Modified carbon adsorbent

Abstract

Certain activated carbonaceous materials are provided that have been treated with dilute inorganic acids to modify their surface chemistry and morphology. The modified activated carbonaceous materials of the present disclosure are useful for removing certain contaminants from gas streams. In one embodiment, the contaminants are compounds containing silicon and oxygen moieties, such as alkylsilanols and alkylsiloxanes. The modified activated carbonaceous materials can be incorporated into filters and filter systems.

Description

Technical Field

[0001] The present invention generally relates to a specific carbonaceous material modified to advantageously absorb compounds containing silicon and oxygen, such as trimethylsilanol.

Background Art

[0002] Modern semiconductor manufacturing plants have multiple sections, many of which are highly specialized and require the use of expensive equipment. One such section requires the use of photolithography operations. Photolithography operations utilize devices such as scanners that include performance-oriented optical systems (i.e., lenses). When there are chemical contaminants in the atmosphere or within the system, such as those contaminants containing trialkylsilanol and / or alkylsiloxane, the combination of DUV light and oxygen produces SiO2. The SiO2 thus produced has a tendency to irreversibly deposit on the lens, thereby causing lens fogging and pattern non-uniformity. Since the lens ultimately becomes unsuitable for use, such contamination leads to the inevitable replacement of these lenses. Therefore, there is a need to remove chemical contaminants in the atmosphere and within the system, such as trialkylsilanol and / or alkylsiloxane, in such photolithography operations.

[0003] Siloxanes are used in many industrial products and, in the case of low molecular weight siloxanes, can exist in the form of vapors at room temperature. Such siloxanes, like trialkylsilanol, can react with oxygen to produce silicon dioxide and can form harmful deposits on equipment and instruments.

Summary of the Invention

[0004] In summary, the present disclosure relates to an activated carbon material treated with a dilute inorganic acid to modify its surface chemistry and surface morphology. The modified activated carbon of the present invention is useful for removing specific contaminants from a gas stream. In one embodiment, the contaminant is a compound containing silicon and oxygen moieties such as alkylsilanol and alkylsiloxane. In another aspect, the modified activated carbon may be incorporated into filters and filter systems. In one embodiment, the materials described herein can be used with a scanner prefilter system such as a filter system integrated with an OEM scanner sold by Entegris, Inc., such as those marketed under the names VaporSorb and SilverSet.

[0005] The present disclosure can be more fully understood by considering the following description of various exemplary embodiments in connection with the accompanying drawings.

Brief Description of the Drawings

[0006]

Figure 1

Figure 2

Mode for Carrying Out the Invention

[0007] As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is used in its inclusive sense of "and / or" unless the context clearly dictates otherwise.

[0008] The term "about" generally refers to a range of numbers that are considered equivalent to the stated value (e.g., having the same function or result). In many instances, the term "about" may include numbers rounded to the nearest significant digit.

[0009] A numerical range expressed using endpoints includes all numerical values that fall within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0010] One aspect of the present disclosure is a method for removing contaminants from a gas stream, comprising contacting the gas stream with an adsorbent comprising an activated carbonaceous material treated with a dilute solution of at least one acid having a pKa of about 1 to about 5 (e.g., an inorganic or organic acid), followed by washing with water and drying. comprising wherein the contaminant is (i) a C1-C 20 alkylsilanol, (ii) a C1-C 20 silanol substituted by one or more halogen atoms (e.g., fluorine, chlorine, bromine, etc.), or (iii) a compound of the formula (R)3Si-O-Si(R)3 [wherein R is selected from C1-C 20 alkyl, or C1-C 20 alkyl substituted by one or more halogen atoms (e.g., fluorine, chlorine, bromine, etc.)] selected from compounds of

[0011] In this aspect, the present disclosure provides an easy method for removing various contaminants having silicon atoms and oxygen atoms as basic features. In some embodiments, the contaminant is trimethylsilanol or the like that may be present in atmospheric air and in system-internal process photolithography operations, such as C1-C 20alkyl silanol, and 15 to 20 carbon alkyls which may be found in industrial greases and lubricating oils, and higher carbon siloxanes containing fluoroalkyl chains, etc., thus providing means for exposing important optical systems to reaction by-products such as SiO2. In some embodiments, the siloxane is selected from (CH3)3Si-O-Si(CH3)3; (CH3CH2)3Si-O-Si(CH2CH3)3; hexamethylcyclotrisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, dodecamethylcyclohexasiloxane, or any combination thereof.

[0012] The adsorbent of the present disclosure can be derived from any carbonaceous material that can be converted into activated carbon. Examples of such carbonaceous materials include, but are not limited to, wood, corn cobs, husks, coffee beans, rice husks, fruit pits, peat, lignite, coconut shells, petroleum and / or pitch coke, coke, carbon black, phenolic resins, polyvinyl chloride, and the like. The form of the carbonaceous material is not strict and can be selected from granules, particles, fibers, sheets, etc., but granules can be advantageously used in certain gas filter designs such as air filters. In some embodiments, the carbonaceous material is in granular or extruded form. In some embodiments, the carbonaceous material is derived from coconut shells. As used herein, the term "activated carbonaceous material" refers to a solid microporous material having a high surface area mainly containing elemental carbon, and in the case of a carbonaceous material derived from lignin, further contains a small amount of other trace elements originally found in the carbonaceous material from which the activated carbon is formed. In addition, the activated carbon may be derived from a synthetic (i.e., petrochemical) source as a whole, such as polystyrene or poly(vinylidene chloride), but in any case, the final activated carbon surface, after modification, must have the porosity required to be effective in the method of the present disclosure as taught herein. In this context, activated carbon is a microcrystalline, non-graphitic form of carbon processed to increase its porosity. The surface area of activated carbon depends on its pore volume. Since the surface area per unit volume decreases as the individual pore diameters increase, the surface area is maximized by increasing the number of pores of very small dimensions and / or limiting the number of pores of large dimensions. Pore diameters are defined by the International Union of Pure and Applied Chemistry, such as micropores (pore width < 2 nm), mesopores (pore width 2 - 50 nm), and macropores (pore width > 50 nm). Furthermore, in such activated carbon, micropores and mesopores contribute to the adsorption capacity of the activated carbon, while macropores actually reduce the density and may be disadvantageous to the adsorption effect of the activated carbon on a carbon volume basis.Also, as used herein, the term "primary micropore" refers to a pore width that is 0 or greater but less than 0.8 nm, and the term "secondary micropore" refers to a pore width that is 0.8 nm or greater but less than 2 nm.

[0013] Activation of the carbonaceous material can be carried out by known methods. For example, the carbonaceous material can be activated by an oxidizable chemical substance such as zinc chloride, phosphoric acid, sulfuric acid, calcium chloride, sodium hydroxide, potassium dichromate, or potassium permanganate (chemical activation); or by steam, propane gas, exhaust gas generated from combustion gas which is a mixture of CO2 and H2O, or carbon dioxide gas, etc. (gas activation). See, for example, U.S. Patent No. 6,589,904, which is incorporated herein by reference in its entirety.

[0014] Generally, commercially available activated carbon usually has a surface area in the range of about 400 - 2500 m 2 / g; this characteristic enables its use in the purification of liquids and gases by adsorption of various contaminants. The adsorbent of the present disclosure is activated carbon treated with a dilute acid having a pKa in the range of about 1 to about 5, washed with water, and dried. In some embodiments, the acid has a pKa within the range of about 1 to about 5, about 1 to about 4, about 1 to about 3, about 2 to about 5, about 2 to about 4, and all ranges and sub - ranges therebetween. In some examples, the acid is an inorganic acid or an organic acid. Examples of inorganic acids having a pKa of about 1 to about 5 include, but are not limited to, hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, or nitric acid. Examples of organic acids having a pKa of about 1 to about 5 include, but are not limited to, citric acid, chloroacetic acid, formic acid, lactic acid, and ascorbic acid. This dilute acid treatment has been found to affect both the surface chemistry of the activated carbon, as well as its pore diameter, pore shape, and pore size distribution, along with its relative hydrophilicity. The activated carbon so modified has been found to be particularly effective in removing contaminants such as those described herein, especially trimethylsilanol. The modified activated carbon of the present disclosure has a surface area of about 500 or more to about 1400 m 2Below about 900 to about 1200 m 2 / g or less, and any and all ranges and sub-ranges therebetween, such as about 1050 to about 1150 m 2 / g or less. Additionally, the modified carbon of the present disclosure can have a surface area ratio of micropores to mesopores measured by the t-plot method of about 13 to about 17, and about 13 to about 15, or about 14, and can have any and all ranges and sub-ranges therebetween. Additionally, the modified carbon of the present disclosure can have a pore volume ratio of (primary micropores):(secondary micropores + mesopores) of any and all ranges and sub-ranges therebetween, such as about 0.4 to about 1.4, and about 0.5 to about 1.35, or about 0.9 to about 1.3, as measured by the DFT method. It should be noted that all possible subsets of the numerical ranges therebetween referred to herein are contemplated in the present disclosure.

[0015] Accordingly, another aspect of the present disclosure is an adsorbent comprising an activated carbonaceous material, wherein the material comprises micropores, mesopores, and macropores and has the following properties: a. A surface area of about 500 to about 1400 m 2 / g or less as measured by the BET method; b. A surface area ratio of micropores to mesopores measured by the t-plot method of about 13 to about 17; c. A pore volume ratio of (primary micropores):(secondary micropores + mesopores) measured by the DFT method of about 0.4 to about 1.4 and having one or more of the above.

[0016] In one embodiment of this aspect, the adsorbent has property a. In another embodiment, the adsorbent has property b. In another embodiment, the adsorbent has property c. In another embodiment, the adsorbent has properties a and b. In another embodiment, the adsorbent has properties a and c. In another embodiment, the adsorbent has properties b and c. In another embodiment, the adsorbent has properties a, b, and c.

[0017] As described above, in certain embodiments, the adsorbent is in granular or extruded form. Advantageously, such a physical form provides a convenient size for application to a filter module for filtration of a gas stream, particularly when adapted for use of the adsorbent in a fixed bed for such filtration of the flow.

[0018] In some embodiments, the dilute acid is in water at about 0.05 to about 1.0 M, about 0.05 to about 0.9 M, about 0.05 to about 0.8 M, about 0.05 to about 0.7 M, about 0.05 to about 0.6 M, about 0.05 to about 0.5 M, about 0.05 to about 0.4 M, about 0.05 to about 0.3 M, about 0.05 to about 0.2 M, about 0.05 to about 0.1 M, about 0.1 to about 1.0 M, about 0.1 to about 0.9 M, about 0.1 to about 0.8 M, about 0.1 to about 0.7 M, about 0.1 to about 0.6 M, about 0.1 to about 0.5 M, about 0.1 to about 0.4 M, about 0.1 to about 0.3 M, about 0.1 to about 0.2 M, about 0.2 to about 1.0 M, about 0.2 to about 0.9 M, about 0.2 to about 0.8 M, about 0.2 to about 0.7 M, about 0.2 to about 0.6 M, about 0.2 to about 0.5 M, about 0.2 to about 0.4 M, about 0.2 to about 0.3 M, and all ranges and sub-ranges of concentrations therebetween. In some embodiments, the acid is an inorganic acid, and in some embodiments, the inorganic acid is sulfuric acid.

[0019] A further aspect of the present disclosure is an adsorbent comprising a granular or extruded activated carbonaceous material, the material being treated with at least one acid having a pKa of about 1 to about 5, such as an inorganic or organic acid, treated with a solution of the acid at a concentration of about 0.05 to 1.0 M, and washed with water.

[0020] Referring to the details of the following experiment, the treated carbon was exposed to a continuous flow of a target contaminant at a constant concentration, and its removal efficiency (RE = 100 * (calculated as the concentration after passing through the adsorbent bed / the trial concentration) was measured. The capacity is the amount of the target contaminant that the adsorbent can remove and is calculated by the time required to reach a specific RE (removal efficiency) and the concentration to which the adsorbent was exposed.

[0021] The adsorbent of this embodiment provides improved removal characteristics of trimethylsilanol and showed a capacity of 70% RE at about 63,000 ppb - hours.

[0022] A further aspect includes a filter comprising an adsorbent of any aspect of this specification.

[0023] Referring to the data in Figure 1, the data described in more detail in Example 1 shows the effect of the treatment of GAC (granular activated carbon) A on the TMS removal ability of carbon. GAC A shows a capacity of about 21,000 ppb - hours, but after surface modification (GAC B) shows a six - fold capacity increase of 63,000 ppb - hours. GAC C is not shown in Figure 1 because its initial removal efficiency is less than 70% which is determined to be the end point of this test.

[0024] Figure 2 is a diagram of a filter cartridge system 100 according to the mode of the present disclosure as a means for storing the modified activated carbonaceous material of the present disclosure. The disposable filter cartridge 101 can be fitted within a reusable metal frame (not shown). See also U.S. Patent Publication No. 2019 / 0291027A1, which is hereby incorporated by reference in its entirety.

Examples

[0025] Example 1 A sample of granular activated carbon (GAC) derived from 20 g of coconut shells (minimum activity 60% - CCl4) was placed in a beaker, treated with 50 mL of 0.1 M H2SO4, and allowed to stand at room temperature for 15 minutes. Subsequently, the mixture was stirred for 4 hours and then allowed to stand for about 30 minutes to settle, at which point the pH was determined to be 2.101. The resulting carbonaceous material was removed and rinsed with deionized water (twice). The carbonaceous material was then placed in an oven at 210 °C without air flow and dried for 24 hours.

[0026] Characterization of the Carbonaceous Material The following table describes various physical properties of the granulated activated carbon of the present disclosure. TIFF0007714034000001.tif69170

[0027] In Table 2 below, the surface area (SA) is determined using an Autosorb iQ instrument available from Anton-Paar, together with an apparatus set for using the BET (Brunauer, Emmett, and Teller) method. Accordingly, this data is expressed in units of area per mass of the sample (m 2 / g).

[0028] In Table 2 below, the pore volume (PV), as well as the pore size distribution (PSD) for pore volume and surface area, are determined using an Autosorb iQ instrument available from Anton-Paar, together with an apparatus set for using the DFT (density functional theory) method. DFT is based on molecular modeling and takes into account the direct interaction of the adsorbate with the adsorbent surface, the micropore filling process (not the condensation process), the development of the adsorbed film thickness, and capillary condensation (adsorption) and capillary evaporation (desorption). In the table below, PV is the pore volume and SA is the surface area. TIFF0007714034000002.tif74170

[0029] The information in Table 3 - pore volume, micropore surface area, external surface area, and surface area ratio was obtained and determined using an Autosorb iQ instrument available from Anton - Paar, calculated using the t - plot method. TIFF0007714034000003.tif84170

[0030] As can be understood from Table 2 above, the PV ratios of the treated samples GAC B and GAC C decreased compared to the untreated sample GAC A. As can be understood from Table 3 above, the surface area ratios of the treated samples GAC B and GAC C decreased compared to the untreated sample GAC A.

[0031] Aspect In a first aspect, the present disclosure provides an adsorbent comprising an activated carbonaceous material, wherein the material is treated with a solution of an acid having a pKa of about 1 to about 5 at a concentration of about 0.05 - 1.0 M and washed with water.

[0032] In a second aspect, the present disclosure provides the adsorbent of the first aspect, wherein the acid is an inorganic acid selected from hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, and nitric acid.

[0033] In a third aspect, the present disclosure provides the adsorbent of the first or second aspect, wherein the inorganic acid is sulfuric acid at a concentration of about 0.05 M to about 0.5 M.

[0034] In a fourth aspect, the present disclosure provides the adsorbent of the first aspect, wherein the acid is an organic acid.

[0035] In a fifth aspect, the present disclosure provides an adsorbent comprising an activated carbonaceous material, wherein the material (i) micropores including primary micropores and secondary micropores, (ii) mesopores, and (iii) macropores, and having the following property: a surface area ratio of micropores to mesopores of about 13 to about 17 or less, measured using the t - plot method is provided.

[0036] In a sixth aspect, the present disclosure provides an adsorbent comprising an activated carbonaceous material, wherein the material (i) micropores including primary micropores and secondary micropores, (ii) mesopores, and (iii) macropores, and has the following properties: a. A pore volume ratio of (primary micropores):(secondary micropores + mesopores) of about 0.4 or more and about 1.4 or less as measured using the DFT method and provides an adsorbent having the same.

[0037] In a seventh aspect, the present disclosure provides the adsorbent of the fifth or sixth aspect, wherein the micropores have a surface area of about 500 or more and about 1400 m 2 / g or less as measured using the BET method.

[0038] In an eighth aspect, the present disclosure provides the adsorbent of the fifth to seventh aspects, wherein the micropores have a surface area of about 900 or more and about 1200 m 2 / g or less as measured using the BET method.

[0039] In a ninth aspect, the present disclosure provides the adsorbent of any of the fifth to eighth aspects, wherein the micropores have a surface area of about 1050 or more and about 1150 m 2 / g or less as measured using the BET method.

[0040] In a tenth aspect, the present disclosure provides the adsorbent of any of the fifth to ninth aspects, wherein the surface area ratio of the micropores to the mesopores as measured using the t-plot method is about 13 or more and about 15 or less.

[0041] In an eleventh aspect, the present disclosure provides the adsorbent of any of the fifth to tenth aspects, wherein the surface area ratio of the micropores to the mesopores as measured using the t-plot method is about 14.

[0042] In a 12th aspect, the present disclosure provides an adsorbent according to any one of the 5th to 11th aspects, wherein the pore volume ratio (primary micropores):(secondary micropores + mesopores) measured using the DFT method is from about 0.5 or more to about 1.35 or less.

[0043] In a 13th aspect, the present disclosure provides an adsorbent according to any one of the 5th to 12th aspects, wherein the pore volume ratio (primary micropores):(secondary micropores + mesopores) measured using the DFT method is from about 0.9 or more and about 1.3 or less.

[0044] In a 14th aspect, the present disclosure provides an adsorbent according to any one of the 1st to 13th aspects, wherein the carbonaceous material is derived from coconut shell.

[0045] In a 15th aspect, the present disclosure provides a filter comprising an adsorbent according to any one of the 1st to 14th aspects.

[0046] In a 16th aspect, the present disclosure provides a method for removing contaminants from a gas stream, comprising contacting the gas stream with an adsorbent comprising an activated carbonaceous material treated with a dilute solution of at least one acid having a pKa of from about 1 to about 5, followed by washing with water and drying, wherein the contaminants are selected from (i) C1 - C 20 alkylsilanols, (ii) C1 - C 20 silanols substituted with one or more halogen atoms, and (iii) compounds of the formula (R)3Si - O - Si(R)3 [wherein R is selected from C1 - C 20 alkyls and C1 - C 20 alkyls substituted with one or more halogen atoms] selected from the compounds of.

[0047] In a 17th aspect, the present disclosure provides the method according to the 15th aspect, wherein the gas stream is composed of a gas selected from air, nitrogen, oxygen, or an inert gas.

[0048] In the 18th aspect, the present disclosure provides the method of the 15th or 17th aspect, wherein the contaminant is selected from trimethylsilanol, triethylsilanol, tripropylsilanol, triiospropyl silanol, and tributylsilanol.

[0049] In the 19th aspect, the present disclosure provides the method of the 16th, 17th, or 18th aspect, wherein the contaminant is trimethylsilanol.

[0050] In the 20th aspect, the present disclosure provides the method of the 16th or 17th aspect, wherein the contaminant is a compound selected from (CH3)3Si-O-Si(CH3)3; (CH3CH2)3Si-O-Si(CH2CH3)3; hexamethylcyclotrisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, dodecamethylcyclohexasiloxane, or any combination thereof.

[0051] In the 21st aspect, the present disclosure provides any one of the methods of the 16th to 19th aspects, wherein the gas stream is air and the contaminant is trimethylsilanol.

[0052] In the 22nd aspect, the present disclosure provides any one of the methods of the 16th to 21st aspects, wherein the adsorbent is an activated carbonaceous material treated with a solution of sulfuric acid at a concentration of about 0.05 to 1.0 M and washed with water.

[0053] In the 23rd aspect, the present disclosure provides any one of the methods of the 16th to 21st aspects, wherein the adsorbent is an activated carbonaceous material treated with a solution of sulfuric acid at a concentration of about 0.05 to about 0.15 M in water.

[0054] In a 24th aspect, the present disclosure provides a method according to any one of aspects 16 to 23, wherein the activated carbonaceous material is granular or extruded activated carbon.

[0055] In a 25th aspect, the present disclosure provides a method according to any one of aspects 16 to 24, wherein the activated carbonaceous material is derived from a lignin source.

[0056] In a 26th aspect, the present disclosure provides a method according to any one of aspects 16 to 24, wherein the activated carbonaceous material is derived from coconut shells.

[0057] In a 27th aspect, the present disclosure provides a method according to any one of aspects 16 to 26, wherein the acid is an inorganic acid or an organic acid.

[0058] Although several exemplary embodiments of the present disclosure have been described as above, those skilled in the art will readily understand that other embodiments can be implemented and used within the scope of the claims appended hereto. Numerous advantages of the disclosure covered by this document are described in the foregoing explanation. However, it can be understood that the present disclosure is merely illustrative in many respects. The scope of the present disclosure is, of course, defined by the language represented in the appended patent claims.

Claims

1. An adsorbent comprising an activated carbonaceous material, wherein the activated carbonaceous material (i) micropores including primary micropores and secondary micropores, (ii) mesopores, and (iii) macropores, and the activated carbonaceous material has a surface area ratio of micropores to mesopores of 13 or more and 17 or less measured using the t-plot method, the adsorbent.

2. The adsorbent according to claim 1, wherein the pore width of the primary micropores is 0 or more and less than 0.8 nm, and the pore width of the secondary micropores is 0.8 nm or more and less than 2 nm.

3. The adsorbent according to claim 1, wherein the pore volume ratio (primary micropores):(secondary micropores + mesopores) measured using the DFT method is 0.4 or more and 1.4 or less.

4. The adsorbent according to claim 1, wherein the activated carbonaceous material has a surface area of 500 or more to 1400 m ２ / g or less as measured using the BET method.

5. The adsorbent according to claim 1, wherein the surface area ratio of micropores to mesopores measured using the t-plot method is 13 or more and 15 or less.

6. The adsorbent according to claim 1, wherein the pore volume ratio (primary micropores):(secondary micropores + mesopores) measured using the DFT method is 0.5 or more and 1.35 or less.

7. An adsorbent comprising an activated carbonaceous material, wherein the activated carbonaceous material (i) micropores including primary micropores and secondary micropores, (ii) mesopores, and (iii) macropores, and the activated carbonaceous material has a pore volume ratio of (primary micropores):(secondary micropores + mesopores) of 0.4 or more and 1.4 or less measured using the DFT method, the adsorbent.

8. The adsorbent according to claim 7, wherein the pore width of the primary micropores is 0 or more and less than 0.8 nm, and the pore width of the secondary micropores is 0.8 nm or more and less than 2 nm.

9. The adsorbent according to claim 7, wherein the activated carbonaceous material has a surface area of 500 or more to 1400 m ２ / g or less measured using the BET method.

10. The adsorbent according to claim 7, wherein the surface area ratio of micropores to mesopores measured using the t-plot method is 13 or more and 15 or less.

11. The adsorbent according to claim 7, wherein the pore volume ratio (primary micropores):(secondary micropores + mesopores) measured using the DFT method is 0.5 or more and 1.35 or less.

12. A filter comprising the adsorbent according to claim 1.

13. A filter comprising the adsorbent according to claim 7.

14. A method for removing contaminants from a gas stream, comprising contacting the gas stream with the adsorbent according to any one of claims 1, 2, 7, and 8 and the contaminants are (i) C １ ~ C ２０ alkylsilanols of (ii) C substituted by one or more halogen atoms １ ~C ２０ of silanol, or (iii) Formula (R) ３ Si−O−Si(R) ３ [wherein, R is C １ -C ２０ alkyl, or C substituted by one or more halogen atoms １ -C ２０ selected from alkyl of]] the compound A method selected from

15. The method according to claim 14, wherein the contaminant is selected from trimethylsilanol, triethylsilanol, tripropylsilanol, triisopropylsilanol, and tributylsilanol.

16. The contaminant is (CH ３ ) ３ Si-O-Si(CH ３ ) ３ ; (CH ３ CH ２ ) ３ Si-O-Si(CH ２ CH ３ ) ３ 15. The method of claim 14, wherein the compound is selected from the group consisting of hexamethylcyclotrisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, dodecamethylcyclohexasiloxane, and any combination thereof.

17. The method according to claim 14, wherein the gas stream comprises a gas selected from air, nitrogen, oxygen, or an inert gas.

18. The method according to claim 17, wherein the contaminant is selected from trimethylsilanol, triethylsilanol, tripropylsilanol, triisopropylsilanol, and tributylsilanol.

19. The contaminant is (CH ３ ) ３ Si-O-Si(CH ３ ) ３ ; (CH ３ CH ２ ) ３ Si-O-Si(CH ２ CH ３ ) ３ 18. The method of claim 17, wherein the compound is selected from the group consisting of hexamethylcyclotrisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, dodecamethylcyclohexasiloxane, and any combination thereof.

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