Process for removal of an acid gas contaminant from a liquid or gas by adsorption

Description

[001] This invention relates to the removal of acid gases from liquid or gas streams by selective adsorption of the acid gases onto an alumina adsorbent. Basis of the invention

[002] Acid gases are undesirable impurities in materials such as, for example, petroleum hydrocarbons because several of these gases, such as COS and H2S, contain sulfur and are therefore a potential air pollutant. COS and H2S also act as an undesirable contaminant in industrial processes, such as, for example, by poisoning polymerization catalysts when the contaminant is present in polymerizable olefins derived from petroleum, such as propylene. Acid gases can be introduced into such processes as contaminants initially present in the raw material or they can be formed in the treatment process as a result of the catalyzed molecular sieve reaction of carbon dioxide with hydrogen sulfide or other sulfur compounds.For example, acidic gases can be found in natural gas streams, and although they are pollutants, acidic gases such as COS, H2S, CO2, CS2, SO2, HCl, HF, and HBr can be corrosive to natural gas pipelines, pipeline equipment, and other chemical processing apparatus.

[003] Depending on the process and the required purity of the product, COS levels in the starting material may be required to be reduced below 1 part per million by weight (ppmw) and sometimes to levels below 100 parts per billion by weight (ppbw). COS concentrations in the range of a small ppmw cannot be efficiently separated from a petroleum feedstock, such as propylene, by fractional distillation because the Petition 870220069794, dated 05 / 08 / 2022, p. 11 / 33 2 / 16 The boiling point of COS differs from that of propene by only 3.4 °C.

[004] US Patent No. 3,315,003 by Khelghatian teaches a process for removing COS from a hydrocarbon by first contacting the hydrocarbon with a liquid, such as monoethanolamine, which purifies the hydrocarbon to remove acidic gases such as H2S and CO2 and some of the COS. The hydrocarbon is then distilled. After several subsequent distillations, the bottom liquid product is treated with soda lime to remove any remaining COS.

[005] However, the separation of COS by processes involving distillation, in addition, is extremely costly due to the energy cost of vaporizing virtually all the liquid. It is therefore desirable to provide other means for removing COS impurities from organic liquids.

[006] It has also been proposed to remove COS from hydrocarbons by catalytic hydrolysis to form H2S, for example, using alumina as a catalyst. US Patent No. 3,265,757 by Frevel et al. teaches the hydrolysis of COS contained in a liquid hydrocarbon by contacting a mixture of the liquid hydrocarbon and water, at a temperature from 20 to 50 °C, with a highly alkaline surface area, active alumina containing from 0.15 to 3% by weight of sodium or potassium. The patent applicants report that the hydrolysis reaction will not start, however, if the alumina is too dry. They suggest either wetting the alumina catalyst with ion-free water before the reaction or passing a mixture of ion-free water and the liquid hydrocarbon through the catalyst bed until a sufficient amount of water has been incorporated into the alumina to allow the hydrolysis reaction to proceed.However, while this process removes COS (by converting it to H2S), it does not remove sulfur from the hydrocarbon, but merely changes the form of the sulfur compound that it still is. Petition 870220069794, dated 05 / 08 / 2022, page 12 / 33 3 / 16 subsequently removed from the hydrocarbon by another process step.

[007] In a more recent patent dealing with the same type of reaction, US Patent No. 4,491,516 by Polleck et al. teaches that the reaction rate for the hydrolysis of COS with water on alumina can be significantly increased if the water to COS ratio varies from 1 to 10 moles of water per mole of COS, preferably 1.5 to 6 moles of water per mole of COS, or about 30% saturation of the hydrocarbon, whichever is greater, the higher the upper limit, the less water it provides.

[008] US Patent No. 4,455,446 by Brownell et al. teaches the removal of COS from propylene by hydrolysis over a catalyst comprising platinum sulfide in alumina. The patent holders report that the hydrolysis reaction can be carried out in either the gas or liquid phase with a temperature of 35 to 65 °C used for the liquid phase. An amount of water at least twice the stoichiometric amount of COS to be hydrolyzed must also be present.

[009] US Patent No. 4,391,677 by Harris et al. describes a process for desulfurizing a butene-1 rich stock containing sulfur impurities such as H2S, COS, and CH3SH. The process comprises passing the feed stream through a desulfurization zone maintained under desulfurization conditions and containing a charge of at least one desulfurization medium capable of adsorbing, absorbing, or converting H2S, COS, and CH3SH to high-boiling sulfur compounds. The feed stream thus treated, now essentially free from H2S, COS, and CH3SH, is then passed to a distillation zone and recovered as a bottom product, as a butene-2 ​​rich stream containing high-boiling sulfur compounds. The desulfurization zone comprises a bed of activated alumina followed by a bed of zinc oxide. The activated alumina is referred to Petition 870220069794, dated 05 / 08 / 2022, page 13 / 33 4 / 16 hydrolyze COS in the presence of 20 to 1000 ppm of water to H2S and partially remove H2S and methyl mercaptan. Zinc oxide is referred to as removing any H2S and methyl mercaptan not removed by the alumina bed.

[010] COS has also been removed from liquid hydrocarbons by adsorption onto a zeolite adsorbent. US Patent No. 3,654,144 by Collins discloses removing COS by adsorbing it onto a particular modified zeolite adsorbent A comprising an alkali metal cation form of zeolite A, which has been ionically exchanged with alkaline earth metal cations, preferably calcium cations, to the extent from 20 to about 100 percent equivalent.

[011] US Patent No. 4,098,684 by Innes describes the removal of COS and other sulfur compounds by passing them through a double bed of zeolites comprising, respectively, a 13X molecular sieve, and a zeolite A sieve having a pore size of 4 angstroms. The commercially available 13X zeolite is reported to remove any H2S and mercaptans present. The adsorption capacity of COS by the 13X sieve is reported to be small. The 13X zeolite is described as a three-dimensional network with mutually connected intracrystalline voids accessible through pore openings that will admit molecules with critical dimensions up to 10 angstroms and having the general chemical formula: 0.83 ± 0.05 Na2O / 1.00 Al2O3 / 2.48 ± 0.038 SiO2. Molecular sieve beds can be regenerated by passing a substantially non-adsorbable hot purge gas through the beds at a temperature of about 177 to 316 °C.

[012] While zeolite materials have thus been used as adsorbent agents to remove sulfur compounds, such as COS, from liquid hydrocarbons, it has been found that zeolite, with its cage-like structure, has a low adsorption rate at room temperature and is therefore impractical for treating liquids at such temperatures. Petition 870220069794, dated 05 / 08 / 2022, page 14 / 33 5 / 16

[013] Therefore, it would be highly desirable to provide a process for the removal of acidic gases including sulfur impurities such as COS from liquids or gases, preferably in the absence of water, using an alumina adsorbent having high adsorption characteristics yet capable of being regenerated without substantial loss of adsorption capacity. Removal of other acidic gases besides COS from liquids or gases to minimum ppm levels using an absorbent alumina would also be desirable.

[014] US 4,835,338 to Liu provides an improved process for removing carbonyl sulfide from a liquid hydrocarbon by adsorption on an adsorption medium comprising an activated alumina adsorbent followed by regeneration of the activated alumina after adsorption capacity has been achieved. The activated alumina adsorbent is pretreated with a compound selected from the class consisting of one or more alkali metal compounds, one or more alkaline earth metal compounds, or mixtures of any two or more of such compounds; then used to adsorb carbonyl sulfide from a hydrocarbon; and then regenerated by passing a gas through the adsorbent. Useful activated alumina is disclosed as a commercial product having a particle size range from 1Λ mesh to 100 inches (150 microns).In practice, alumina particles are formed by agglomerating 5-micron alumina powders onto larger particles suitable for the adsorption process. Summary of the invention

[015] It is an object of this invention to provide an improved process for removing acid gases from liquids or gases, comprising adsorbing the acid gases onto an adsorption medium comprising activated alumina, which has been previously treated with one or more alkali metal compounds, one or more metal compounds Petition 870220069794, dated 05 / 08 / 2022, page 15 / 33 6 / 16 alkaline earth metals, or a mixture thereof. It has been found that if the alumina adsorbent is formed from agglomerated alumina powder and provided with a mercury pore volume after treatment with the alkali metal and / or alkaline earth metal compounds of at least 0.10 cc / g of pores larger than 500 angstroms, enhanced adsorbent capacity for acid gases is achieved. Detailed description of the invention

[016] The invention comprises an improved process for removing acidic gases, as described above, including carbonyl sulfide (COS), from liquids or gases by adsorption onto an activated alumina adsorbent. Regeneration of the adsorbent can be achieved and conducted when the adsorbent capacity has been reached. The activated alumina adsorbent used in the process of the invention comprises activated particulate alumina having a particle size range from approximately 1 / 4'' mesh to about 100 (US Series). These particles are formed from agglomerated alumina powders having an average size from about 1 to 10 microns. The alumina particles are formed with a total mercury pore volume of at least 0.45 cc / g, generally at least 0.50 cc / g, preferably at least 0.60 cc / g, more preferably at least 0.70 cc / g.

[017] The desired pore volume of the alumina particles can be achieved by several methods, including agglomerating alumina powders having an average size range from about 1 to 4 microns. If larger alumina powders, for example, above 4 microns, are used, a depletion additive can be agglomerated with the powders. The depletion additive is removed and / or carbonized during subsequent calcination.

[018] Suitable starting materials for the practice of the present invention include pseudoboehmite, gibbsite, baierite and any other form of Petition 870220069794, dated 05 / 08 / 2022, page 16 / 33 7 / 16 alumina, which when properly treated, yields adsorbents having a sodium oxide concentration of 0.10 to 2.5% by weight (calcined basis at 1100 °C), a LOI (hydroxyl content determined by heating from 400 to 1100 °C) of 2.0 to 9.0% by weight, and a surface area of ​​100 to 500 m2 / g (BET).

[019] The starting material of the present invention may have particles having a particle size of 75 microns or larger. These particles should be ground to a particle size of about 1-10 microns to achieve a particularly advantageous adsorbent. Any grinding technique known to those skilled in the art may be used.

[020] Because the starting material alumina has an average particle size of approximately 1 to 10 microns, alumina is rapidly activated by exposure to high temperature for a short period of time. Methods for such rapid activation are well known in the art. One technique that has been found to be particularly useful is that described in U.S. Patent No. 2,915,365. In accordance with this patent disclosure, alumina is injected into a stream of highly heated gases (e.g., air) at gas temperatures greater than 300 °C, such as 300 to 1000 °C. The contact duration between the alumina and the hot gas can be less than one minute, such as from a fraction of a second to several seconds, with two or three seconds being the preferred contact time. The alumina, once activated, is either in the gamma phase or in an amorphous phase or a mixture thereof.In a preferred embodiment of the present invention, rapidly activated alumina is formed into spheres (agglomerates) in the presence of water and then reactivated by any of a number of methods known to those skilled in the art. One method that yields good activated alumina is to expose aged alumina to a temperature in the range of 300 to 800 °C for a period of 10 minutes to about four hours, with temperatures of 350 to 450 °C for 15 minutes to two hours being typical conditions. Activation. Petition 870220069794, dated 05 / 08 / 2022, page 17 / 33 Appropriate final 8 / 16, such as powder activation, is important in developing an adsorbent with low LOI but high surface area.

[021] In general, the depletion additive is a carbon-based material. Examples of depletion additives include sugars, starches, and lignin or grain flours, such as wood, wheat, corn, rye, etc. Water-soluble polymers, such as polyethylene oxide, polyvinyl alcohol, etc., can also be used.

[022] Activated alumina is preferably impregnated with one or more alkali metal compounds, one or more alkaline earth metal compounds, or a mixture thereof in an amount that may vary from about 0.01 to about 15% by weight, preferably from about 1.0 to about 8.0% by weight, more preferably from about 2.0 to about 8.0% by weight and, most preferably, from about 3.0 to about 6.0% by weight, wherein the % by weight is measured as the percentage weight of the impregnated alkali metal or alkaline earth metal as oxide to the total weight of the impregnated alumina adsorbent. The alkali metal compound or alkaline earth metal compound will preferably comprise a material with a decomposable anion so that no other undesirable material is left in the alumina after impregnation.Examples of such alkali metal / alkaline earth metal compounds include, for example, the hydroxides, carbonates, and nitrates of sodium, potassium, lithium, calcium, and magnesium.

[023] Activated alumina can be impregnated with the alkali metal / alkaline earth metal compound by soaking the activated alumina for at least about 5 minutes up to 1 hour or more in an aqueous solution containing the dissolved alkali metal / alkaline earth metal compound, then drying the impregnated alumina and reactivating it at 300 to 450 °C for one or two hours. More than one impregnation and drying cycle can be used if desired. The compound Petition 870220069794, dated 05 / 08 / 2022, p. 18 / 33 9 / 16 can also be applied to spray-activated alumina or similar, if desired.

[024] The reactivated and impregnated alumina adsorbent is enhanced if the treated adsorbent has a total mercury pore volume of at least 0.4 cc / g, typically at least 0.45 cc / g, preferably at least 0.5 cc / g, more preferably at least 0.55 cc / g. Additionally, strongly enhanced acid gas adsorption is achieved if the reactivated and impregnated alumina adsorbent has a pore volume of pores larger than 500 angstroms of at least 0.1 cc / g, typically at least 0.15 cc / g, preferably at least 0.30 cc / g, more preferably at least 0.40 cc / g.

[025] Enhanced activated alumina adsorbents are capable of treating a gas or liquid containing an acid gas impurity concentration of as much as 200 ppm and reducing the concentration to below 1 ppm. Since the removal of COS or other acid gases from a liquid or gas containing such impurities is primarily through adsorption, the presence or absence of any specific amounts of moisture is not critical to the operation of the process. However, since it has been found that the adsorbent's ability to handle acid gases varies inversely with the amount of water present, it is preferable to operate with as little water present as possible. It should also be noted that no water needs to be present for the adsorption process to operate successfully.

[026] In a preferred embodiment, the acid gas impurity is removed from a liquid or gaseous hydrocarbon stream. The hydrocarbon stream to be purified may first be passed through a drying bed, such as a molecular or silica sieve or the like, to remove most, if not all, of the moisture present before Petition 870220069794, dated 05 / 08 / 2022, p. 19 / 33 10 / 16 pass the hydrocarbon stream through the adsorbent to avoid the reduction in adsorption capacity already discussed above. Contaminants to be removed by the adsorbents of this invention are acid gases or acid gases dissolved in liquids comprising COS, H2S, CO2, CS2, SO2, HCl, HF, HBr, with the main constituents of the streams consisting predominantly of ethylene, propylene, butane, or mixtures of various olefins, natural gas, synthesized gas derived from biomass, hydrogen, nitrogen, or air. The main constituent of the stream may be in either gaseous or liquid form.

[027] If moisture is present in the hydrocarbon stream, some of the acid gases may be converted by hydrolysis to other reaction products, which may be adsorbed onto the activated alumina adsorbent impregnated with alkali metal. Such adsorbed reaction products may then be removed along with the adsorbed acid gas by subsequent regeneration of the adsorbent, if desired.

[028] The adsorption process can be carried out at room temperature, although temperatures from 15 to 100 °C can be used if convenient, for example, if the contaminated liquid or gas is at that temperature from previous processing, it needs to be heated or cooled before passing through the adsorbent.

[029] Adsorption can be advantageously carried out in a packed column, although any other convenient way of maintaining contact between the adsorbent and the acid gas-contaminated feed may be employed, such as a slurry process. The feed flow rate through the adsorbent should be slow enough to allow sufficient contact time for the desired adsorption of the acid gas from the feed to the alkali / alkaline earth metal-impregnated activated alumina to occur. The actual amount of contact time will vary. Petition 870220069794, dated 05 / 08 / 2022, page 20 / 33 11 / 16 with the particle size of the adsorbent.

[030] The adsorption capacity of the activated alumina adsorbent impregnated with alkali / alkaline earth metal for sulfur-containing acid gases is determined by monitoring the sulfur content of the effluent from the adsorbent. Before reaching its adsorption capacity, the effluent will contain less than 1 ppm of sulfur. After such monitoring, it indicates that the adsorbent's capacity has been reached, i.e., by an increase in the effluent's sulfur content, the adsorbent can be regenerated by passing a heated gas, such as air, hydrocarbon gases, nitrogen, or other inert gases through the adsorbent. The heated gas is preferably heated to a temperature from about 100 to 300 °C, more preferably about 150 to 250 °C, and most preferably about 250 °C, and passed through the adsorbent at a rate of about 1 to 10 cc / min. until a substantial amount of the sulfur adsorbed on it is removed.A substantial amount is around 40% by weight or higher of adsorbed sulfur. This can be easily determined by analyzing the amount of residual sulfur in the adsorbent. The flow direction of the regenerating gas through the adsorbent can be in the same direction as the feed flow, for example, when the adsorbent is packed in a column, or the regenerating gas can be passed through the adsorbent in a direction opposite to the normal feed flow through it. The adsorption capacity for other acidic gases can be determined by known means for measuring other anionic species, for example, Cl, F, etc.

[031] The following examples will serve to better illustrate the invention process. Examples

[032] COS adsorbents were prepared as described below. The adsorbents were placed in their respective beds and subjected to Petition 870220069794, dated 05 / 08 / 2022, page 21 / 33 12 / 16 rapid aging test and progress test conditions as described below. Test conditions Rapid aging (Rapid regeneration)

[033] Each bed was loaded with 78 grams of adsorbent. The adsorbent beds were then subjected to an adsorption, regeneration, and cooling cycle. The three steps were repeated a total of 35 times. At the end of the 35th cycle, each bed was heated for an additional 2 hours with a flow rate of 0.5 slpm at 270 °C and then cooled to room temperature. During the rapid aging adsorption step, the bed was fed 450 ppm of COS in nitrogen at a flow rate of 8.7 slpm at a temperature of 35 °C and a pressure of 80 psia for 35 minutes. During the regeneration step, the bed was at a pressure of 15 psia and a temperature of 270 °C with a nitrogen feed flow rate of 0.5 slpm countercurrent to the adsorption step. During the rapid aging cooling stage, the bed was at a pressure of 15 psia and a temperature of 35 °C with a 0.5 slpm nitrogen feed flow rate against the current for the adsorption stage. Progress test

[034] After the beds had completed the rapid aging test, a progress test was completed. During this test the beds were fed 75 ppm of COS in nitrogen at a flow rate of 6.45 slpm and a temperature of 35 °C. The beds were run for a time such that the COS at the bed outlet reached the feeding condition. Example 1

[035] Granules were prepared by mixing 15 grams of pore former with 85 grams of flash-calcined alumina powders approximately 5 microns in size. The material was formed into granules. Petition 870220069794, dated 05 / 08 / 2022, page 22 / 33 13 / 16 using a tray agglomeration technique and sieved to a 7x14 Tyler mesh. The material was then calcined at a temperature of 450 °C (842 °F) for 2 hours. The activated material was then immersed in a 9.8 wt% NaOH solution for 20 minutes and the material was reactivated at a temperature of 300 °C (572 °F) for 2 hours. The resulting material had a 6 wt% Na2O content. Example 2

[036] The material from Example 1 was rapidly aged as described in the rapid aging protocol. After aging, the material from Example 1 was then tested in the progress test. The material progressed to 2 ppm COS in 640 minutes and 25 ppm COS in 880 minutes. Example 3

[037] Granules were prepared by grinding alumina powders of approximately 5 microns to a powder of approximately 1.5 microns. The alumina powder was formed into granules using a tray agglomeration technique and screened to a 7x14 Tyler mesh. The granules were then calcined at a temperature of 371.11 °C (700 °F) for a time of 2 hours. The activated granules were then immersed in a 9.8 wt% NaOH solution for 20 minutes and the granules were reactivated in a tray activator at a temperature of 300 °C (572 °F) for a period of 2 hours. The resulting material had a content of 6 wt% Na2O. Example 4

[038] The material from example 3 was rapidly aged as described in the rapid aging protocol. After aging, the material from example 3 was then tested in the progress test. The material progressed to 2 ppm COS in 640 minutes and 25 ppm COS in 880 minutes. Petition 870220069794, dated 05 / 08 / 2022, page 23 / 33 14 / 16 Example 5 (Control)

[039] Granules were prepared by flash-activating approximately 5 microns of alumina powder and then forming the activated powder into granules using a tray agglomeration technique. The granules were sorted to a 7x14 Tyler mesh. The material was then calcined at a temperature of 404.44 °C (760 °F) for 2 hours. The activated material was then immersed in a 9.8 wt% NaOH solution for 20 minutes and re-activated in a tray activator at a temperature of 300 °C (572 °F) for 2 hours. The resulting material had a wt% Na2O content of 4%. Example 6 (Control result)

[040] The control material from example 5 was rapidly aged as described in the rapid aging protocol. It was then tested in the progress test. The control material progressed to 2 ppm COS in 250 minutes and 25 ppm COS in 497 minutes. Example 7 (Control)

[041] Granules were prepared by flash-activating approximately 5 microns of alumina powder and then forming granules using a tray agglomeration technique. The granules were screened to a 7x14 mesh. The material was then calcined at a temperature of 404.44 °C (760 °F) for 2 hours. The activated material was then immersed in a 12 wt% NaOH solution for 20 minutes and the material was reactivated at a temperature of 300 °C (572 °F) for 2 hours. The resulting material had a 6 wt% Na2O content. Example 8 (Control result)

[042] The control material from example 7 was rapidly aged as described in the rapid aging protocol, and then tested in the progress test. The material progressed to 2 ppm of COS in 300 Petition 870220069794, dated 05 / 08 / 2022, page 24 / 33 15 / 16 minutes and 25 ppm of COS in 500 minutes. Example 9

[043] The pore volume of the material from Example 1 was measured prior to immersion by mercury pore symmetry using an instrument from Micromeritics. The total pore volume of the material was 0.63 cc / g. The pore volume of pores larger than 500 angstroms was 0.61 cc / g. Example 10

[044] The pore volume of the material from example 3 was measured prior to immersion by mercury pore symmetry using an instrument from Micromeritics. The total pore volume of the material was 0.72 cc / g. The pore volume of pores larger than 500 angstroms was 0.29 cc / g. Example 11

[045] The pore volumes of the control materials from Examples 5 and 7 were measured prior to immersion by mercury pore symmetry using a Micromeritics instrument. The total pore volume of each material was 0.38 cc / g. Pore volume of pores larger than 500 angstroms was 0.11 cc / g.

[046] Table 1 below summarizes the results of the tests described above. Table 1 Aged cycles 35 times Aged cycles 35 times Total Example No. COS time at 2ppm (min) COS time at 25ppm (min) PV starting granule (cc / g) 1 640 880 0.63 3 638 880 0.72 5 250 497 0.38 7 300 500 0.38 Petition 870220069794, dated 05 / 08 / 2022, page 25 / 33 16 / 16 Example 12

[047] The materials in examples 1, 3, 5, and 7 were measured by pore volume after immersion and activation. The material in example 1, after immersion and activation, had a total pore volume of 0.56 g / cc and, for pores larger than 500 angstroms, a pore volume of 0.15 g / cc. The material in example 3, after immersion and activation, had a total pore volume of 0.59 g / cc and, for pores larger than 500 angstroms, a pore volume of 0.41 g / cc. The control material in example 5, after immersion and activation, had a total pore volume of 0.36 g / cc and, for pores larger than 500 angstroms, a pore volume of 0.07 g / cc. The control sample 7, after immersion and reactivation, had a total pore volume of 0.34 g / cc, and for pores larger than 500 angstroms, it had a pore volume of 0.04 g / cc. Total PV in cc / g 500 A and greater in cc / g Example 1 0.56 0.15 Example 3 0.59 0.41 Example 5 0.36 0.07 Example 7 0.34 0.04

Claims

1. PROCESS FOR REMOVING AN ACID GAS CONTAMINANT FROM A LIQUID OR GAS BY ADSORPTION, characterized by comprising: providing an activated alumina adsorbent by rapidly activating an alumina starting material formed by agglomerating alumina powder having an average particle size greater than 4 microns with a depletion additive that is a carbon-based material in granules and calcining the granules to remove the depletion additive that is a carbon-based material, or by agglomerating calcined alumina powder having an average particle size of 1 to 4 microns, contacting the liquid or gas containing the acid gas contaminant with the activated alumina adsorbent impregnated with from 1.0 to 8.0% by weight of a metal compound, based on the weight ratio of the metal as oxide in said compound to said impregnated adsorbent,said metal compound selected from the group consisting of one or more alkali metal compounds, one or more alkaline earth metal compounds, or a mixture of such compounds, for adsorbing the acid gas contaminant in the liquid or gas for a period of time sufficient to decrease the acid gas contaminant content of the liquid or gas; and wherein said impregnated alumina adsorbent has a mercury pore volume, with pores greater than 500 angstroms, of at least 0.10 cc / g and an overall mercury pore volume greater than 0.40 cc / g, wherein said liquid or gas is a hydrocarbon stream that is an olefin stream or a natural gas stream, and wherein said acid gas is COS, H2S, CS2 or SO2.

2. PROCESS, according to claim 1, characterized in that said impregnated metal compound comprises from 2.0 to 8.0% Petition 870220069794, dated 05 / 08 / 2022, page 27 / 33 2 / 3 by weight as metal oxide in relation to said impregnated adsorbent.

3. PROCESS, according to claim 2, characterized in that said impregnated metal compound comprises from 2.0 to 6.0% by weight as metal oxide in relation to said impregnated adsorbent.

4. PROCESS, according to claim 1, characterized in that the metal in said metal compound impregnated in said activated alumina adsorbent consists essentially of sodium.

5. PROCESS, according to claim 1, characterized in that said liquid or gas is a hydrocarbon stream.

6. PROCESS, according to claim 5, characterized in that said hydrocarbon stream is an olefin stream.

7. PROCESS, according to claim 5, characterized in that said hydrocarbon stream is a natural gas stream.

8. PROCESS, according to claim 1, characterized in that said alumina adsorbent is formed by agglomerating a calcined alumina powder having an average particle size from 1 to 4 microns.

9. PROCESS, according to claim 6, characterized in that said olefin is ethylene and / or propylene.

10. PROCESS, according to claim 1, characterized in that said impregnated adsorbent has an overall mercury pore volume of at least 0.5 cc / g.

11. PROCESS, according to claim 1, characterized in that said impregnated absorbent has a mercury pore volume, with pores larger than 500 angstroms, of at least 0.15 cc / g.

12. PROCESS, according to claim 1, characterized in that said impregnated absorbent has a mercury pore volume, with pores larger than 500 angstroms, of at least 0.30 cc / g. Petition 870220069794, dated 05 / 08 / 2022, p. 28 / 33 3 / 3 13. PROCESS, according to claim 1, characterized by comprising regenerating the activated alumina adsorbent to remove a substantial amount of acid gas contaminant absorbed therein.

14. PROCESS, according to claim 13, characterized in that said activated alumina adsorbent is regenerated by passing a heated gas through the absorbent.

15. PROCESS, according to claim 8, characterized in that said alumina adsorbent has a total mercury pore volume of at least 0.45 cc / g before impregnation.

16. PROCESS, according to claim 8, characterized in that said alumina adsorbent has a total mercury pore volume of at least 0.5 cc / g before impregnation.

17. PROCESS, according to claim 8, characterized in that said alumina adsorbent has a total mercury pore volume of at least 0.6 cc / g before impregnation.

18. PROCESS, according to claim 1, characterized in that said liquid or gas is a synthetic liquid or gas formed from biomass.

19. PROCESS, according to claim 18, characterized by sulfur-containing acid gas.