A method for removing water and carbon dioxide from a gas mixture

Abstract

This invention discloses a method for removing water and carbon dioxide from a mixed gas, comprising: contacting the mixed gas with a weak acid salt molecular sieve adsorbent, wherein the weak acid salt molecular sieve adsorbent selectively adsorbs water and carbon dioxide molecules, while simultaneously excluding other gases with molecular dynamic diameters larger than that of the mixed gas, thereby achieving the removal of water and carbon dioxide from the mixed gas. The preparation method of the weak acid salt molecular sieve adsorbent includes the following steps: (1) selective adsorption of weak acid salt species: placing the molecular sieve in a weak acid salt solution and allowing the two to come into full contact at a certain temperature, so that the weak acid salt species are selectively adsorbed into the molecular sieve channels; (2) high-temperature calcination: drying the molecular sieve after the selective adsorption of weak acid salt species in step (1) and calcining it at 350-650°C in an inert atmosphere and / or air atmosphere to obtain the weak acid salt molecular sieve adsorbent.

Description

Technical Field

[0001] This invention relates to the field of gas separation technology, and more specifically to a method for removing water and carbon dioxide from a mixed gas. Background Technology

[0002] Currently, carbon dioxide and water vapor are the main impurities in the production of high-purity gases in industry. The presence of water and carbon dioxide impurities not only severely affects the quality of high-purity gases, but excessively high water and carbon dioxide content in the mixed gas also has a significant impact on further processing or direct application of the high-purity gases. For example, it can cause catalyst poisoning and deactivation in downstream processes, corrosion of gas transport pipelines, valves, and flow meters, and affect equipment operation and maintenance. High-purity electronic gases (high-purity HF, HBr, HCl), which have important applications in semiconductor production and plasma etching of polysilicon, are crucial for ensuring the quality of various high-performance electronic devices. Their market demand is increasing year by year with the rapid development of the semiconductor and polysilicon industries. A key step in the production process of high-purity electronic gases (high-purity HF, HBr, HCl) is controlling their water content to the nL / L (ppb) level. However, because water easily forms hydrogen bonds and has a low partial pressure, water removal under high-purity gas standards is difficult. Therefore, developing an efficient and cost-effective water and carbon dioxide removal technology has significant industrial value.

[0003] Based on different removal principles, existing technologies for removing H2O and CO2 from mixed gases include solvent absorption, membrane separation, cryogenic distillation, and solid adsorption. Solid adsorption separation technology based on porous materials is currently a mature technology for water and carbon dioxide removal, widely used in practical industrial processes for removing H2O and CO2 from mixed gases. Adsorption separation processes do not involve chemical reactions; instead, they rely on the physical adsorption of gas (adsorbate) on a solid surface (adsorbent) to achieve separation. Regeneration can be achieved through temperature or pressure changes in the system. Compared to other traditional processes, it is simpler to operate and offers higher purification levels, making it widely used for water and carbon dioxide removal. Therefore, the simultaneous removal of water and carbon dioxide based on adsorption separation technology is considered to have good industrial application prospects, and its core lies in the development of highly efficient adsorbents.

[0004] Currently, adsorbents applicable to water and carbon dioxide removal mainly include porous silica, activated alumina, porous carbon materials, metal-organic frameworks, porous polymers, and zeolite molecular sieves. However, the development of highly efficient adsorbents in adsorption separation systems for removing H2O and CO2 still faces the following challenges: (1) low low-pressure adsorption capacity of the materials; (2) difficulty in combining the removal depth and high separation selectivity of H2O and CO2 gases. The molecular sieve adsorbents commonly used in industry are mainly 13X molecular sieves and 3A molecular sieves, but 13X molecular sieves have a larger pore size. Its adsorption force for small molecules is relatively weak, and while removing H2O and CO2 gases, it also adsorbs other gas components in the gas mixture. Therefore, its removal depth and separation selectivity for impurity gases are both low. Meanwhile, 3A molecular sieves, due to their smaller pore size... It can only adsorb molecules with a size of Water molecules, and cannot be removed Carbon dioxide impurities. Therefore, there is an urgent need to develop adsorbent materials that combine high removal depth and high separation selectivity with low cost and stability to achieve efficient removal of water and carbon dioxide. Summary of the Invention

[0005] To address the aforementioned technical problems and shortcomings in the field, this invention provides a method for removing water and carbon dioxide from a mixed gas. The method uses a weak acid salt molecular sieve as an adsorbent, bringing the mixed gas into contact with the weak acid salt molecular sieve adsorbent. The weak acid salt molecular sieve adsorbent selectively adsorbs water and carbon dioxide molecules in the mixed gas, thereby removing water and carbon dioxide from the mixed gas. The adsorbent used for adsorption separation includes a weak acid salt-modified zeolite molecular sieve.

[0006] Specifically, the following technical solutions are included:

[0007] [1] A method for removing water and carbon dioxide from a mixed gas includes: contacting the mixed gas with a weak acid salt molecular sieve adsorbent, wherein the weak acid salt molecular sieve adsorbent selectively adsorbs water and carbon dioxide molecules, and the exclusion molecular dynamics diameter is greater than that of the adsorbent. Other gases are used to remove water and carbon dioxide from the gas mixture.

[0008] [2] A method for deep water removal from a mixed gas includes: contacting the mixed gas with a weak acid salt molecular sieve adsorbent, wherein the weak acid salt molecular sieve adsorbent selectively adsorbs water molecules, and the exclusion molecular dynamics diameter is greater than that of the water molecules. Other gases are used to achieve deep removal of water from the gas mixture.

[0009] [3] A method for deep removal of carbon dioxide from a mixed gas includes: contacting the mixed gas with a weak acid salt molecular sieve adsorbent, wherein the weak acid salt molecular sieve adsorbent selectively adsorbs carbon dioxide molecules, and the exclusion molecular dynamics diameter is greater than that of the carbon dioxide molecules. Other gases can be used to achieve deep removal of carbon dioxide from the gas mixture.

[0010] In any one of the methods described in [1] to [3], the preparation method of the weak acid salt molecular sieve adsorbent includes the following steps:

[0011] (1) Selective adsorption of weak acid salt species: The molecular sieve is placed in a weak acid salt solution and the two are brought into full contact at a certain temperature, so that the weak acid salt species are selectively adsorbed into the molecular sieve pores.

[0012] The molecular sieve is selected from at least one of MFI molecular sieve, FAU molecular sieve, MOR molecular sieve, BETA molecular sieve, CHA molecular sieve, MEL molecular sieve, FER molecular sieve, and EMT molecular sieve.

[0013] The anion of the weak acid salt is selected from metaborate ion (BO2). - ), silicate ions (SiO3) 2- aluminate ions (AlO2) - ), vanadate ions (VO4) 3- ), tellurite ions (TeO3) 2- ), phosphate ions (PO4) 3- At least one of the following, wherein the cation is a metal ion;

[0014] (2) High-temperature calcination: After drying the molecular sieve after selective adsorption of weak acid salt species in step (1), it is calcined in an inert atmosphere and / or air atmosphere at 350-650℃ (e.g. 450℃) to obtain the weak acid salt molecular sieve adsorbent.

[0015] In the weak acid salt molecular sieve adsorbent, the weak acid salt species are adsorbed in the molecular sieve channels in the form of a single or 2 to 3 oligomers.

[0016] In step (1), the crystal size of the molecular sieve can be 0.03 to 100 μm, and more specifically 30 to 50 μm.

[0017] In step (1), the cation of the weak acid salt can be Li. + Na + K + Mg 2+ Ca 2+ Ba 2+ At least one of the following. For example, the weak acid salt may be at least one of NaBO2, Na2SiO3, NaAlO2, Na3PO4, Na3VO4, and Na2TeO3.

[0018] In step (1), the concentration of the weak acid salt solution can be 0.1 to 2 mol / L, for example 0.5 mol / L.

[0019] In step (1), the mass ratio of the molecular sieve to the weak acid salt solution can be 1:2 to 20, for example, 1:10.

[0020] In step (1), the certain temperature can be 30 to 90°C, for example, 50°C.

[0021] In step (1), the time for sufficient contact can be 2 to 48 hours, for example, 24 hours.

[0022] In step (2), the roasting time can be 2 to 10 hours, for example 5 hours.

[0023] The mass percentage of weak acid salt species in the weak acid salt molecular sieve adsorbent can be 0.1% to 2%, and more preferably 0.5% to 1%.

[0024] This invention provides a weak acid salt molecular sieve adsorbent material with molecular sieving function by adsorbing weak acid salt species as modifiers into the molecular sieve channels and then calcining them at high temperature. This achieves precise control of the pore size and gas molecule diffusion dynamics of the zeolite molecular sieve material. Because the molecular dynamic diameters of water and carbon dioxide are smaller than those of other gas molecules in the gas mixture (such as acetylene, nitrogen, methane, ethylene, ethane, hydrogen bromide, etc.), and the pore size of the molecular sieve material after selective adsorption of weak acid salt species is significantly reduced, this type of weak acid salt molecular sieve adsorbent only adsorbs water and carbon dioxide with smaller molecular dynamic diameters, while adsorbing molecules with larger molecular dynamic diameters... Gas molecules cannot enter the pores, thus achieving selective removal of water and carbon dioxide from the mixed gas. Therefore, this type of weak acid salt molecular sieve material possesses both high adsorption capacity and high adsorption separation selectivity for water and carbon dioxide, making it a promising adsorbent for the removal of water and carbon dioxide from mixed gases.

[0025] In any of the methods described in [1] to [3], the adsorption temperature can be 0 to 120°C, further 0 to 100°C, and even further 25 to 60°C. The separation effect is best within this adsorption temperature range.

[0026] In any of the methods described in [1] to [3], the adsorption pressure can be 0 to 70 bar, further 0 to 30 bar, and even further 0.5 to 10 bar. The separation effect is best within this adsorption pressure range.

[0027] The method described in any one of [1] to [3] may further include a desorption and regeneration process, wherein the desorption and regeneration process may employ one or more of the following methods to treat the adsorbent: inert gas purging, heated desorption, and vacuum desorption; the desorption temperature may be 0 to 400°C, further 50 to 300°C, and even further 150 to 200°C; and the desorption pressure may be 0 to 2 bar, further 0 to 1 bar, and even further 0 to 0.2 bar.

[0028] In any one of the methods described in [1] to [3], the mixed gas may contain one or a combination of two or more gases selected from hydrocarbons (e.g., acetylene, ethylene, ethane, methane, etc.), carbon dioxide, carbon monoxide, hydrogen, nitrogen, inert gases (e.g., helium, etc.), air, hydrogen chloride, hydrogen bromide, and nitrous oxide.

[0029] In any one of the methods described in [1] to [3], the mixed gas may be one or more of the following: natural gas, flue gas, biogas, petroleum cracking gas, biomass cracking gas, coal cracking gas, hydrocarbon gas, neutral high-purity electronic special gas, alkaline high-purity electronic special gas, acidic high-purity electronic special gas, bulk industrial gas, rare gas, and air.

[0030] In any of the methods described in [1] to [3], when the mixed gas is an acidic high-purity electronic special gas (e.g., HF, HBr, HCl, etc.), the silica-to-alumina ratio (Si / Al) of the molecular sieve in the weak acid salt molecular sieve adsorbent is preferably greater than 10.

[0031] In a preferred embodiment, the weak acid salt solution is a Na2SiO3 solution, the molecular sieve is a MOR molecular sieve, and the modified zeolite molecular sieve material, i.e., the weak acid salt molecular sieve adsorbent, is Si@MOR-450 (450 represents the calcination temperature). Si@MOR-450 has an adsorption capacity of 8.3 mmol / g for water and 2.9 mmol / g for carbon dioxide at 1 bar and 298 K, while exhibiting almost no adsorption for gases such as acetylene, nitrogen, methane, ethylene, and ethane. It can selectively remove water and carbon dioxide from a gas mixture.

[0032] In any of the methods described in [1] to [3], the molar percentage of water in the mixed gas can be 100 ppm to 3%. Under this gas composition, the water removal rate in the mixed gas is greater than 99%, and the molecular dynamic diameter is greater than... The recovery rate of other gases is greater than 99%, and the concentration of water in the gas after removal is less than 1 ppm, and can be further reduced to less than 100 ppb.

[0033] In any of the methods described in [1] to [3], the molar percentage of carbon dioxide in the mixed gas can be 5000 ppm to 50%. Under this gas composition, the removal rate of carbon dioxide in the mixed gas is greater than 99%, and the molecular dynamic diameter is greater than... The recovery rate of other gases is greater than 99%, and the concentration of carbon dioxide in the gas after removal is less than 50 ppm, and can be further reduced to less than 5 ppm.

[0034] This invention also provides the application of the aforementioned weak acid salt molecular sieve adsorbent for removing water and / or carbon dioxide from a mixed gas. The mixed gas contacts the weak acid salt molecular sieve adsorbent, which selectively adsorbs water and / or carbon dioxide molecules, while the exclusion molecular kinetic diameter is greater than [missing information]. Other gases, to achieve the removal of water and / or carbon dioxide from the mixture.

[0035] For details regarding the weak acid salt molecular sieve adsorbent and its specific adsorption and desorption processes in the aforementioned applications, please refer to the above description.

[0036] The weak acid salt molecular sieve adsorbent exhibits a carbon dioxide adsorption capacity of 2.5–3.5 mmol / g and a water adsorption capacity of 8–10 mmol / g at 1 bar. At a low pressure of 0.04 bar, its carbon dioxide adsorption capacity is 1.9–2.5 mmol / g, and at a low pressure of 100 ppm, its water adsorption capacity is 2.7–3.3 mmol / g. The molecular dynamic diameter in the non-adsorbed gas mixture is greater than [missing value]. Gas molecules.

[0037] The weak acid salt molecular sieve adsorbent has a molecular dynamic diameter greater than [value missing] in a water-carbon dioxide relative mixture under 1 bar conditions. The separation selectivity for other gas components is 10. 10 ~10 30 After the mixed gas is desorbed, the water concentration is less than 1 ppm, preferably less than 100 ppb, and the carbon dioxide concentration is less than 50 ppm, preferably less than 5 ppm.

[0038] Compared with the prior art, the beneficial effects of this invention are as follows:

[0039] 1) A method for removing water and carbon dioxide from a mixed gas using a weak acid salt molecular sieve material with molecular sieving function is provided. This method involves precisely controlling the pore size of the zeolite molecular sieve material and regulating the gas molecule diffusion kinetics to ensure that it adsorbs only water and carbon dioxide molecules, while the molecular dynamic diameter is greater than [missing information]. The gas molecules are excluded, thus selectively removing water and carbon dioxide from the gas mixture.

[0040] 2) This method achieves a removal rate of over 99% for water and carbon dioxide in the gas mixture, and the molecular dynamic diameter is greater than [missing value]. The recovery rate of other gases is greater than 99%.

[0041] 3) The separation method provided by this invention has outstanding advantages over traditional processes, such as energy saving, low equipment investment, and no environmental pollution.

[0042] 4) The method for preparing the weak acid salt molecular sieve adsorbent described in this invention is simple, low in cost, easy to regenerate, reusable, has a long service life, and has good prospects for industrial application. Attached Figure Description

[0043] Figure 1 The adsorption isotherms of the material MOR obtained in Comparative Example 1 for carbon dioxide, acetylene, nitrogen, methane, ethylene, and ethane at 298 K are shown.

[0044] Figure 2 The adsorption isotherm of water on material MOR obtained in Comparative Example 1 at 298 K is shown.

[0045] Figure 3The adsorption isotherms of H3BO3@MOR-450 obtained in Comparative Example 2 for carbon dioxide, acetylene, ethylene, and ethane at 298 K are shown.

[0046] Figure 4 The adsorption isotherms of the weak acid salt molecular sieve adsorbent material Si@MOR-450 obtained in Example 1 for carbon dioxide, acetylene, nitrogen, methane, ethylene, and ethane at 298 K are shown.

[0047] Figure 5 The adsorption isotherm of water on the weak acid salt molecular sieve adsorbent material Si@MOR-450 obtained in Example 1 at 298K;

[0048] Figure 6 The breakthrough curves of the weak acid salt molecular sieve adsorbent material Si@MOR-450 obtained in Example 1 for carbon dioxide / acetylene (50 / 50) mixture (100 ppm water content) at 298 K, 313 K, and 333 K.

[0049] Figure 7 The image shows the breakthrough curve of the weak acid salt molecular sieve adsorbent material Si@MOR-450 obtained in Example 1 for a mixture of carbon dioxide / acetylene / helium (5 / 10 / 85) gas (100 ppm water content) at 298 K.

[0050] Figure 8 The adsorption isotherms of the weak acid salt molecular sieve adsorbent material B@MOR-450 obtained in Example 2 for carbon dioxide, acetylene, methane, ethylene, and ethane at 298 K are shown.

[0051] Figure 9 The weak acid salt molecular sieve adsorbent material B@MOR-450 obtained in Example 2 11 B-solid NMR;

[0052] Figure 10 The adsorption isotherms of the weak acid salt molecular sieve adsorbent material Te@MOR-450 obtained in Example 3 for carbon dioxide and acetylene at 298 K are shown.

[0053] Figure 11 The adsorption isotherms of Al@MOR-450, a weak acid salt molecular sieve adsorbent material obtained in Example 4, for carbon dioxide and acetylene at 298 K. Detailed Implementation

[0054] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Operating methods not specifically specified in the following embodiments are generally performed under conventional conditions or as recommended by the manufacturer.

[0055] Comparative Example 1

[0056] The MOR molecular sieve was calcined at 450℃ for 5 hours without any modification and was recorded as the MOR sample.

[0057] The single-component adsorption isotherms of the MOR sample at 298 K for water, carbon dioxide, acetylene, nitrogen, methane, ethylene, and ethane were measured, and the results are as follows: Figure 1 , Figure 2 As shown in the figure. The results show that the MOR sample adsorbed 8.5 mmol / g of water and 2.7 mmol / g of carbon dioxide at 298 K and 1 bar. The adsorption capacities of acetylene, nitrogen, methane, ethylene, and ethane were 2.4 mmol / g, 0.44 mmol / g, 1.1 mmol / g, 1.9 mmol / g, and 1.2 mmol / g, respectively. It could not achieve selective removal of water and carbon dioxide from the mixed gas.

[0058] Comparative Example 2

[0059] 5 mmol H3BO3 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L H3BO3 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain H3BO3@MOR-450 material.

[0060] The single-component adsorption isotherms of H3BO3@MOR-450 sample for carbon dioxide, acetylene, ethylene, and ethane were measured at 298 K. The results are as follows: Figure 3 As shown in the figure. The results show that the H3BO3@MOR-450 sample adsorbed 1.77 mmol / g of carbon dioxide at 298 K and 1 bar, and 2.02 mmol / g, 0.44 mmol / g, 0.98 mmol / g, and 0.34 mmol / g of acetylene, ethylene, and ethane, respectively. It could not achieve selective removal of water and carbon dioxide from the mixed gas.

[0061] Example 1

[0062] 5 mmol Na2SiO3 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L Na2SiO3 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain Si@MOR-450 material.

[0063] The single-component adsorption isotherms of Si@MOR-450 material at 298 K for water, carbon dioxide, acetylene, nitrogen, methane, ethylene, and ethane were measured, and the results are as follows: Figure 4 , Figure 5 As shown in the figure. The results show that the Si@MOR-450 sample adsorbs 8.3 mmol / g of water and 2.9 mmol / g of carbon dioxide at 298 K and 1 bar. It does not adsorb acetylene, nitrogen, methane, ethylene, or ethane, and can specifically remove water and carbon dioxide from the mixed gas.

[0064] The obtained Si@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (50:50 molar ratio) mixture (100 ppm water content) at 0.1 MPa was introduced into the column at a rate of 0.5 mL / min within the temperature range of 25-60 °C. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The concentration of water in the adsorbed gas was below 100 ppb, and the concentration of carbon dioxide was below 5 ppm. The removal rates of water and carbon dioxide were greater than 99%, and the acetylene recovery rate was greater than 99%. The breakthrough curves of the Si@MOR-450 material for the carbon dioxide / acetylene (50:50 molar ratio) mixture (100 ppm water content) at 298 K, 313 K, and 333 K are shown below. Figure 6 As shown.

[0065] The obtained Si@MOR-450 material was packed into a 5 cm adsorption column. A mixture of carbon dioxide / acetylene / helium (molar ratio 5:10:85) (100 ppm water content) at 0.1 MPa was introduced into the column at 25 °C at a rate of 0.5 mL / min. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The concentration of water in the adsorbed gas was below 100 ppb, and the concentration of carbon dioxide was below 5 ppm. The removal rates of water and carbon dioxide were greater than 99%, and the acetylene recovery rate was greater than 99%. The breakthrough curve of Si@MOR-450 material at 298 K for a mixture of carbon dioxide / acetylene / helium (molar ratio 5:10:85) (100 ppm water content) is shown below. Figure 7 As shown.

[0066] Example 2

[0067] 5 mmol NaBO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L NaBO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain B@MOR-450 material.

[0068] The adsorption isotherms of B@MOR-450 material for carbon dioxide, acetylene, methane, ethylene, and ethane at 298 K were measured, and the results are as follows: Figure 8 As shown in the figure. The results show that the B@MOR-450 sample adsorbs 2.7 mmol / g of carbon dioxide at 298 K and 1 bar, and does not adsorb acetylene, methane, ethylene, or ethane, thus achieving specific removal of water and carbon dioxide from the mixed gas. Figure 9 For B@MOR-450 material 11 The solid NMR spectrum of B confirmed that the B species adsorbed in the channels to regulate the pore size is tetracoordinated, consistent with the weak acid salt NaBO2, further indicating that the weak acid salt species is adsorbed in the molecular sieve channels in the form of a single or 2-3 oligomers.

[0069] The obtained B@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (molar ratio 50:50) mixture (water content 100 ppm) was introduced into the adsorption column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. Nitrogen gas was then used to purge the adsorption column at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, the carbon dioxide concentration was below 5 ppm, the water and carbon dioxide removal rates were greater than 99%, and the acetylene recovery rate was greater than 99%.

[0070] Example 3

[0071] 5 mmol Na2TeO3 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L Na2TeO3 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain Te@MOR-450 material.

[0072] The adsorption isotherms of Te@MOR-450 material for carbon dioxide and acetylene at 298 K were measured, and the results are as follows: Figure 10 As shown.

[0073] The obtained Te@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (molar ratio 50:50) mixture (100 ppm water content) was introduced into the adsorption column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The adsorption column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The concentration of water in the adsorbed gas was below 100 ppb, the concentration of carbon dioxide was below 5 ppm, the removal rates of water and carbon dioxide were greater than 99%, and the acetylene recovery rate was greater than 99%.

[0074] Example 4

[0075] 5 mmol NaAlO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L NaAlO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain Al@MOR-450 material.

[0076] The adsorption isotherms of Al@MOR-450 material for carbon dioxide and acetylene at 298 K were measured, and the results are as follows: Figure 11 As shown.

[0077] The obtained Al@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (molar ratio 50:50) mixture (water content 100 ppm) was introduced into the adsorption column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. Nitrogen gas was then used to purge the adsorption column at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, the carbon dioxide concentration was below 5 ppm, the water and carbon dioxide removal rates were greater than 99%, and the acetylene recovery rate was greater than 99%.

[0078] Example 5

[0079] 5 mmol Na3VO4 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L Na3VO4 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain V@MOR-450 material.

[0080] The obtained V@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (molar ratio 50:50) mixture (water content 100 ppm) was introduced into the adsorption column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The adsorption column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, the carbon dioxide concentration was below 5 ppm, the water and carbon dioxide removal rates were greater than 99%, and the acetylene recovery rate was greater than 99%.

[0081] Example 6

[0082] 5 mmol Na3PO4 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L Na3PO4 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain P@MOR-450 material.

[0083] The obtained P@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (molar ratio 50:50) mixture (water content 100 ppm) was introduced into the adsorption column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. Nitrogen gas was then used to purge the adsorption column at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, the carbon dioxide concentration was below 5 ppm, the water and carbon dioxide removal rates were greater than 99%, and the acetylene recovery rate was greater than 99%.

[0084] Example 7

[0085] 5 mmol Na2SiO3 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of FAU molecular sieve was added to the 0.5 mol / L Na2SiO3 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain Si@FAU-450 material.

[0086] The obtained Si@FAU-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (molar ratio 50:50) mixture (100 ppm water content) was introduced into the column at 0.5 mL / min at 25 °C using 0.1 MPa. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, and the carbon dioxide concentration was below 5 ppm, with a water and carbon dioxide removal rate greater than 99%.

[0087] Example 8

[0088] 5 mmol K2SiO3 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L K2SiO3 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain Si@KMOR-450 material.

[0089] The obtained Si@KMOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene mixture (molar ratio 50:50) with a water content of 100 ppm was introduced into the column at 0.5 mL / min at 25 °C using 0.1 MPa. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, the carbon dioxide concentration was below 5 ppm, the water and carbon dioxide removal rates were greater than 99%, and the acetylene recovery rate was greater than 99%.

[0090] Example 9

[0091] 5 mmol NaBO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L NaBO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain B@MOR-450 material.

[0092] The obtained B@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / nitrous oxide (50:50 molar ratio) mixture (100 ppm water content) at 0.1 MPa was introduced into the column at 25 °C at a rate of 0.5 mL / min. High-purity nitrous oxide (greater than 99.9%) gas was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, the carbon dioxide concentration was below 5 ppm, the water and carbon dioxide removal rates were greater than 99%, and the nitrous oxide recovery rate was greater than 99%.

[0093] Example 10

[0094] 5 mmol NaBO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L NaBO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain B@MOR-450 material.

[0095] The obtained B@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / hydrogen bromide mixture (molar ratio 50:50) with a water content of 100 ppm was introduced into the column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity hydrogen bromide (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The concentration of water in the adsorbed gas was below 100 ppb, the concentration of carbon dioxide was below 5 ppm, the removal rates of water and carbon dioxide were greater than 99%, and the recovery rate of hydrogen bromide was greater than 99%.

[0096] Example 11

[0097] 5 mmol NaBO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L NaBO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain B@MOR-450 material.

[0098] The obtained B@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / methane (50:50 molar ratio) mixture (100 ppm water content) at 0.1 MPa was introduced into the column at 25 °C at a rate of 0.5 mL / min. High-purity methane (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, the carbon dioxide concentration was below 5 ppm, the water and carbon dioxide removal rates were greater than 99%, and the methane recovery rate was greater than 99%.

[0099] Example 12

[0100] 5 mmol NaBO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L NaBO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain B@MOR-450 material.

[0101] The obtained B@MOR-450 material was packed into a 5 cm adsorption column. A carbon dioxide / nitrogen mixture (molar ratio 50:50) with a water content of 100 ppm was introduced into the column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity nitrogen (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, the carbon dioxide concentration was below 5 ppm, the water and carbon dioxide removal rates were greater than 99%, and the nitrogen recovery rate was greater than 99%.

[0102] Example 13

[0103] 5 mmol NaBO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MOR molecular sieve was added to the 0.5 mol / L NaBO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain B@MOR-450 material.

[0104] The obtained B@MOR-450 material was packed into a 5 cm adsorption column. Petroleum cracking gas (100 ppm water content) at 0.1 MPa was introduced into the column at 0.5 mL / min at 25 °C. Adsorption was stopped when water and carbon dioxide permeated through. Nitrogen gas was then used to purge the column at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, and the carbon dioxide concentration was below 5 ppm. The removal rates of water and carbon dioxide were greater than 99%, and the recovery rate of hydrocarbon components in the petroleum cracking gas was greater than 99%.

[0105] Example 14

[0106] 5 mmol NaBO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of FER molecular sieve was added to the 0.5 mol / L NaBO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain B@FER-450 material.

[0107] The obtained B@FER-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (molar ratio 50:50) mixture (water content 100 ppm) was introduced into the adsorption column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The adsorption column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, and the carbon dioxide concentration was below 5 ppm, with a water and carbon dioxide removal rate greater than 99%.

[0108] Example 15

[0109] 5 mmol NaBO2 was dissolved in 10 mL of water to prepare a solution with a concentration of 0.5 mol / L. 1 g of MEL molecular sieve was added to the 0.5 mol / L NaBO2 solution and mixed thoroughly in a constant temperature shaker at 50 °C for 24 h. The resulting slurry was filtered and dried at 100 °C for 12 h, and then calcined in a muffle furnace at 450 °C for 5 h to obtain B@MEL-450 material.

[0110] The obtained B@MEL-450 material was packed into a 5 cm adsorption column. A carbon dioxide / acetylene (molar ratio 50:50) mixture (water content 100 ppm) was introduced into the adsorption column at 0.1 MPa at 25 °C at a rate of 0.5 mL / min. High-purity acetylene (greater than 99.9%) was obtained in the effluent. Adsorption was stopped when water and carbon dioxide permeated through. The adsorption column was then purged with nitrogen at 200 °C at a flow rate of 3.0 mL / min, achieving complete desorption and regeneration. The adsorption column can be recycled. The water concentration in the adsorbed gas was below 100 ppb, and the carbon dioxide concentration was below 5 ppm, with a water and carbon dioxide removal rate greater than 99%.

[0111] Furthermore, it should be understood that after reading the above description of the present invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A method for removing water and / or carbon dioxide from a gas mixture, characterized in that, include: The mixed gas is brought into contact with a weak acid salt molecular sieve adsorbent, which selectively adsorbs water and / or carbon dioxide molecules while excluding other gases with a molecular dynamic diameter greater than 3.3 Å, thereby removing water and / or carbon dioxide from the mixed gas. The preparation method of the weak acid salt molecular sieve adsorbent includes the following steps: (1) Selective adsorption of weak acid salt species: The molecular sieve is placed in a weak acid salt solution and the two are brought into full contact at a certain temperature, so that the weak acid salt species are selectively adsorbed into the molecular sieve pores. The molecular sieve is selected from at least one of MFI molecular sieve, FAU molecular sieve, MOR molecular sieve, BETA molecular sieve, CHA molecular sieve, MEL molecular sieve, FER molecular sieve, and EMT molecular sieve. The anion of the weak acid salt is selected from at least one of metaborate ion, silicate ion, aluminate ion, vanadate ion, tellurite ion, and phosphate ion, and the cation is a metal ion. (2) High-temperature calcination: After drying the molecular sieve after selective adsorption of weak acid salt species in step (1), it is calcined at 350~650℃ in an inert atmosphere and / or air atmosphere to obtain the weak acid salt molecular sieve adsorbent. In the weak acid salt molecular sieve adsorbent, the weak acid salt species are adsorbed in the molecular sieve channels in the form of a single or 2-3 oligomers.

2. The method according to claim 1, characterized in that, In step (1): the crystal size of the molecular sieve is 0.03~100 μm; the cation of the weak acid salt is Li. + Na + K + Mg 2+ Ca 2+ Ba 2+ At least one of the following: the concentration of the weak acid salt solution is 0.1~2 mol / L; the mass ratio of the molecular sieve to the weak acid salt solution is 1:2~20; the specific temperature is 30~90℃; the sufficient contact time is 2~48 hours; In step (2), the roasting time is 2 to 10 hours; The mass percentage of weak acid salt species in the weak acid salt molecular sieve adsorbent is 0.1% to 2%.

3. The method according to claim 2, characterized in that, In step (1), the crystal size of the molecular sieve is 30~50 μm; The mass percentage of weak acid salt species in the weak acid salt molecular sieve adsorbent is 0.5% to 1%.

4. The method according to claim 1, characterized in that, The adsorption temperature of the mixed gas is 0~120℃; The adsorption pressure of the mixed gas is 0~70 bar; The method further includes a desorption and regeneration process, in which the adsorbent is treated by one or more of the following methods: inert gas purging, heated desorption, and vacuum desorption. The desorption temperature is 0~400℃ and the desorption pressure is 0~2 bar.

5. The method according to claim 4, characterized in that, The adsorption temperature of the mixed gas is 0~100℃; The adsorption pressure of the mixed gas is 0~30 bar; The desorption temperature is 50~300℃, and the desorption pressure is 0~1 bar.

6. The method according to claim 5, characterized in that, The adsorption temperature of the mixed gas is 25~60℃.

7. The method according to claim 1, characterized in that, The mixed gas is one or more of the following: natural gas, flue gas, biogas, petroleum cracking gas, biomass cracking gas, coal cracking gas, hydrocarbon gas, neutral high-purity electronic special gas, alkaline high-purity electronic special gas, acidic high-purity electronic special gas, bulk industrial gas, rare gas, and air.

8. The method according to claim 1, characterized in that, When the mixed gas is an acidic high-purity electronic special gas, the silica-alumina ratio of the molecular sieve in the weak acid salt molecular sieve adsorbent is greater than 10.

9. An application of a weak acid salt molecular sieve adsorbent for removing water and / or carbon dioxide from a mixed gas, characterized in that, The mixed gas is brought into contact with a weak acid salt molecular sieve adsorbent, which selectively adsorbs water and / or carbon dioxide molecules while excluding other gases with a molecular dynamic diameter greater than 3.3 Å, thereby removing water and / or carbon dioxide from the mixed gas. The preparation method of the weak acid salt molecular sieve adsorbent includes the following steps: (1) Selective adsorption of weak acid salt species: The molecular sieve is placed in a weak acid salt solution and the two are brought into full contact at a certain temperature, so that the weak acid salt species are selectively adsorbed into the molecular sieve pores. The molecular sieve is selected from at least one of MFI molecular sieve, FAU molecular sieve, MOR molecular sieve, BETA molecular sieve, and CHA molecular sieve; The anion of the weak acid salt is selected from at least one of metaborate ion, silicate ion, aluminate ion, vanadate ion, tellurite ion, and phosphate ion, and the cation is a metal ion. (2) High-temperature calcination: After drying the molecular sieve after selective adsorption of weak acid salt species in step (1), it is calcined at 350~650℃ in an inert atmosphere and / or air atmosphere to obtain the weak acid salt molecular sieve adsorbent. In the weak acid salt molecular sieve adsorbent, the weak acid salt species are adsorbed in the molecular sieve channels in the form of a single or 2-3 oligomers.

10. The application according to claim 9, characterized in that, The weak acid salt molecular sieve adsorbent has a carbon dioxide adsorption capacity of 2.5~3.5 mmol / g and a water adsorption capacity of 8~10 mmol / g under 1 bar conditions, but does not adsorb gas molecules with a molecular dynamic diameter greater than 3.3 Å in the mixed gas. The weak acid salt molecular sieve adsorbent exhibits a separation selectivity of 10 for water and carbon dioxide relative to other gas components in the mixed gas with a molecular dynamic diameter greater than 3.3 Å at 1 bar. 10 ~10 30 After the mixed gas is desorbed, the concentration of water is less than 1 ppm and the concentration of carbon dioxide is less than 50 ppm.

11. The application according to claim 10, characterized in that, After removal, the concentration of water in the mixed gas is less than 100 ppb, and the concentration of carbon dioxide is less than 5 ppm.

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