Novel sterically hindered amine composite desulfurizer and preparation method thereof

Abstract

The invention discloses a novel sterically hindered amine compound desulfurizer and a preparation method thereof, and belongs to the technical field of desulfurization of petrochemical gases such as natural gas and coal chemical industry, the compound desulfurizer comprises the following components in percentage by mass: 20-50% of sterically hindered amine, 10-28% of a synergistic aid, 10-20% of an additive and the balance of a solvent, the preparation method comprises the following steps: brominating, then carrying out quaternization with vinyl imidazole, and finally carrying out cross-linking polymerization to obtain the product. The novel composite desulfurizer disclosed by the invention has excellent absorption selectivity while keeping a good removal rate on hydrogen sulfide, and is especially suitable for removing hydrogen sulfide in natural gas, coal chemical industry and petrochemical industry processes.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of natural gas, coal chemical industry and other petroleum and chemical gas desulfurization technology, and particularly relates to a novel steric amine composite desulfurizer and a preparation method thereof. BACKGROUND

[0002] Mixed gas includes natural gas, petroleum refinery gas, synthesis gas and liquefied petroleum gas and other gases. In natural gas, synthesis gas, petroleum refinery gas and other industrial gases, hydrogen sulfide (H2S) and organic sulfides are usually contained, and the organic sulfides mainly include carbonyl sulfide, carbon disulfide and different carbon number mercaptans and sulfides, etc. The existence of various organic / inorganic sulfide components not only easily causes corrosion of equipment and pipelines in the process of exploitation, treatment, transportation and use, but also brings environmental pollution when used as fuel, and also causes serious harm to human health. Therefore, before further processing and utilization of the mixed gas, purification treatment must be carried out to meet the subsequent utilization requirements.

[0003] At present, there are many methods for desulfurization treatment of mixed gas at home and abroad, and the desulfurization can be divided into dry desulfurization and wet desulfurization according to the weak acidity and strong reducibility. Dry desulfurization is to use the reducibility and combustibility of hydrogen sulfide to desulfurize with solid oxidants and adsorbents or to directly burn, and wet desulfurization is to use liquid desulfurizer to desulfurize by physical and chemical principles and then to recover by desorption. Wet desulfurization mainly uses organic amine liquid (alcohol amine), and mainly experiences monoethanolamine (MEA), diethanolamine (DEA), diglycolamine (DGA), diisopropanolamine (DIPA), triethanolamine (TEA) and N-methyldiethanolamine (MDEA) as main desulfurizers. Alcohol amine wet desulfurization is a commonly used method for removing hydrogen sulfide in natural gas and refinery gas. The alcohol amine used at present is mainly N-methyldiethanolamine (MDEA) or its mixture with steric hindrance effect. Such desulfurizer has certain selectivity for removal of H2S / CO2, but the removal selectivity is poor, and a large amount of carbon dioxide is removed at the same time of removing hydrogen sulfide. For mixed gas with higher CO2 / H2S ratio, the removal selectivity still needs to be improved. The lower removal selectivity will cause the increase of processing capacity of the subsequent device, the large amount of amine liquid circulation and the increase of production energy consumption, resulting in high energy consumption of the device. Therefore, it is imperative to improve the removal selectivity of H2S. The existing technology has developed corresponding desulfurization additives based on the difference in reduction and oxidation activity of H2S and CO2 on the basis of steric amine desulfurizer, which effectively improves the selectivity. The present application attempts to develop another new desulfurizer from the perspective of the difference in kinetic diameter of H2S and CO2 and porous adsorption. SUMMARY

[0004] In view of the above problems, the present application provides a novel steric amine composite desulfurizer and a preparation method thereof.

[0005] The object of the application is achieved by the technical scheme that A novel steric amine composite desulfurizer has the following composition in mass fraction: steric amine 20-50%, synergistic additive 10-28%, additive 10-20%, and the balance is solvent, wherein the preparation method of the synergistic additive comprises the following steps: (1) bromination reaction is carried out with triptycene as raw material to obtain a bromination product; (2) the bromination product is dissolved in acetonitrile solvent, N-vinylimidazole and tert-butyl-4-hydroxyanisole are added, and the reaction is stirred and incubated at 60-80℃ for 48-72h; after the reaction is completed, the precipitate is separated and dissolved in water, and the solvent is removed under reduced pressure to obtain a modified monomer; (3) the modified monomer is dissolved in an ethanol aqueous solution, an initiator is added, oxygen is removed after nitrogen is passed, and then the mixture is fully stirred and mixed under a protective atmosphere, heated to 70-78℃ and incubated and stirred for 4-12h; after the reaction is completed, the reaction system is dialyzed with a dialysis membrane, and the dialysis product is concentrated and dried to obtain the product.

[0006] In some preferred embodiments of the application, the steric amine is one or more of N-diphenylmethylazetidin-3-ol, tert-butylaminoethoxyethanol, 1,3-di-tert-butylamino-2-propanol, and 1-cyclohexyl-3-azetidinol.

[0007] In some preferred embodiments of the application, the additive comprises an inhibitor, a defoaming agent, and a stabilizer.

[0008] In some preferred embodiments of the application, the inhibitor is one or more of imidazolyl dithiourea, 2-amino-imidazolinone, di(propargyloxy methyl)isopropyl benzyl ammonium chloride, and di(propargyloxy methyl)butyl benzyl ammonium chloride; the defoaming agent is one or more of dimethyl silicone oil, ethyl silicone oil, methyl phenyl silicone oil, and polyether modified silicone oil; and the stabilizer is one or more of N-(tert-butoxycarbonyl)ethanolamine, morpholine, and piperazine.

[0009] In some preferred embodiments of the application, the solvent is a mixed solvent of deionized water and a dihydric alcohol, and the dihydric alcohol is propylene glycol, 1,4-butanediol, or 1,5-pentanediol.

[0010] In some preferred embodiments of the application, the bromination reaction in step (1) comprises the following steps: The triphenylene is weighed and dissolved in dichloroethane solvent, powder iron is added as a catalyst, under the protection of atmosphere and ice water bath, the elemental bromine is slowly added into the reaction system under stirring, after the addition is completed, the reaction is kept at 60-80 DEG C for 5-8h, after the reaction is completed, the reaction system is cooled to room temperature, the aqueous sodium bisulfite is added, after the mixture is stirred sufficiently, the organic solvent is extracted, the organic solvent layer is washed with brine and dried with inorganic salt, the solvent is removed under reduced pressure to obtain the bromination product.

[0011] In some preferred embodiments of the present application, the mass ratio of the triphenylene, the powder iron, the elemental bromine is 1: (0.05-0.08): (3.5-4.5).

[0012] In some preferred embodiments of the present application, the mass ratio of the bromination product, the N-vinylimidazole, the tert-butyl-4-hydroxyanisole in step (2) is 1: (0.5-0.7): (0.03-0.05).

[0013] In some preferred embodiments of the present application, the mass ratio of the modified monomer, the initiator in step (3) is 1: (0.01-0.03).

[0014] In some preferred embodiments of the present application, the molecular weight cut-off of the dialysis membrane is 1500-3000.

[0015] Another object of the present application is to provide a preparation method of the novel steric amine composite desulfurizer, comprising the following steps: S1, the synergistic adjuvant is prepared and the components are weighed according to the proportion, and is prepared for use; S2, the solvent is mixed with the steric amine, the synergistic adjuvant is added and stirred for 20-30min, finally the additive is added and the circulation stirring reflux is carried out for 40-60min, and the preparation is prepared.

[0016] The present application has the following beneficial effects: In view of the problem that the existing alcohol amine desulfurizer has poor selectivity for hydrogen sulfide removal, the application provides a novel composite desulfurizer based on steric amine, which has excellent absorption selectivity while maintaining good removal rate of hydrogen sulfide, and is especially suitable for hydrogen sulfide removal in natural gas, coal chemical industry and petroleum chemical industry; specifically, the application improves the removal rate of hydrogen sulfide on the basis of the existing steric amine alkaline absorbent by adding a synergistic additive, wherein the synergistic additive is a product prepared by bromination of triptycene, then quaternary amination with vinyl imidazole, and finally crosslinking polymerization, triptycene is a three-dimensional rigid structure compound formed by three benzene rings connected by saturated carbon, and its unique Y-shaped space configuration endows it with excellent physical and chemical properties, the application uses triptycene as a skeleton and imidazole ring crosslinking to obtain a crosslinked oligomer with special pore structure, and benefits from its appropriate pore size and imidazole active site, the adsorption and capture of hydrogen sulfide in mixed gas are improved, and compared with carbon dioxide, hydrogen sulfide is more easily combined with weakly basic bromide ion sites, further improving the selectivity. DETAILED DESCRIPTION

[0017] The application will be further described in combination with the following examples. Example 1

[0018] This embodiment relates to a novel steric amine composite desulfurizer, which has the following composition in terms of mass fraction: steric amine 30%, synergistic additive 18%, 2-amino-imidazolinone 0.1%, dimethyl silicone oil 0.5%, N-(tert-butoxycarbonyl) ethanolamine 16%, and the balance is solvent, wherein, The steric amine is a mixture of tert-butyl amine ethoxy ethanol and 1,3-di-tert-butyl amine-2-propanol in a mass ratio of 1:1; The preparation method of the synergistic additive comprises the following steps: (1) weigh triptycene and dissolve it in dichloroethane solvent, add powdered iron as a catalyst, under the condition of protective atmosphere and ice water bath, slowly add elemental bromine to the reaction system while stirring, after the addition is completed, heat at 70 DEG C for 7h, after the reaction is completed, cool to room temperature, add 1 / 10 volume of saturated sodium bisulfite aqueous solution to the reaction system, mix thoroughly, then extract with dichloromethane, wash the organic layer with saturated brine in turn, dry with anhydrous sodium sulfate, and remove the solvent under reduced pressure to obtain the bromination product; the mass ratio of the triptycene to the powdered iron and the elemental bromine is 1:0.07:4.1; (2) The brominated product was dissolved in acetonitrile solvent, N-vinylimidazolium and tert-butyl-4-hydroxyanisole were added, and the mixture was stirred at 65°C for 60 h. After the reaction was completed, the mixture was cooled, the precipitate was separated and dissolved in water, and the solvent was removed by vacuum evaporation to obtain the modified monomer. The mass ratio of the brominated product to the N-vinylimidazolium and the tert-butyl-4-hydroxyanisole was 1:0.57:0.03. (3) The modified monomer was dissolved in an ethanol-water (v / v=3:1) solution, azobisisobutyronitrile was added, nitrogen was purged to remove oxygen, and then the mixture was stirred thoroughly under a protective atmosphere. The temperature was raised to 70°C and stirred for 6 hours. After the reaction was completed, the mixture was cooled to room temperature. The reaction system was dialyzed with a dialysis membrane, and the dialysis product was concentrated and dried to obtain the product. The mass ratio of the modified monomer to the azobisisobutyronitrile was 1:0.02. The molecular weight cutoff of the dialysis membrane was 2500. The solvent is a mixture of deionized water and 1,4-butanediol (v / v=5:1); The preparation method of the novel hindered amine composite desulfurizer includes the following steps: S1. Prepare the synergistic agent and weigh each component according to the proportion, for later use; S2. Mix the solvent with the hindered amine, add the synergist and stir for 30 min, and finally add the 2-amino-imidazolinone, the dimethyl silicone oil and the N-(tert-butoxycarbonyl)ethanolamine, and circulate and reflux for 60 min to obtain the final product. Example 2

[0019] This embodiment relates to a novel hindered amine composite desulfurizer, which, by mass fraction, has the following composition: 24% hindered amine, 10% synergist, 0.1% 2-amino-imidazolinone, 0.5% dimethyl silicone oil, 16% N-(tert-butyloxycarbonyl)ethanolamine, and the balance being solvent. The hindered amine is a mixture of tert-butylaminoethoxyethanol and 1,3-di-tert-butylamino-2-propanol in a mass ratio of 1:1; The preparation method of the synergistic agent is the same as in Example 1; The solvent is a mixture of deionized water and 1,4-butanediol (v / v=5:1); The preparation method of the novel hindered amine composite desulfurizer is the same as in Example 1. Example 3

[0020] This embodiment relates to a hindered amine composite desulfurizing agent, which, by mass fraction, has the following composition: 30% hindered amine, 18% additives, 0.1% 2-amino-imidazolinone, 0.5% dimethyl silicone oil, 16% N-(tert-butyloxycarbonyl)ethanolamine, and the balance being solvent. The hindered amine is a mixture of tert-butylaminoethoxyethanol and 1,3-di-tert-butylamino-2-propanol in a mass ratio of 1:1; The preparation method of the auxiliary agent includes the following steps: (1) Benzene was weighed and dissolved in dichloroethane solvent. Powdered iron was added as a catalyst. Under a protective atmosphere and ice-water bath conditions, elemental bromine was slowly added to the reaction system while stirring. After the addition was completed, the reaction was kept at 70°C for 7 hours. After the reaction was completed, the mixture was cooled to room temperature. 1 / 10 volume of saturated sodium bisulfite aqueous solution was added to the reaction system. After thorough mixing, the mixture was extracted with dichloromethane. The organic layer was washed with saturated brine and dried with anhydrous sodium sulfate. The solvent was removed by vacuum evaporation to obtain the bromination product. The mass ratio of benzene to powdered iron and elemental bromine was 1:0.07:4.1. (2) The brominated product was dissolved in acetonitrile solvent, N-vinylimidazolium and tert-butyl-4-hydroxyanisole were added, and the mixture was stirred at 65°C for 60 h. After the reaction was completed, the mixture was cooled, the precipitate was separated and dissolved in water, and the solvent was removed by vacuum evaporation to obtain the modified monomer. The mass ratio of the brominated product to the N-vinylimidazolium and the tert-butyl-4-hydroxyanisole was 1:0.57:0.03. (3) The modified monomer was dissolved in an ethanol-water (v / v=3:1) solution, azobisisobutyronitrile was added, nitrogen was purged to remove oxygen, and then the mixture was stirred thoroughly under a protective atmosphere. The temperature was raised to 70°C and stirred for 6 hours. After the reaction was completed, the mixture was cooled to room temperature. The reaction system was dialyzed with a dialysis membrane, and the dialysis product was concentrated and dried to obtain the product. The mass ratio of the modified monomer to the azobisisobutyronitrile was 1:0.02. The molecular weight cutoff of the dialysis membrane was 2500. The solvent is a mixture of deionized water and 1,4-butanediol (v / v=5:1); The preparation method of the hindered amine composite desulfurizer is the same as in Example 1. Example 4

[0021] This embodiment relates to a hindered amine composite desulfurizing agent, which, by mass fraction, has the following composition: 30% hindered amine, 18% additives, 0.1% 2-amino-imidazolinone, 0.5% dimethyl silicone oil, 16% N-(tert-butyloxycarbonyl)ethanolamine, and the balance being solvent. The hindered amine is a mixture of tert-butylaminoethoxyethanol and 1,3-di-tert-butylamino-2-propanol in a mass ratio of 1:1; The additive is the modified monomer described in Example 1; The solvent is a mixture of deionized water and 1,4-butanediol (v / v=5:1); The preparation method of the hindered amine composite desulfurizer is the same as in Example 1. Example 5

[0022] This embodiment relates to a hindered amine composite desulfurizer, which, by mass fraction, has the following composition: 30% hindered amine, 0.1% 2-amino-imidazolinone, 0.5% dimethyl silicone oil, 16% N-(tert-butyloxycarbonyl)ethanolamine, and the balance being solvent. The hindered amine is a mixture of tert-butylaminoethoxyethanol and 1,3-di-tert-butylamino-2-propanol in a mass ratio of 1:1; The solvent is a mixture of deionized water and 1,4-butanediol (v / v=5:1); The preparation method of the hindered amine composite desulfurizer is the same as in Example 1.

[0023] Experimental Example The performance of the hindered amine composite desulfurizers described in Examples 1-5 was tested using a simulated absorption device. Specifically, a mixed gas containing a certain proportion of nitrogen, hydrogen sulfide, and carbon dioxide was introduced into an absorption container containing 1L of the hindered amine composite desulfurizers described in Examples 1-5 at a certain flow rate (100mL / min) at room temperature for bubbling absorption. After absorption for a certain time (30min), the components of the tail gas at the outlet of the absorption container were analyzed. The contents of hydrogen sulfide and carbon dioxide were determined by gas chromatography. The results are shown in the table below.

[0024] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A novel sterically hindered amine complex desulfurizer characterized in that, By mass fraction, having the following composition: hindered amine 20-50%, synergistic adjuvant 10-28%, additive 10-20%, the balance is solvent, wherein, the preparation method of the synergistic adjuvant comprises the following steps: (1) triptycene is used as raw material to carry out bromination reaction, and bromination product is obtained; (2) the bromination product is dissolved in acetonitrile solvent, N-vinylimidazole and tert-butyl-4-hydroxyanisole are added, and the reaction is stirred and incubated at 60-80 DEG C for 48-72h, after the reaction is completed, cooling, separation of the precipitate and dissolving in water, the solvent is removed under reduced pressure, and the modified monomer is obtained; (3) the modified monomer is dissolved in ethanol aqueous solution, initiator is added, after nitrogen deoxygenation, the mixture is fully stirred under protective atmosphere, heated to 70-78 DEG C and incubated and stirred for 4-12h, after the reaction is completed, cooling to room temperature, the reaction system is dialyzed with dialysis membrane, and the dialysis product is concentrated and dried to obtain.

2. A novel sterically hindered amine composite desulfurizer according to claim 1, characterized in that, The hindered amine is one or more of N-diphenylmethyl azetidin-3-ol, tert-butyl amino ethoxy ethanol, 1,3-di-tert-butyl amino-2-propanol, 1-cyclohexyl-3-azetidinol.

3. A novel sterically hindered amine composite desulfurizer according to claim 1, characterized by, The additive includes corrosion inhibitor, defoaming agent and stabilizer.

4. A novel sterically hindered amine composite desulfurizer according to claim 3, characterized by, The corrosion inhibitor is one or more of imidazolyl dithiourea, 2-amino-imidazolinone, di(propargyloxy methyl) isopropyl benzyl ammonium chloride, di(propargyloxy methyl) butyl benzyl ammonium chloride; the defoaming agent is one or more of dimethyl silicone oil, ethyl silicone oil, methyl phenyl silicone oil, polyether modified silicone oil; the stabilizer is one or more of N-(tert-butoxycarbonyl) ethanolamine, morpholine, piperazine.

5. A novel sterically hindered amine composite desulfurizer according to claim 1, characterized by, The bromination reaction comprises the following steps: Triptycene is weighed and dissolved in dichloroethane solvent, powder iron is added as catalyst, under the condition of protective atmosphere and ice water bath, elemental bromine is slowly added to the reaction system while stirring, after the addition is completed, incubation reaction is carried out at 60-80 DEG C for 5-8h, after the reaction is completed, cooling to room temperature, sodium bisulfite aqueous solution is added, after fully stirring and mixing, the organic solvent is extracted, the organic solvent layer is washed with brine in turn, dried with inorganic salt, and the solvent is removed under reduced pressure to obtain the bromination product.

6. A novel sterically hindered amine composite desulfurizer according to claim 5, characterized by, The mass ratio of triptycene to powder iron and elemental bromine is 1: (0.05-0.08): (3.5-4.5).

7. A novel sterically hindered amine composite desulfurizer according to claim 1, characterized by, In step (2), the mass ratio of the bromination product to N-vinylimidazole and tert-butyl-4-hydroxyanisole is 1: (0.5-0.7): (0.03-0.05).

8. A novel sterically hindered amine composite desulfurizer according to claim 1, characterized by, In step (3), the mass ratio of the modified monomer to the initiator is 1: (0.01-0.03).

9. A novel sterically hindered amine composite desulfurizer according to claim 1, characterized by, The molecular weight cut-off of the dialysis membrane is 1500-3000.

10. A process for the preparation of a novel sterically hindered amine composite desulfurizer according to any one of claims 1 to 9, characterized in that, Comprise the following steps: S1, the synergistic adjuvant is prepared and the components are weighed in proportion, ready for use; S2, the solvent is mixed with the hindered amine, the synergistic adjuvant is added and stirred for 20-30min, finally the additive is added and circulated and stirred to reflux for 40-60min, and it is prepared.

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