Methods for characterizing adsorbents

Abstract

A method for characterizing a sorbent is provided, comprising providing the sorbent, suspending the sorbent in a fluid, agitating the sorbent in the fluid, filtering the sorbent from the fluid to separate a filtrate, measuring the electrical conductivity of the filtrate, and measuring the alkalinity of the filtrate.

Description

[Technical Field]

[0001] REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Application No. 63 / 386,381, filed December 7, 2022, which is incorporated by reference in its entirety into this application.

[0002] Field The present disclosure relates generally to methods for characterizing adsorbents, and more particularly to methods for measuring the electrical conductivity, alkalinity, and ion concentration of adsorbents.

[0003] background High-temperature calcination induces changes to the surface of activated carbon, including the removal of adsorbed water, the removal of surface oxygen and other acidic groups, and the addition of basic groups that increase alkalinity. These changes may be advantageous in certain applications, such as immersion cooling. In immersion cooling, activated carbon is used to filter non-conductive liquids used in baths that remove heat from immersed computer equipment. Removing acidic groups, such as surface oxygen groups, and reducing the water content of the activated carbon is believed to reduce secondary reactions between the activated carbon surface and chemical components, including ketones, in the coolant. Without being bound by theory, the reduction of these undesirable reactions should minimize the generation of harmful by-products that could damage sensitive and expensive electronics immersed in the bath. The method described in this study offers a new, simple experimental approach to track the effects of the calcination process on activated carbon to produce consistent products at a production scale, and may also provide insight into the physical changes in the activated carbon itself.

[0004] As client computing demand and data center density continue to increase, so too do the heat dissipation requirements of electronic components such as microprocessors, chipsets, graphics processing units (GPUs), and memory modules. Traditional client computing equipment and data centers are often air-cooled using heat sinks, cooling fins, and fans that deliver cool air to the electronic components and remove waste heat through conduction and convection. Such devices and techniques have drawbacks. While air is electrically insulating and non-corrosive, it has a very high volume-to-heat ratio, making the processes of delivering cool air to the electronic components, removing the heated exhaust air, and cooling the exhaust air (typically through air conditioning) and recirculating it as cool air very mechanically energy intensive.

[0005] Immersion cooling, on the other hand, encases electronic components in a thermally conductive but electrically insulating (dielectric) coolant. This allows waste heat to be removed by the coolant, which transfers heat from the electronic components to the coolant. The heated coolant is then pumped through a heat exchanger where it is cooled by contact with another fluid, such as air or water. The coolant is electrically insulating and designed to be safe for contact with exposed, live leads, traces, surface mount pads, solder, and other electronic components during normal operation.

[0006] In immersion cooling systems, the electronic device being cooled is typically submerged in a coolant. Over time, various material components of the electronic device can leach into the coolant. While the coolant itself is electrically insulating, metals from solder and metallic electronic components, elastomers, solder flux, resistive materials, PVC insulation, foams, adhesives, and hydrocarbon oils contained in the reaction products of these materials with the coolant introduce contaminants that increase the coolant's electrical conductivity. This is undesirable, and these contaminants must be removed.

[0007] While filtration systems for immersion cooling systems currently exist, the materials used require large amounts of adsorbent, resulting in very frequent filter replacement. For example, typically, a volume of adsorbent approximately five times the mass of contaminants expected in the coolant is provided within the vessel. Optimizing adsorbent materials, particularly those within filters, to improve their efficiency and adsorption capacity would be an industrial advancement that would reduce the costs associated with immersion cooling. This would not only reduce the frequency of adsorbent replacement, but also improve efficiency by allowing the use of a higher-purity coolant. Such adsorbents also have the advantage of not introducing contaminants into the coolant itself. Summary of the Invention

[0008] In some aspects, the technology described herein relates to a method of characterizing a sorbent, comprising providing a sorbent, suspending the sorbent in a fluid, agitating the sorbent in the fluid, filtering the sorbent from the fluid to isolate a filtrate, measuring the electrical conductivity of the filtrate, and measuring the alkalinity of the filtrate.

[0009] In some aspects, the technology described herein relates to methods wherein the fluid is deionized water.

[0010] In some embodiments, the technology described herein relates to methods wherein the step of agitating the adsorbent is carried out for a time period of about 1 hour to about 24 hours.

[0011] In some embodiments, the technology described herein relates to a method comprising measuring the alkalinity of a filtrate, comprising providing a sample of the filtrate, performing a first titration on the sample with a first acid and a first indicator to a first endpoint pH to provide a first alkalinity measurement, performing a second titration on the sample with a second acid and a second indicator to a second endpoint pH to provide a second alkalinity measurement, and calculating the total alkalinity of the sample.

[0012] In some embodiments, the technology described herein relates to methods wherein the first acid and the second acid comprise sulfuric acid.

[0013] In some embodiments, the technology described herein relates to methods wherein the first indicator comprises phenolphthalein.

[0014] In some embodiments, the technology described herein relates to methods wherein the first endpoint pH is from about 7.5 to about 9.0.

[0015] In some embodiments, the technology described herein relates to methods wherein the second indicator comprises bromocresol green-methyl red.

[0016] In some embodiments, the technology described herein relates to methods wherein the second endpoint pH is from about 4.0 to about 5.0.

[0017] In some embodiments, the technology described herein relates to a method, wherein calculating the total alkalinity of the sample comprises adding the first alkalinity measurement and the second alkalinity measurement.

[0018] In some embodiments, the techniques described herein relate to methods that further include measuring the concentrations of carbonate ions, bicarbonate ions, and hydroxide ions in the filtrate.

[0019] In some embodiments, the technology described herein relates to methods in which the total alkalinity is substantially attributable to bicarbonate ions.

[0020] In some embodiments, the technology described herein relates to methods in which the total alkalinity is substantially attributable to hydroxide ions.

[0021] In some embodiments, the technology described herein relates to methods in which the total alkalinity is substantially attributable to carbonate ions.

[0022] In some embodiments, the technology described herein relates to methods in which the total alkalinity is substantially attributable to a combination of carbonate and bicarbonate ions.

[0023] In some embodiments, the technology described herein relates to methods in which the total alkalinity is substantially attributable to a combination of carbonate and hydroxide ions.

[0024] In some embodiments, the technology described herein relates to a method of purifying a refrigerant containing one or more electrically conductive contaminants, the method comprising contacting the refrigerant with a sorbent such that the sorbent adsorbs the one or more electrically conductive contaminants, wherein the sorbent has a filtrate alkalinity of between about 10 mg / L CaCO and about 60 mg / L CaCO and a filtrate electrical conductivity of less than about 650 μS, and the sorbent comprises activated carbon.

[0025] In some embodiments, the technology described herein relates to methods wherein the sorbent has a filtrate alkalinity of about 30 mg / L CaCO to about 50 mg / L CaCO.

[0026] In some embodiments, the technology described herein relates to methods wherein the adsorbent has a filtrate conductivity of about 5 μS to about 200 μS.

[0027] In some embodiments, the technology described herein relates to methods in which activated carbon is formed from bituminous coal, sub-bituminous coal, lignite, anthracite, wood, peat, nut shells, pits, coconut, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, bagasse, rice bran, corn husks, wheat husks, polymers, resins, petroleum pitch, other charred materials, or combinations thereof.

[0028] In some embodiments, the technology described herein relates to a composition for purifying a coolant containing one or more electrically conductive contaminants, the composition comprising a sorbent having a filtrate alkalinity of between about 10 mg / L CaCO and about 60 mg / L CaCO and a filtrate electrical conductivity of less than about 650 μS, wherein the sorbent comprises activated carbon.

[0029] In some embodiments, the technology described herein relates to methods wherein the sorbent has a filtrate alkalinity of about 30 mg / L CaCO to about 50 mg / L CaCO.

[0030] In some embodiments, the technology described herein relates to methods wherein the adsorbent has a filtrate conductivity of about 5 μS to about 200 μS.

[0031] In some embodiments, the technology described herein relates to methods in which activated carbon is formed from bituminous coal, sub-bituminous coal, lignite, anthracite, wood, peat, nut shells, pits, coconut, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, bagasse, rice bran, corn husks, wheat husks, polymers, resins, petroleum pitch, other charred materials, or combinations thereof.

[0032] In some embodiments, the technology described herein relates to a method for producing a sorbent for purifying a refrigerant containing one or more electrically conductive contaminants, the method comprising providing a precursor sorbent material and subjecting the precursor sorbent material to at least one treatment method to form a sorbent having a filtrate alkalinity of between about 10 mg / L CaCO and about 60 mg / L CaCO and a filtrate electrical conductivity of less than about 650 μS, wherein the sorbent comprises activated carbon.

[0033] In some embodiments, the technology described herein relates to methods where the precursor sorbent material is formed from one or more of bituminous coal, sub-bituminous coal, lignite, anthracite, wood, peat, nut shells, pits, coconut, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, bagasse, rice bran, corn husks, wheat husks, polymers, resins, petroleum pitch, other charred materials, or combinations thereof.

[0034] In some embodiments, the technology described herein relates to methods wherein at least one treatment method comprises one or more of calcining, drying, treating under vacuum, nitrogen, hydrogen, carbon monoxide, ammonia, methane, argon, or combinations thereof, microwave-assisted heat treating, immersion with a metal or oxygen scavenger, or combinations thereof.

[0035] In some embodiments, the technology described herein relates to methods wherein the sorbent has a filtrate alkalinity of about 30 mg / L CaCO to about 50 mg / L CaCO.

[0036] In some embodiments, the technology described herein relates to methods wherein the adsorbent has a filtrate conductivity of about 5 μS to about 200 μS. [Brief explanation of the drawings]

[0037] Aspects, features, benefits, and advantages of the embodiments described herein will become apparent with reference to the following description, appended claims, and accompanying drawings.

[0038] [Figure 1] FIG. 1 shows a schematic diagram of an immersion cooling system that can use the adsorbents disclosed herein. [Figure 2] FIG. 2 shows a schematic diagram of a two-phase immersion cooling system that can use the adsorbents disclosed herein. [Figure 3]FIG. 3 shows the decolorization curve of the adsorbent material, showing the relative amount of decolorization achieved versus the measured molasses number of the adsorbent material. [Figure 4] FIG. 4 shows an example of a spectral scan showing the transmittance of a molasses filter as a function of wavelength of light. [Figure 5] FIG. 5 is a bar graph of filtrate conductivity for a first set of representative adsorbent samples. [Figure 6] FIG. 6 is a bar graph of filtrate conductivity for a second set of representative adsorbent samples. [Figure 7] FIG. 7 is a bar graph of filtrate conductivity for a third set of representative adsorbent samples. [Figure 8] FIG. 8 is a bar graph showing the filtrate conductivity of five lots (Lot #1, Lot #2, Lot #3, Lot #4, and Lot #5) of untreated, dried, or calcined F / S RB material stirred for 1 hour. DETAILED DESCRIPTION OF THE INVENTION

[0039] Before describing the compositions and methods of the present invention, it is to be understood that the scope of this invention is not limited to the particular steps, compositions, or methods described herein, as these may vary. Furthermore, the terminology used in the description is for the purpose of describing particular versions or examples only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims. Unless otherwise defined, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, the preferred methods, devices, and materials are described below. All publications mentioned herein are incorporated by reference insofar as the publication is specifically identified as describing them. Nothing contained herein should be construed as an admission that the invention is not entitled to priority by virtue of prior invention.

[0040] As used in this document, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. Unless otherwise defined, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art. This disclosure should not be construed as an admission that the embodiments described herein are not entitled to priority over the present disclosure by virtue of prior invention. As used herein, the term "comprising" means "including, but not limited to."

[0041] As used herein, the term "about" means plus or minus 10% of the numerical value with which it is used. For example, "about 50%" means a range of 45% to 55%.

[0042] As used herein, "electronics rack" refers to a housing, frame, rack, compartment, blade server system, or the like that contains one or more heat-generating components of a computer system, electronic system, or information technology equipment, and may include, for example, independent computer processors with high, medium, or low performance processing capabilities. As used herein, "electronic components" refer to heat-generating electronic components that require cooling, such as those of a computer system or other electronics unit. For example, electronic components may include one or more integrated circuit dies and / or other electronic devices that require cooling, including one or more processor dies, memory dies, or memory support dies. As used herein, "data center" refers to a computer installation that includes one or more electronics racks that require cooling. As a specific example, a data center may include one or more rows of rack-mounted computing units, such as server units. A data center may include one or more processing resources, including random access memory (RAM), central processing units (CPUs) or hardware or software control logic, ROM, and / or other types of non-volatile memory. Additional components of a data center may include one or more disk drives, one or more network ports for communication with external devices, and various input / output (I / O) devices such as a keyboard, mouse, video display, etc. An information handling system may include one or more buses for carrying communications between various hardware components.

[0043] As used herein, the term "adsorbent material" refers to a material that exhibits adsorption, absorption, or a combination of adsorption and absorption properties. Adsorption refers to the attachment of atoms, ions, or molecules to the surface of the material. Absorption refers to the insertion and retention of atoms, ions, or molecules into the bulk phase of the material. Examples of adsorbent materials include, but are not limited to, activated carbon, reactivated carbon, natural and synthetic zeolites, silica, silica gel, alumina, zirconia, and diatomaceous earth. As used herein, the term "adsorbent material" refers to a material whose constituent components are substantially adsorbent and / or absorbent and which contains only minimal components that are not adsorbent and / or absorbent (e.g., the minimum binder required to maintain the shape of activated carbon pellets).

[0044] As used herein, the term "sorbent" refers to any composition or composite that includes a sorbent material as a blend, mixture, composite, or compound with one or more additional materials that do not have adsorbent properties. For example, one embodiment of a sorbent includes an activated carbon sorbent material mixed with a thermally conductive filler.

[0045] The adsorbents described herein can be characterized by a variety of properties, including density, porosity, transport structure, weight molasses number, weight iodine number, volumetric iodine number, alkalinity, filtrate alkalinity, electrical conductivity, filtrate electrical conductivity, oxygen concentration, and mixed concentration. Many of these properties can be characterized using standardized methods from ASTM International. For example, pore (or void) volume can be measured using ASTM D4284-12(2017)e1 or equivalent. Pores can be classified into three general size ranges: micropores have a pore diameter of less than about 2 nm; mesopores have a pore diameter ranging from 2 nm to 50 nm; and macropores have a pore diameter greater than 50 nm. Particle size distribution can be determined according to ASTM D2862-16 or equivalent. Moisture content can be measured using ASTM D2867-17 or equivalent. Gravimetric iodine number can be measured according to standard test method ASTM D4607-14 or equivalent. Volumetric iodine number can be calculated using gravimetric iodine number and apparent density, which can be measured according to ASTM D2854-09(2019) or equivalent.

[0046] As used herein, "gravity molasses number" refers to measuring the decolorizing capacity of an adsorbent or adsorbent material according to Calgon Carbon Method No. TM-3, "Determination of the Molasses Number of Activated Carbon." The full test procedure is described in detail herein. Gravity molasses number is reported as a unitless amount per mass of adsorbent or adsorbent material.

[0047] The adsorbents (and enclosures and systems containing them) are used to purify coolants that become contaminated during use. For example, one or more components (e.g., polymers, metals) of data center construction materials can leach into the coolant. In another example, the coolant can react with one or more components of the construction materials to produce reaction products that contaminate the coolant. These contaminants can increase the electrical conductivity of the coolant, potentially posing a risk to the operation of electronic components. Therefore, systems for removing such contaminants can be implemented. Against this background, provided herein are apparatus assemblies and methods for use in purifying coolants, such as those used for purifying coolants in immersion cooling applications. Details of such assemblies and methods used for purifying coolants are further described in U.S. Patent Application No. 17 / 805,628, which is incorporated herein by reference in its entirety.

[0048] Such an assembly of devices includes a container configured to contain a coolant and a sorbent within a housing, the housing configured to contact the sorbent with the coolant. The assembly of devices may be housed within a system for immersion cooling, such as an immersion cooling system for electronic components in a data center or other location requiring cooling. As shown in FIG. 1, such a system 100 may include a tank 102 filled with a volume of coolant 104, an electronic component 106, and a housing 110 containing the sorbent.

[0049] Examples of adsorbents compatible with the methods and apparatus assemblies disclosed herein include, but are not limited to, carbide carbon, activated carbon, reactivated carbon, natural zeolites, synthetic zeolites, silica, silica clay, carbon nanotubes, graphene, etc. Preferably, the adsorbent comprises activated carbon, which is used below to illustrate various aspects of methods and apparatus assemblies compatible with refrigerant purification. However, the use of any of the above-listed adsorbents in any of the methods and apparatus assemblies described below does not depart from the methods and systems disclosed and contemplated herein.

[0050] In any embodiment, the adsorbent can include activated carbon. Examples of activated carbon include, but are not limited to, bituminous coal, subbituminous coal, lignite, anthracite, wood, peat, nut shells, pits, coconut, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, bagasse, rice bran, corn husks, wheat husks, polymers, resins, petroleum pitch, other charcoal materials (e.g., extruded pellets), or combinations thereof. Commercially available sources of activated carbon include, but are not limited to, ACTICARBONE® activated carbon (supplied by Calgon Carbon Corporation), BGX (a wood / plant-derived activated carbon, granular grade activated with phosphoric acid), RB (manufactured by Calgon Carbon Corporation), a coal-derived activated carbon, or Kuraray (e.g., Kuraray Coal™) activated carbon.

[0051] In any embodiment, the adsorbent (activated carbon or other) may be provided in powder, granular, or pellet form. For example, activated carbon may be provided in powder form, or may be provided in granular form, such as (but not limited to) reagglomerated carbon powder, crushed granules, etc., obtained by processing (e.g., grinding, crushing, etc.) the above materials. As used herein, "granular activated carbon (GAC)" refers to activated carbon particles of a size that will be retained on a 50-mesh sieve (approximately 0.300 mm openings). As used herein, "powdered activated carbon (PAC)" refers to activated carbon particles of a size that will pass through an 80-mesh sieve (approximately 0.180 mm openings).

[0052] Activated carbon may be formed by known methods, such as carbonization and activation or direct activation. For example, wood, nutshells, coal, pitch, or similar raw materials may be oxidized and devolatilized with steam and / or carbon dioxide to create pore structures in the carbonaceous material and generate adsorption sites. The oxidation and devolatilization process may include, for example, chemical treatment with dehydration chemicals including phosphoric acid, boric acid, sulfuric acid, sodium hydroxide, potassium hydroxide, or combinations thereof. In some embodiments, a method for producing a sorbent for purifying one or more electrically conductive contaminants contained in a refrigerant is provided, the method comprising providing a precursor sorbent material and subjecting the precursor sorbent material to at least one treatment process to form a sorbent having a filtrate alkalinity of 10 mg / L CaCO3 to about 60 mg / L CaCO3 and a filtrate electrical conductivity of less than 650 μS, the sorbent comprising activated carbon. In some embodiments, the at least one treatment method may include calcining, drying, treatment under vacuum, nitrogen, hydrogen, carbon monoxide, ammonia, methane, argon, or a combination thereof, microwave-assisted heat treatment, metal or oxygen scavenger immersion, or a combination thereof.

[0053] The performance of adsorbents in liquid coolants may be improved by reducing the moisture and / or oxygen content of the adsorbent. Therefore, the adsorbent can be dried to remove moisture. Suitable drying methods include known methods under vacuum or by heating (e.g., in an oven), for example, in air, in an inert atmosphere, or under vacuum at temperatures between about 105°C and about 175°C. The adsorbent can be calcined to remove surface oxygen groups. Calcination is a known process that can be carried out at temperatures between about 500°C and about 1000°C under an inert atmosphere. In some embodiments, drying of the adsorbent may be omitted.

[0054] The adsorbent material can be activated to a desired apparent density, molasses number, and iodine number by controlling the steam injection rate, temperature, residence time, and activation gas (e.g., steam, carbon dioxide, or the like) content. One skilled in the art can determine and, if necessary, optimize appropriate activation conditions to provide an adsorbent having the desired disclosed properties.

[0055] For example, a suitable adsorbent (e.g., activated carbon) for the methods and systems disclosed herein has a sorbent density of about 0.2 g / cm 3 ~Approx. 1g / cm 3 may exhibit apparent densities in the range of, for example, about 0.3 g / cm 3 ~about 0.7g / cm 3 , about 0.2g / cm 3 ~ approx. 0.4g / cm 3 , or about 0.2 g / cm 3 ~about 0.5g / cm 3In addition, or alternatively, adsorbents such as activated carbon may exhibit an iodine number of at least about 800 mg / g, e.g., from about 800 mg / g to about 2000 mg / g, from about 900 mg / g to about 1500 mg / g, or from about 1000 mg / g to about 1500 mg / g. Suitable adsorbents (e.g., activated carbon) have a weight-based molasses number (GMT) of at least about 330, e.g., from about 330 to 6000, or from about 330 to about 900 (e.g., if derived from coal), or from about 1000 to about 6000 (e.g., if derived from wood). Suitable adsorbents such as activated carbon may also have a moisture content of less than about 15%, more preferably less than about 10%, less than about 2.5%, or from about 0.6% to about 2.5%. Regardless of the origin of the sorbent, it is preferred that less than about 5% by weight of the sorbent have a particle size of 40 mesh (US standard) or 0.425 mm or less, as measured by ASTM D2862-16 (or equivalent test method). Suitable sorbents also desirably have an ash content of not more than about 23% by weight. Suitable sorbents may, for example, have an ash content of about 23% or less, e.g., about 20% or less, about 15% or less, about 10% or less, 5%, or about 3% or less. In some embodiments, a sorbent is provided for purifying a refrigerant containing one or more conductive contaminants, the sorbent having an ash content of about 10 mg / L CaCO3 to about 60 mg / L CaCO3 (e.g., about 10 mg / L CaCO3). 3、 Approximately 20mg / L CaCO 3、 Approx. 30mg / L CaCO3, approx. 40mg / L CaCO 3、 Approximately 50mg / L CaCO 3、 The adsorbent has a filtrate alkalinity of about 60 mg / L CaCO, or any range or value therein, and a filtrate conductivity of less than about 650 μS, e.g., about 5 μS, about 10 μS, about 50 μS, about 100 μS, about 150 μS, about 200 μS, about 300 μS, about 400 μS, about 500 μS, about 600 μS, about 650 μS, or any range or value therein, and the adsorbent comprises activated carbon. In some embodiments, the adsorbent exhibits a combination of one or more of the properties described herein.

[0056] In either embodiment, the adsorbent, such as activated carbon, can be subjected to a process to desorb or react (oxidize) surface products, the presence of which can be measured by X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), elemental analysis, temperature programmed desorption, temperature programmed desorption with mass spectroscopy, Boehm titration, water adsorption, water equilibrium, or measuring the mass difference before and after drying of the activated carbon, or a combination thereof.

[0057] For example, the adsorbent can be provided after being degassed under nitrogen to remove oxygen-containing surface groups and moisture. Optionally, the adsorbent can be provided packaged in a vacuum-packaged container, for example, according to the method disclosed in U.S. Pat. No. 6,131,368, the entire contents of which are incorporated herein by reference. For example, the adsorbent can be heated and cooled in a gas-impermeable packaging material (e.g., a bag) under nitrogen, and the packaging can be hermetically sealed after creating a sufficient vacuum within the packaging. For example, in any embodiment in which the adsorbent includes activated carbon, the carbonized material can be heated to about 500°C to about 950°C under an inert atmosphere, calcined for a predetermined period of time, cooled to about 100°C under an inert atmosphere, packed into a packaging material under an inert atmosphere, further cooled under an inert atmosphere, and sealed.

[0058] The present disclosure further provides a method for purifying a refrigerant using such a sorbent, comprising contacting the refrigerant with the sorbent under conditions effective to transfer contaminants in the refrigerant to the sorbent, such as by adsorption or absorption. Examples of sorbents suitable for use in the methods and systems disclosed herein include, but are not limited to, carbide carbon, activated carbon, reactivated carbon, natural and synthetic zeolites, silica, silica clay, carbon nanotubes, graphene, and the like. For example, a suitable sorbent, such as activated carbon, has a sorbent density of about 0.2 g / cm. 3 ~Approx. 1g / cm 3 may exhibit apparent densities in the range of, for example, about 0.3 g / cm 3 ~about 0.7g / cm 3 , about 0.2g / cm 3 ~ approx. 0.4g / cm 3, or about 0.2 g / cm 3 ~about 0.5g / cm 3 In addition, or alternatively, adsorbents such as activated carbon may exhibit an iodine number of at least about 800 mg / g, e.g., from about 800 mg / g to about 2000 mg / g, from about 900 mg / g to about 1500 mg / g, or from about 1000 mg / g to about 1500 mg / g. Suitable adsorbents (e.g., activated carbon) have a weight-based molasses number (GMT) of at least about 330, e.g., from about 330 to 6000, or from about 330 to about 900 (e.g., if derived from coal), or from about 1000 to about 6000 (e.g., if derived from wood). Suitable adsorbents such as activated carbon may also have a moisture content of less than about 15%, more preferably less than about 10%, less than about 2.5%, or from about 0.6% to about 2.5%. Regardless of the origin of the sorbent, it is preferred that less than about 5% by weight of the sorbent have a particle size of 40 mesh (US standard) or 0.425 mm or less, as measured by ASTM D2862-16 (or an equivalent test method). Suitable sorbents may, for example, have an ash content of about 23% or less, e.g., about 20% or less, about 15% or less, about 10% or less, 5%, or about 3% or less. In some embodiments, a method for purifying a refrigerant containing one or more electrically conductive contaminants is provided, the method comprising contacting the refrigerant with a sorbent to adsorb the one or more electrically conductive contaminants onto the sorbent, the sorbent having a sorbent content of between about 10 mg / L CaCO3 and about 60 mg / L CaCO3 (e.g., about 10 mg / L CaCO3). 3、 Approximately 20mg / L CaCO 3、 Approx. 30mg / L CaCO3, approx. 40mg / L CaCO 3、 Approximately 50mg / L CaCO 3、 The adsorbent has a filtrate alkalinity of about 60 mg / L CaCO, or any range or value therein, and a filtrate conductivity of less than about 650 μS, e.g., about 5 μS, about 10 μS, about 50 μS, about 100 μS, about 150 μS, about 200 μS, about 300 μS, about 400 μS, about 500 μS, about 600 μS, about 650 μS, or any range or value therein, and the adsorbent comprises activated carbon. In some embodiments, the adsorbent exhibits a combination of one or more of the properties described herein.

[0059] To effectively contact the refrigerant with the sorbent, the sorbent can be provided in a form suitable for passive or active filtering of the refrigerant. For example, referring back to FIG. 1 , the sorbent can be provided in cartridge form and used in combination with a housing 110, configured to be replaceable as needed. The housing 110 includes an inlet 114, an outlet 116, and a pump 112 that actively transports the refrigerant through the sorbent cartridge within the housing 110. Methods and devices for using a pump to force the refrigerant through a sorbent filter are well known to those skilled in the art. For example, pumps commonly used in automotive fuel pumps can be used. Alternatively, the housing itself can have a permeable structure that allows the refrigerant to pass through, such as a perforated wall, allowing the refrigerant to passively contact the sorbent. This configuration is particularly useful when the required amount of refrigerant is low or when diffusion of contaminants is sufficient to remove them to the filter. Optionally, the container can incorporate or be connected to a size exclusion filter downstream of the sorbent to capture the sorbent material, including the sorbent, contained in the container's wastewater. For example, the mesh size of the filter can be about 325 mesh to about 40 mesh, for example, about 200 mesh to about 40 mesh, about 100 mesh to about 40 mesh, or about 80 mesh to about 40 mesh. In this specification, mesh sizes conform to US standards, with 325 mesh corresponding to an opening size of about 44 μm, 200 mesh corresponding to an opening size of about 75 μm, 100 mesh corresponding to an opening size of about 150 μm, 80 mesh corresponding to an opening size of about 180 μm, and 40 mesh corresponding to an opening size of about 425 μm.

[0060] The adsorbent is placed in the enclosure in an amount approximately two to three times the mass of contaminants expected in the refrigerant. This amount is less than that recommended by current technology. For example, calculate the total mass of elastomer that will come into contact with the refrigerant and assume that approximately 0.1% (in a relatively clean case) to approximately 25% (in an extreme case) of that mass is contaminants that may leach into the refrigerant. In either embodiment, approximately 200 g of adsorbent can be used to remove contaminants from up to approximately 800 L of refrigerant. In either embodiment, the method for purifying a refrigerant can include removing the adsorbent and replacing it with new adsorbent. Optionally, the adsorbent, particularly in embodiments where the adsorbent includes activated carbon, can be reactivated or calcined by known methods for this purpose.

[0061] The immersion cooling system, equipment assembly, and adsorbent therein are not particularly limited in terms of compatible coolants and can be used to purify any coolant suitable for cooling electronic components. Those skilled in the art will be familiar with the types of useful coolants and their desirable properties. Generally, immersion cooling employs single-phase or two-phase cooling systems to dissipate heat generated by electronic components. In single-phase cooling systems, the coolant is typically supplied in liquid phase and remains liquid during cooling. Energy transferred from the electronic components to the coolant is dissipated by convection, mechanical agitation, or a combination thereof. The direction of energy flow (from or to the device) is determined by the relative energy (i.e., temperature) difference between the device and the heat transfer mechanism. In two-phase systems, the coolant is typically supplied as a liquid. Heat generated on the surface of the electronic components is transferred to the liquid coolant, where it evaporates, forming vapor bubbles that rise to the liquid coolant's surface. A condenser placed on the liquid coolant's surface can operate at a temperature lower than the condensation temperature of the rising vapor, condensing the evaporated coolant back into a liquid phase.

[0062] In any application, a coolant suitable for cooling electronic components must have a dielectric constant and electrical conductivity low enough so as not to cause problems in the circuitry of the electronic components. For example, a suitable coolant may have a dielectric constant (e.g., as measured by ASTM D924) at 1 kHz of less than about 10 (e.g., from about 0.1 to about 10), preferably less than about 7.5 (e.g., from about 0.1 to about 7.5). Suitable coolants also have a dielectric constant of less than about 10 8 Ω cm ~ approx. 10 15 It may have an electrical resistivity (eg, as measured by ASTM D257-14) of less than Ω·cm.

[0063] Additionally, the coolant may have sufficient thermal conductivity and specific heat capacity to efficiently transfer energy from the electronic component, and a viscosity that allows the coolant to move freely. For example, a suitable coolant may have a specific heat (e.g., as measured by ASTM E1269-11(2018)) of about 1000 J / kg·K to about 1350 J / kg·K. A suitable coolant may have a thermal conductivity (e.g., as measured by ASTM D2717-86) in the range of about 0.05 W / m°C to about 0.5 W / m°C. A suitable coolant may have a kinematic viscosity (e.g., as measured by ASTM D341-77) of about 0.80 cSt or less, e.g., about 0.25 cSt to about 0.80 cSt.

[0064] A suitable coolant for use in a single-phase cooling system may have, for example, a high atmospheric boiling point. In a two-phase cooling system, the boiling point of the coolant is set lower than the operating surface temperature of the electronic component (to ensure evaporation at the interface) and higher than the ambient operating temperature, so that the majority of the coolant remains in the liquid phase. For example, a suitable coolant in a two-phase system may have a boiling point in the range of about 34°C to about 175°C. A coolant in a two-phase system may also exhibit a high latent heat of vaporization.

[0065] The coolant can be a single fluid or a mixture of fluids. Examples of suitable coolants include oils (e.g., mineral oil, vegetable oil, castor oil, silicone oil), ketones and perfluorinated ketones (e.g., 3M™ Novec™ 649 or 774 sold by 3M™), hydrocarbons and perfluorinated hydrocarbons (e.g., FC-72, FC-84, FC-3284, FC-3283, FC-40 sold by 3M™), polyphenyl ether or hydrofluoroether (HFE) fluids (e.g., Santovac™ 5 pump fluid, sold by 3M™). 3M™ Novec™ 7000, 7100, 7200, 7300, 7500, or 7700), hydrofluoroether olefins (HFEOs), hydrofluoroolefins (HFOs), hexafluoropropylene trimers (including, for example, those disclosed in U.S. Pat. No. 10,662,359, the disclosure of which regarding trimers is incorporated herein by reference), diphenyl ether / biphenyl, or mixtures thereof.

[0066] The adsorbent-based immersion cooling system disclosed herein may include other components in addition to those listed above. As shown in FIG. 1, the coolant 104 and electronic components 106 are contained within a tank 102, which may be formed from welded metal (e.g., carbon steel, aluminum, stainless steel) or glass and insulated to prevent heat loss. The tank has a capacity sufficient to hold a sufficient amount of coolant to cool the electronic components therein. For example, the tank may have a capacity of 500 L to 1000 L. In a two-phase cooling system such as that shown in FIG. 2 (identical components described in FIG. 1 are designated by the same numerals), evaporated coolant 226 rises to the coolant surface 208 and forms a vapor layer above the coolant surface 208, referred to as the vapor zone 218. The two-phase cooling system 200 therefore further includes a condenser 220 disposed within the vapor zone 218 to re-condense the evaporated coolant. A two-phase system may also include a desiccant 222 to collect water that migrates to a headspace 224 above the vapor zone. The desiccant 222 may be placed above the vapor region 218 and provided in a volume at least five times the expected volume of water. The immersion cooling system and equipment assembly may include pressure control, for example via a bellows connected to a solenoid valve controlled by a mechanical and pressure switch, a pump to control fluid level, a heat source, a heat sink, a refrigeration system, an active or passive temperature control system, a heat exchanger, or any combination thereof.

[0067] Methods for characterizing adsorbents are provided, the methods including providing an adsorbent, and in some embodiments including suspending the adsorbent in a fluid, agitating the adsorbent in the fluid, filtering the adsorbent from the fluid to isolate a filtrate, measuring the electrical conductivity of the filtrate, and measuring the alkalinity of the filtrate.

[0068] The adsorbent may include activated carbon, reactivated carbon, natural zeolite, synthetic zeolite, silica, silica gel, alumina, zirconia, and diatomaceous earth. In some embodiments, the adsorbent has undergone thermal or chemical treatment, including impregnation with additives, calcination, or a combination thereof. The treatment or treatments that the adsorbent has undergone prior to evaluation by this method are not particularly limited.

[0069] In some embodiments, the fluid is deionized water. In some embodiments, the fluid has a resistivity in the range of about 15 MΩ to about 20 MΩ. In some embodiments, the adsorbent is stirred for a period of about 1 hour to about 24 hours. Stirring can be accomplished by methods known to those skilled in the art, including magnetic stirring, ultrasonic stirring, or other methods, or combinations thereof.

[0070] In some embodiments, measuring the alkalinity of the filtrate includes providing a sample of the filtrate, performing a first titration on the sample with a first acid and a first indicator, titrating to a first endpoint pH to provide a first alkalinity measurement, performing a second titration on the sample with a second acid and a second indicator, titrating to a second endpoint pH to provide a second alkalinity measurement, and calculating the total alkalinity of the sample.

[0071] In some embodiments, the first acid and the second acid comprise sulfuric acid. The sulfuric acid may be dilute or concentrated, and the concentration of the sulfuric acid is not particularly limited. In some embodiments, other strong acids may be used in the method, including, but not limited to, nitric acid, hydrochloric acid, hydrobromic acid, or hydroiodic acid. In some embodiments, the first indicator comprises phenolphthalein. In some embodiments, the second indicator comprises bromocresol green-methyl red.

[0072] In some embodiments, the first endpoint pH is in the range of about 7.5 to about 9.0, including, for example, about 7.5, about 8.0, about 8.5, about 9.0, or any value within that range. In some embodiments, the second endpoint pH is in the range of about 4.0 to about 5.0, including, for example, about 4.0, about 4.1, about 4.2, about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8, about 4.9, about 5.0, or any value within that range.

[0073] In some embodiments, the first alkalinity measurement and the second alkalinity measurement are added to calculate the total alkalinity of the sample. In some embodiments, the disclosed methods further include measuring the concentrations of carbonate, bicarbonate, and hydroxide ions in the filtrate. The first alkalinity measurement may be referred to as P-alkalinity or phenolphthalein alkalinity. Determining the concentrations of carbonate, bicarbonate, and hydroxide ions in the filtrate, in some embodiments, includes determining the alkalinity contribution of each ion: carbonate, bicarbonate, and hydroxide, and using this information to calculate the concentration of each ion.

[0074] The relationship between total alkalinity and P-alkalinity can be used to determine the individual alkalinity contributions of carbonate, bicarbonate, and hydroxide in a particular sample. When P-alkalinity is zero, total alkalinity equals bicarbonate alkalinity. When P-alkalinity equals total alkalinity, total alkalinity equals hydroxide alkalinity. When P-alkalinity is less than half of total alkalinity, carbonate alkalinity equals twice P-alkalinity, and bicarbonate alkalinity equals total alkalinity minus carbonate alkalinity. When P-alkalinity equals half total alkalinity, carbonate alkalinity equals total alkalinity. When P-alkalinity is greater than half total alkalinity, hydroxide alkalinity equals twice P-alkalinity minus total alkalinity, and carbonate alkalinity equals twice total alkalinity minus P-alkalinity. Table 1 summarizes these relationships and is adapted from the accompanying Hach Method 8203. [Table 1]

[0075] Equations are provided for determining hydroxide, carbonate, and bicarbonate alkalinity based on the P-alkalinity and total alkalinity of a sample, as shown in Table 1. In embodiments of the method, when the first alkalinity measurement is zero, the total alkalinity is substantially attributable to bicarbonate ions; when the second alkalinity measurement is zero, the total alkalinity is substantially attributable to hydroxide ions; and when the first alkalinity measurement is equal to half the total alkalinity, the total alkalinity is substantially attributable to carbonate ions. In some embodiments of the present disclosure, when the P-alkalinity is less than half the total alkalinity, the carbonate alkalinity is equal to two times the P-alkalinity, and the bicarbonate alkalinity is equal to the total alkalinity minus the carbonate alkalinity. In some embodiments, when the P-alkalinity is more than half the total alkalinity, the hydroxide alkalinity is equal to two times the P-alkalinity minus the total alkalinity, and the carbonate alkalinity is equal to two times the total alkalinity minus the P-alkalinity. In some embodiments, without being bound by theory, the methods of the present disclosure can be used to determine the types and concentrations of ions eluted from a sorbent and to evaluate the effect of sorbent treatment methods, such as calcination, on the ions eluted from the sorbent. In some embodiments, observing the ions eluted from a sorbent can be advantageous for selecting a sorbent and treatment method appropriate for a particular application. In some embodiments, observing trends in alkalinity, electrical conductivity, and / or ion concentrations measured by the methods described herein can be used to develop new sorbent treatment methods optimized for specific applications, depending on the needs of the sorbent user.

[0076] Example Before describing the examples, the test methods will be described in detail.

[0077] Measurement of weight molasses number

[0078] Calgon Carbon Corporation Test Method No. TM-3 ("TM-3") was used to determine the gravimetric molasses number. TM-3 is intended to determine the decolorization capacity of activated carbon. The decolorization capacity of activated carbon represents the pore structure and mass transport properties of activated carbon. The gravimetric molasses number was determined according to TM-3. The volumetric molasses number was calculated by multiplying the TM-3 molasses number by the apparent density obtained according to ASTM D2854-09(2019). The gravimetric molasses number was determined according to TM-3 as follows:

[0079] Limitations: The concentration of the molasses solution used in the test depends on the standard charcoal. As used herein, "standard charcoal" refers to an activated charcoal adsorbent material used as a reference for molasses number characteristics. As one skilled in the art would understand, "200 standard charcoal" is expected to produce a molasses number of 200, "250 standard charcoal" is expected to produce a molasses number of 250, and so on. For activated charcoal products expected to have a molasses number less than 230, 200 standard charcoal must be used. For activated charcoal products expected to have a molasses number less than 350, 250 standard charcoal must be used. For activated charcoal products with a molasses number of 350 or greater, 400 standard charcoal must be used. If the product falls within the molasses specification range, a higher standard charcoal must be used. In such cases, it is appropriate to include the molasses standard charcoal used in the product specification as a manufacturing note. The molasses solution cannot be diluted. A fixed optical path length of 2.5 mm must be used.

[0080] As experts understand, standard coal is not limited as long as it is suitable as a reference material for the molasses number. One example of a 400 standard coal is "RB," available from Calgon Carbon Corporation, Moon Township, Pennsylvania. RB is a powdered, steam-activated coal made from bituminous coal, with a minimum weight iodine number of 1070 mg / g, a weight molasses number of 400, a maximum ash content of 23% by weight, a maximum moisture content of 2% by weight, and a content of 325 mesh particles or particles smaller than 44 μm by weight of 60% to 75% by weight. A second example of a 320 standard coal is "RC," available from Calgon Carbon Corporation, Moon Township, Pennsylvania. RC is a powdered steam-activated charcoal made from bituminous coal with a minimum weight iodine count of 1020 mg / g, a weight molasses count of 320, a maximum ash content of 23% by weight, a maximum moisture content of 2% by weight, and a content of 60% to 75% by weight of particles sieved through a 325 mesh or particles smaller than 44 μm. A third example of a 230 standard coal is "BL," available from Calgon Carbon Corporation, Moon Township, Pennsylvania. BL is a powdered steam-activated charcoal made from bituminous coal with a minimum weight iodine count of 1000 mg / g, a weight molasses count of 230, a maximum ash content of 10% by weight, a maximum moisture content of 2% by weight, and a content of 60% to 75% by weight of particles sieved through a 325 mesh or particles smaller than 44 μm.

[0081] Principle of the method: A solution of blackstrap molasses is treated with a charcoal of unknown decolorization capacity and a standard charcoal with a designated molasses number as described above. The higher of the two standards is used to measure the value in the flat portion of the decolorization curve shown in Figure 3. The absorbance of the filtrate is measured using a standard spectrophotometer with a wavelength of 472 nm and a path length of 2.5 mm. The molasses number of the sample is calculated from the ratio of the absorbance values ​​of the sample and the standard charcoal.

[0082] Safety Precautions: Careful handling and good laboratory techniques should always be used when using laboratory equipment. Personnel performing this study should be made aware of potential safety hazards associated with the equipment used in this procedure.

[0083] The equipment used in TM-3 is shown in Table 2 below: [Table 2] TIFF2026500179000004.tif74157

[0084] The reagents used in TM-3 are shown in Table 3 below: [Table 3] TIFF2026500179000006.tif116155

[0085] The molasses solution was prepared according to the following procedure: 1. Weigh approximately 50 grams of blackstrap molasses into a clean, dry beaker and set aside until the water is heated to 95°C. 2. Using a graduated cylinder, 1000 mL of ASTM Type 2 water was added to a stainless steel beaker. 3. Cover the beaker with aluminum foil or a large glass lid, place on a hot plate, and heat to 95°C. 4. Once the water reached 95°C, the weighed amount of molasses was transferred to the stainless steel beaker and stirred well to mix. The stainless steel beaker was removed from the hot plate. 5. The solution was cooled to room temperature (approximately 25°C). 6. The molasses solution in the stainless steel beaker was siphoned into a suitable container. A TYGON tube was inserted into the beaker so that the tip of the tube was 1 inch from the bottom of the beaker. The siphon was initiated using the pipette bulb, and the solution was siphoned into another container (e.g., a large glass bottle). 7. Any remaining contents of the beaker were discarded. The molasses solution was stored in the refrigerator for a maximum of 24 hours. The molasses solution was kept on ice throughout the test method. 8. Weigh 0.46 ± 0.0002 grams of 250 Molasses Standard Charcoal into a clean, dry 400 mL beaker.

[0086] Standardization of 200 and 250 standard coal 9. 50 mL of the molasses solution was pipetted into the beaker. The beaker was gently swirled while adding the molasses solution until the charcoal was thoroughly wet. 10. The beaker was placed on a hot plate and the thermocouple / thermometer was placed in the beaker with the tip touching the bottom of the beaker. The solution was heated until the thermocouple / thermometer reached 98°C and a stopwatch was started. The thermocouple or thermometer was removed and the solution was allowed to boil for 30 seconds. 11. The sample was vacuum filtered through a Buchner funnel using previously prepared Whatman® No. 3 filter paper. Approximately 20 mL of the solution was poured onto the filter paper and the filtrate was discarded. The remaining portion was filtered. 12. The absorbance of the filtrate was measured and recorded using a spectrophotometer at a wavelength of 472 nm. A fixed path length cell (2.5 mm) was used. The solution was considered standardized if the absorbance was within the range of 0.630–0.650. 13. If the absorbance was above 0.650, the solution was deemed too concentrated. To determine the amount of water to add, measure the volume of molasses solution, multiply this by 0.640, and multiply this by the absorbance recorded in step 12. The difference was the amount of water, in milliliters, to add. The water was added and the solution was thoroughly mixed. Steps 8 through 13 were repeated until the absorbance of three consecutive analytical samples was between 0.630 and 0.650. 14. If the absorbance was less than 0.630, the solution was deemed too dilute. To determine the amount of molasses to add, the volume of molasses solution was multiplied by 0.640 and the absorbance recorded in step 12. The two values ​​were subtracted, the result was divided by 10, and that value was used as the amount of molasses (by weight) to add to a small glass beaker. Approximately 25 mL of molasses solution was added to the beaker to dissolve the molasses. The beaker was heated to 90°C on a hot plate and then allowed to cool slightly. The contents were added to the molasses solution and mixed well. Steps 8 through 14 were repeated until three consecutive samples with absorbances between 0.630 and 0.650 were obtained.

[0087] Standardization of 400 standard charcoal 15. 0.46 ± 0.0002 grams of 400 Molasses Standard Charcoal was weighed into a clean, dry 400 ml beaker. 16. 50 mL of molasses solution was pipetted into the beaker. The beaker was swirled while the molasses solution was added and mixed until the charcoal was thoroughly wetted. 17. The beaker was placed on a hot plate and the thermocouple / thermometer was placed in the beaker with the tip touching the bottom of the beaker. The solution was heated until the thermocouple / thermometer reached 98°C and a stopwatch was started. The thermocouple or thermometer was removed and the solution was allowed to boil for 30 seconds. 18. The sample was vacuum filtered through a Buchner funnel using pre-prepared Whatman® No. 3 filter paper. Approximately 20 mL of the solution was poured onto the filter paper, and the filtrate was discarded. The remaining 30 mL was filtered and used for subsequent measurements. 19. The absorbance of the filtrate was measured and recorded in a spectrophotometer at a wavelength of 472 nm. A fixed path length cell (2.5 mm) was used. The solution was considered standardized if the absorbance was within the range of 0.390–0.410. 20. If the absorbance was above 0.410, the solution was deemed too concentrated. To determine the amount of water to add, measure the volume of molasses solution and multiply it by 0.400 and the absorbance recorded in step 19. Subtract this value to determine the amount of water (in milliliters) to add to the molasses solution. The water was added and the solution was mixed thoroughly. Steps 15-20 were repeated until three consecutive samples with absorbances between 0.390 and 0.410 were obtained. 21. If the absorbance was less than 0.390, the solution was deemed too dilute. To determine the amount of molasses to add, the amount of molasses solution was measured and multiplied by 0.400 and the absorbance recorded in step 19. The two values ​​were subtracted and the difference was divided by 10. The quotient was the amount of molasses (by weight) to add to the small glass beaker. Approximately 25 mL of molasses solution was added to the beaker to dissolve the molasses. The resulting solution was heated to 90°C on a hot plate and then allowed to cool slightly. The contents were added to the molasses solution and mixed well. Steps 15 through 21 were repeated until three consecutive samples with absorbance values ​​between 0.390 and 0.410 were obtained.

[0088] Beakers were standardized where necessary. Beaker standardization aims to identify and eliminate beakers whose boil times differ significantly from other beakers used in the test. Eliminating these beakers improves precision within the same laboratory. If a supplier is unable to provide consistent beakers over time, a new average value for all beakers used in the test should be established. This average value should not include beakers that differ by more than three standard deviations.

[0089] The beakers were standardized according to the following procedure: 1. Identify all beakers that have numbers or other specific markings. 2. Using a 50 mL pipette, add 50 mL of deionized or distilled water to each 400 mL beaker to be standardized for use in TM-3. 3. Place the beaker on the hot plate, insert the thermocouple or thermometer so that it touches the bottom of the beaker, and start the stopwatch. 4. Measure the time it takes for the water in the beaker to reach 95°C and record it in seconds. 5. Calculate the average time for the set of beakers to be standardized. 6. Beakers ±20 seconds from the average time are available for sample analysis and standardization of TM-3. 7. Beakers outside the 20 second range cannot be used for TM-3 sample analysis or standardization.

[0090] The samples were analyzed according to the following procedure: 1. Charcoal samples were provided and crushed until 95% or more passed through a 325-mesh sieve. If the sample was not recently manufactured, it was dried at 150°C to a constant weight before use. Standard charcoal and internal carbon standards were also prepared in the same manner. Equal amounts of sample were crushed to ensure consistent particle size of the materials. 2. 0.46±0.0002 grams of each dried and crushed charcoal sample was weighed into a clean, dry 400 mL beaker. 3. The apparatus for filtering the sample was prepared. A circular Whatman® No. 3 filter paper was placed in a Buchner funnel, the funnel was connected to a 250 mL filter flask, and the filtration vacuum was initiated. 50 mL of the filter paper suspension was added, taking care to cover the entire surface of the filter paper. After all the liquid had drained, the filtrate collected in the filter flask was discarded. 4. 50 mL of the standardized molasses solution was pipetted into the beaker containing the charcoal to be analyzed. The beaker was stirred while the molasses solution was added until the charcoal was completely wetted. 5. Place the beaker on a hot plate and place the thermocouple or thermometer in the beaker so that its tip is touching the bottom of the beaker. Heat the solution until the thermocouple registers 98°C and start a stopwatch. Remove the thermocouple or thermometer and boil the solution for 30 seconds. 6. The sample was vacuum filtered through a Buchner funnel using Whatman® No. 3 filter paper previously prepared according to step 3. Approximately 20 mL of the sample was poured onto the filter and the filtrate was discarded. The remainder was filtered. 7. The absorbance of the filtrate was measured and recorded using a spectrophotometer at a wavelength of 472 nm. A Klett™ Summerson Cell with a fixed path length of 2.5 mm was used for the measurement. Deionized or distilled water was used as a reference. 8. Molasses number was calculated using the following formula: Molasses number = (A x B) / C where A is the molasses number of the standard charcoal (250 or other), B is the average absorbance of three measurements of the 250 standard charcoal or other standard charcoal, and C is the absorbance of the filtrate of the activated charcoal being analyzed. 9. Molasses numbers were reported to the nearest multiple of 10 using conventional rounding techniques (e.g., 226 = 230).

[0091] Example 1 - Filtrate Conductivity Method

[0092] The filtrate conductivity method described herein was performed on several representative adsorbent samples. The method is as follows: 100 ml of deionized water is added to a 125 ml Erlenmeyer flask that has been pre-washed with deionized water (DI water). The DI water is of sufficient "quality" to have a resistivity ranging from approximately 17.5 MΩ to approximately 18.2 MΩ. For each charcoal sample to be tested, a flask containing 100 ml of DI water is prepared, along with a "blank" control containing no charcoal. The flasks are stirred at 300 rpm using a pre-washed magnetic stir bar. Ten grams of activated charcoal sample are then weighed and added to each flask except one, creating a suspension of activated charcoal in aqueous solution. Activated charcoal samples that have not recently undergone heat treatment can be dried in air at 150 °C for 3 hours to remove surface moisture, which can affect the actual mass of charcoal added to the flask. Each flask is stirred for 1, 4, or 24 hours. Each flask is capped or covered with parafilm during stirring.

[0093] After stirring, the Erlenmeyer flask is removed from the stir plate and allowed to stand for 5 minutes to allow the activated carbon to settle. The clear portion of the activated carbon suspension is then filtered through a syringe fitted with a 0.7 micron syringe filter previously rinsed with DI water. 40 ml of filtrate is collected. A DI water blank is filtered using the same procedure. The filtrate samples are transferred to 50 ml test tubes containing small magnetic stir bars (both the test tube and the stir bar were previously rinsed with DI water). At this point, the solution conductivity of each filtrate is measured under gentle stirring using a calibrated Oakton 2700 Series Conductivity Meter. Conductivity is reported in microsiemens (μS).

[0094] F / S RB result

[0095] The 8x40 mesh coal-based activated carbon used in this study is called F / S RB and is manufactured by Calgon Carbon. F / S RB is steam activated and exhibits higher iodine and molasses numbers than other coal-based activated carbons, such as F400. Filtrates obtained from suspensions of dried and calcined F / S RB were analyzed by the filtrate conductivity method. The results are shown below.

[0096] Figure 5 is a bar graph of filtrate conductivity for the first set of representative adsorbent samples. Figure 5 shows filtrate conductivity results from a specific lot of F / S RB (referred to herein as Lot #1) manufactured in 2017. Filtrates collected from aqueous suspensions of dried and calcined F / S RB after 1 hour, 4 hours, or 24 hours of stirring were used. The electrical conductivity of the filtrate measured from the aqueous suspension of dried F / S RB is shown in light gray bars, while the filtrate collected from the calcined F / S RB is represented in dark gray bars. In Figure 5, the measured conductivity of the filtrate collected from the calcined activated carbon suspension was approximately 2.0–2.5 times higher than the electrical conductivity of the filtrate collected from the dried carbon suspension, regardless of stirring time. This suggests that calcination induces changes to the activated carbon surface, creating a tendency for ionic species to elute into the liquid phase of the suspension, resulting in changes quantifiable by the filtrate conductivity measurement method described herein. There is a clear distinction between the electrical conductivity data of the dried and calcined filtrates, as the measurement variability, indicated by the error bars in Figure 5, is small and highly reproducible, suggesting that this measurement may be useful as a production or quality control (QA) tool to help monitor the calcination process and product quality.

[0097] Because the difference in filtrate conductivity between the dried and calcined F / S RBs was unexpected, we conducted a repeat filtrate conductivity experiment using a larger batch of F / S RBs (Lot #2) manufactured in 2020. The results are shown in Figure 6 and confirm the same trend observed in Figure 5. Figure 6 is a bar graph of filtrate conductivity for a second set of representative adsorbent samples. In this data set, the electrical conductivity of the filtrate collected from the calcined F / S RB suspension was, on average, approximately 1.7-2.0 times higher than that of the filtrate collected from the dried F / S RB suspension. As before, this difference was observed at all stirring times, with low variation. Taking the results shown in Figures 5 and 6 together, a stirring time of 1 hour is sufficient for robust QA-type method development purposes.

[0098] Figure 8 is a bar graph showing the filtrate conductivity of five lots of F / S RB material agitated for one hour (Lot #1, Lot #2, Lot #3, Lot #4, and Lot #5). Lot #3 was produced in 2021, and Lots #4-5 were produced in 2022. Figure 8 shows similar trends observed in Figures 5 and 6, with the calcined material showing higher filtrate conductivity than the dried or raw (untreated) material. The testing of Lots #1-5 shown in Figure 8 was conducted several months after the original testing shown in Figures 5 and 6, demonstrating the reproducibility of the currently disclosed method.

[0099] BGX results

[0100] These experiments used a 12x40 mesh wood-based activated carbon called BGX. This is a commercial product from Calgon that has been activated with phosphoric acid. This acidic activation process gives BGX activated carbon its acidic properties, characterized by a contact pH typically below 5 (Calgon TM-62 method). BGX differs significantly from steam-activated F / S RB, which typically has an alkaline contact pH above 9.5. Due to the differences in substrate and activation method, the filtrate conductivity trends for BGX are different, as shown in Figure 7. Figure 7 is a bar graph of the filtrate conductivity for the third set of representative adsorbent samples. Comparing the filtrate conductivity results for BGX in Figure 7 with those for F / S RB in Figures 5 and 6, the electrical conductivity of BGX is significantly higher, measured in the range of approximately 290–565 μS, whereas the maximum value for F / S RB was only 160 μS (Figure 6). This higher electrical conductivity of BGX may be due to residual phosphoric acid or phosphate groups within the pore structure of the activated carbon, without being bound by theory.

[0101] The data shown in blue in Figure 7 reveal that the electrical conductivity measurements of the filtrate collected from the dried BGX suspension showed little difference regardless of the stirring time. The electrical conductivity varied by approximately 10%, ranging from approximately 510 to 565 μS. However, as shown in orange in Figure 7, the electrical conductivity of the filtrate from the calcined BGX suspension changed dramatically depending on the stirring time. Here, the electrical conductivity of the filtrate after 15 minutes and 24 hours of stirring showed a difference of almost 250 μS. This dynamics suggests that the calcination process may remove some of the residual ionic species from the activated carbon surface. This is evidenced by the low electrical conductivity measured between 15 minutes and 4 hours of stirring. However, residual phosphate groups (or other ionic species) adsorbed within the activated carbon pore structure or present in the finer pores may require a longer residence time to elute into the aqueous phase of the suspension. This is evident from the significant increase in electrical conductivity at 4 and 24 hours for the calcined filtrate in Figure 7, starting from 1 hour of stirring.

[0102] Although the trends and magnitude of electrical conductivity in the BGX experiments differ from those in the F / S RB evaluation, it may be possible to use the filtrate's electrical conductivity as a quality control tool to track differences between calcined and dried BGX. Additional experiments using more severe calcination conditions (longer heating times, higher temperatures, or different atmospheres) may further remove surface functionality in BGX and improve its performance in applications affected by acidic surface groups.

[0103] Example 2 - Filtrate alkalinity and pH measurement

[0104] Alkalinity in water with a pH above 7 is due to dissolved species such as bicarbonate, carbonate, and hydroxide ions and can be expressed in parts per million (ppm CaCO3) of calcium carbonate by titrating a water sample with acid to different endpoints. Hach (Cat. No. 24443-01) provides a method for measuring the alkalinity of a sample by titrating it with dilute sulfuric acid in the presence of a color-change phenolphthalein indicator until a pH of 8.3 is reached. This titration determines the type of alkalinity known as phenolphthalein (P-type) alkalinity. After reaching a pH endpoint of 8.3, the sample is further titrated with dilute sulfuric acid to a pH endpoint of approximately 4.3 to 4.6 using bromocresol green-methyl red (BCG-MR), a color-change indicator that changes color from blue to pink as the pH decreases. Once this acidic endpoint is reached, the concentrations of all ionic species contributing to the total alkalinity must be calculated. The total alkalinity of the sample can be determined by summing the phenolphthalein alkalinity measurement and the BCG-MR alkalinity measurement.

[0105] To further advance alkalinity analysis, the relationship between phenolphthalein and total alkalinity provided in Hach Method 8203 (which can be performed in multiple experimental configurations, including Hach Catalog #2444301) can be used to estimate the specific concentrations of carbonate, bicarbonate, or hydroxide ions that comprise the alkalinity of a sample. The alkalinity of a sample and the concentrations of these ions are important because they affect the electrical conductivity measured by the filtrate conductivity method described herein. Speciation of the alkalinity of a sample may provide additional insight into the surface chemistry of the activated carbon, especially if specific ions are eluted in the DI water portion of the activated carbon suspension. Finally, measuring the pH of the filtrate using a standard pH probe can be used to further understand differences in the alkalinity of the filtrate and the associated electrical conductivity of the solution.

[0106] To better understand the results observed in the filtrate conductivity tests, filtrate alkalinity tests were performed on filtrate samples from F / S RB Lot #1, following the methodology shown in Figure 5 above. Table 4 shows these filtrate alkalinity results, measured using the Hach Alkalinity Test Kit Catalog (#24443-01). Regardless of the agitation time, the phenolphthalein (P-form) alkalinity and total alkalinity of the filtrates obtained from the calcined F / S RB suspensions were higher than those of the dried F / S RB filtrates. This is consistent with the increased filtrate conductivity reported in Figure 5. Additionally, the pH values ​​of the filtrates obtained from the calcined F / S RB suspensions were higher regardless of agitation time. The total alkalinity of the control DI water (DI water not exposed to activated carbon) was measured at 15 mg / L CaCO3. 、 There was no contribution of P-type alkalinity. [Table 4]

[0107] The main form of alkalinity in the filtrate is hydroxide ions (OH - ), carbonate ions (CO3 2- ), and / or bicarbonate ions (HCO3 - ), the alkalinity measurements listed in Table 4 can be used to calculate the amount of these species in the filtrate using the relationships provided in Hach Method 8203 (as reported in Table 1). These relationships indicate that when P-alkalinity is zero, the alkalinity contributions of hydroxide and carbonate species are zero. Therefore, the total alkalinity of the sample can be assumed to be due to the presence of bicarbonate ions. However, according to Hach Method 8203, if P-alkalinity is non-zero but less than half of the total alkalinity, the hydroxide ion contribution to alkalinity is assumed to be zero, and the carbonate alkalinity is twice the P-alkalinity. Therefore, the remaining alkalinity contribution to the total alkalinity measurement can be assumed to be due to the presence of bicarbonate ions (bicarbonate alkalinity), which is calculated by subtracting the total alkalinity from the carbonate alkalinity.

[0108] Using these relationships, Table 5 describes the alkalinity of the charcoal suspension filtrates based on estimated carbonate and / or bicarbonate alkalinity values. The pH of each suspension filtrate is also shown for reference. In all cases, the hydroxide ion alkalinity was zero, either because P alkalinity was not measured, as in the case of the dried F / S RB filtrate, or because P alkalinity was less than half of the total alkalinity, as in the case of the calcined F / S RB filtrate (see Table 4). In all cases, the calcined F / S RB suspension appears to contribute additional alkalinity to the filtrate alkalinity by adding carbonate alkalinity to bicarbonate alkalinity. In contrast, the alkalinity of the filtrate obtained from the dried F / S RB is solely attributable to bicarbonate alkalinity. [Table 5]

[0109] The presence of carbonate alkalinity in the calcined F / S RB filtrate and the higher pH value of the filtrate (compared to the dried F / S RB filtrate) suggest that there may be a unique carbonate-bicarbonate equilibrium in the filtrate from the calcined F / S RB. This equilibrium can be expressed as Equation 1.

[0110] TIFF2026500179000009.tif10159

[0111] Without wishing to be bound by theory, using Equation 1 and the data in Table 5, we speculate that calcination of F / S RB generates hydroxyl groups on the surface of the activated carbon, which react with bicarbonate ions to form carbonate ions, thereby increasing the pH of the filtrate. The generation of these hydroxyl groups shifts the filtrate pH above 10 and contributes to the generation of carbonate ions. However, because the presence of hydroxyl groups was not directly measured (by the Hach Method), it is unlikely that there is an excess of hydroxyl groups. However, the increase in filtrate alkalinity due to the generation of hydroxyl groups on the surface of the calcined activated carbon may be beneficial in immersion cooling applications where secondary acidic or acid-catalyzed reactions must be suppressed.

[0112] Table 6 expands on the types of data presented in Table 4, providing additional information on the P alkalinity and total alkalinity of filtrate collected from five lots of F / S RB activated carbon. The methods used to generate the data were identical to those described above, and filtrate for all products (raw, dried, or calcined) was collected after 1 hour of stirring. In Table 6, "raw" refers to filtrate collected from F / S RB that had not undergone any further heat treatment after production, "dried" refers to filtrate collected from F / S RB that had been dried according to the method described above, and "calcined" refers to filtrate collected from F / S RB that had been calcined at high temperatures under a nitrogen atmosphere according to the method described above. [Table 6]

[0113] As shown in Table 6, the filtrate pH, P-alkalinity, and total alkalinity of the calcined product filtrate increased compared to the dried and untreated product filtrates. However, although the initial untreated product filtrate from Lot #3 had the highest pH, P-alkalinity, and total alkalinity, the increasing trends of these values ​​compared to the other lots were similar. As shown in Table 6, the filtrate pH increased for all five lots, from untreated to dried and from dried to calcined, further supporting the accuracy of the disclosed data.

[0114] Table 7 expands on the types of data presented in Table 5. It provides additional information on the bicarbonate and carbonate alkalinity of the filtrates described in Table 6, using the relationships described in Table 1. [Table 7]

[0115] As shown in Table 7, the filtrate taken from the baked product had increased carbonate alkalinity and decreased bicarbonate alkalinity compared to the filtrates taken from the untreated and dried products.

[0116] Figure 8 shows the electrical conductivity data for the filtrates in the examples shown in Tables 6 and 7. As before, the electrical conductivity of the calcined F / S RB filtrate is increased compared to the dried F / S RB filtrate. Furthermore, the calcined F / S RB filtrate exhibits higher electrical conductivity than the untreated F / S RB filtrate.

[0117] Example 3 - Characterization

[0118] The F / S RB activated carbons of Lots 1-5 referenced in Tables 6 and 7 and Figure 8 were characterized for apparent density (AD), moisture content, and oxygen content by elemental analysis, where applicable. This data is presented in Table 8. [Table 8]

[0119] The decrease in oxygen concentration in the calcined product can be attributed to the removal and / or modification of certain acidic oxygen-containing groups present on the carbon surface, which enhances the alkalinity of the activated carbon. This change is reflected in the increased alkalinity of the filtrate recovered from the calcined F / S RB material compared to other filtrates.

[0120] Table 9 presents characterization data for the "untreated" F / S RB activated carbon used as the feedstock for all data presented in Tables 6-8 and Figure 8. The data includes elemental analysis results for nitrogen, carbon, hydrogen, and sulfur, as well as iodine number, molasses number, and ash content. No strong correlation was observed between the data in Table 9 and the filtrate electrical conductivity or alkalinity obtained from the calcined product. This data indicates that the differences observed after calcination are due to the heat treatment itself, rather than to specific attributes of the feedstock. [Table 9]

[0121] The above examples show that filtrate conductivity generally decreases from raw to dried and from dried to calcined. After calcination, P alkalinity generally increases and bicarbonate alkalinity is converted to carbonate alkalinity. Increases in filtrate pH and contact pH, and decreases in oxygen content were observed in all five lots of RB product.

[0122] In the above detailed description, reference is made to the accompanying drawings, which form a part of this specification. In the drawings, like symbols typically identify like elements and are so construed unless the context dictates otherwise. The embodiments described in the detailed description, drawings, and claims are not limiting. Other embodiments may be used or changes may be made without departing from the spirit or scope of the subject matter disclosed herein. The aspects of the present disclosure as shown in the general description and drawings of this disclosure can be arranged, substituted, combined, separated, or designed in widely different configurations, all of which are expressly contemplated.

[0123] The present disclosure is not limited to the specific examples described in this application; these examples are illustrative of various aspects. As will be apparent to those skilled in the art, many modifications and variations are possible without departing from the spirit and scope of the present disclosure. Functionally equivalent methods and apparatuses within the scope of the present disclosure, in addition to those described herein, will be apparent to those skilled in the art from the above description. The present disclosure is, of course, not limited to particular methods, reagents, compounds, compositions, or biological systems, which can, of course, vary. Furthermore, the terminology used herein is for the purpose of describing particular examples only, and is not intended to be limiting.

[0124] With respect to the use of virtually any plural and / or singular term herein, those skilled in the art can translate from the plural to the singular or from the singular to the plural as appropriate to the context and / or application. Various singular / plural variations may be expressly set forth herein for clarity.

[0125] Those skilled in the art will generally understand that the terms used herein, and particularly the terms used in the appended claims (e.g., the body of the appended claims), are generally intended as "open" terms (e.g., the term "including" is interpreted as "including but not limited to," the term "having" is interpreted as "having at least," the term "includes" is interpreted as "including but not limited to," etc.). Although various compositions, methods, and devices are described using terms "comprising" (but interpreted as "including, but not limited to") various components or steps, these compositions, methods, and devices may also "consist essentially of" or "consist of" various components and steps, and such terms should be interpreted as terms defining an essentially closed group of components. Those skilled in the art will understand that when a specific number is intended in the appended claim recitation, such intention will be explicitly recited in the claim; otherwise, no such intention exists.

[0126] For example, as an aid to understanding, the following appended claims may use the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed as introducing a claim recitation with the indefinite article "a" or "an" to limit a particular claim that includes such an introduced claim recitation to embodiments that include only one such recitation. This is true even when the same claim includes both the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be interpreted as "at least one" or "one or more"). A similar principle applies to definite articles used to introduce claim recitations.

[0127] Furthermore, even if a specific number of recitations in an introduced claim is explicitly recited, one of ordinary skill in the art should interpret such recitation to mean at least the recited number or more (e.g., the mere recitation of "two recitations," in the absence of other modifiers, means at least two recitations, or more than two recitations). Furthermore, when phrases similar to, for example, "at least one of A, B, and C, etc." are used, they are generally intended in the sense that one of ordinary skill in the art would understand the phrase (e.g., "a system having at least one of A, B, and C" includes systems including, but not limited to, A only, B only, C only, a combination of A and B, a combination of A and C, a combination of B and C, and / or a combination of A, B, and C). When phrases similar to "at least one of A, B, or C, etc." are used, such phrases are generally intended in the sense that one skilled in the art would understand the practice (e.g., the phrase "a system having at least one of A, B, or C" means, but is not limited to, a system having only A, a system having only B, a system having only C, a system combining A and B, a system combining A and C, a system combining B and C, and / or a system combining A, B, and C). Furthermore, one skilled in the art will understand that almost all alternative words and / or phrases in the description, claims, or drawings that present two or more alternative terms contemplate the possibility of including either term, either term, or both terms. For example, the phrase "A or B" is understood to include the possibilities of "A" or "B" or "A and B."

[0128] Furthermore, when a feature of the disclosure is described in terms of a Markush group, one of skill in the art will recognize that the disclosure is described as including each individual member or subgroup of members of the Markush group.

[0129] As will be understood by those skilled in the art, for all purposes, including providing a written description, all ranges disclosed herein are intended to include all possible subranges and combinations of subranges within that range. A stated range can be readily recognized as fully describing and enabling the same range divided into halves, thirds, quarters, fifths, tenths, etc., equal to at least . As a non-limiting example, each range discussed herein can be readily divided into a lower third, middle third, upper third, etc. As will be understood by those skilled in the art, phrases such as "up to," "at least," etc., refer to ranges that are inclusive of the recited numerical values ​​and that can be divided into subranges as described above. Finally, as will be understood by those skilled in the art, a range includes each individual element. For example, a group containing 1 to 3 compounds refers to a group containing 1, 2, or 3 compounds. Similarly, a group containing 1 to 5 compounds refers to a group containing 1, 2, 3, 4, or 5 compounds, and so on.

[0130] The above-disclosed features and functions, or alternatives thereof, may be combined into many other different systems or applications. Presently unforeseen or unanticipated alternatives, modifications, variations, or improvements may subsequently occur to those skilled in the art, and are intended to be included in the disclosed embodiments.

Claims

1. 1. A method for characterizing an adsorbent, comprising: providing an adsorbent; suspending the adsorbent in a fluid; agitating the adsorbent in the fluid; filtering the adsorbent from the fluid to isolate a filtrate; measuring the electrical conductivity of the filtrate; and measuring the alkalinity of the filtrate; A method comprising:

2. The method of claim 1 , wherein the fluid is deionized water.

3. 10. The method of claim 1, wherein the step of agitating the adsorbent occurs for a time period of from about 1 hour to about 24 hours.

4. 2. The method of claim 1, wherein the step of measuring the alkalinity of the filtrate comprises: providing a sample of said filtrate; performing a first titration on the sample with a first acid and a first indicator to a first endpoint pH to provide a first alkalinity measurement; performing a second titration on the sample with a second acid and a second indicator to a second endpoint pH to provide a second alkalinity measurement; and calculating the total alkalinity of the sample; A method comprising:

5. 5. The method of claim 4, wherein the first acid and the second acid comprise sulfuric acid.

6. 5. The method of claim 4, wherein the first indicator comprises phenolphthalein.

7. 5. The method of claim 4, wherein the first endpoint pH is from about 7.5 to about 9.

0.

8. 5. The method of claim 4, wherein the second indicator comprises bromocresol green-methyl red.

9. 5. The method of claim 4, wherein the second endpoint pH is from about 4.0 to about 5.

0.

10. 5. The method of claim 4, wherein calculating the total alkalinity of the sample comprises adding the first alkalinity measurement and the second alkalinity measurement.

11. 5. The method of claim 4, further comprising measuring the concentrations of carbonate ions, bicarbonate ions, and hydroxide ions in the filtrate.

12. 12. The method of claim 11, wherein the total alkalinity is substantially attributable to bicarbonate ions.

13. 12. The method of claim 11, wherein the total alkalinity is substantially attributable to hydroxide ions.

14. 12. The method of claim 11, wherein the total alkalinity is substantially attributable to carbonate ions.

15. 12. The method of claim 11, wherein the total alkalinity is substantially attributable to a combination of carbonate and bicarbonate ions.

16. 12. The method of claim 11, wherein the total alkalinity is substantially attributable to a combination of carbonate ions and hydroxide ions.

17. 1. A method for purifying a coolant containing one or more electrically conductive contaminants, comprising: contacting the coolant with an adsorbent so that the adsorbent adsorbs the one or more electrically conductive contaminants; The adsorbent has a concentration of about 10 mg / L CaCO ３ ~Approx. 60mg / L CaCO ３ and a filtrate conductivity of less than about 650 μS; and the adsorbent comprises activated carbon; method.

18. 18. The method of claim 17, wherein the adsorbent has a concentration of about 30 mg / L CaCO ３ ~Approx. 50mg / L CaCO ３ having a filtrate alkalinity of

19. 18. The method of claim 17, wherein the adsorbent has a filtrate conductivity of about 5 μS to about 200 μS.

20. 18. The method of claim 17, wherein the activated carbon is formed from one or more of bituminous coal, sub-bituminous coal, lignite, anthracite, wood, peat, nut shells, pits, coconut, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, bagasse, rice bran, corn husks, wheat husks, polymers, resins, petroleum pitch, other charred materials, or combinations thereof.

21. 1. A composition for purifying a coolant containing one or more electrically conductive contaminants, said composition comprising: Approximately 10mg / L CaCO ３ ~Approx. 60mg / L CaCO ３ and a filtrate conductivity of less than about 650 μS; the adsorbent comprises activated carbon; composition.

22. 22. The composition of claim 21, wherein the activated carbon is formed from one or more of bituminous coal, sub-bituminous coal, lignite, anthracite, wood, peat, nut shells, pits, coconut, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, bagasse, rice bran, corn husks, wheat husks, polymers, resins, petroleum pitch, other charred materials, or combinations thereof.

23. 1. A method for producing a sorbent for purifying a refrigerant containing one or more electrically conductive contaminants, comprising: providing a precursor adsorbent material; and The precursor sorbent material is subjected to at least one treatment method to obtain a sorbent having a concentration of about 10 mg / L CaCO. ３ ~Approx. 60mg / L CaCO ３ forming a sorbent having a filtrate alkalinity of less than about 1000 s and a filtrate conductivity of less than about 650 μS; Including, the adsorbent comprises activated carbon; method.

24. 24. The method of claim 23, wherein the precursor sorbent material is formed from one or more of bituminous coal, sub-bituminous coal, lignite, anthracite, wood, peat, nut shells, pits, coconut, babassu nuts, macadamia nuts, denden nuts, peach pits, cherry pits, olive pits, walnut shells, wood, bagasse, rice bran, corn husks, wheat husks, polymers, resins, petroleum pitch, other charred materials, or combinations thereof.

25. 24. The method of claim 23, wherein the at least one processing method comprises: A baking step, Drying process, treating under vacuum, nitrogen, hydrogen, carbon monoxide, ammonia, methane, argon, or a combination thereof; microwave-assisted heat treatment; Immersion in metal or oxygen absorbers, or These combinations, A method comprising one or more of the following:

26. 24. The method of claim 23, wherein the adsorbent has a concentration of about 30 mg / L CaCO ３ ~Approx. 50mg / L CaCO ３ having a filtrate alkalinity of

27. 24. The method of claim 23, wherein the adsorbent has a filtrate conductivity of about 5 μS to about 200 μS.

Images