A compound, a method of preparation and use in desulfurization and a desulfurizer composition

Abstract

The application provides a compound, a preparation method, and application in desulfurization and a desulfurizer, a structural formula of the compound is as follows: the preparation method is as follows: diisopropanolamine, ethylene glycol diglycidyl ether, and a solvent are uniformly mixed and then are added into a high-temperature and high-pressure reaction kettle, reaction is carried out at 80-120 DEG C for 4-8 h, the solution is poured out after cooling, and the solution is distilled under reduced pressure to obtain a solid product steric amine; then the prepared steric amine and N-methyldiethanolamine are uniformly mixed at a mass ratio of 1-2:2-3, and are compounded into a 40-50 wt% aqueous solution, and the desulfurizer is preferably applied to natural gas desulfurization.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of natural gas development, and particularly relates to a compound, a composition, a preparation method and application in a desulfurizer. BACKGROUND

[0002] Natural gas is a valuable resource and has extremely wide application in production and life. With the rising position of natural gas in the world energy structure, the position of natural gas purification industry is also rising. In the development process of natural gas, natural gas resources are often accompanied by H2S and CO2 and other acid gases. These acid gases inevitably cause corrosion to pipelines and other equipment in the process of mining, gathering and transportation, thereby reducing the service life of the equipment and causing safety hazards. In addition, hydrogen sulfide as a toxic substance, associated gas and secondary hydrogen sulfide will form potential safety hazards to oil well workers and surrounding residents. In addition, when the concentration of hydrogen sulfide and other gases in natural gas is too high, it will have a great impact on the sale of natural gas. After decades of research, China has made certain achievements in natural gas desulfurization, but there is still a certain gap compared with the world advanced level. For the removal of sulfides in the process of oil and gas field mining and gathering, the most commonly used method in industry is wet desulfurization, which has simple process, high removal efficiency and strong environmental protection, and can be well applied to large-scale production and transportation of natural gas. However, at present, the most commonly used in wet desulfurization is amine desulfurization technology. Among them, MDEA (methyl diethanolamine) has the advantages of high acid gas load, low corrosion to H2S, and not easy to foam, and becomes the most widely used desulfurization solvent in amine desulfurization. However, using MDEA alone cannot solve various complex engineering problems, especially the general selectivity to H2S, which removes a large amount of carbon dioxide while removing hydrogen sulfide, especially for high CO2 / H2S ratio gas, which will increase the processing capacity of the subsequent device and increase the production energy consumption. Therefore, the desulfurizer based on steric hindrance cannot meet the increasingly high desulfurization requirements in the process of natural gas development. SUMMARY

[0003] In view of the problem that the conventional alcohol amine desulfurizer used in the existing wet desulfurization technology cannot meet the increasingly high desulfurization requirements in the process of natural gas development, the present application provides a compound, a preparation method and application thereof in a desulfurizer.

[0004] The technical scheme of the present application is as follows:

[0005] A compound, characterized in that the structural formula is shown as formula I.

[0006]

[0007] The preparation method of the compound is characterized by comprising the following steps: uniformly mixing diisopropanolamine, ethylene glycol diglycidyl ether and a first solvent, adding them into a high-temperature and high-pressure reaction kettle, reacting at 80-120 DEG C for 4-8 hours, pouring out after cooling, and distilling the solution under reduced pressure to obtain the crystal product, the steric amine.

[0008] Preferably, the molar ratio of the diisopropanolamine and the ethylene glycol diglycidyl ether is 2-3:1 to 2.

[0009] Further preferably, the first solvent is at least one of water, methanol and ethanol.

[0010] A desulfurizer is characterized by comprising the aforementioned compound and N-methyldiethanolamine.

[0011] Preferably, the mass ratio of the steric amine and the N-methyldiethanolamine is 1-2:2-3.

[0012] Preferably, the composition further comprises a second solvent.

[0013] Further preferably, the second solvent is water; the total mass of the compound and the N-methyldiethanolamine accounts for 40% to 50% of the total mass of the composition.

[0014] The aforementioned compound or desulfurizer is applied to desulfurization, in particular, natural gas desulfurization.

[0015] The present application has the following beneficial technical effects:

[0016] The present application provides a new compound, which is a novel steric amine prepared by the nucleophilic addition reaction of diisopropanolamine and ethylene glycol diglycidyl ether.

[0017] The compound is used as an auxiliary agent to be compounded with N-methyldiethanolamine to obtain a composition which can be used as a natural gas desulfurizer, wherein the N-methyldiethanolamine is a main agent and the synthesized steric amine is an auxiliary agent, and the addition of the auxiliary agent can improve the selectivity of hydrogen sulfide, the absorption rate of hydrogen sulfide is fast, the absorption capacity is high, the selectivity is good, the preparation is simple and convenient, and the composition can be reused. As a natural gas desulfurizer, the desulfurization efficiency can reach more than 99.5%, and the selectivity of hydrogen sulfide is good. Therefore, the natural gas desulfurizer prepared by the present application has good desulfurization performance and good application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The chemical reaction equation for synthesizing the steric amine disclosed in the present application. DETAILED DESCRIPTION

[0019] The present application will be further described in detail below in combination with the drawings and specific embodiments.

[0020] Example 1

[0021] First, the diisopropanolamine and ethylene glycol diglycidyl ether with a molar ratio of 2:1 were mixed and added into a high-temperature and high-pressure reactor, methanol was added as a solvent, and the mixture was reacted at 120°C for 8h. After cooling, the solution was poured out, distilled under reduced pressure, and the crystal product, the steric amine, was obtained.

[0022] The structure of the steric amine is as follows:

[0023]

[0024] The steric amine and N-methyldiethanolamine prepared were mixed at a mass ratio of 1:3 to obtain a natural gas desulfurizer A in a 40wt% aqueous solution.

[0025] The synthesis equation is as follows: Figure 1 .

[0026] Example 2

[0027] The natural gas desulfurizer of the present example was obtained by compounding the steric amine with the same structure as that of Example 1 and N-methyldiethanolamine at a mass ratio of 1:2.

[0028] The specific preparation method is as follows:

[0029] First, the diisopropanolamine and ethylene glycol diglycidyl ether with a molar ratio of 3:1 were mixed and added into a high-temperature and high-pressure reactor, a certain amount of methanol was added as a solvent, and the mixture was reacted at 120°C for 8h. After cooling, the solution was poured out, distilled under reduced pressure, and the crystal product, the steric amine, was obtained in a solid state. Then, the steric amine and N-methyldiethanolamine prepared were mixed at a mass ratio of 1:2 to obtain a natural gas desulfurizer B in a 45wt% aqueous solution.

[0030] Example 3

[0031] The natural gas desulfurizer of the present example was obtained by compounding the steric amine with the same structure as that of Example 1 and N-methyldiethanolamine at a mass ratio of 1:2.

[0032] The specific preparation method is as follows:

[0033] First, the diisopropanolamine and ethylene glycol diglycidyl ether with a molar ratio of 3:2 were mixed and added into a high-temperature and high-pressure reactor, a certain amount of methanol was added as a solvent, and the mixture was reacted at 120°C for 8h. After cooling, the solution was poured out, distilled under reduced pressure, and the crystal product, the steric amine, was obtained in a solid state. Then, the steric amine and N-methyldiethanolamine prepared were mixed at a mass ratio of 1:2 to obtain a natural gas desulfurizer C in a 50wt% aqueous solution.

[0034] Example 4

[0035] A natural gas desulfurizer of this example is obtained by compounding a steric hindrance amine with the same structural formula as that of Example 1 and N-methyl diethanolamine, and the molar ratio of the two is 1:3.

[0036] The specific preparation method is as follows:

[0037] First, the diisopropanolamine and ethylene glycol diglycidyl ether with a molar ratio of 3:2 are mixed uniformly and added into a high-temperature and high-pressure reaction kettle, a certain amount of methanol is added as a solvent, and the reaction is carried out at 120°C for 8h. After cooling, pour out, and after cooling, pour out, the solution is distilled under reduced pressure to obtain a crystal product, i.e. a solid state steric hindrance amine; then the prepared steric hindrance amine and N-methyl diethanolamine are mixed uniformly at a mass ratio of 1:3, and a 50wt% aqueous solution is obtained to obtain a natural gas desulfurizer D.

[0038] Example 5

[0039] A natural gas desulfurizer of this example is obtained by compounding a steric hindrance amine with the same structural formula as that of Example 1 and N-methyl diethanolamine, and the mass ratio of the two is 1:3.

[0040] The specific preparation method is as follows:

[0041] First, the diisopropanolamine and ethylene glycol diglycidyl ether with a molar ratio of 3:2 are mixed uniformly and added into a high-temperature and high-pressure reaction kettle, a certain amount of methanol is added as a solvent, and the reaction is carried out at 80°C for 4h. After cooling, pour out, and after cooling, pour out, the solution is distilled under reduced pressure to obtain a crystal product, i.e. a solid state steric hindrance amine; then the prepared steric hindrance amine and N-methyl diethanolamine are mixed uniformly at a mass ratio of 1:3, and a 50wt% aqueous solution is obtained to obtain a natural gas desulfurizer E.

[0042] Example 6

[0043] A natural gas desulfurizer of this example is obtained by compounding a steric hindrance amine with the same structural formula as that of Example 1 and N-methyl diethanolamine, and the mass ratio of the two is 2:3.

[0044] The specific preparation method is as follows:

[0045] First, the diisopropanolamine and ethylene glycol diglycidyl ether with a molar ratio of 3:2 are mixed uniformly and added into a high-temperature and high-pressure reaction kettle, a certain amount of methanol is added as a solvent, and the reaction is carried out at 120°C for 8h. After cooling, pour out, and after cooling, pour out, the solution is distilled under reduced pressure to obtain a crystal product, i.e. a solid state steric hindrance amine; then the prepared steric hindrance amine and N-methyl diethanolamine are mixed uniformly at a mass ratio of 1:3, and a 50wt% aqueous solution is obtained to obtain a natural gas desulfurizer D.

[0046] Comparative Example 1

[0047] 40% N-methyldiethanolamine aqueous solution to obtain Comparative Sample 1.

[0048] The desulfurization rates and selectivities of the products A to G obtained in Examples 1 to 7 and Comparative Sample 1 obtained in Comparative Example 1 were measured; the raw gas (CO2: H2S = 10) was used, and the test results are as follows.

[0049] Experimental evaluation

[0050] Evaluation of desulfurization performance and selectivity of compounds and compositions: first, a simulated gas was prepared using nitrogen, hydrogen sulfide and carbon dioxide, the molar concentration of hydrogen sulfide in the simulated gas was 0.1%, and the molar concentration of CO2 was 1% (CO2: H2S = 10); after the desulfurization solvent absorbed the acid gas under certain conditions, the contents of H2S and CO2 in the tail gas were analyzed, and the desulfurization rate and selectivity were calculated.

[0051] Table 1 Desulfurization efficiency comparison

[0052] Serial number Desulfurization rate (%) Selectivity S (%) Desulfurizer A 99.87 8.83 Desulfurizer B 99.85 8.75 Desulfurizer C 99.90 8.53 Desulfurizer D 99.84 7.21 Desulfurizer E 99.87 7.35 Desulfurizer F 99.89 8.85 Comparative Sample 1 99.77 3.78

[0053] Note: the calculation formula of selectivity S is:

[0054]

[0055] As can be seen from Table 1, the desulfurization rates of products A to G and the comparative sample all reach more than 99.8%, all showing good desulfurization rates. Compared with MDEA, the selectivity is poor, only 3.78, and with the addition of steric amine and the increase of the amount, the selectivity increases obviously, and hydrogen sulfide can be selectively removed.

[0056] The representative examples and test examples of the present application are described in detail above, but the present application is not limited to the specific details in the above-described embodiments, and within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, and changes and combinations obvious to those skilled in the art all belong to the protection scope of the present application.

Claims

1. Application of a desulfurizer in natural gas desulfurization, characterized in that The desulfurizing agent includes N-methyldiethanolamine and a compound, the structural formula of the compound is shown in Formula I: Formula I; The preparation method of the compound comprises the following steps: uniformly mixing diisopropanolamine, ethylene glycol diglycidyl ether, and a first solvent, adding the mixture into a high-temperature and high-pressure reactor, reacting at 80-120° C. for 4-8 hours, cooling and then pouring out the mixture, and distilling the solution under reduced pressure to obtain a crystalline product, the hindered amine, namely the compound; The mass ratio of the compound to N-methyldiethanolamine is 1-2:2-3; The desulfurizer further includes a second solvent; the second solvent is water; taking the total mass of the desulfurizer as 100%, the total mass of the compound and the N-methyldiethanolamine accounts for 40% to 50% of the desulfurizer.

2. The use according to claim 1, characterized in that The molar ratio of the diisopropanolamine to ethylene glycol diglycidyl ether is 2-3:1-2.

3. The use according to claim 1 or 2, characterized in that The first solvent is at least one of water, methanol and ethanol.

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