserted into the desktop computer. When the computer was started, the system loaded without problems, and the BIOS was accessed and evaluated normally. Therefore, immersion in P2 at 50°C for 83 hours had no adverse effects, and the computer with the reinserted RAM board functioned as before.

[0163] Example 4: Data Center Cooling Simulation Three different cooling liquids, namely the renewable paraffin-based composition P2(P2) from Example 1, Fluorinert® FC-40 (perfluorotri-n-butylamine) commercially available from 3M®, and S5X (fossil-based alkane) commercially available from Royal Dutch Shell, were compared in data center cooling simulation tests.

[0164] The properties of the coolants P2, FC-40, and S5X as a function of temperature (T increased from 15°C to 50°C) are shown in Figures 6a) to 6d). As can be seen from Figure 6a), P2 has a low viscosity coefficient, which decreases further as the temperature increases. Low viscosity improves heat exchange between the object being cooled and the coolant, as the coolant can circulate through all parts of the object being cooled and even reach its very small cavities. As seen in Figures 6b), 6c), and 6d), respectively, the density, specific heat capacity (mass heat capacity), and thermal conductivity of P2 are maintained relatively constant within the temperature range of 15°C to 50°C. The relative constant density, specific heat capacity, and thermal conductivity improve the predictability and, consequently, the reliability of P2 as a coolant. From Figures 6a) to 6d), it can be inferred that P2 can be used at higher temperatures, which is a temperature range that makes secondary applications such as district heating realistically conceivable.

[0165] The simulation was performed using EDR (Exact Heat Exchanger). 42 server racks were simulated as heat exchangers, and the size of one server chassis was multiplied by 42 from the dimensions of the server chassis to 33m². 2 The heat exchanger area was estimated (the dimensions of one server chassis were 0.71m × 0.483m × 0.0444m). The system of 42 server racks immersed in their respective coolants was modeled in the simulation test as a shell-and-tube heat exchanger, where steam was used on the tube side (hot side) to provide a uniform temperature profile, and the respective coolants were used on the shell side.

[0166] Figure 7 is a schematic diagram of the flow sheet used in the simulation. In Figure 7, steam 710 is supplied to the system and led to three separate heat exchange systems 720, 730, and 740, each of which has its own heat exchangers 750, 760, and 770, a cooling liquid, and a cooling liquid circulation. Each heat exchanger 750, 760, and 770 represents a rack of 42 servers. In each heat exchange system, steam 710 is supplied to the tubular side of the respective heat exchangers 750, 760, and 770, and then discharged from the heat exchangers.

[0167] In the heat exchange system 720, depicted as the top row in Figure 7, the cooling liquid 780 is P2. P2 780 is supplied to the shell side of each heat exchanger 750 and then circulated by a first pump 790 to return to the shell side of the heat exchanger 750, which is configured to cool P2 through a second heat exchanger 800, representing a simulation of a rack of 42 servers.

[0168] In the heat exchange system 730 depicted in the center of Figure 7, the cooling liquid 810 is FC-40. The FC-40 810 is supplied to the shell side of each heat exchanger 760 and then circulated by a second pump 820 to return to the shell side of the heat exchanger 760, which is configured to cool the FC-40 through a third heat exchanger 830, representing a simulation of a rack of 42 servers.

[0169] In the heat exchange system 740, shown as the bottom row in Figure 7, the cooling liquid 840 is S5X. The S5X 840 is supplied to the shell side of each heat exchanger 770 and then circulated by a third pump 850 back to the shell side of the heat exchanger 770, which is configured to cool the S5X through a fourth heat exchanger 860, representing a simulation of a rack of 42 servers.

[0170] The cooling capacity of each rack (each heat exchanger 750, 760, 770) was set to 50 kW. The mass flow of the cooling liquid was changed, and the temperature of the cooling liquid in the racks (heat exchangers 750, 760, 770) increased by 4-5°C. The pressure rise inside the pump was set to 50 kP, and a mechanical efficiency of 0.6 was estimated.

[0171] Two cases were simulated: one where the rack temperature (tube side of heat exchangers 750, 760, and 770) was 37°C, and another where the rack temperature (tube side of heat exchangers 750, 760, and 770) was 27°C. The simulation results are shown in Tables 10 and 11, respectively. Note that the results shown in Tables 10 and 11 are normalized values ​​with the obtained value for P2 set to 1.

[0172] [Table 10]

[0173] [Table 11]

[0174] The results shown in Tables 10 and 11 demonstrate that P2 performs better as a coolant in single-phase direct liquid immersion cooling of server racks than either of the commercially available coolants FC-40 or S5X.

[0175] Comparing the results obtained with P2, as shown in Table 10, with those obtained with FC-40, it can be seen that P2 requires less than 1 / 4 the mass flow of the coolant, 70-80% less volume flow of the coolant, 70-80% less power consumption of the pump, and has 21% better heat conduction compared to FC-40.

[0176] In the results shown in Tables 10 and 11, the difference between P2 and S5X is smaller than the difference between P2 and FC-40. However, the performance of P2 is still superior to that of S5X in all aspects tested.

[0177] Table 12 shows the calculated practical significance of using P2 as the coolant versus using FC-40 as the coolant in single-phase direct liquid immersion cooling in a small data center (500 racks of 42 servers) and a standard-sized data center (10,000 racks of 42 servers). The calculations estimate that the results in Tables 10 and 11 are valid, and that 1.11 m³ per rack is effective. 3 A certain amount of cooling liquid was estimated.

[0178] [Table 12]

[0179] As can be inferred from Table 12, using P2 instead of FC-40 in single-phase direct liquid immersion cooling is estimated to result in approximately 600 tons less coolant required and approximately 180 kW less power usage for cooling (pumps) in a small data center, or 12,000 tons less coolant required and approximately 3,500 kW less power usage for cooling (pumps) in a standard-sized data center. In addition, capital expenditures for designing piping, pumps, and cooling with 70% to 80% lower flow rates will also be lower.

[0180] Example 5: Thermal conductivity test The thermal conductivity, thermal diffusivity, and volumetric heat capacity (volume specific heat) of the renewable paraffinic composition P2 (P2) of Example 1, and of Fluorinert® FC-40 (perfluorotri-n-butylamine), commercially available from 3M®, were measured according to ASTM D7896-19. The measurement time was 1 second, and the predicted accuracy was within 5%. The results are shown in Table 13 below. In Table 13, rsd represents the relative standard deviation.

[0181] [Table 13]

[0182] As can be seen from Table 13, P2 has a significantly higher thermal conductivity compared to FC-40. Furthermore, the thermal diffusivity and volumetric specific heat of P2 are clearly higher than those of FC-40. Higher thermal conductivity and thermal diffusivity are beneficial in single-phase direct liquid immersion cooling because they allow for faster heat transfer from the immersed object to the cooling liquid. A higher volumetric specific heat is also beneficial because, compared to cooling liquids with lower volumetric specific heat, it allows the cooling liquid to absorb more heat while causing a smaller temperature rise in the cooling liquid. Therefore, in light of Table 13, P2 is clearly more advantageous than FC-40 as a cooling liquid in single-phase direct liquid immersion cooling.

[0183] The embodiments and implementations of the present invention are further described in the following numbered sections.

[0184] Item 1. Use of a renewable paraffin-based composition for single-phase liquid direct immersion cooling, comprising at least 80 wt-% paraffin in the C16-C19 range, based on the total weight of the renewable paraffin composition. Item 2. Use of the renewable paraffin-based composition according to Item 1 for single-phase liquid direct immersion cooling of electronic hardware, preferably computer hardware, more preferably servers, or fuel cells. Item 3. Use of the recyclable paraffin-based composition according to item 1 or 2, comprising circulating the recyclable paraffin-based composition through a heat exchange unit. Item 4. Use of any one of the recyclable paraffin-based compositions described in any one of items 1 to 3, wherein the operating temperature is within a temperature range of 15°C to 90°C, preferably 15°C to 75°C, and more preferably 20°C to 65°C. Item 5. Use of the renewable paraffin-based composition according to any one of items 1 to 4, wherein the renewable paraffin-based composition comprises more than 90 wt-%, preferably at least 95 wt-%, and more preferably at least 98 wt-%, of paraffin based on the total weight of the renewable paraffin-based composition. Item 6. Use of the renewable paraffin-based composition according to any one of items 1 to 5, wherein the renewable paraffin-based composition comprises paraffin in the C16-C19 range, based on the total weight of the renewable paraffin-based composition, at a rate of 90 wt-%, preferably 95 wt-%, and more preferably 98 wt-%, of 90 wt-% or more. Item 7. Use of the renewable paraffin-based composition according to any one of items 1 to 6, wherein the renewable paraffin-based composition comprises more than 60 wt-%, preferably more than 70 wt-%, more preferably more than 80 wt-%, even more preferably more than 90 wt-%, and most preferably more than 95 wt-%, of isoparaffin on a basis of the total weight of the renewable paraffin-based composition. Item 8. Use of the renewable paraffin-based composition according to any one of items 1 to 7, wherein the renewable paraffin-based composition contains 5 wt-% or less, preferably 2 wt-% or less, of naphthenes based on the total weight of the renewable paraffin-based composition, and more preferably the renewable paraffin-based composition is substantially free of naphthenes. Item 9. Use of the renewable paraffin-based composition according to any one of items 1 to 8, wherein the renewable paraffin-based composition comprises, on a basis of the total weight of the renewable paraffin-based composition, less than 2 wt-% of C15 and lighter paraffins, and preferably less than 5 wt-%, more preferably less than 2 wt-% of C20 and heavier paraffins. Item 10. Use of the renewable paraffin-based composition according to any one of items 1 to 9, wherein the renewable paraffin-based composition contains more than 37 wt-% of C17 paraffin, based on the total weight of the renewable paraffin-based composition. Item 11. Use of the renewable paraffin-based composition according to any one of Items 1 to 10, wherein the renewable paraffin-based composition comprises more than 90 wt-% of C17-C18 paraffins, and the ratio of the amount of C18 i-paraffins to the amount of C18 n-paraffins is greater than 40, based on the weight of the C18 n-paraffins and the weight of the C18 i-paraffins in the renewable paraffin-based composition. Item 12. Use of a renewable paraffin-based composition according to any one of items 1 to 11 of (ENISO2719:2016), wherein the renewable paraffin-based composition has a flash point of at least 125°C, preferably at least 135°C, more preferably at least 140°C, and even more preferably at least 145°C. Item 13. The regenerative paraffin-based composition is 15 mm at 40°C. 2 Less than / s, preferably 10 mm 2 Less than / s, more preferably 5mm 2 Use of a renewable paraffinic composition described in any one of EN ISO 3104 sections 1 to 12, having a kinematic viscosity of less than / s. Item 14. The renewable paraffin-based composition has a yield of 700-850 kg / m³ at 20°C. 3 Preferably 760-800 kg / m 3 More preferably 770-790 kg / m 3 Use of a renewable paraffinic composition having a density within the range of any one of the following (EN ISO 12185) sections 1 to 13. Item 15. Use of a renewable paraffin-based composition according to any one of items 1 to 14 of ISO 6297:1997, wherein the renewable paraffin-based composition has an electrical conductivity of less than 1 pS / m at 22°C. Item 16. Use of a renewable paraffin-based composition according to any one of items 1 to 15, wherein the bio-derived carbon content of the renewable paraffin-based composition is at least 50 wt-%, preferably at least 70 wt-%, more preferably at least 80 wt-%, and even more preferably at least 90 wt-%, based on the total weight of carbon in the renewable paraffin-based composition (ASTM D6866 (2020) or EN 16640 (2017)). Item 17. A vessel containing a renewable paraffin-based composition comprising at least 80 wt-% paraffin in the C16-C19 range, based on the total weight of the renewable paraffin composition, and Objects to be immersed and cooled in the aforementioned recyclable paraffin composition A single-phase liquid direct immersion cooling system equipped with the following features. Item 18. Heat exchange unit; and means for circulating the recyclable paraffin-based composition through the heat exchange unit. A single-phase liquid direct immersion cooling system according to item 17, comprising: Item 19. The single-phase liquid direct immersion cooling system according to item 17 or 18, wherein the single-phase liquid direct immersion cooling system is configured to maintain the temperature of the regenerative paraffin-based composition in the tank within a temperature range of 15°C to 90°C, preferably 15°C to 65°C, more preferably 20°C to 75°C. Item 20. A single-phase liquid direct immersion cooling system according to any one of items 17 to 19, wherein two or more objects to be cooled are immersed in the regenerative paraffinic composition. Item 21. A single-phase liquid direct immersion cooling system according to any one of items 17 to 20, wherein the object or object to be cooled is electronic hardware, preferably computer hardware, more preferably a server or a group of servers, or the object or object to be cooled is a fuel cell or a group of fuel cells. Item 22. A single-phase liquid direct immersion cooling system according to any one of items 17 to 21, wherein the means for circulating the regenerative paraffin-based composition through the heat exchange unit comprises pipes and optionally a pump or a plurality of pumps. Item 23. To provide a vessel containing a renewable paraffin-based composition comprising at least 80 wt-% paraffin in the C16-C19 range, based on the total weight of the renewable paraffin composition, and Immersing the object to be cooled in the aforementioned regenerative paraffin composition. A method for single-phase liquid direct immersion cooling, including a method for such cooling. Item 24. A method for single-phase liquid direct immersion cooling according to Item 23, comprising circulating the recyclable paraffin-based composition through a heat exchange unit. Item 25. A method for single-phase liquid direct immersion cooling according to item 23 or 24, comprising maintaining the temperature of the regenerative paraffin-based composition in the tank within a temperature range of 15°C to 90°C, preferably 15°C to 75°C, more preferably 20°C to 65°C. Item 26. A method for single-phase liquid direct immersion cooling according to any one of items 23 to 25, comprising immersing two or more objects to be cooled in the regenerative paraffinic composition. Item 27. A method for single-phase liquid direct immersion cooling according to any one of items 23 to 26, wherein the object or object to be cooled is electronic hardware, preferably computer hardware, more preferably a server or a group of servers, or the object or object to be cooled is a fuel cell or a group of fuel cells.

[0185] Various embodiments are presented. Please understand that in this book, the terms "comprise," "include," and "contain" are used as open-ended expressions that do not imply exclusivity.

[0186] The foregoing description provides a complete and useful description of the best modes currently considered by the inventors for carrying out the invention, by non-limiting examples of specific embodiments and models. However, it will be apparent to those skilled in the art that the invention is not limited to the details of the embodiments presented above and can be carried out in other embodiments using equivalent means, or in various combinations of embodiments, without departing from the features of the invention. Embodiments of the Disclosure may be combined, in whole or in part, to form further embodiments (multiple embodiments) of the Disclosure. Furthermore, certain features or characteristics illustrated or described in relation to various embodiments may be combined, in whole or in part, with features or characteristics of one or more other embodiments, without limitation. Such modifications and variations are intended to be within the scope of the Disclosure.

[0187] Furthermore, some of the features of the exemplary embodiments disclosed above may be used advantageously without corresponding use of other features. Thus, the above description should be considered merely illustrative of the principles of the present invention and not limited thereto. Accordingly, the scope of the present invention is limited only by the appended claims.

Claims

1. Use of a renewable paraffin-based composition for single-phase liquid direct immersion cooling of electronic hardware, comprising, on a basis by the total weight of the renewable paraffin-based composition, at least 80 wt-% of paraffin in the C16-C19 range, wherein, on a basis by the total weight of the renewable paraffin-based composition, the renewable paraffin-based composition comprises, on a basis by the total weight of the renewable paraffin-based composition, more than 90 wt-% of paraffin, at least 99 wt-% of hydrocarbons, 5 wt-% or less of naphthenes, less than 10 wt-% of olefins, and less than 2 wt-% of C20 and heavier paraffins, and the bio-based carbon content of the renewable paraffin-based composition is at least 50 wt-% on a basis by the total weight of carbon in the renewable paraffin-based composition (ASTM D6866 (2020) or EN 16640 (2017), the renewable paraffin-based composition is used having a flash point of at least 125°C (ENISO 2719:2016).

2. The use of the renewable paraffin-based composition according to claim 1, wherein the electronic hardware is computer hardware.

3. The use of the recyclable paraffin-based composition according to claim 1 or 2, comprising circulating the recyclable paraffin-based composition through a heat exchange unit.

4. Use of a recyclable paraffin-based composition according to any one of claims 1 to 3, wherein the operating temperature is within a temperature range of 15°C to 90°C.

5. Use of the renewable paraffin-based composition according to any one of claims 1 to 4, wherein the renewable paraffin-based composition comprises at least 95 wt-% paraffin based on the total weight of the renewable paraffin-based composition.

6. Use of the renewable paraffin-based composition according to any one of claims 1 to 5, wherein the renewable paraffin-based composition comprises 90 wt-% or more of paraffin in the C16 to C19 range, based on the total weight of the renewable paraffin-based composition.

7. The use of the renewable paraffin-based composition according to any one of claims 1 to 6, wherein the renewable paraffin-based composition comprises more than 60 wt-% of isoparaffin based on the total weight of the renewable paraffin-based composition.

8. The use of the renewable paraffin-based composition according to any one of claims 1 to 7, wherein the renewable paraffin-based composition comprises less than 2 wt-% of C15 and lighter paraffins based on the total weight of the renewable paraffin-based composition.

9. The use of the renewable paraffin-based composition according to any one of claims 1 to 8, wherein the renewable paraffin-based composition comprises more than 37 wt-% of C17 paraffin based on the total weight of the renewable paraffin-based composition.

10. The use of the renewable paraffin-based composition according to any one of claims 1 to 9, wherein the renewable paraffin-based composition comprises more than 90 wt-% of paraffins in the C17-C18 range, and the ratio of the amount of C18 i-paraffin to the amount of C18 n-paraffin is greater than 40, based on the weight of the C18 n-paraffin and the weight of the C18 i-paraffin in the renewable paraffin-based composition.

11. The aforementioned recyclable paraffin-based composition is 15 mm at 40°C. 2 Use of a renewable paraffin-based composition according to any one of claims 1 to 10 having a kinematic viscosity of less than 1 / s (EN ISO 3104).

12. The aforementioned renewable paraffin-based composition has a density of 700 to 850 kg / m³ at 20°C. 3 Use of a renewable paraffin-based composition according to any one of claims 1 to 11 (EN ISO 12185) having a density within the range of .

13. Use of the renewable paraffin-based composition according to any one of claims 1 to 12, wherein the renewable paraffin-based composition has an electrical conductivity of less than 1 pS / m at 22°C (ISO 6297:1997).

14. The renewable paraffin-based composition was measured at 20°C according to ASTM D7896-19 and yielded 1.60 MJ / (m³). 3 K) ~1.90MJ / (m 3 Volumetric specific heat within the range of K, and / or thermal conductivity in the range of 0.11 W / (m·K) to 0.15 W / (m·K) as measured according to ASTM D7896-19 at 20°C, and / or 0.06 mm as measured according to ASTM D7896-19 at 20°C 2 / s ~ 0.09 mm 2 Use of a renewable paraffin-based composition according to any one of claims 1 to 13, having a thermal diffusivity in the range of / s.

15. Use of the renewable paraffin-based composition according to any one of claims 1 to 14, wherein the bio-based carbon content of the renewable paraffin-based composition is at least 70 wt-% based on the total weight of carbon in the renewable paraffin-based composition (ASTM D6866 (2020) or EN 16640 (2017)).

16. A tank containing a renewable paraffin-based composition, which includes at least 80 wt-% of paraffin in the C16-C19 range, based on the total weight of the renewable paraffin-based composition, and Electronic hardware immersed in the aforementioned renewable paraffin-based composition A single-phase liquid direct immersion cooling system comprising: a renewable paraffinic composition comprising, on a basis of the total weight of the renewable paraffinic composition, more than 90 wt-% paraffin, at least 99 wt-% hydrocarbons, 5 wt-% or less naphthenes, less than 10 wt-% olefins, and less than 2 wt-% C20 and heavier paraffins; the bio-derived carbon content of the renewable paraffinic composition being at least 50 wt-% on a basis of the total weight of carbon in the renewable paraffinic composition (ASTM D6866 (2020) or EN 16640 (2017)); and the renewable paraffinic composition having a flash point of at least 125°C (ENISO 2719:2016).

17. To provide a tank containing a renewable paraffin-based composition, based on the total weight of the renewable paraffin-based composition, which contains at least 80 wt-% of paraffin in the C16-C19 range, and Immersing electronic hardware in the aforementioned renewable paraffin-based composition. A method for single-phase liquid direct immersion cooling comprising a renewable paraffinic composition comprising, on a basis of the total weight of the renewable paraffinic composition, more than 90 wt-% paraffin, at least 99 wt-% hydrocarbons, 5 wt-% or less naphthenes, less than 10 wt-% olefins, and less than 2 wt-% C20 and heavier paraffins, wherein the bio-based carbon content of the renewable paraffinic composition is at least 50 wt-% on a basis of the total weight of carbon in the renewable paraffinic composition (ASTM D6866 (2020) or EN 16640 (2017)), and the renewable paraffinic composition has a flash point of at least 125°C (ENISO 2719:2016).

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