Nanocomposite desulfurization and decarburization solvent and preparation method thereof

Abstract

The application discloses a kind of nanocomposite desulfurization and decarburization solvent and preparation method thereof, belong to natural gas desulfurization and decarburization technical field, including the following components: alcohol amine solvent 20wt%~65wt%, accelerator 5 wt%~40wt%, activating agent 5 wt%~20wt%, nanoscale oxide 0.1 wt%~1.5wt%, antifoaming agent 0.001 wt%~1wt%, corrosion inhibitor 0.0005 wt%~1wt% and the rest is water, total 100 wt%.The application has obvious applicability, avoids excessive removal of carbon dioxide, has obvious selective control advantage, through chemical absorption, physical absorption, nanoscale oxide mass transfer strengthening etc. Synergistic effect, can realize to meet the quality requirements of a kind of natural gas, while reasonably retaining carbon dioxide volume concentration in 2% (mol) ~3% (mol) range, can be popularized and applied to other industries similar gas desulfurization and decarburization.

Description

Technical Field

[0001] This invention relates to the field of natural gas desulfurization and decarbonization technology, and in particular to a nanocomposite desulfurization and decarbonization solvent and its preparation method. Background Technology

[0002] Extracted natural gas typically contains impurities such as hydrogen sulfide, carbon dioxide, and organic sulfur compounds (carbonyl sulfide, thiols). GB17820-2018, "Natural Gas," sets strict requirements for purified commercial natural gas, including a requirement for Class I gas to have CO2 ≤ 3% and H2S content ≤ 6 mg / Nm³. 3 Total sulfur ≤20mg / Nm 3 Therefore, it is necessary to remove sulfur compounds and carbon dioxide from natural gas to meet the requirements of commercial natural gas. In addition, production units also need to make reasonable energy conservation and consumption reduction. Multifunctional selective removal of impurity components from natural gas has always been a complex technical problem.

[0003] The above background information is provided to facilitate understanding of the present invention and is not intended to be publicly known technology disclosed to the general public prior to the application of this invention. Summary of the Invention

[0004] To address the aforementioned shortcomings, this invention provides a nanocomposite desulfurization and decarbonization solvent and its preparation method, which selectively removes hydrogen sulfide, carbon dioxide, and organic sulfur from extracted natural gas simultaneously, and optimizes its selectivity with the participation of nanoscale oxides.

[0005] The technical solution is: a nanocomposite desulfurization and decarbonization solvent, comprising the following components: Alkylamine solvent 20 wt%~65 wt%; Accelerator 5 wt%~40 wt%; Activator 5 wt%~20 wt%; Nanoscale oxides: 0.1 wt%–1.5 wt%; Defoamer 0.001 wt%~1 wt%; Corrosion inhibitor 0.0005 wt%~1 wt% and The remainder is water, totaling 100 wt%.

[0006] This invention first employs an alkanolamine solvent, an activator, and a promoter in combination to selectively remove impurities according to gas and gas conditions. At the same time, it introduces nano-sized oxides to enhance fluid turbulence and further promote the regulation of its selective function, so as to meet the standards for commercial natural gas while avoiding excessive removal of carbon dioxide, thus achieving reasonable energy saving.

[0007] Further, the amine solvent is one or more selected from N-methyldiethanolamine, tert-butylaminoethoxyethanol, tert-butylethanolamine, and 2-amino-2-methyl-1-propanol. The amine solvent can be N-methyldiethanolamine, tert-butylaminoethoxyethanol, tert-butylethanolamine, or 2-amino-2-methyl-1-propanol; or, for example, a mixture of N-methyldiethanolamine and tert-butylaminoethoxyethanol, a mixture of N-methyldiethanolamine and tert-butylethanolamine, or a mixture of N-methyldiethanolamine and 2-amino-2-methyl-1-propanol; or, for example, an amine solvent... It can be a mixture of N-methyldiethanolamine, tert-butylaminoethoxyethanol, and tert-butylethanolamine; the alcohol amine solvent can be a mixture of N-methyldiethanolamine, tert-butylaminoethoxyethanol, and 2-amino-2-methyl-1-propanol; or, for example, the alcohol amine solvent can be a mixture of N-methyldiethanolamine, tert-butylaminoethoxyethanol, tert-butylethanolamine, and 2-amino-2-methyl-1-propanol.

[0008] Further, the accelerator is one or more selected from polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone. The accelerator can be polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, or N-methylpyrrolidone; or, for example, a mixture of polyethylene glycol dimethyl ether and sulfolane, a mixture of polyethylene glycol dimethyl ether and ethylene glycol, a mixture of polyethylene glycol dimethyl ether and glycerol, a mixture of polyethylene glycol dimethyl ether and diethylene glycol, or a mixture of polyethylene glycol dimethyl ether and N-methylpyrrolidone; or, for example, a mixture of polyethylene glycol dimethyl ether and N-methylpyrrolidone. A mixture of polyethylene glycol dimethyl ether, sulfolane, and ethylene glycol; the accelerator can be a mixture of polyethylene glycol dimethyl ether, sulfolane, and glycerol; a mixture of polyethylene glycol dimethyl ether, sulfolane, and diethylene glycol; a mixture of polyethylene glycol dimethyl ether, sulfolane, and N-methylpyrrolidone; a mixture of sulfolane, ethylene glycol, and glycerol; a mixture of sulfolane, ethylene glycol, and diethylene glycol; a mixture of sulfolane, ethylene glycol, and N-methylpyrrolidone; a mixture of ethylene glycol, glycerol, and diethylene glycol; the accelerator... The accelerator can be a mixture of ethylene glycol, glycerol, and N-methylpyrrolidone, and the accelerator can be a mixture of glycerol, diethylene glycol, and N-methylpyrrolidone; or, for example, the accelerator can be a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, and glycerol, or a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, and diethylene glycol, or a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, and N-methylpyrrolidone, or a mixture of sulfolane, ethylene glycol, glycerol, and diethylene glycol, or a mixture of sulfolane, ethylene glycol, glycerol, and N-methylpyrrolidone. The mixture of pyrrolidones may have an accelerator that is a mixture of ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone; or, for example, an accelerator that is a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, and diethylene glycol; or, for example, an accelerator that is a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone; or, for example, an accelerator that is a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone.

[0009] Furthermore, the activator is one or more of monoethanolamine, piperazine compounds, and their derivatives.

[0010] Further, the alcoholic solvent is N-methyldiethanolamine and tert-butylaminoethoxyethanol, wherein the weight ratio of N-methyldiethanolamine to tert-butylaminoethoxyethanol is 1 to 3:1.

[0011] Furthermore, the nanoscale oxide is one or more of nanoscale aluminum oxide, nanoscale titanium dioxide, and nanoscale silicon dioxide, and the size of the nanoscale oxide is 5 nm to 40 nm.

[0012] Furthermore, the nanoscale oxide is a nanoscale hydroxy oxide, and the size of the nanoscale oxide is 5 nm to 40 nm.

[0013] Furthermore, the nano-sized hydroxyl oxide is one or more of nano-sized hydroxyl aluminum oxide, nano-sized hydroxyl titanium dioxide, and nano-sized hydroxyl silicon dioxide.

[0014] Furthermore, the nano-sized hydroxyl oxide is a hydroxide that has lost some of its hydroxyl groups.

[0015] Furthermore, the nanoscale hydroxyl oxide is prepared through the following steps: Hydroxides are obtained by drying at 110℃~140℃ to remove free water, heating at a rate of 10℃ / minute, followed by heat treatment at 180℃~200℃ for 1 to 3 hours, and then slowly cooling naturally.

[0016] Furthermore, the hydroxide has a specific surface area ≥100 m². 2 / g of hydroxide.

[0017] In this invention, N-methyldiethanolamine and tert-butylaminoethoxyethanol work synergistically to achieve initial selective regulation of carbon dioxide. To address the weakness of organic sulfur compounds in their poor chemical reaction with alkanolamines, sulfolane is introduced to further promote the removal of organic sulfur. Since most physical solvents also have strong solubility for carbon dioxide, piperazine is introduced to further selectively regulate impurities. Given that hydrogen sulfide reacts rapidly with alkanolamine solvents, while the reaction between carbon dioxide and organic sulfur is significantly affected by mass transfer, especially organic sulfur, a novel nanoscale oxide material is introduced to enhance the solvent's perturbation effect, improve the gas-solution contact effect, and further enhance the selective regulation of the desulfurization and decarbonization solvent.

[0018] The composite desulfurization and decarbonization solvent of this invention has significant applicability, avoids excessive carbon dioxide removal, and has obvious selective control advantages. This nanocomposite desulfurization and decarbonization solvent, through the synergistic effects of chemical absorption, physical absorption, and enhanced mass transfer using nanoscale oxides, can meet the quality requirements of Class I natural gas while reasonably retaining a carbon dioxide volume concentration within the range of 2% (mol) to 3% (mol).

[0019] The present invention also provides a method for preparing a nanocomposite desulfurization and decarbonization solvent.

[0020] The technical solution is: a method for preparing the above-mentioned nanocomposite desulfurization and decarbonization solvent, comprising the following steps: S1. The nano-sized oxide is premixed with a portion of activator and water at 50℃~80℃ for 30 minutes~60 minutes to form a homogeneous slurry for later use. S2, In the slurry obtained in S1, add an alcohol amine solvent, an accelerator, the remaining activator, an antifoaming agent and a corrosion inhibitor, and stir thoroughly to obtain the nanocomposite desulfurization and decarbonization solvent.

[0021] The two-step preparation method of this invention aims to obtain a more uniform product and reduce production costs. In step S1, the slurry contains nano-sized hydroxyl titanium dioxide dispersed in primary particle form with aggregate sizes ≤100nm. This ensures that the nanocomposite desulfurization and decarbonization solvent prepared after stirring in step S2 better meets the requirements for nanoparticles and also better guarantees the uniformity of the solution.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows: For natural gas containing high levels of hydrogen sulfide, carbon dioxide, and complex organic sulfur, the composite desulfurization and decarbonization solvent of this invention exhibits significant adaptability, avoids excessive removal of carbon dioxide, and has a clear advantage in selective regulation.

[0023] For products containing COS (≤150mg / Nm 3 CH3SH (≤150mg / Nm 3 The sulfur-containing natural gas will have its total organic sulfur removed to ≤16 mg / Nm³. 3 The composite desulfurization and decarbonization solvent of this invention solves the problem that when there is a high level of complex organic sulfur, the purified natural gas can meet the total sulfur requirements of Class I natural gas.

[0024] When natural gas contains high levels of organic sulfur, it is necessary to remove both organic sulfur and carbon dioxide simultaneously. However, this often results in excessive carbon dioxide removal, leading to unnecessary energy consumption. The nanocomposite desulfurization and decarbonization solvent of this invention, through the coordinated action of chemical absorption, physical absorption, and enhanced mass transfer by nano-scale oxides, can achieve a reasonable retention of carbon dioxide volume concentration within the range of 2% (mol) to 3% (mol) when meeting the quality requirements of Class I natural gas. Detailed Implementation

[0025] As used in this article: "Prepared from" is synonymous with "comprising". The terms "comprising", "including", "having", "containing", or any other variations thereof as used herein are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0026] The conjunction "composed of..." excludes any unspecified elements, steps, or components. If used in a claim, this phrase makes the claim closed, excluding materials other than those described, except for associated conventional impurities. When the phrase "composed of..." appears in a clause of the body of a claim rather than immediately following it, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0027] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1–5” is disclosed, the described range should be interpreted as including ranges “1–4”, “1–3”, “1–2”, “1–2 and 4–5”, “1–3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0028] A nanocomposite desulfurization and decarbonization solvent, comprising the following components: Alkylamine solvent 20 wt%~65 wt%; Accelerator 5 wt%~40 wt%; Activator 5 wt%~20 wt%; Nanoscale oxides: 0.1 wt%–1.5 wt%; Defoamer 0.001 wt%~1 wt%; Corrosion inhibitor 0.0005 wt%~1 wt% and The remainder is water, totaling 100 wt%.

[0029] To achieve better results, the present invention further specifies that the amine solvent is one or more selected from N-methyldiethanolamine, tert-butylaminoethoxyethanol, tert-butylethanolamine, and 2-amino-2-methyl-1-propanol. For example, the amine solvent can be N-methyldiethanolamine, tert-butylaminoethoxyethanol, tert-butylethanolamine, or 2-amino-2-methyl-1-propanol; or, for example, a mixture of N-methyldiethanolamine and tert-butylaminoethoxyethanol, a mixture of N-methyldiethanolamine and tert-butylethanolamine, or a mixture of N-methyldiethanolamine and 2-amino-2-methyl-1-propanol; or, for example, an amine solvent... The solvent can be a mixture of N-methyldiethanolamine, tert-butylaminoethoxyethanol, and tert-butylethanolamine; the amine solvent can be a mixture of N-methyldiethanolamine, tert-butylaminoethoxyethanol, and 2-amino-2-methyl-1-propanol; or, for example, the amine solvent can be a mixture of N-methyldiethanolamine, tert-butylaminoethoxyethanol, tert-butylethanolamine, and 2-amino-2-methyl-1-propanol.

[0030] To achieve better results, the present invention further specifies that the accelerator is one or more of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone. For example, the accelerator can be polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, or N-methylpyrrolidone; or, for example, a mixture of polyethylene glycol dimethyl ether and sulfolane, a mixture of polyethylene glycol dimethyl ether and ethylene glycol, a mixture of polyethylene glycol dimethyl ether and glycerol, a mixture of polyethylene glycol dimethyl ether and diethylene glycol, or a mixture of polyethylene glycol dimethyl ether and N-methylpyrrolidone; or, for example, the accelerator can be... The accelerator can be a mixture of polyethylene glycol dimethyl ether, sulfolane, and ethylene glycol, or a mixture of polyethylene glycol dimethyl ether, sulfolane, and glycerol. The accelerator can be a mixture of ethylene glycol, glycerol, and N-methylpyrrolidone, and the accelerator can be a mixture of glycerol, diethylene glycol, and N-methylpyrrolidone; or, for example, the accelerator can be a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, and glycerol, or a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, and diethylene glycol, or a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, and N-methylpyrrolidone, or a mixture of sulfolane, ethylene glycol, glycerol, and diethylene glycol, or a mixture of sulfolane, ethylene glycol, glycerol, and N-methylpyrrolidone. The mixture of pyrrolidones may have an accelerator that is a mixture of ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone; or, for example, an accelerator that is a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, and diethylene glycol; or, for example, an accelerator that is a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone; or, for example, an accelerator that is a mixture of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone.

[0031] To achieve better results, the present invention further specifies that the activator is one or more of monoethanolamine, piperazine compounds, and their derivatives. For example, the activator may be monoethanolamine, a piperazine compound, or a piperazine compound derivative; or, for example, a mixture of monoethanolamine and piperazine compounds, or a mixture of monoethanolamine and piperazine compound derivatives; or, for example, a mixture of monoethanolamine, piperazine compounds, and their derivatives.

[0032] To achieve better results, the present invention further uses N-methyldiethanolamine and tert-butylaminoethoxyethanol as the amine solvent, wherein the weight ratio of N-methyldiethanolamine to tert-butylaminoethoxyethanol is 1 to 3:1.

[0033] To achieve better results, the present invention further specifies that the nanoscale oxide is one or more of nanoscale aluminum oxide, nanoscale titanium dioxide, and nanoscale silicon dioxide, and the size of the nanoscale oxide is 5 nm to 40 nm.

[0034] To achieve better results, the present invention further specifies that the nano-sized oxide is a nano-sized hydroxyl oxide, wherein the size of the nano-sized oxide is 5 nm to 40 nm.

[0035] To achieve better results, the present invention further specifies that the nano-sized hydroxyl oxide is one or more of nano-sized hydroxyl aluminum oxide, nano-sized hydroxyl titanium dioxide, and nano-sized hydroxyl silicon dioxide.

[0036] To achieve better results, the present invention further specifies that the nano-sized hydroxyl oxide is a hydroxide that has lost some of its hydroxyl groups.

[0037] To achieve better results, the present invention further provides that the nano-sized hydroxy oxides are prepared through the following steps: Hydroxides are obtained by drying to remove free water, followed by heat treatment at 180℃~200℃ for 1 to 3 hours.

[0038] To achieve better results, the present invention further specifies that the hydroxide has a specific surface area ≥100 m². 2 / g of hydroxide.

[0039] This invention also provides a method for preparing the above-mentioned nanocomposite desulfurization and decarbonization solvent, comprising the following steps: S1. The nano-sized oxide is premixed with a portion of activator and water at 50℃~80℃ for 30 minutes~60 minutes to form a homogeneous slurry for later use. S2, In the slurry obtained in S1, add an alcohol amine solvent, an accelerator, the remaining activator, an antifoaming agent and a corrosion inhibitor, and stir thoroughly to obtain the nanocomposite desulfurization and decarbonization solvent.

[0040] In this invention, nano-sized hydroxyl titanium dioxide is dispersed in the form of primary particles with an aggregate size ≤100nm and a nanoparticle concentration of 20-30wt% in the slurry. This ensures that the nano-composite desulfurization and decarbonization solvent prepared after stirring S2 better meets the requirements of nanoparticles and also helps to better ensure the uniformity of the solution.

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be construed as limiting the scope of this application. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0043] In these embodiments, unless otherwise specified, the parts and percentages mentioned in the solution are by mass.

[0044] "Parts by mass" refers to the basic unit of measurement that expresses the mass ratio of multiple components. One part can represent any unit mass, such as 1g or 2.689g. If we say that component A has "a" parts by mass and component B has "b" parts by mass, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it can mean that the mass of component A is aK and the mass of component B is bK (K is any number representing a multiplier). It is important to understand that, unlike the number of parts by mass, the sum of the mass parts of all components is not limited to 100 parts.

[0045] "And / or" is used to indicate that one or both of the described situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0046] The evaluation method for the desulfurization and decarbonization solvent effect in Examples 1-7 and Comparative Examples 1-4 of this invention is as follows: The experiment simulated the extraction of natural gas as feedstock, with impurities of H2S 4% (mol), CO2 6% (mol), and COS 150 mg / Nm³. 3 CH3SH 150mg / Nm 3A conventional absorption-regeneration cycle process is adopted. The feed gas enters the absorption tower from the bottom, where it comes into countercurrent contact with the lean liquid entering from the top. The top of the tower contains purified gas after impurities have been removed, while the rich liquid from the bottom enters the top of the regeneration tower, where it is regenerated into lean liquid. The regenerated lean liquid is then recycled back into the absorption tower. The inlet temperature is 25℃ (room temperature), the absorption tower pressure is 3.5 MPa, the top temperature of the regeneration tower is 105℃, the lean liquid inlet temperature is 38℃, the gas-liquid ratio is 500 L / h, and the lean liquid circulation rate is 1 L / h.

[0047] Example 1 The chemical substances in this embodiment are: 40 wt% N-methyldiethanolamine, 16 wt% tert-butylaminoethoxyethanol, 15 wt% sulfolane, 6 wt% piperazine, 0.5 wt% nano-sized hydroxyl titanium dioxide (25 nm), 0.1 wt% defoamer, 0.1 wt% corrosion inhibitor, and the remainder is water.

[0048] A method for preparing a nano-desulfurization and decarbonization solvent includes the following steps: S1. Premix nano-sized hydroxyl titanium dioxide with half the amount of piperazine and an appropriate amount of water at 50℃~80℃ for 30±10 minutes to form a homogeneous slurry for later use.

[0049] S2, In the slurry obtained in S1, N-methyldiethanolamine, tert-butylaminoethoxyethanol, sulfolane, residual piperazine, defoamer, corrosion inhibitor and residual water are added and stirred thoroughly to obtain a nano-composite desulfurization and decarbonization solvent.

[0050] According to the evaluation method of this invention, after the nano-composite desulfurization and decarbonization solvent is absorbed by the nano-desulfurization and decarbonization solvent, the purified gas after removing impurities has residual CO2 2.1% (mol), H2S 2.5 mg / Nm3, and total organic sulfur (calculated as sulfur) 16 mg / Nm3.

[0051] In this embodiment, nano-sized hydroxyl titanium dioxide was obtained by the following method: Hydroxide particles with a specific surface area ≥100 m² 2 / g, slowly heat up at a rate ≤10℃ / h, hold at 150℃ for 1 hour, then continue heating at a rate 15℃ / h, hold at 190℃±10℃ for 2 hours, then slowly cool to room temperature for later use.

[0052] Example 2 The chemical substances in this embodiment are: 40 wt% N-methyldiethanolamine, 16 wt% tert-butylaminoethoxyethanol, 15 wt% sulfolane, 6 wt% piperazine, 1 wt% nano-sized hydroxyl titanium dioxide (25 nm), 0.1 wt% defoamer, 0.1 wt% corrosion inhibitor, and the remainder is water.

[0053] A method for preparing a nano-desulfurization and decarbonization solvent includes the following steps: S1. Premix nano-sized hydroxyl titanium dioxide with half the amount of piperazine and an appropriate amount of water at 50℃~80℃ for 30±10 minutes to form a homogeneous slurry for later use.

[0054] S2, In the slurry obtained in S1, add the amine solvent N-methyldiethanolamine, tert-butylaminoethoxyethanol, sulfolane, residual piperazine, defoamer, corrosion inhibitor and residual water, and stir thoroughly to obtain the nano-composite desulfurization and decarbonization solvent.

[0055] The prepared nanocomposite desulfurization and decarbonization solvent was evaluated according to the method of this invention. Using the nanocomposite desulfurization and decarbonization solvent as a lean solution, the residual CO2 in the purified gas after impurity removal was 2.0% (mol) and H2S was 2.3 mg / Nm³. 3 The total organic sulfur content (as sulfur) is 10 mg / Nm³. 3 .

[0056] In this embodiment, nano-sized hydroxyl titanium dioxide was obtained by the following method: Hydroxide particles with a specific surface area ≥100 m² 2 / g, slowly heat up at a rate ≤10℃ / h, hold at 150℃ for 1 hour, then continue heating at a rate 15℃ / h, hold at 190℃±10℃ for 2 hours, then slowly cool to room temperature for later use.

[0057] Example 3 The chemical substances in this embodiment are: 40 wt% N-methyldiethanolamine, 16 wt% tert-butylaminoethoxyethanol, 10 wt% sulfolane, 6 wt% piperazine, 1 wt% nano-sized aluminum oxide (25 nm), 0.1 wt% defoamer, 0.1 wt% corrosion inhibitor, and the remainder is water.

[0058] A method for preparing a nano-desulfurization and decarbonization solvent includes the following steps: S1. Premix nano-sized hydroxyl titanium dioxide with piperazine and an appropriate amount of water at 50℃~80℃ for 30±10 minutes to form a homogeneous slurry for later use.

[0059] S2, In the slurry obtained in S1, N-methyldiethanolamine, tert-butylaminoethoxyethanol, sulfolane, residual piperazine, defoamer, corrosion inhibitor and residual water are added and stirred thoroughly to obtain the nanocomposite desulfurization and decarbonization solvent.

[0060] The prepared nanocomposite desulfurization and decarbonization solvent was evaluated according to the method of this invention. The nanocomposite desulfurization and decarbonization solvent was used as a lean solution. The residual CO2 in the purified gas after removing impurities was 2.8% (mol), H2S was 2.3 mg / Nm3, and the total organic sulfur (calculated as sulfur) was 12 mg / Nm3.

[0061] In this embodiment, nano-sized hydroxyl titanium dioxide was obtained by the following method: Hydroxide particles with a specific surface area ≥100 m² 2 / g, slowly heat up at a rate ≤10℃ / h, hold at 150℃ for 1 hour, then continue heating at a rate 15℃ / h, hold at 190℃±10℃ for 2 hours, then slowly cool to room temperature for later use.

[0062] To further reflect the selectivity of the nanocomposite desulfurization and decarbonization solvent, Examples 4-6 were conducted.

[0063] Example 4 The chemical substances in this embodiment are: 40 wt% N-methyldiethanolamine, 16 wt% tert-butylaminoethoxyethanol, 15 wt% sulfolane, 6 wt% piperazine, 0.5 wt% nano-sized hydroxyl titanium dioxide (5 nm), 0.1 wt% defoamer, 0.1 wt% corrosion inhibitor, and the remainder is water.

[0064] A method for preparing a nano-desulfurization and decarbonization solvent includes the following steps: S1. Premix nano-sized hydroxyl titanium dioxide with half the amount of piperazine and an appropriate amount of water at 50℃~80℃ for 30±10 minutes to form a homogeneous slurry for later use.

[0065] S2, In the slurry obtained in S1, N-methyldiethanolamine, tert-butylaminoethoxyethanol, sulfolane, residual piperazine, defoamer, corrosion inhibitor and residual water are added and stirred thoroughly to obtain the nanocomposite desulfurization and decarbonization solvent.

[0066] The prepared nanocomposite desulfurization and decarbonization solvent was evaluated according to the method of this invention. Using the nanocomposite desulfurization and decarbonization solvent as a lean solution, the residual CO2 in the purified gas after impurity removal was 2.0% (mol) and H2S was 2.2 mg / Nm³. 3 The total organic sulfur content (as sulfur) is 17 mg / Nm³. 3 .

[0067] In this embodiment, nano-sized hydroxyl titanium dioxide was obtained by the following method: Hydroxide particles with a specific surface area ≥100m² 2 / g, slowly heat up at a rate ≤10℃ / h, hold at 150℃ for 1 hour, then continue heating at a rate 15℃ / h, hold at 190℃±10℃ for 2 hours, then slowly cool to room temperature for later use.

[0068] Example 5 The chemical substances in this embodiment are: 40wt% N-methyldiethanolamine, 16wt% tert-butylaminoethoxyethanol, 15wt% sulfolane, 6wt% piperazine, 0.5wt% nano-sized hydroxyl titanium dioxide (40nm), 0.1wt% defoamer, 0.1wt% corrosion inhibitor, and the remainder is water.

[0069] A method for preparing a nano-desulfurization and decarbonization solvent includes the following steps: S1. Premix nano-sized hydroxyl titanium dioxide with half the amount of piperazine and an appropriate amount of water at 50℃~80℃ for 30±60 minutes to form a homogeneous slurry for later use.

[0070] S2, In the slurry obtained in S1, N-methyldiethanolamine, tert-butylaminoethoxyethanol, sulfolane, residual piperazine, defoamer, corrosion inhibitor and residual water are added and stirred thoroughly to obtain the nanocomposite desulfurization and decarbonization solvent.

[0071] The prepared nanocomposite desulfurization and decarbonization solvent was evaluated according to the method of this invention. The purified gas after impurity removal contained 2.1% (mol) residual CO2 and 2.3 mg / Nm³ of H₂S. 3 The total organic sulfur content (calculated as sulfur) is 17.5 mg / Nm³. 3 .

[0072] In this embodiment, nano-sized hydroxyl titanium dioxide was obtained by the following method: Hydroxide particles with a specific surface area ≥100 m² 2 / g, slowly heat up at a rate ≤10℃ / h, hold at 150℃ for 1 hour, then continue heating at a rate 15℃ / h, hold at 190℃±10℃ for 2 hours, then slowly cool to room temperature for later use.

[0073] As can be seen from Examples 1 to 5 above, different nanoscale hydroxyl oxide particle sizes have a certain impact on the desulfurization and decarbonization solution, and have a greater impact on the removal of organic sulfur. Among them, particles around 25 nm have a better effect.

[0074] Example 6 The chemical substances in this embodiment are: 40 wt% N-methyldiethanolamine, 16 wt% tert-butylaminoethoxyethanol, 15 wt% sulfolane, 6 wt% piperazine, 0.5 wt% nano-sized titanium dioxide (25 nm) (non-hydroxyl), 0.1 wt% defoamer, 0.1 wt% corrosion inhibitor, and the remainder is water.

[0075] A method for preparing a nano-desulfurization and decarbonization solvent includes the following steps: S1. Premix nano-sized titanium dioxide with half the amount of piperazine and an appropriate amount of water at 50℃~80℃ for 30±10 minutes to form a homogeneous slurry for later use.

[0076] S2, In the slurry obtained in S1, N-methyldiethanolamine, tert-butylaminoethoxyethanol, sulfolane, residual piperazine, defoamer, corrosion inhibitor and residual water are added and stirred thoroughly to obtain the nanocomposite desulfurization and decarbonization solvent.

[0077] The prepared nanocomposite desulfurization and decarbonization solvent was evaluated according to the method of this invention. Using the nanocomposite desulfurization and decarbonization solvent as a lean solution, the residual CO2 in the purified gas after impurity removal was 2.3% (mol) and H2S was 2.6 mg / Nm³. 3 The total organic sulfur content (calculated as sulfur) is 18.5 mg / Nm³. 3 .

[0078] In this embodiment, nano-sized titanium dioxide is obtained by the following method: Hydroxide particles with a specific surface area ≥100 m² 2 / g, slowly heat up at a rate ≤10℃ / h, hold at 150℃ for 1 hour, then continue heating at a rate 15℃ / h, hold at 190℃±10℃ for 2 hours, then further heat up at a rate 15℃ / h, hold at 500℃ for 2 hours, and then slowly cool down to room temperature for later use.

[0079] As can be seen from Examples 1 and 6, complete water loss has a relatively small impact on dehydrogenation, but it affects both carbon dioxide and organic sulfur, with organic sulfur having a greater impact.

[0080] Comparative Example 1 The chemical substances in this embodiment are: 40 wt% N-methyldiethanolamine, 16 wt% tert-butylaminoethoxyethanol, 15 wt% sulfolane, 6 wt% piperazine, 0.1 wt% defoamer, 0.1 wt% corrosion inhibitor, and the remainder is water.

[0081] A method for preparing a nano-desulfurization and decarbonization solvent includes the following steps: S1. Premix half of the piperazine and an appropriate amount of water at 50℃~80℃ for 30±10 minutes to form a homogeneous slurry for later use.

[0082] S2, In the slurry obtained in S1, N-methyldiethanolamine, tert-butylaminoethoxyethanol, sulfolane, residual piperazine, defoamer, corrosion inhibitor and residual water are added and stirred thoroughly to obtain a nano-composite desulfurization and decarbonization solvent.

[0083] The desulfurization and decarbonization solvent obtained, after absorption by the solvent according to the evaluation method of this invention, showed that the residual CO2 in the purified gas after impurity removal was 0.9% (mol), H2S was 7.6 mg / Nm3, and total organic sulfur (calculated as sulfur) was 66 mg / Nm3. 3 .

[0084] As can be seen from Examples 1 to 6 and Comparative Example 1, the desulfurization and decarbonization solvent with added nanoparticles significantly improved the removal capacity of organic sulfur compared to the solvent without added nanoparticles, with an improvement of more than 10 percentage points. Simultaneously, it could also adjust the removal capacity of carbon dioxide, avoiding energy loss due to excessive carbon dioxide removal. The treated titanium dioxide nanoparticles exhibited a better effect in promoting the removal of organic sulfur by the solvent, indicating that the addition of nanoparticles not only enhanced gas-liquid mass transfer but may also have promoted the chemical absorption of the solvent.

[0085] Example 8 In Example 2, the lean solution was repeatedly absorbed and regenerated with the raw gas, then absorbed and regenerated again for two cycles. After standing for one week (176 hours), no obvious agglomeration or precipitation was observed visually; only a slight color difference was observed from top to bottom. Using the lean solution again, according to the evaluation method of this invention, the purified gas after impurity removal had residual CO2 of 2.1% (mol), H2S of 2.3 mg / Nm3, and total organic sulfur (as sulfur) of 10.5 mg / Nm3. 3 .

[0086] The removal results were basically consistent with those of Example 2, indicating that the nanoscale desulfurization and decarbonization solvent has good stability.

[0087] After 176 hours, and following a second evaluation, the color difference disappeared after the regenerated lean solution was removed and allowed to stand.

[0088] To compare the removal effects of other nanoparticles, the following comparative examples 2-4 were conducted.

[0089] Comparative Example 1 Compared with Example 1, the difference is that commercially available nano-silica (25nm) is used instead of the nano-silica in the nano-desulfurization and decarbonization solvent formulation of Example 1.

[0090] According to the evaluation method of this invention, after absorption by the nano-desulfurization and decarbonization solvent, the purified gas after impurity removal has residual CO2 of 1.9% (mol), H2S of 6.2 mg / Nm3, and total organic sulfur (calculated as sulfur) of 20 mg / Nm3. 3 .

[0091] Comparing Example 1 and Comparative Example 1, although nano-silica has a certain mass transfer enhancement effect on gas-liquid absorption, the effect is significantly lower than that of the nano-hydroxyl titanium dioxide of the present invention.

[0092] Comparative Example 2 The desulfurization and decarbonization solvent used in this comparative example is the commercially available solvent CT85. CT85 is an MDEA solvent, which is the most widely used chemical desulfurization and decarbonization solvent, mainly based on chemical absorption.

[0093] According to the evaluation method of this invention, the residual CO2 in the purified gas after impurity removal by CT85 is 3.6% (mol), H2S is 4 mg / Nm3, and total organic sulfur (calculated as sulfur) is 140 mg / Nm3. 3 .

[0094] Comparative Example 3 Safino-M is a mixed amine desulfurization and decarbonization solvent, which is a traditional and typical solvent for removing organic sulfur.

[0095] According to the evaluation method of this invention, the purified gas after impurity removal by Safino-M contains 1.2% (mol) residual CO2, 8 mg / Nm3 H2S, and 72 mg / Nm3 total organic sulfur (calculated as sulfur). 3 .

[0096] From the above embodiments and comparative examples, the nanocomposite desulfurization and decarbonization solvent of the present invention, through the synergistic effects of chemical absorption, physical absorption, and enhanced mass transfer by nano-scale oxides, can meet the quality requirements of Class I natural gas while reasonably retaining the carbon dioxide volume concentration in the range of 2-3 wt%, exhibiting significant selective removal and control advantages, and is significantly superior to traditional desulfurization and decarbonization performance.

[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0098] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, in the foregoing claims, any of the claimed embodiments can be used in any combination. The information disclosed in this background section is intended only to enhance the understanding of the general background of this application and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

Claims

1. A nanocomposite desulfurization and decarbonization solvent, characterized in that, Includes the following ingredients: Alkylamine solvent 20 wt%~65 wt% Accelerator 5 wt%~40 wt% Activator 5 wt%~20 wt% Nano-sized hydroxyl oxides, 0.1 wt%–1.5 wt%. Defoamer 0.001 wt%~1 wt% Corrosion inhibitor 0.0005 wt%~1 wt% and The remainder is water, totaling 100 wt%; The nano-sized hydroxy oxides are prepared by the following steps: The hydroxide is obtained by drying to remove free water, followed by heat treatment at 180℃~200℃ for 1 to 3 hours. The nano-sized hydroxyl oxide is one or more of nano-sized hydroxyl aluminum oxide, nano-sized hydroxyl titanium dioxide, and nano-sized hydroxyl silicon dioxide; The hydroxide is a hydroxide with a specific surface area ≥100 m2 / g.

2. The nanocomposite desulfurization and decarbonization solvent according to claim 1, characterized in that, The alkanolamine solvent is one or more selected from N-methyldiethanolamine, tert-butylaminoethoxyethanol, tert-butylethanolamine, and 2-amino-2-methyl-1-propanol; and / or The accelerator is one or more of polyethylene glycol dimethyl ether, sulfolane, ethylene glycol, glycerol, diethylene glycol, and N-methylpyrrolidone; and / or The activator is one or more of monoethanolamine, piperazine compounds, and their derivatives.

3. The nanocomposite desulfurization and decarbonization solvent according to claim 2, characterized in that, The alcoholic solvent is N-methyldiethanolamine and tert-butylaminoethoxyethanol, wherein the weight ratio of N-methyldiethanolamine to tert-butylaminoethoxyethanol is 1 to 3:

1.

4. A method for preparing the nanocomposite desulfurization and decarbonization solvent according to any one of claims 1-3, characterized in that, Includes the following steps: S1, premix nano-sized hydroxy oxides with a portion of activator and water at 50℃~80℃ for 30 minutes~60 minutes to form a homogeneous slurry for later use; S2, In the slurry obtained in S1, add an alcohol amine solvent, an accelerator, the remaining activator, an antifoaming agent and a corrosion inhibitor, and stir thoroughly to obtain the nanocomposite desulfurization and decarbonization solvent.