Composite solvent for removing organic sulfur in industrial synthesis gas and preparation method thereof

Abstract

The invention discloses a composite solvent for removing organic sulfur in industrial synthesis gas and a preparation method thereof, and belongs to the technical field of separation and purification, the composite solvent comprises 40-60 parts of a main desulfurizer, 8-12 parts of a dynamic modifier, 5-15 parts of a mass transfer enhancer, 20-30 parts of a temperature-sensitive phase change skeleton and 8-14 parts of an auxiliary agent, and the auxiliary agent comprises an antioxidant, a corrosion inhibitor and a polar mixed solution. According to the present invention, the multistage pore channel micelle structure of the introduced mass transfer reinforcing agent provides the rich and efficient transmission channel for the diffusion of the sulfide, such that the diffusion rate of the sulfide penetrating the ionic liquid layer is substantially accelerated, and the liquid phase mass transfer coefficient is effectively improved; the core principle is that the diffusion path of sulfide molecules in the ionic liquid environment is optimized, the mass transfer bottleneck caused by high viscosity of the traditional ionic liquid is broken through, and excessive accumulation of the sulfide molecules on the surface of an ionic liquid layer due to mass transfer obstacle is avoided, so that the desulfurization efficiency is remarkably improved; the problem of slow mass transfer caused by high viscosity of the ionic liquid in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of separation and purification, and in particular to a composite solvent for removing organic sulfur from industrial synthesis gas and a preparation method thereof. Background Art

[0002] Organic sulfur in industrial synthesis gas (such as thiophene, mercaptan, sulfide, etc.) is difficult to remove efficiently through traditional desulfurization technology due to its chemical stability and low polarity, and it is easy to cause catalyst poisoning, equipment corrosion and subsequent process pollution. There is an urgent need to develop purification technology with high selectivity, high mass transfer efficiency and regeneration stability.

[0003] In recent years, ionic liquids and dynamic functional materials have demonstrated unique advantages in the field of organic sulfur removal. However, although the high viscosity of ionic liquids is conducive to the selective dissolution of sulfides, it significantly inhibits the diffusion rate of molecules such as mercaptans and thiophenes in the liquid phase, resulting in hysteresis in the reaction kinetics. Sulfides need to penetrate the ionic liquid layer to contact the active sites of the carrier. Excessive viscosity may form a "mass transfer barrier" and reduce the overall desulfurization efficiency.

[0004] In addition, although large-pore carriers improve mass transfer efficiency, their ability to recognize and separate target molecules may decrease due to excessive relaxation of the dynamic network; although small-pore carriers enhance their ability to recognize and separate target molecules, they are prone to pore blockage due to uneven filling of ionic liquids. Summary of the invention

[0005] In view of the above-mentioned shortcomings of the prior art, the present invention provides a composite solvent for removing organic sulfur from industrial synthesis gas and a preparation method thereof.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: The composite solvent for removing organic sulfur from industrial synthesis gas comprises the following components by weight: 40-60 parts of a main desulfurizing agent, which is composed of an organic amine compound and an ionic liquid in a mass ratio of 3-5:1, wherein the organic amine compound is selected from 4-pyrrolidinobutylamine, bis(4-pyridine)amine or a derivative thereof, and the ionic liquid is selected from 1-butyl-3-methylimidazole dihydrogen phosphate or tetramethylammonium glycine; 8-12 parts of a dynamic modifier, a gradient dynamic bond network material formed by pre-hydrolysis and gradient temperature reaction of 3-mercaptopropyltrimethoxysilane and bismaleimide compounds, the outer layer of which is a stable amino coordination bond and the inner layer is a reversibly reorganized dynamic disulfide bond; 5-15 parts of a mass transfer enhancer, which is a multi-level porous micelle structure prepared by thermally initiating RAFT polymerization of polyethylene glycol monomethyl ether and styrene; 20 - 30 parts of thermosensitive phase change skeletons, with mesoporous silica as the substrate, after being grafted with dynamic modifiers and hydrophobically modified with styrene - maleic anhydride alternating copolymer, are loaded with sodium lignosulfonate / chitosan composite carbon sources, and hierarchical pores are formed through staged pyrolysis and reduction; 8 - 14 parts of additives, including antioxidants, corrosion inhibitors and polar mixtures.

[0007] The preparation method of the composite solvent for removing organic sulfur from industrial synthesis gas includes the following steps: S1: Prepare dynamic modifiers; Mix 3 - mercaptopropyltrimethoxysilane with absolute ethanol, add acetic acid as a catalyst, and pre - hydrolyze to generate a partially hydrolyzed silane intermediate; Add the bismaleimide compound in three portions, control the reaction temperature gradient, and stir - react under nitrogen protection; Form outer - layer amino coordination bonds and dynamic disulfide bonds by adjusting the pH; Treat under microwave, and then introduce an Ar / N 2 mixed gas for plasma surface etching to promote the three - dimensional anchoring of the dynamic silane on the carrier surface, and obtain the dynamic modifier; S2: Prepare the thermosensitive phase change skeleton; Prepare the composite carbon source. Mix sodium lignosulfonate and chitosan, add water, and stir ultrasonically until completely dissolved to form a homogeneous composite solution; then freeze - dry and grind to obtain the composite carbon source powder; Mix the composite carbon source powder with mesoporous silica, add ethanol / water as a dispersant, perform ultrasonic treatment, centrifuge to remove the unadsorbed carbon source, retain the uniform coating layer, and dry to obtain the precursor; Staged grafting modification: The first stage: Immerse the precursor in the dynamic modifier, perform ultrasonic treatment and then dry. After modification, wash with ethanol to remove the unbonded modifier; The second stage: Repeat grafting, add styrene - maleic anhydride alternating copolymer, and improve the density of hydrophobic anchoring sites through the esterification reaction of anhydride groups with hydroxyl groups on the carrier surface to obtain the grafted precursor; Gradient carbon layer deposition: The first - stage pyrolysis: Pyrolyze the grafted precursor in a nitrogen atmosphere by heating to 400 - 500 °C, so that sodium lignosulfonate / chitosan is carbonized to form a porous carbon skeleton, and at the same time, styrene - maleic anhydride decomposes to generate micropores; The second - stage reduction: Switch to H 2 / N 2 mixed gas, first heat to 550 - 580 °C for insulation, then heat to 600 - 650 °C and keep warm, and repair the graphitization defects of the carbon layer through hydrogen reduction to obtain the thermosensitive phase change skeleton; S3: Prepare the mass transfer enhancer; Styrene was added dropwise to methoxypolyethylene glycol in four batches, with cuprous bromide / bipyridine as the catalyst, and the reaction was carried out under controlled temperature gradient to form a PEG-b-PS block copolymer; The PEG-b-PS block copolymer was placed in supercritical CO 2 / ethanol, and foaming treatment was carried out to form a multi-porous micelle structure, obtaining a mass transfer enhancer; S4: Composite solvent blending; An ionic liquid and a composite amine were mixed and stirred until homogeneous to obtain a main desulfurizer; a thermosensitive phase change framework was added and treated by microwave; The dynamic modifier and the mass transfer enhancer were each divided into three portions and added alternately three times, followed by ultrasonic dispersion; Irradiation with near-infrared light and synchronous external heat source were used to raise the temperature and trigger the contraction of the thermosensitive phase change framework; An antioxidant, a corrosion inhibitor, and a polar mixture were added in sequence and mixed evenly to obtain a composite solvent for removing organic sulfur in industrial synthesis gas.

[0008] Furthermore, S1 specifically is: 3-mercaptopropyltrimethoxysilane and absolute ethanol were mixed at a volume ratio of 1:4 - 6, and 0.1 - 0.3% of acetic acid based on the sum of the masses of 3-mercaptopropyltrimethoxysilane and absolute ethanol was added as a catalyst, and pre-hydrolysis was carried out at 40 - 60 °C for 30 - 60 min to generate a partially hydrolyzed silane intermediate; The bismaleimide compound was added in three batches (with an interval of 15 - 30 min between each batch), and the mass ratio of the bismaleimide compound to the mass of 3-mercaptopropyltrimethoxysilane was 1:5 - 8. The reaction temperature gradient was controlled as 80 °C → 100 °C → 120 °C, and stirring reaction was carried out for 2 - 4 h under nitrogen protection; By adjusting the pH to 4 - 5 and standing for 20 - 30 min, an outer layer of amino coordination bonds was formed; The pH was adjusted to 7 - 8 and standing for 20 - 30 min to form dynamic disulfide bonds; It was treated at a microwave power of 200 - 400 W for 20 - 40 min, and then an Ar / N 2 mixed gas (volume ratio 9:1) was introduced, and plasma surface etching (power 300 - 500 W) was carried out to promote the three-dimensional anchoring of the dynamic silane on the carrier surface, obtaining a dynamic modifier.

[0009] Furthermore, S2: Preparation of the thermosensitive phase change framework; Preparation of the composite carbon source: Sodium lignosulfonate and chitosan were mixed at a mass ratio of 3:1, deionized water was added (solid-liquid ratio 1:10 - 20), and ultrasonic stirring was carried out at 60 - 80 °C for 2 - 4 h until completely dissolved to form a homogeneous composite solution; subsequently, freeze-drying was carried out for 24 - 48 h, and grinding was carried out to obtain a composite carbon source powder; Mix the composite carbon source powder with mesoporous silica (pore size 10 - 50 nm) at a mass ratio of 1:5 - 10, add ethanol / water (volume ratio 1:1) as a dispersant, ultrasonically treat for 30 - 60 min, centrifuge (3000 rpm, 10 min) to remove the unadsorbed carbon source, retain the uniform coating layer, and dry at 60 °C to obtain the precursor; Segmented graft modification: First stage: Immerse the precursor in the dynamic modifier, with a mass ratio of the dynamic modifier to the precursor of 1:5 - 10, ultrasonically treat at 40 - 50 °C for 1 - 2 h, dry at 60 °C. After modification, wash with ethanol 3 times to remove the unbonded modifier; Second stage: Repeat grafting, adjust the pH to acidic with sulfuric acid, add a styrene - maleic anhydride alternating copolymer accounting for 8 - 15% of the mass of the precursor, and control the reaction temperature at 80 - 90 °C. Improve the density of hydrophobic anchoring sites through the esterification reaction between the anhydride group and the hydroxyl group on the carrier surface to obtain the grafted precursor; Gradient carbon layer deposition: First - stage pyrolysis: Pyrolyze the grafted precursor in a nitrogen atmosphere, heating at 5 °C / min to 400 - 500 °C for 1 - 2 h, carbonizing sodium lignosulfonate / chitosan to form a porous carbon skeleton, and simultaneously decomposing styrene - maleic anhydride to generate micropores; Second - stage reduction: Switch to H 2 / N 2 mixed gas (H 2 accounting for 5 - 10%), first heat to 550 - 580 °C at 5 °C / min and hold for 30 min, then heat to 600 - 650 °C at 3 °C / min and hold for 30 - 50 min. Repair the graphitization defects of the carbon layer through hydrogen reduction to obtain the thermosensitive phase - change skeleton.

[0010] Furthermore, in S2, the pyrolysis / reduction of the composite carbon source forms a three - level channel structure of macropores (30 - 50 nm, derived from the mesoporous silica template), mesopores (2 - 5 nm, generated by the decomposition of styrene - maleic anhydride), and micropores (<1 nm, from carbonization shrinkage), with a specific surface area of 1000 - 1500 m 2 / g.

[0011] Furthermore, S3 is specifically: Dropwise add styrene in four batches (with an interval of 15 - 20 min) to polyethylene glycol monomethyl ether (molecular weight 1000 - 2000), with a mass ratio of polyethylene glycol monomethyl ether to styrene of 1:3 - 5, use cuprous bromide / bipyridine as a catalyst, and the dosage of cuprous bromide / bipyridine is 0.5 - 1.2% of the mass of styrene. Control the temperature gradient as 60 °C → 65 °C → 70 °C → 80 °C, and react for 1 - 3 h to form a PEG - b - PS block copolymer; Pre - swelling treatment: Swell the PEG - b - PS block copolymer in ethanol at 40 °C for 2 h; Place the PEG-b-PS block copolymer in supercritical CO 2 / ethanol (volume ratio 7:3) (pressure 15 - 25 MPa, temperature 35 - 45 °C), and perform foaming treatment for 1 - 2 h to form a multi-level pore micelle structure, obtaining a mass transfer enhancer.

[0012] Furthermore, S4 specifically is: Mix an ionic liquid ([EMIM][H 2 PO 4 ) and a composite amine (tetraethylenepentamine / N-methylpiperazine, mass ratio 7:3) in a mass ratio of 6 - 7:3 - 4, stir at 50 - 60 °C until homogeneous to obtain the main desulfurizer; add a thermosensitive phase change framework, and perform intermittent (working for 20 s, pausing for 10 s) microwave treatment (power 200 - 300 W) for 30 - 60 min; Divide the dynamic modifier and the mass transfer enhancer into three equal parts each, add them alternately in three times, with an interval of 10 - 15 min each time, and perform ultrasonic dispersion (frequency 40 - 60 kHz) for 1 - 2 h; Irradiate with near-infrared light (wavelength 800 nm, power 1.5 - 2 W / cm 2 ), and synchronously apply an external heat source to raise the temperature to 200 - 250 °C to trigger the contraction of the thermosensitive phase change framework; Add an antioxidant (pentaerythritol ester), a corrosion inhibitor (boric acid / PVP), and a polar mixture (ethylene glycol / NMP 3 - 5:1) in sequence, and mix evenly to obtain a composite solvent for removing organic sulfur in industrial synthesis gas.

[0013] Furthermore, in S4, the mass ratio of the antioxidant (pentaerythritol ester), the corrosion inhibitor (boric acid / PVP), and the polar mixture is 0.5 - 1:0.3 - 0.8:3 - 5, and mix evenly to obtain a composite solvent for removing organic sulfur in industrial synthesis gas.

[0014] The beneficial effects of the present invention compared with the prior art are as follows: 1. The multi-level pore micelle structure of the mass transfer enhancer introduced in the present invention provides a rich and efficient transport channel for the diffusion of sulfides, greatly accelerating the diffusion rate of sulfides through the ionic liquid layer, effectively improving the liquid-phase mass transfer coefficient. Its core principle lies in optimizing the diffusion path of sulfide molecules in the ionic liquid environment, breaking through the mass transfer bottleneck caused by the high viscosity of traditional ionic liquids, and avoiding the excessive accumulation of sulfide molecules on the surface of the ionic liquid layer due to mass transfer obstacles, thereby significantly improving the desulfurization efficiency and solving the problem of slow mass transfer caused by the high viscosity of ionic liquids in the prior art.

[0015] 2. The dynamic modifier of the present invention strengthens the interaction force between the ionic liquid and the carrier by precisely regulating the surface energy of the carrier. On the one hand, it makes the spreading and adsorption of the ionic liquid on the carrier surface more uniform and firm, reducing the leakage phenomenon of the ionic liquid. On the other hand, since the active sites are mostly distributed inside the ionic liquid or at the interface between the ionic liquid and the carrier, reducing the leakage of the ionic liquid can effectively reduce the loss of active sites, ensuring that the active sites continuously and stably play their roles during the desulfurization process, thereby promoting the desorption of sulfides and improving the dynamic equilibrium efficiency of the desulfurization reaction, making up for the defects of the traditional physical loading method that is prone to ionic liquid leakage and the single chemical bonding method that limits the dynamic reconstruction ability of the ionic liquid.

[0016] 3. The temperature-sensitive phase change framework of the present invention is based on mesoporous silica. After being grafted with a dynamic modifier and hydrophobically modified with a styrene-maleic anhydride alternating copolymer, it is loaded with a sodium lignosulfonate / chitosan composite carbon source, and a hierarchical pore structure is formed through segmented pyrolysis and reduction. The grafting of the dynamic modifier enhances the compatibility and adsorption of the carrier for the ionic liquid, enabling the ionic liquid to be uniformly loaded. The hydrophobic modification of the styrene-maleic anhydride alternating copolymer prevents the disordered diffusion and aggregation of the ionic liquid in the pores, avoiding pore blockage. The hierarchical pore structure combines the advantages of large-pore and small-pore carriers, while ensuring the efficient mass transfer of sulfides, improving the recognition and separation ability of target sulfide molecules, achieving a stable improvement in the desorption ability after multiple cycles, and effectively solving the contradiction between the poor recognition ability of large-pore carriers and the uneven filling of small-pore carriers in the prior art.

[0017] 4. The present invention further combines the dynamic modifier with the hierarchical pore structure, which has a synergistic effect. The combination of the dynamic modifier and the hierarchical pore provides an ordered distribution and a stable diffusion path for the ionic liquid, reducing the leakage caused by the disordered flow or aggregation of the ionic liquid, and ensuring the long-term stability of the ionic liquid in the framework. During multiple cycles of use, this composite system, on the one hand, ensures the stability and availability of the active sites, enables the desorption process to proceed efficiently, and significantly improves the desorption ability after multiple cycles. On the other hand, the hierarchical pores continuously promote the mass transfer and diffusion of sulfides, enabling sulfides to continuously and efficiently contact and react with the active sites during multiple cycles, unexpectedly achieving a stable improvement in the desulfurization efficiency after multiple cycles, overcoming the problem that the desulfurization efficiency and desorption ability are prone to attenuation during the recycling process in the prior art, and providing a purification and separation solution with high selectivity, high mass transfer efficiency, and regeneration stability for the deep desulfurization of industrial synthesis gas. Detailed implementation mode

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] Example 1: This example provides a composite solvent for removing organic sulfur from industrial synthesis gas, which comprises the following components in parts by weight: 60 parts of a main desulfurizing agent, which is composed of an organic amine compound and an ionic liquid in a mass ratio of 5:1, wherein the organic amine compound is selected from 4-pyrrolidinobutylamine, bis(4-pyridine)amine or a derivative thereof, and the ionic liquid is selected from 1-butyl-3-methylimidazole dihydrogen phosphate or tetramethylammonium glycine; 12 parts of dynamic modifier, a gradient dynamic bond network material formed by pre-hydrolysis and gradient temperature reaction of 3-mercaptopropyltrimethoxysilane and bismaleimide compound, the outer layer of which is a stable amino coordination bond and the inner layer is a reversibly reorganized dynamic disulfide bond; 15 parts of mass transfer enhancer, which is a multi-level porous micelle structure prepared by thermally initiating RAFT polymerization of polyethylene glycol monomethyl ether and styrene; 30 parts of thermosensitive phase change framework, with mesoporous silica as the substrate, after dynamic modifier grafting and styrene-maleic anhydride alternating copolymer hydrophobic modification, loaded with sodium lignin sulfonate / chitosan composite carbon source, and formed hierarchical channels through segmented pyrolysis and reduction; 14 parts of additives, including antioxidants, corrosion inhibitors and polar mixed liquids.

[0020] The method for preparing the composite solvent for removing organic sulfur from industrial synthesis gas comprises the following steps: S1: preparing a dynamic modifier; mixing 3-mercaptopropyltrimethoxysilane and anhydrous ethanol in a volume ratio of 1:6, adding 0.3% acetic acid to the sum of the mass of 3-mercaptopropyltrimethoxysilane and anhydrous ethanol as a catalyst, and pre-hydrolyzing at 60° C. for 60 min to generate a partially hydrolyzed silane intermediate; The bismaleimide compound was added three times (with an interval of 15-30 minutes between each batch), the mass ratio of the bismaleimide compound to 3-mercaptopropyltrimethoxysilane was 1:8, the reaction temperature gradient was controlled to be kept at 80°C for 1 hour, 100°C for 1 hour, and 120°C for 2 hours, and the reaction was stirred for 4 hours under nitrogen protection; The outer amino coordination bonds were formed by adjusting the pH to 5 and standing for 30 min; Adjust the pH to 8 and let stand for 30 min to form dynamic disulfide bonds; Treat for 40 min under a microwave power of 400 W, and then introduce an Ar / N 2 mixed gas (volume ratio 9:1) for plasma surface etching (power 500 W) to promote the three-dimensional anchoring of the dynamic silane on the carrier surface and obtain a dynamic modifier; S2: Preparation of the thermosensitive phase change skeleton; Preparation of the composite carbon source. Mix sodium lignosulfonate and chitosan at a mass ratio of 3:1, add deionized water (solid-liquid ratio 1:20), and ultrasonically stir at 80 °C for 4 h until completely dissolved to form a homogeneous composite solution; then freeze-dry for 48 h and grind to obtain the composite carbon source powder; Mix the composite carbon source powder and mesoporous silica (pore diameter 50 nm) at a mass ratio of 1:10, add ethanol / water (volume ratio 1:1) as a dispersant, ultrasonically treat for 60 min, and centrifuge (3000 rpm, 10 min) to remove the unadsorbed carbon source, retain the uniform coating layer, and dry at 60 °C to obtain the precursor; Segmented grafting modification: First stage: Immerse the precursor in the dynamic modifier, with a mass ratio of the dynamic modifier to the precursor of 1:10, ultrasonically treat at 50 °C for 2 h, dry at 60 °C, and after modification, wash with ethanol 3 times to remove the unbonded modifier to avoid the competitive reaction between the anhydride group and the hydroxyl group of the silane; Second stage: Repeat grafting. Adjust the pH to acidic with sulfuric acid, add a styrene-maleic anhydride alternating copolymer accounting for 15% of the mass of the precursor, and control the reaction temperature at 90 °C to increase the density of hydrophobic anchoring sites through the esterification reaction between the anhydride group and the hydroxyl group on the carrier surface to obtain the grafted precursor; Gradient carbon layer deposition: First-stage pyrolysis: Pyrolyze the grafted precursor in a nitrogen atmosphere, heat it to 500 °C at a rate of 5 °C / min and pyrolyze for 2 h to carbonize sodium lignosulfonate / chitosan to form a porous carbon skeleton, and at the same time, styrene-maleic anhydride decomposes to produce micropores; Second-stage reduction: Switch to H 2 / N 2 mixed gas (H 2 accounting for 10%), first heat it to 580 °C at a rate of 5 °C / min and hold for 30 min, then heat it to 650 °C at a rate of 3 °C / min and hold for 50 min. Repair the graphitization defects of the carbon layer through hydrogen reduction to enhance the conductivity and mechanical strength of the skeleton and obtain the thermosensitive phase change skeleton; The pyrolysis / reduction of the composite carbon source forms a three-level channel structure of macropores (50 nm, derived from the mesoporous silica template), mesopores (5 nm, generated by the decomposition of styrene-maleic anhydride), and micropores (<1 nm, from carbonization shrinkage), with a specific surface area of 1500 m 2 / g.

[0021] S3: Prepare a mass transfer enhancer; add styrene dropwise in four equal portions at intervals (interval of 20 min) to methoxypolyethylene glycol (molecular weight 1000 - 2000), with a mass ratio of methoxypolyethylene glycol to styrene of 1:5. Cuprous bromide / bipyridine is used as a catalyst, and the dosage of cuprous bromide / bipyridine is 1.2% of the mass of styrene. The temperature gradient is controlled to keep warm at 60 °C for 40 min, 65 °C for 40 min, 70 °C for 40 min, and 80 °C for 60 min to form a PEG-b-PS block copolymer; Pre-swelling treatment: Swell the PEG-b-PS block copolymer in ethanol at 40 °C for 2 h; Place the PEG-b-PS block copolymer in supercritical CO 2 / ethanol (volume ratio 7:3) (pressure 25 MPa, temperature 45 °C), and perform foaming treatment for 2 h to form a multi-level pore micelle structure to obtain a mass transfer enhancer; S4: Compound solvent compounding; mix an ionic liquid ([EMIM][H 2 PO 4 ) and a compound amine (tetraethylenepentamine / N-methylpiperazine, mass ratio 7:3) in a mass ratio of 7:4, and stir at 60 °C until homogeneous to obtain a main desulfurization agent; add a thermosensitive phase change skeleton and perform intermittent (work for 20 s, pause for 10 s) microwave treatment (power 300 W) for 60 min; Divide the dynamic modifier and the mass transfer enhancer into three equal portions each, and alternately add them in three times at intervals of 15 min, and perform ultrasonic dispersion (frequency 60 kHz) for 2 h; Irradiate with near-infrared light (power 2 W / cm 2 ), and simultaneously apply an external heat source to raise the temperature to 250 °C to trigger the contraction of the thermosensitive phase change skeleton; Add an antioxidant (pentaerythritol ester), a corrosion inhibitor (boric acid / PVP), and a polar mixture (ethylene glycol / NMP 3 - 5:1) in sequence. The mass ratio of the antioxidant (pentaerythritol ester), the corrosion inhibitor (boric acid / PVP), and the polar mixture is 1:0.8:5, and mix evenly to obtain a compound solvent for removing organic sulfur from industrial synthesis gas.

[0022] Example 2: This example provides a compound solvent for removing organic sulfur from industrial synthesis gas, which includes the following components by weight: 40 parts of the main desulfurization agent, which is compounded by an organic amine compound and an ionic liquid in a mass ratio of 3:1. The organic amine compound is selected from 4-pyrrolidinobutylamine, bis(4-pyridyl)amine or its derivatives, and the ionic liquid is selected from 1-butyl-3-methylimidazolium dihydrogen phosphate or tetramethylammonium glycine; 8 parts of dynamic modifier, a gradient dynamic bond network material formed by pre-hydrolysis and gradient temperature reaction of 3-mercaptopropyltrimethoxysilane and bismaleimide compound, with a stable amino coordination bond on the outer layer and a reversibly reorganized dynamic disulfide bond on the inner layer; 5 parts of mass transfer enhancer, a multi-level pore micelle structure prepared by thermal initiation of polyethylene glycol monomethyl ether and styrene to initiate RAFT polymerization; 20 parts of thermosensitive phase change framework, using mesoporous silica as the substrate, after grafting with dynamic modifier and hydrophobic modification with styrene-maleic anhydride alternating copolymer, loading sodium lignosulfonate / chitosan composite carbon source, and forming hierarchical pores through segmented pyrolysis and reduction; 8 parts of additives, including antioxidants, corrosion inhibitors and polar mixtures.

[0023] The preparation method of the composite solvent for removing organic sulfur from industrial synthesis gas includes the following steps: S1: Prepare the dynamic modifier; Mix 3-mercaptopropyltrimethoxysilane and absolute ethanol at a volume ratio of 1:4, add 0.1% acetic acid of the sum of the masses of 3-mercaptopropyltrimethoxysilane and absolute ethanol as a catalyst, and pre-hydrolyze at 40°C for 30 min to generate a partially hydrolyzed silane intermediate; Add the bismaleimide compound in three batches (with an interval of 15 min between each batch), the mass ratio of the bismaleimide compound to the mass of 3-mercaptopropyltrimethoxysilane is 1:5, control the reaction temperature gradient to hold at 80°C for 0.5 h, 100°C for 0.5 h, and 120°C for 1 h, and stir and react under nitrogen protection; Adjust the pH to 4 and let it stand for 20 min to form the outer layer of amino coordination bond; Adjust the pH to 7 and let it stand for 20 min to form dynamic disulfide bonds; Treat it at a microwave power of 200 W for 20 min, and then introduce Ar / N 2 Mixed gas (volume ratio 9:1), and perform plasma surface etching (power 300 W) to promote the three-dimensional anchoring of the dynamic silane on the carrier surface to obtain the dynamic modifier; S2: Preparation of the thermosensitive phase change framework; Preparation of the composite carbon source, mix sodium lignosulfonate and chitosan at a mass ratio of 3:1, add deionized water (solid-liquid ratio 1:10), and ultrasonically stir at 60°C for 2 h until completely dissolved to form a homogeneous composite solution; then freeze-dry for 24 h and grind to obtain the composite carbon source powder; Mix the composite carbon source powder and mesoporous silica (pore diameter 10 nm) at a mass ratio of 1:5, add ethanol / water (volume ratio 1:1) as a dispersant, ultrasonically treat for 30 min, centrifuge (3000 rpm, 10 min) to remove the unadsorbed carbon source, retain the uniform coating layer, and dry at 60°C to obtain the precursor; Segmented graft modification: The first stage: Immerse the precursor in the dynamic modifier. The mass ratio of the dynamic modifier to the precursor is 1:5. Perform ultrasonic treatment at 40 °C for 1 h, then dry at 60 °C. After modification, wash with ethanol three times to remove the unbonded modifier to avoid the competitive reaction between the anhydride group and the hydroxyl group of the silane; The second stage: Repeat grafting. Adjust the pH to acidic with sulfuric acid. Add a styrene-maleic anhydride alternating copolymer accounting for 8% of the mass of the precursor, and control the reaction temperature at 80 °C. Improve the density of hydrophobic anchoring sites through the esterification reaction between the anhydride group and the hydroxyl group on the surface of the carrier to obtain the grafted precursor; Gradient carbon layer deposition: The first-stage pyrolysis: Pyrolyze the grafted precursor in a nitrogen atmosphere, heating up to 400 °C at a rate of 5 °C / min and pyrolyzing for 1 h to carbonize sodium lignosulfonate / chitosan to form a porous carbon skeleton. At the same time, styrene-maleic anhydride decomposes to generate micropores; The second-stage reduction: Switch to H 2 / N 2 mixed gas (H 2 with a proportion of 5%). First, heat up to 550 °C at a rate of 5 °C / min and keep it warm for 30 min, then heat up to 600 °C at a rate of 3 °C / min and keep it warm for 30 min. Repair the graphitization defects of the carbon layer through hydrogen reduction to enhance the conductivity and mechanical strength of the skeleton to obtain the thermosensitive phase change skeleton; The pyrolysis / reduction of the composite carbon source forms a three-level channel structure of macropores (30 nm, derived from the mesoporous silica template), mesopores (2 nm, generated by the decomposition of styrene-maleic anhydride), and micropores (<1 nm, from carbonization shrinkage), with a specific surface area of 1000 m 2 / g.

[0024] S3: Prepare the mass transfer enhancer; Add styrene in four equal portions at intervals (interval of 15 min) to polyethylene glycol monomethyl ether (molecular weight 1000). The mass ratio of polyethylene glycol monomethyl ether to styrene is 1:3. Cuprous bromide / bipyridine is used as the catalyst, and the dosage of cuprous bromide / bipyridine is 0.5% of the mass of styrene. Control the temperature gradient to keep it warm at 60 °C for 20 min, 65 °C for 20 min, 70 °C for 30 min, and 80 °C for 40 min to form a PEG-b-PS block copolymer; Pre-swelling treatment: Swell the PEG-b-PS block copolymer in ethanol at 40 °C for 2 h; Place the PEG-b-PS block copolymer in supercritical CO 2 / ethanol (volume ratio 7:3) (pressure 15 MPa, temperature 35 °C), and perform foaming treatment for 1 h to form a multi-level pore micelle structure to obtain the mass transfer enhancer; S4: Composite solvent compounding; The ionic liquid ([EMIM][H2 PO 4 ) Mix with polyamine (tetraethylenepentamine / N-methylpiperazine, mass ratio 7:3), stir at 50 °C until homogeneous to obtain the main desulfurizer; add a thermosensitive phase change framework, and perform intermittent (work for 20 s, pause for 10 s) microwave treatment (power 200 W) for 30 min; Divide the dynamic modifier and the mass transfer enhancer into three equal parts each, add them alternately three times, with an interval of 10 min each time, and perform ultrasonic dispersion (frequency 40 kHz) for 1 h; Near-infrared light irradiation (power 1.5 W / cm 2 ), and synchronously apply an external heat source to raise the temperature to 200 °C to trigger the contraction of the thermosensitive phase change framework; Add an antioxidant (pentaerythritol ester), a corrosion inhibitor (boric acid / PVP), and a polar mixture (ethylene glycol / NMP 3-5:1) in sequence. The mass ratio of the antioxidant (pentaerythritol ester), the corrosion inhibitor (boric acid / PVP), and the polar mixture is 0.5:0.3:3, and mix evenly to obtain a composite solvent for removing organic sulfur in industrial synthesis gas.

[0025] Example 3: This example provides a composite solvent for removing organic sulfur in industrial synthesis gas. By weight, it includes the following components: 55 parts of the main desulfurizer, which is composed of a compound of an organic amine and an ionic liquid with a mass ratio of 4:1. The organic amine compound is selected from 4-pyrrolidinobutylamine, bis(4-pyridine)amine or its derivatives, and the ionic liquid is selected from 1-butyl-3-methylimidazolium dihydrogen phosphate or tetramethylammonium glycine; 9 parts of the dynamic modifier, which is a gradient dynamic bond network material formed by the pre-hydrolysis and gradient temperature reaction of 3-mercaptopropyltrimethoxysilane and a bismaleimide compound, with a stable amino coordination bond on the outer layer and a reversibly reorganized dynamic disulfide bond on the inner layer; 12 parts of the mass transfer enhancer, which is a multi-stage pore micelle structure prepared by the thermal initiation of RAFT polymerization of methoxypolyethylene glycol and styrene; 21 parts of the thermosensitive phase change framework, with mesoporous silica as the substrate, after grafting with a dynamic modifier and hydrophobic modification with a styrene-maleic anhydride alternating copolymer, loading a lignosulfonate / chitosan composite carbon source, and forming hierarchical pores through segmented pyrolysis and reduction; 10 parts of additives, including an antioxidant, a corrosion inhibitor, and a polar mixture.

[0026] The preparation method of the composite solvent for removing organic sulfur in industrial synthesis gas includes the following steps: S1: Preparation of dynamic modifier; Mix 3-mercaptopropyltrimethoxysilane and absolute ethanol at a volume ratio of 1:5, add acetic acid accounting for 0.2% of the sum of the masses of 3-mercaptopropyltrimethoxysilane and absolute ethanol as a catalyst, and pre-hydrolyze at 55 °C for 40 min to generate a partially hydrolyzed silane intermediate; Add the bismaleimide compound in three batches (with an interval of 20 min between each batch). The mass ratio of the bismaleimide compound to the mass of 3-mercaptopropyltrimethoxysilane is 1:7. Control the reaction temperature gradient to hold at 80 °C for 1 h, 100 °C for 1 h, and 120 °C for 1 h, and stir and react under nitrogen protection; Adjust the pH to 4.5 and let it stand for 21 min to form an outer layer of amino coordination bonds; Adjust the pH to 7.6 and let it stand for 28 min to form dynamic disulfide bonds; Treat at a microwave power of 300 W for 25 min, and then introduce an Ar / N 2 mixed gas (volume ratio 9:1) and perform plasma surface etching (power 400 W) to promote the three-dimensional anchoring of the dynamic silane on the carrier surface to obtain the dynamic modifier; S2: Preparation of thermosensitive phase change skeleton; Preparation of composite carbon source. Mix sodium lignosulfonate and chitosan at a mass ratio of 3:1, add deionized water (solid-liquid ratio 1:18), and ultrasonically stir at 74 °C for 3 h until completely dissolved to form a homogeneous composite solution; then freeze-dry for 40 h and grind to obtain the composite carbon source powder; Mix the composite carbon source powder and mesoporous silica (pore diameter 30 nm) at a mass ratio of 1:6, add ethanol / water (volume ratio 1:1) as a dispersant, ultrasonically treat for 50 min, centrifuge (3000 rpm, 10 min) to remove the unadsorbed carbon source, retain the uniform coating layer, and dry at 60 °C to obtain the precursor; Segmented graft modification: The first stage: Immerse the precursor in the dynamic modifier. The mass ratio of the dynamic modifier to the precursor is 1:6. Ultrasonically treat at 48 °C for 5 h and dry at 60 °C. After modification, wash with ethanol 3 times to remove the unbonded modifier to avoid the competitive reaction between the anhydride group and the hydroxyl group of the silane; The second stage: Repeat grafting. Adjust the pH to acidic with sulfuric acid, add a styrene-maleic anhydride alternating copolymer accounting for 12% of the mass of the precursor, and control the reaction temperature at 88 °C. Improve the density of hydrophobic anchoring sites through the esterification reaction between the anhydride group and the hydroxyl group on the carrier surface to obtain the grafted precursor; Gradient carbon layer deposition: The first-stage pyrolysis: Pyrolyze the grafted precursor in a nitrogen atmosphere at a heating rate of 5 °C / min to 430 °C for 2 h to carbonize sodium lignosulfonate / chitosan to form a porous carbon skeleton, and at the same time decompose styrene-maleic anhydride to generate micropores; Second-stage reduction: Switch to H 2 / N 2 Mixed gas (H 2 with a proportion of 8%) is first heated to 560 °C at a rate of 5 °C / min and held for 30 min, then heated to 620 °C at a rate of 3 °C / min and held for 40 min. The graphite defect of the carbon layer is repaired by hydrogen reduction to enhance the skeleton conductivity and mechanical strength, and a thermosensitive phase-change skeleton is obtained; The pyrolysis / reduction of the composite carbon source forms a three-level channel structure of macropores (40 nm, derived from the mesoporous silica template), mesopores (3 nm, generated by the decomposition of styrene-maleic anhydride), and micropores (<1 nm, from carbonization shrinkage), and the specific surface area reaches 1100 m 2 / g.

[0027] S3: Preparation of mass transfer enhancer; Styrene is added dropwise in four equal portions at intervals (interval 17 min) to polyethylene glycol monomethyl ether (molecular weight 1500). The mass ratio of polyethylene glycol monomethyl ether to styrene is 1:4, and cuprous bromide / bipyridine is used as a catalyst. The dosage of cuprous bromide / bipyridine is 0.9% of the mass of styrene. The temperature gradient is controlled to hold at 60 °C for 10 min, 65 °C for 10 min, 70 °C for 20 min, and 80 °C for 20 min to form a PEG-b-PS block copolymer; Pre-swelling treatment: The PEG-b-PS block copolymer is swollen in ethanol at 40 °C for 2 h; The PEG-b-PS block copolymer is placed in supercritical CO 2 / ethanol (volume ratio 7:3) (pressure 20 MPa, temperature 40 °C), and foaming treatment is carried out for 2 h to form a multi-level pore micelle structure, and a mass transfer enhancer is obtained; S4: Composite solvent compounding; An ionic liquid ([EMIM][H 2 PO 4 ) and a composite amine (tetraethylenepentamine / N-methylpiperazine, mass ratio 7:3) with a mass ratio of 6:4 are mixed and stirred at 56 °C until homogeneous to obtain a main desulfurizer; The thermosensitive phase-change skeleton is added, and intermittent (working for 20 s, pausing for 10 s) microwave treatment (power 250 W) is carried out for 50 min; The dynamic modifier and the mass transfer enhancer are each divided into three equal parts and added alternately three times at intervals of 12 min, and ultrasonic dispersion (frequency 50 kHz) is carried out for 2 h; Near-infrared light irradiation (power 2 W / cm 2 ) and a synchronous external heat source are used to heat up to 220 °C to trigger the shrinkage of the thermosensitive phase-change skeleton; An antioxidant (pentaerythritol ester), a corrosion inhibitor (boric acid / PVP), and a polar mixture (ethylene glycol / NMP 4:1) are added in sequence. The mass ratio of the antioxidant (pentaerythritol ester), the corrosion inhibitor (boric acid / PVP), and the polar mixture is 0.7:0.5:4. After mixing evenly, a composite solvent for removing organic sulfur in industrial synthesis gas is obtained.

[0028] Comparative Example 1: The difference between this comparative example and Example 3 is that no dynamic modifier is added; (enhancing the desorption capacity) Comparative Example 2: The difference between this comparative example and Example 3 is that no gradient carbon layer deposition is carried out on S2, (enhancing the desorption capacity after cycling) The specific steps are as follows: Preparation of the phase change skeleton; Preparation of the composite carbon source. Sodium lignosulfonate and chitosan are mixed at a mass ratio of 3:1, deionized water is added (solid-liquid ratio 1:18), and ultrasonic stirring is carried out at 74 °C for 3 h until completely dissolved to form a homogeneous composite solution; Subsequently, freeze-drying is carried out for 40 h, and grinding is carried out to obtain the composite carbon source powder; The composite carbon source powder and mesoporous silica (pore diameter 30 nm) are mixed at a mass ratio of 1:6, ethanol / water (volume ratio 1:1) is added as a dispersant, ultrasonic treatment is carried out for 50 min, centrifugation (3000 rpm, 10 min) is carried out to remove the unadsorbed carbon source, and the uniform coating layer is retained. Drying is carried out at 60 °C to obtain the precursor; Segmented graft modification: The first stage: The precursor is immersed in the dynamic modifier. The mass ratio of the dynamic modifier to the precursor is 1:6. Ultrasonic treatment is carried out at 48 °C for 5 h, and drying is carried out at 60 °C. After modification, it is washed 3 times with ethanol to remove the unbonded modifier to avoid the competitive reaction between the anhydride group and the hydroxyl group of the silane; The second stage: Repeat grafting. The pH is adjusted to acidic by sulfuric acid, a styrene-maleic anhydride alternating copolymer accounting for 12% of the mass of the precursor is added, and the reaction temperature is controlled at 88 °C. The density of hydrophobic anchoring sites is increased through the esterification reaction between the anhydride group and the hydroxyl group on the surface of the carrier to obtain the grafted precursor; Carbon layer deposition: The grafted precursor is heated to 620 °C at a rate of 5 °C / min in a nitrogen atmosphere and held for 190 min to obtain the phase change skeleton.

[0029] Comparative Example 3: The difference between this comparative example and Example 3 is that no mass transfer enhancer is added. (Enhancing the desulfurization efficiency) Comparative Example 4: The difference between this comparative example and Example 3 is that neither the dynamic modifier is added nor the gradient carbon layer deposition is carried out in S2. (Enhancing the desorption capacity before and after) Experimental example: 1. Sulfur capacity test; Basis of the test method: Refer to "GB / T 16157-1996 Determination of Particulate Matter in Exhaust Gas from Stationary Pollution Sources and Sampling Method for Gaseous Pollutants", and the sulfur capacity is determined by the dynamic adsorption breakthrough method.

[0030] Experimental procedures; For the dynamic adsorption breakthrough test, the composite solvents of Examples 1-3 and Comparative Examples 1-4 were filled into a fixed-bed reactor (inner diameter 20 mm, length 500 mm), and the temperature was controlled at 80 °C, the pressure at 0.5 MPa, and the space velocity at 1000 m 3 / h.

[0031] Simulated industrial synthesis gas (H 2 S 200 ppm, COS 150 ppm, mercaptan 100 ppm, thiophene 50 ppm, thioether 30 ppm, and the rest is N 2 ) was introduced.

[0032] An H 2 S sensor (accuracy ±1 ppm) and an on-line GC (Agilent 7890B) were used to monitor the sulfur content in the outlet gas until breakthrough (the outlet concentration reached 5% of the inlet).

[0033] Calculation of the total sulfur capacity (mg S / g solvent): Among them, C in is the inlet sulfur concentration (mg / m 3 ), V is the gas flow rate (m 3 / h), t is the breakthrough time (h), and m is the mass of the solvent (g); 2. Removal rate test; Refer to "HJ 2026-2013 Engineering Technical Specification for Treatment of Industrial Organic Waste Gas by Adsorption Method", and the removal efficiency of different organic sulfur components was analyzed by gas chromatography (GC-FID).

[0034] For selectivity analysis, after adsorption saturation, thermal desorption (250 °C) combined with GC-MS (Thermo ISQ 7000) was used to analyze the desorption amount of each organic sulfur component, and the removal rate was calculated; Removal rate calculation formula: Among them, C 初始 is the pollutant concentration before treatment, and C 处理后 is the pollutant concentration after treatment; After the sample was subjected to 50 adsorption-desorption cycles, Q1 and P1 were calculated again by the above method.

[0035] 3. Refer to the "Technical Specification for Monitoring of Exhaust Gases from Stationary Sources - HJ / T 397-2007", and calculate the liquid-phase mass transfer coefficient (k L ) using the two-film theory model; Use a stirred tank reactor (volume 1 L), control the temperature at 60 °C and the stirring rate at 500 rpm; Introduce a sulfur-containing gas (H 2 S 500 ppm), and monitor the change in the sulfur concentration in the liquid phase in real time through an electrochemical sensor, and calculate according to the formula: where C 0 is the initial concentration, C t is the concentration at time t, A is the gas-liquid contact area (m 2 ), and V is the liquid-phase volume (m 3 ).

[0036] 4. Test the leakage rate of ionic liquid; Experimental steps: Step 1: Determine the initial loading (M 0 ) Sample pretreatment: Take a fresh adsorbent sample and completely dissolve it by acid digestion (such as nitric acid + hydrofluoric acid).

[0037] ICP-OES detection: After diluting the digestion solution, determine the concentration of P through ICP-OES (select the characteristic spectral line, P178.287 nm); Calculate the initial loading M 0 = C 初始 × V 初始 .

[0038] Step 2: Collect and process the cyclic desorption liquid; Collect the desorption liquid. After each desorption (every 5 cycles), collect the desorption liquid condensed in the N 2 gas stream or the washing liquid of the adsorbent.

[0039] Sample digestion (to prevent interference from organic matter or particles), add concentrated nitric acid and hydrogen peroxide (H 2 O 2 ), heat until completely digested, and make up to a fixed volume (such as 50 mL), and measure after filtration.

[0040] Step 3: Calculate the leakage rate; Single-cycle leakage amount: m = C × V; Accumulated leakage amount: ∑m i = m 1 + m 2 + …… + m n (the number of cycles is 50); The leakage rate calculation formula. The calculation of the ionic liquid leakage rate (%) is based on the ratio of the mass of leaked P element to the initial loading amount: C i is the concentration of Si in the desorption liquid in the i-th cycle (unit: μg / mL or mg / L); V is the volume of each desorption liquid (constant volume each time, unit: mL); M 0 is the total amount of Si initially loaded on the adsorbent (unit: μg or mg); n is the current cycle number (when it is the 50th cycle, n = 50).

[0041] The experimental results are shown in the following table: As can be seen from the above table, the mass transfer enhancer in Comparative Example 3 (a multi-porous micelle structure prepared by RAFT polymerization of methoxypolyethylene glycol and styrene under thermal initiation) provides more channels and faster diffusion paths for the diffusion of sulfides, and can effectively improve the diffusion rate of sulfides through the ionic liquid layer, that is, the liquid-phase mass transfer coefficient. This is like opening up "fast channels" in the originally relatively dense ionic liquid environment, enabling sulfide molecules to move and transfer more rapidly, thus significantly improving the desulfurization efficiency.

[0042] The dynamic modifier in Comparative Example 1 mainly plays a role by increasing the surface energy of the carrier. When the surface energy of the carrier increases, the interaction between the ionic liquid and the carrier is enhanced, making the spreading and adsorption of the ionic liquid on the carrier surface more stable, thereby reducing the leakage rate of the ionic liquid. And the active sites are usually located inside the ionic liquid or at the interface interacting with the ionic liquid. Reducing the leakage of the ionic liquid means reducing the possibility of the loss of active sites with the ionic liquid, and thus ensuring that a sufficient number of active sites can continuously participate in the adsorption and desorption processes of sulfides, promoting the desorption of sulfides.

[0043] In Comparative Example 2, the dynamic modifier adjusted the properties of the carrier surface through grafting, enhanced the compatibility and adsorption performance with the ionic liquid, and enabled the ionic liquid to be more evenly loaded on the framework. Secondly, the styrene-maleic anhydride alternating copolymer is hydrophobic. After hydrophobic modification, it can prevent the excessive diffusion and aggregation of the ionic liquid in the framework pores, avoid pore blockage caused by uneven filling of the ionic liquid, and ensure the smoothness of the framework pores. During the segmented pyrolysis and reduction process of the loaded sodium lignosulfonate / chitosan composite carbon source, a hierarchical pore structure will be formed inside the framework. This hierarchical pore not only retains the high-mass transfer characteristics of the large-pore diameter pores, which is beneficial to the rapid diffusion and transfer of sulfides, but also has the ability to recognize and separate target sulfide molecules, and can accurately adsorb and desorb sulfides, thereby achieving an improvement in the desorption ability after multiple cycles.

[0044] In Comparative Example 4, the compounding of the dynamic modifier and the hierarchical pores further reduced the leakage rate and improved the desorption ability and desulfurization efficiency before and after multiple cycles. After the dynamic modifier is combined with the hierarchical pore structure, the hierarchical pores provide an ordered distribution and diffusion path for the ionic liquid, making the existence of the ionic liquid in the framework more stable and reducing the leakage phenomenon caused by the disordered flow or aggregation of the ionic liquid. From the performance after multiple cycles, on the one hand, the compounding of the dynamic modifier and the hierarchical pores ensures the stability and availability of the active sites during each cycle, which helps the desorption process to proceed, thus improving the desorption ability after multiple cycles; on the other hand, the hierarchical pores promote the mass transfer and diffusion of sulfides, enabling sulfides to continuously and efficiently contact and react with the active sites during multiple cycles, unexpectedly achieving an improvement in the desulfurization efficiency after multiple cycles.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite solvent for removing organic sulfur from industrial synthesis gas, characterized in that: By weight, it includes the following components: 40-60 parts of a main desulfurizing agent, which is composed of an organic amine compound and an ionic liquid in a mass ratio of 3-5:1, wherein the organic amine compound is selected from 4-pyrrolidinobutylamine, bis(4-pyridine)amine or a derivative thereof, and the ionic liquid is selected from 1-butyl-3-methylimidazole dihydrogen phosphate or tetramethylammonium glycine; 8-12 parts of a dynamic modifier, a gradient dynamic bond network material formed by pre-hydrolysis and gradient temperature reaction of 3-mercaptopropyltrimethoxysilane and bismaleimide compounds, the outer layer of which is a stable amino coordination bond and the inner layer is a reversibly reorganized dynamic disulfide bond; 5-15 parts of a mass transfer enhancer, which is a multi-level porous micelle structure prepared by thermally initiating RAFT polymerization of polyethylene glycol monomethyl ether and styrene; 20-30 parts of thermosensitive phase change framework, with mesoporous silica as the substrate, after dynamic modifier grafting and styrene-maleic anhydride alternating copolymer hydrophobic modification, loaded with sodium lignin sulfonate / chitosan composite carbon source, and formed hierarchical channels through segmented pyrolysis and reduction; 8-14 parts of additives, including antioxidants, corrosion inhibitors and polar mixed liquids.

2. The method for preparing a composite solvent for removing organic sulfur from industrial synthesis gas according to claim 1, characterized in that: The following steps are involved: S1: preparation of dynamic modifier; 3-mercaptopropyltrimethoxysilane is mixed with anhydrous ethanol, acetic acid is added as a catalyst, and pre-hydrolyzed to generate a partially hydrolyzed silane intermediate; Add the bismaleimide compound three times, control the reaction temperature gradient, and stir the reaction under nitrogen protection; The outer amino coordination bonds and dynamic disulfide bonds are formed by adjusting the pH; Treating under microwave, then introducing Ar / N2 mixed gas, plasma surface etching, promoting three-dimensional anchoring of dynamic silane on the carrier surface, and obtaining a dynamic modifier; S2: Preparation of thermosensitive phase change framework; Preparation of composite carbon source: Sodium lignin sulfonate and chitosan are mixed, water is added, ultrasonic stirring is performed until they are completely dissolved to form a homogeneous composite solution; then freeze drying is performed, and grinding is performed to obtain composite carbon source powder; The composite carbon source powder is mixed with mesoporous silica, ethanol / water is added as a dispersant, ultrasonic treatment is performed, and the unadsorbed carbon source is removed by centrifugation to retain a uniform coating layer, and drying is performed to obtain a precursor; Segmented grafting modification: The first stage: immersing the precursor in the dynamic modifier, drying after ultrasonic treatment, and after modification, washing with ethanol to remove the unbonded modifier; The second stage: repeated grafting, adding styrene-maleic anhydride alternating copolymer, increasing the density of hydrophobic anchoring sites through esterification reaction between anhydride groups and hydroxyl groups on the carrier surface, and obtaining a grafting precursor; Gradient carbon layer deposition: The first stage of pyrolysis: the grafted precursor is heated to 400-500℃ in a nitrogen atmosphere to pyrolyze, so that the sodium lignin sulfonate / chitosan is carbonized to form a porous carbon skeleton, and styrene-maleic anhydride is decomposed to produce micropores; The second stage of reduction: switch to H2 / N2 mixed gas, first raise the temperature to 550-580℃ and keep it warm, then raise the temperature to 600-650℃ and keep it warm, repair the graphitization defects of the carbon layer by hydrogen reduction, and obtain a temperature-sensitive phase change skeleton; S3: preparing a mass transfer enhancer; Styrene was added dropwise to polyethylene glycol monomethyl ether in four batches, cuprous bromide / bipyridine was used as a catalyst, and the temperature gradient was controlled to react to form PEG-b-PS block copolymers; The PEG-b-PS block copolymer was placed in supercritical CO2 / ethanol and foamed to form a multi-level pore micelle structure to obtain a mass transfer enhancer. S4: compound solvent preparation; The ionic liquid and the complex amine are mixed and stirred until a homogeneous phase is obtained to obtain a main desulfurizing agent; a thermosensitive phase change skeleton is added and subjected to microwave treatment; The dynamic modifier and mass transfer enhancer were divided into three parts each, added alternately three times, and dispersed by ultrasonication; Irradiate with near-infrared light and simultaneously apply an external heat source to increase the temperature, triggering the contraction of the thermosensitive phase change skeleton; An antioxidant, a corrosion inhibitor and a polar mixed liquid are added in sequence and mixed evenly to obtain a composite solvent for removing organic sulfur from industrial synthesis gas.

3. The method for preparing a composite solvent for removing organic sulfur from industrial synthesis gas according to claim 2, characterized in that: S1 is specifically: 3-mercaptopropyltrimethoxysilane and anhydrous ethanol are mixed in a volume ratio of 1:4-6, 0.1-0.3% of acetic acid based on the sum of the mass of 3-mercaptopropyltrimethoxysilane and anhydrous ethanol is added as a catalyst, and pre-hydrolyzed at 40-60° C. for 30-60 min to generate a partially hydrolyzed silane intermediate; The bismaleimide compound was added three times, with an interval of 15-30 minutes between each batch, the mass ratio of the bismaleimide compound to 3-mercaptopropyltrimethoxysilane was 1:5-8, the reaction temperature gradient was controlled, and the reaction was stirred for 2-4 hours under nitrogen protection; The outer amino coordination bond is formed by adjusting the pH to 4-5 and standing for 20-30 minutes; Adjust the pH to 7-8 and let stand for 20-30 min to form dynamic disulfide bonds; The substrate is treated at a microwave power of 200-400 W for 20-40 minutes, and then Ar / N2 mixed gas is introduced to perform plasma surface etching at a power of 300-500 W to promote the three-dimensional anchoring of dynamic silane on the carrier surface to obtain a dynamic modifier.

4. The method for preparing a composite solvent for removing organic sulfur from industrial synthesis gas according to claim 2, characterized in that: S2 is specifically as follows: preparing the composite carbon source, mixing sodium lignin sulfonate and chitosan in a mass ratio of 3:1, adding deionized water in a solid-liquid ratio of 1:10-20, and stirring ultrasonically at 60-80°C for 2-4h until completely dissolved to form a homogeneous composite solution; then freeze-drying for 24-48h, and grinding to obtain a composite carbon source powder; The composite carbon source powder and mesoporous silica are mixed in a mass ratio of 1:5-10, ethanol / water is added as a dispersant, ultrasonic treatment is performed for 30-60 minutes, the unadsorbed carbon source is removed by centrifugation, a uniform coating layer is retained, and drying is performed to obtain a precursor; Segmented grafting modification: The first stage: immerse the precursor in a dynamic modifier with a mass ratio of the dynamic modifier to the precursor of 1:5-10, ultrasonically treat at 40-50°C for 1-2h, dry, and after modification, wash with ethanol to remove the unbonded modifier; The second stage: repeated grafting, adjusting the pH to acidic with sulfuric acid, adding 8-15% of the precursor mass of styrene-maleic anhydride alternating copolymer, and controlling the reaction temperature to 80-90°C, increasing the density of hydrophobic anchoring sites through esterification reaction between the anhydride group and the hydroxyl group on the carrier surface, and obtaining a grafted precursor; Gradient carbon layer deposition: The first stage of pyrolysis: the grafted precursor is heated to 400-500℃ for 1-2h in a nitrogen atmosphere to carbonize the sodium lignin sulfonate / chitosan to form a porous carbon skeleton, while styrene-maleic anhydride is decomposed to produce micropores; The second stage of reduction: switch to H2 / N2 mixed gas, in which H2 accounts for 5-10%, first raise the temperature to 550-580℃ and keep it, then raise the temperature to 600-650℃ and keep it for 30-50min, repair the graphitization defects of the carbon layer through hydrogen reduction, and obtain a temperature-sensitive phase change skeleton.

5. The method for preparing a composite solvent for removing organic sulfur from industrial synthesis gas according to claim 4, characterized in that: In S2, the pyrolysis / reduction of the composite carbon source forms a three-level channel structure consisting of 30-50 nm macropores, 2-5 nm mesopores, and <1 nm micropores.

6. The method for preparing a composite solvent for removing organic sulfur from industrial synthesis gas according to claim 2, characterized in that: S3 is specifically as follows: styrene is added dropwise to polyethylene glycol monomethyl ether in four batches at intervals of 15-20 minutes, the mass ratio of polyethylene glycol monomethyl ether to styrene is 1:3-5, cuprous bromide / bipyridine is used as a catalyst, the amount of cuprous bromide / bipyridine is 0.5-1.2% of the mass of styrene, the temperature gradient is controlled, the reaction is performed for 1-3 hours, and a PEG-b-PS block copolymer is formed; Pre-swelling treatment: PEG-b-PS block copolymer was swollen in ethanol; The PEG-b-PS block copolymer is placed in supercritical CO2 / ethanol at a pressure of 15-25 MPa and a temperature of 35-45°C for foaming for 1-2 hours to form a multi-level pore micelle structure to obtain a mass transfer enhancer.

7. The method for preparing a composite solvent for removing organic sulfur from industrial synthesis gas according to claim 2, characterized in that: S4 is specifically as follows: mixing the ionic liquid and the complex amine in a mass ratio of 6-7:3-4, stirring at 50-60°C until a homogeneous phase is obtained to obtain a main desulfurizing agent; adding a thermosensitive phase change skeleton, and intermittently microwave treating for 30-60 minutes at a power of 200-300W; The dynamic modifier and mass transfer enhancer were divided into three equal parts, added alternately three times, each time with an interval of 10-15 minutes, and ultrasonically dispersed for 1-2 hours; Power 1.5-2W / cm 2 Irradiate with near-infrared light and simultaneously apply an external heat source to raise the temperature to 200-250°C to trigger the contraction of the thermosensitive phase change skeleton. An antioxidant, a corrosion inhibitor and a polar mixed liquid are added in sequence and mixed evenly to obtain a composite solvent for removing organic sulfur from industrial synthesis gas.

8. The method for preparing a composite solvent for removing organic sulfur from industrial synthesis gas according to claim 7, characterized in that: In S4, the mass ratio of the antioxidant, the corrosion inhibitor and the polar mixed liquid is 0.5-1:0.3-0.8:3-5, and they are evenly mixed to obtain a composite solvent for removing organic sulfur from industrial synthesis gas.

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