Solid adsorbent and preparation method thereof

Abstract

The invention relates to a solid adsorbent and a preparation method thereof. The solid adsorbent is composed of a porous solid carrier and a load. The porous solid carrier comprises a molecular sieve, silica gel, aluminum oxide, hydrotalcite and derivatives thereof. The load is composed of a main agent and an auxiliary agent, the main agent is polyamide-amine of which the terminal group is modified by amino and hydroxyl, and the molar ratio of the amino to the hydroxyl is 1: 1-1: 1.5; and the auxiliary agent is one or more of AMP (adenosine monophosphate), hydroxyethylpiperazine (HPZ), 1, 8-diazabicyclo undec-7-ene (DBU) and sulfolane (TS). The load accounts for 25%-150% of the weight of the porous solid carrier, and the mass fraction of the main agent in the load is 35%-80%. The method has the advantages of adjustable selectivity, high adsorption speed, large adsorption capacity and high removal rate of COS, methyl mercaptan, ethanethiol and other organic sulfur.

Description

Technical Field

[0001] The present invention belongs to the field of gas purification technology in the energy, petrochemical, environmental protection and other industries, and relates to a method for selectively removing H from a gas mixture. 2 The invention discloses a solid adsorbent for organic sulfur such as S and COS, methyl mercaptan, ethyl mercaptan, and the like, and specifically relates to a solid adsorbent and a preparation method thereof. Background Art

[0002] There are many occasions in industry where it is necessary to selectively remove H from gas mixtures. 2 One or more acidic impurities such as S, COS, mercaptan, etc., such as natural gas, refinery catalytic dry gas, coking dry gas, coalbed methane, biogas, landfill gas, and synthesis gas produced by coal, petroleum naphtha, heavy oil, biomass gasification, etc. 2 There are many mature process methods for the separation of S, such as chemical absorption, physical absorption, adsorption and so on.

[0003] For the chemical absorption method, the one using alcohol amine as solvent is called amine method, and the one using potassium carbonate is called hot potash method. Commonly used alcohol amines are monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), diglycolamine (DGA), etc. The hot potash method uses potassium carbonate as the main absorbent, with activators such as DEA or boric acid. Regardless of whether it is the amine method or the hot potash method, the absorption liquid contains 30%-70% or even 90% water. This part of water needs to be heated and vaporized during the regeneration process of the absorption liquid, and it needs to be cooled and cooled when the regenerated absorption liquid returns to the absorption tower for reabsorption. At the same time, the regeneration process also needs to generate a large amount of water vapor in the regeneration tower, which is then condensed and cooled and returned to the regeneration tower. Therefore, for the chemical absorption method, a lot of heat is wasted in the process of heating and cooling the water.

[0004] Physical absorption method based on H 2 The solubility of acidic impurities such as S, COS, and methyl mercaptan in physical solvents is much greater than that of CH 4 , H 2 , CO and other effective components. The physical absorption method often uses solvents such as methanol (such as Rectisol method), polyethylene glycol dimethyl ether (such as NHD method, Selexol method), N-methylpyrrolidone (such as Purisol method) as absorbents. Compared with the chemical absorption method, the physical absorption method is not only simple in process but also low in energy consumption. However, the physical absorption method requires a higher partial pressure of the removed component and a higher absorption operating pressure. At the same time, the full contact between the heavy component in the mixed gas and the physical solvent also causes the heavy component to be absorbed too much, resulting in large losses or deterioration of the absorption liquid, making it unusable.

[0005] The adsorption method often uses porous media such as molecular sieves, activated carbon, silica gel, and alumina as adsorbents. As far as current industrial applications are concerned, porous media can remove multiple components by physical adsorption at room temperature, but as the adsorption temperature increases, the adsorption capacity decreases. At the same time, the adsorption capacity and selectivity of the adsorbent are not high enough at lower temperatures. Moreover, most of the current adsorbents have a single function and are not suitable for treating 2 S and COS, CS 2 A mixture of organic sulfur such as mercaptans.

[0006] In order to reduce the energy consumption of the acidic impurity removal process and improve the adsorption capacity and selectivity of the adsorbent, researchers began to load alkaline substances on the surface of porous adsorbents. Among them, solid adsorbents loaded with amine compounds are called solid amines. Currently, the research on solid amines is almost all aimed at removing CO 2 The amino compounds used in the design include MEA, DEA, MDEA, AMP, diisopropanolamine (DIPA), diethylenetriamine (DETA), tetraethylenepentamine (TEPA), pentaethylenehexamine, (PEHA) and polyethyleneimine (PEI) of different weights.

[0007] Chinese patent application CN95119387.2 discloses a method for preparing a solid amine resin. Chinese patent CN200780029796.1 discloses a solid adsorbent prepared by loading amino compounds such as MEA and DEA on carriers such as nano-silica, silica-alumina, calcium silicate, and loading glycerol, ethylene glycol, polyethylene glycol, etc. to enhance CO 2 Removal of CO2. Chinese patent CN200880124187.9 discloses the use of silica, zeolite, activated carbon to load alkylamines such as TEPA or aromatic amines to remove CO2. Chinese patent CN201010125416.8 discloses a method for preparing solid amines using coal gangue loaded PEI. Chinese patent CN201110091696.X discloses the preparation of solid amines using carbon nanotubes loaded with TEPA or PEI, and the adsorption capacity of low-content 1.5-2.2 vol% CO2 reaches 2.45 mmol / g. Chinese patent CN201210042863.6 discloses the use of solid amines to remove H2 from synthesis gas. 2 S and CO 2 Chinese patents CN201110165456.X and CN201120207786.6 respectively disclose the use of solid amines to purify CO in vehicles. 2 Chinese patent CN201310566423.5 discloses a method for removing CO from solid amine in air conditioning pipes. 2The solid amine adsorbent can be used in fixed bed, moving bed and other reactors, and can be regenerated by thermal regeneration, vacuum regeneration, steam regeneration, gas stripping regeneration or a combination thereof.

[0008] It can be seen that the current selective desulfurization is mainly based on the liquid absorption method, which involves repeated vaporization, condensation and cooling of water during the solution regeneration process, resulting in high energy consumption.

[0009] Chemical absorption, physical absorption and conventional adsorption methods are used to remove H 2 In order to overcome the shortcomings of organic sulfur such as S, COS, and methyl mercaptan, and considering the advantages of solid amines, the present invention combines the advantages of chemical absorption and adsorption methods to propose a solid amine modified with a special amine for selectively removing H from mixed gas. 2 S, COS, methyl mercaptan and other organic sulfur, achieving high selectivity, high desulfurization accuracy and low energy consumption. Summary of the invention

[0010] The main purpose of the present invention is to overcome the existing method of removing H 2 S and organic sulfur solid adsorbents have defects, and a method is proposed to extract H 2 Selective removal of H2S, COS, methyl mercaptan, ethyl mercaptan and other organic sulfur mixed gases 2 The invention relates to a solid adsorbent for organic sulfur such as S, COS, methyl mercaptan, ethyl mercaptan, etc. The technical problem to be solved is to obtain high desulfurization accuracy and low energy consumption, so as to be more suitable for practical use and have industrial utilization value.

[0011] Another object of the present invention is to provide a method for selectively removing H from mixed gas. 2 The preparation method of the solid adsorbent of S and organic sulfur aims to solve the technical problem of making it more uniform, controllable and efficient, so as to be more suitable for practical use.

[0012] Compared with the prior art, the present invention has obvious advantages and beneficial effects. From the above technical scheme, it can be seen that in order to achieve the above-mentioned invention purpose, the main technical contents of the present invention are as follows:

[0013] The solid adsorbent of the present invention can be used in conventional fixed bed, moving bed and other reactors, has the advantages of adjustable selectivity, fast adsorption speed, large adsorption capacity, and can effectively remove organic sulfur such as COS, methyl mercaptan, ethyl mercaptan, etc., and can be used for desulfurization and decarbonization at low temperatures.

[0014] The solid adsorbent of the present invention is composed of two parts: a porous solid carrier and a load. The porous solid carrier includes molecular sieves, silica gel, alumina, hydrotalcite and its derivatives. The load is composed of a main agent and an auxiliary agent, wherein the main agent is polyamide-amine, and the auxiliary agent is one or more of 2-amino-2-methyl-1-propanol (AMP), hydroxyethylpiperazine (HPZ), 1,8-diazabicycloundec-7-ene (DBU), and cyclopentane (TS), preferably 1-2. The load is 25%-150% of the weight of the porous carrier, and the mass fraction of the main agent in the load is 35%-80%.

[0015] The main agent PAMAM of the present invention can be a compound of one generation from 1 to 5 generations of PAMAM or a mixture of PAMAMs of different generations when used. PAMAM is a polymer prepared by a divergent method using ethylenediamine and propylenediamine as the core, methyl acrylate as the side chain, and terminal hydroxylation using monoethanolamine. The diamine as the core of PAMAM can be different from the diamine of the amidation reaction.

[0016] The terminal groups of the main agent PAMAM of the present invention are amine and hydroxyl, wherein the molar ratio of amine to hydroxyl is 1:1-1:1.5.

[0017] The solid adsorbent of the present invention needs to use methanol, ethanol, or a mixture of methanol and ethanol as a dispersant during preparation. The general preparation process comprises the following steps: (1) a certain mass of a porous solid carrier is dispersed in a dispersant to form a suspension A, and a certain mass and ratio of a main agent and an auxiliary agent are dissolved in the dispersant to form a solution B; (2) B is added during the stirring of A; (3) the mixture of A and B is allowed to stand and continuously stirred for a period of time at intervals; (4) the dispersant is removed by vacuum drying to obtain a solid adsorbent.

[0018] For the present invention, the mixed gas containing one or more of H2S and COS, methyl mercaptan, and ethyl mercaptan is not limited to refinery catalytic dry gas, coking dry gas and liquefied gas, natural gas, coalbed methane, biogas, landfill gas, synthesis gas converted from coal, naphtha, heavy oil, residual oil, biomass, etc., and flue gas.

[0019] In the present invention, the content of the main agent in the support and the composition and content of the auxiliary agent are adjusted according to the gas source composition and the adsorption operation conditions (temperature and pressure) during use.

[0020] For the present invention, the mixed gas may contain water or no water.

[0021] The present invention provides a method for preparing a solid adsorbent, which effectively utilizes methanol, ethanol or a mixture thereof as a dispersant through carefully designed steps to ensure that the porous solid carrier, the main agent and the auxiliary agent can be uniformly mixed and form a good adsorbent structure. The following is a detailed description of the preparation method.

[0022] 1. Dispersed porous solid carrier:

[0023] (1) Porous solid carriers are selected as the base material because they have good adsorption properties and certain mechanical strength.

[0024] (2) The porous solid carrier is dispersed in methanol, ethanol or a mixture of the two to form a suspension A. The purpose of this step is to make the carrier particles evenly dispersed, laying a foundation for the subsequent mixing process.

[0025] 2. Dissolve the main agent and auxiliary agent:

[0026] (2) The main agent is usually a chemical substance with specific adsorption function, while the auxiliary agent is used to adjust the performance of the adsorbent, such as improving adsorption efficiency and enhancing stability.

[0027] (3) Dissolve the main agent and auxiliary agent in the same dispersant as suspension A to form solution B. This ensures that the main agent and auxiliary agent can be evenly distributed on the carrier particles during the subsequent mixing process.

[0028] 3. Mix suspension A and solution B:

[0029] (1) While stirring the suspension A, gradually add solution B. The purpose of stirring is to allow the main agent and auxiliary agent in solution B to fully penetrate into the interior and surface of the carrier particles.

[0030] (2) By controlling the stirring speed and stirring time, the mixing effect can be optimized to ensure uniform distribution of the main agent and auxiliary agent on the carrier.

[0031] 4.Standing and re-stirring:

[0032] (1) After mixing, let the mixture of A and B stand for a while. This step helps the ingredients in the mixture to further interact and blend.

[0033] (2) After a certain period of time, the mixture is stirred again. This step helps to eliminate possible stratification or precipitation and ensure the uniformity of the mixture.

[0034] 5. Vacuum drying to remove dispersant:

[0035] (1) Finally, the dispersant is removed by vacuum drying. Vacuum drying can provide lower temperature and higher drying efficiency, which helps to maintain the structure and performance of the adsorbent.

[0036] (2) After removing the dispersant, the desired solid adsorbent is obtained.

[0037] From the above, it can be seen that the present invention belongs to the field of gas purification technology in the energy, petrochemical, environmental protection and other industries, and specifically relates to a solid adsorbent for selectively removing organic sulfur such as H2S, COS, methyl mercaptan, ethyl mercaptan, etc. from a gas mixture. The solid adsorbent consists of a porous solid carrier and a load. The porous solid carrier includes molecular sieves, silica gel, alumina, hydrotalcite and its derivatives. The load consists of a main agent and an auxiliary agent, wherein the main agent is a polyamide-amine with terminal groups modified by amino groups and hydroxyl groups, wherein the molar ratio of amino groups to hydroxyl groups is 1:1-1:1.5; the auxiliary agent is one or more of AMP, hydroxyethylpiperazine (HPZ), 1,8-diazabicycloundec-7-ene (DBU), and cyclopentane sulfone (TS). The load accounts for 25%-150% of the weight of the porous solid carrier, and the mass fraction of the main agent in the load is 35%-80%. The solid adsorbent of the present invention is used for desulfurization and decarbonization, and can be used in conventional fixed bed, moving bed and other reactors at low temperature, and has adjustable selectivity, fast adsorption speed, large adsorption capacity, and high removal rate of organic sulfur such as COS, methyl mercaptan, and ethyl mercaptan.

[0038] By means of the above technical solution, the present invention provides a method for selectively removing H from mixed gas. 2 Solid adsorbents for sulfur and organic sulfur have at least the following advantages:

[0039] The present application scheme is a solid adsorption method, which avoids repeated vaporization, condensation and cooling in the selective desulfurization process. The prepared adsorbent can selectively remove H2S, COS, methyl mercaptan, ethyl mercaptan and other organic sulfur from the mixed gas containing H2S, COS, methyl mercaptan, ethyl mercaptan and other organic sulfur under low pressure and high pressure, and obtain high desulfurization accuracy.

[0040] The adsorbent proposed in the present invention is suitable for the purification of various sulfur-containing gases, including but not limited to catalytic dry gas, coking dry gas, natural gas, coalbed methane, biogas, landfill gas from refineries, and synthesis gas and flue gas converted from coal, naphtha, heavy oil, residual oil, biomass, etc.

[0041] The invention is of great significance for reducing the content of harmful sulfides in industrial emissions and protecting the environment. At the same time, it also embodies the combination of material science and chemical technology and has broad prospects in practical applications.

[0042] The preparation method proposed by the present invention has the following advantages.

[0043] (1) Uniformity: The uniform distribution of the main agent, auxiliary agent and carrier particles is ensured through the carefully designed mixing and stirring steps.

[0044] (2) Controllability: The type of dispersant, the type and amount of the main agent and auxiliary agent, the stirring speed and time and other parameters can be adjusted as needed to prepare adsorbents with different properties.

[0045] (3) High efficiency: Vacuum drying improves drying efficiency, helps shorten preparation cycle and reduce costs.

[0046] In summary, the preparation method of this solid adsorbent has the advantages of simple preparation process, strong controllability, high efficiency and excellent adsorption performance. By optimizing the preparation conditions, solid adsorbents that meet different application requirements can be prepared.

[0047] In summary, the present invention provides a method for selectively removing H from mixed gas. 2 The solid adsorbent for sulfur and organic sulfur has the above-mentioned advantages and practical values. There is no similar design publicly published or used, so it is indeed innovative, has a great progress in technology, and produces good and practical effects.

[0048] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the preferred embodiments of the present invention are described in detail as follows. DETAILED DESCRIPTION

[0049] In order to further explain the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following is a method for selectively removing H from mixed gas proposed by the present invention in combination with preferred embodiments. 2 The specific implementation manner of the solid adsorbent for S and organic sulfur is described in detail as follows.

[0050] In the examples, various proportions of the solid adsorbent are in mass fractions, and the composition of the gas is in volume fractions.

[0051] Solid amine adsorbents are as follows:

[0052] Methanol was used as a dispersant, the porous solid carrier was amorphous silica gel Q-10 (the silica gel degree of amorphous silica gel was 10), the mass of the load was 35% of Q-10, the main agent in the load was 2nd generation PAMAM, and the ratio of the main agent to the auxiliary agent was 75% and 25% respectively. The ratio of the terminal amino group to the hydroxyl group in the 2nd generation PAMAM was 1:1. The auxiliary agent composition was AMP and HPZ, wherein HPZ and AMP were both 50%. The solid adsorbent prepared in this way was marked as SA-1.

[0053] Methanol was used as a dispersant, the porous solid carrier was amorphous silica gel Q-10, the mass of the load was 80% of Q-10, the main agent in the load was 2nd generation PAMAM, and the ratio of the main agent to the auxiliary agent was 50% and 50% respectively. The ratio of the terminal amino group to the hydroxyl group in the 2nd generation PAMAM was 1:1. The auxiliary agent composition was AMP and DBU, wherein DBU and AMP were 40% and 60% respectively. The solid adsorbent prepared in this way was marked as SA-2.

[0054] Methanol was used as a dispersant, the porous solid carrier was amorphous silica gel Q-10, the load was 150% of Q-10, the main agent in the load was 2nd generation PAMAM, and the ratio of the main agent to the auxiliary agent was 35% and 65% respectively. The ratio of the terminal amino group to the hydroxyl group in the 2nd generation PAMAM was 1:1. The auxiliary agent composition was DBU, and HPZ, wherein DBU, and HPZ were 20% and 80% respectively. The solid adsorbent prepared in this way was marked as SA-3.

[0055] Methanol was used as a dispersant, the porous solid carrier was a molecular sieve MCM-41 (nanostructured material), the loading material was 45% of MCM-41, the main agent in the loading material was the third generation PAMAM, the ratio of the main agent to the auxiliary agent was 70% and 30% respectively, and the auxiliary agent was composed of only AMP. The solid adsorbent prepared in this way was marked as SA-4.

[0056] Methanol was used as a dispersant, the porous solid carrier was a molecular sieve MCM-48, the loading material was 85% of MCM-48, the main agent in the loading material was 4th generation PAMAM, the ratio of the main agent to the auxiliary agent was 70% and 30% respectively, and the auxiliary agent only consisted of TS. The solid adsorbent thus prepared was marked as SA-5.

[0057] Ethanol is used as a dispersant, the porous solid carrier is alumina, the load is 125% of alumina, the main agent in the load is 4th generation PAMAM, the ratio of the main agent to the auxiliary agent is 50% and 50% respectively. The auxiliary agent is composed of only TS (cyclopentane sulfone). The solid adsorbent prepared in this way is marked as SA-6.

[0058] Ethanol is used as a dispersant, the porous solid carrier is hydrotalcite, the load is 30% of the hydrotalcite, the main agent in the load is 1st generation PAMAM, the ratio of the main agent to the auxiliary agent is 70% and 30% respectively. The auxiliary agent composition is DBU and TS, wherein DBU and TS are 40% and 60% respectively. The solid adsorbent prepared in this way is marked as SA-7.

[0059] Example 1

[0060] The gauge pressure of the mixed gas is 6kPa, CO 2 The content is 3.5%, and the rest is N 2The adsorption temperature was 40°C. The mixed gas was saturated at the adsorption temperature in a water bath and then passed through an adsorption column filled with the above-mentioned different solid adsorbents. The breakthrough adsorption capacity results at an air velocity of 550 are shown in Table 1.

[0061] Table 1:

[0062] Adsorbent Absorption capacity mmol / g SA-1 0.53 SA-2 0.51 SA-3 0.54 SA-4 0.55 SA-5 0.48 SA-6 0.49 SA-7 0.50

[0063] Example 2

[0064] The gauge pressure of the mixed gas is 6 kPa, H 2 The S content is 3.5%, and the rest is N 2 The adsorption temperature was 40°C. The mixed gas was saturated at the adsorption temperature in a water bath and then passed through an adsorption column filled with the above-mentioned different solid adsorbents. The breakthrough adsorption capacity results at an air velocity of 550 are shown in Table 2.

[0065] Table 2:

[0066] Adsorbent Absorption capacity mmol / g SA-1 4.67 SA-2 4.59 SA-3 4.73 SA-4 4.55 SA-5 4.53 SA-6 4.69 SA-7 4.81

[0067] Example 3

[0068] The gauge pressure of the mixed gas is 0.11 MPa, H 2 S, CO 2 The contents of COS and methyl mercaptan are 0.5%, 3.5%, 25ppmv and 55ppmv respectively, and the rest are N 2 The adsorption temperature is 50°C. After the mixed gas is saturated at the adsorption temperature in a water bath, it passes through an adsorption column filled with different solid adsorbents. The contents of the components in the purified gas at an air velocity of 550 are shown in Table 3 below.

[0069] Table 3:

[0070] Adsorbent <![CDATA[H 2 S(ppmv)]]> <![CDATA[CO 2 (in%)]]> COS(ppmv) Methyl mercaptan (ppmv) SA-1 2.3 2.8 5.5 1.7 SA-2 2.1 2.7 5.2 1.6 SA-3 1.8 2.6 4.9 1.5 SA-4 2.5 2.9 5.1 1.8 SA-5 2.9 3.1 5.7 2.3 SA-6 3.1 3.2 5.3 2.6 SA-7 1.5 2.4 4.4 1.0

[0071] Example 4

[0072] The gauge pressure of the mixed gas is 1MPa, H 2 S, CO 2 The contents of COS and methyl mercaptan are 0.5%, 3.5%, 25ppmv and 55ppmv respectively, and the rest are N 2 The adsorption temperature is 50°C. The mixed gas is saturated at the adsorption temperature in a water bath and then passes through an adsorption column filled with different solid adsorbents. The contents of the components in the purified gas at an air velocity of 1000 are shown in Table 4.

[0073] Table 4:

[0074] Adsorbent <![CDATA[H 2 S(ppmv)]]> <![CDATA[CO 2 (in%)]]> COS(ppmv) Methyl mercaptan (ppmv) SA-1 2.9 3.3 5.8 2.0 SA-2 2.7 3.2 5.5 1.8 SA-3 2.6 3.1 5.3 1.9 SA-4 3.3 3.3 5.4 2.1 SA-5 3.7 3.6 6.1 2.7 SA-6 4.0 3.5 5.7 2.8 SA-7 2.3 2.8 4.9 1.3

[0075] From Example 1 and Example 2, it is known that the prepared adsorbent has a high affinity for H 2The adsorption capacity of S is large, showing good selectivity. It can be seen from Examples 3 and 4 that the prepared adsorbent can obtain good selective desulfurization results under both low pressure and high pressure.

[0076] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modifications to equivalent embodiments of equivalent changes by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A solid adsorbent, which is composed of a porous solid carrier and a load, wherein the porous solid carrier is selected from at least one of molecular sieves, silica gel, alumina, hydrotalcite and their derivatives; the load comprises a main agent and an auxiliary agent, the main agent is a polyamide-amine (PAMAM) modified with terminal amino groups and hydroxyl groups, and the auxiliary agent is at least one of AMP, hydroxyethylpiperazine (HPZ), 1,8-diazabicycloundec-7-ene (DBU), and cyclopentane (TS), the load accounts for 25% to 150% of the weight of the porous solid carrier, and the mass fraction of the main agent in the load is 35% to 80%.

2. The solid adsorbent according to claim 1, wherein the main agent PAMAM is synthesized with ethylenediamine or propylenediamine as the starting core, and ethylenediamine or propylenediamine is used as a branched chain amidation agent, and ethanolamine is used for modification when the terminal group is hydroxylated.

3. The solid adsorbent according to claim 2, wherein the diamine as the core of the PAMAM is different from the diamine used in the amidation reaction.

4. The solid adsorbent according to claim 1, wherein the PAMAM is any generation from 1st generation PAMAM to 5th generation PAMAM, or a mixture of PAMAMs of different generations.

5. The solid adsorbent according to claim 1 or 2, wherein the terminal group of the PAMAM is a modified compound of a hydroxyl group, wherein the molar ratio of the amine group to the hydroxyl group is in the range of 1:1 to 1:1.

5.

6. The solid adsorbent according to claim 1, wherein the mixed gas is selected from refinery catalytic dry gas, coking dry gas and liquefied gas, natural gas, coalbed methane, biogas, landfill gas, or synthesis gas or flue gas converted from coal, naphtha, heavy oil, and residual oil.

7. The solid adsorbent according to claim 1 or 6, wherein the gas space velocity of the solid adsorbent during use is 400 m / s. 3 -1200 m 3 .

8. A method for preparing a solid adsorbent, wherein the method comprises the following steps: Dispersing the porous solid carrier with a dispersant to form a suspension A; Use a dispersant to dissolve the main agent and the auxiliary agent to form solution B; Mix suspension A and solution B; Standing and re-stirring; and The dispersant is removed by vacuum drying to obtain the solid adsorbent.

9. The method for preparing a solid adsorbent according to claim 8, wherein the porous solid carrier is selected from at least one of molecular sieves, silica gel, alumina, hydrotalcite and derivatives thereof; the main agent is polyamide-amine (PAMAM) modified with terminal amino groups and hydroxyl groups; the auxiliary agent is at least one of AMP, hydroxyethylpiperazine (HPZ), 1,8-diazabicycloundec-7-ene (DBU) and sulfolane (TS); and the dispersant is methanol, ethanol or a mixture of methanol and ethanol.

10. The method for preparing a solid adsorbent according to claim 8 or 9, wherein the main agent and the auxiliary agent account for 25% to 150% of the weight of the porous solid carrier, and the mass fraction of the main agent in the main agent and the auxiliary agent is 35% to 80%.