A natural gas steric amine desulfurizer, a preparation method and application thereof

Abstract

The application provides a natural gas steric amine desulfurizer, a preparation method and application thereof. A chemical structural formula of the natural gas steric amine desulfurizer is shown in formula I).

Description

Technical Field

[0001] This invention provides a sterically hindered amine desulfurizer for natural gas. Background Technology

[0002] Natural gas, widely used as fuel and chemical feedstock in industry, urban life, automobiles, and chemicals, is an important strategic energy resource. However, in addition to containing large amounts of low-molecular-weight saturated hydrocarbons, natural gas extracted from wells also contains varying levels of impurities such as H2S, CO2, and COS. H2S is a harmful substance with a strong, pungent odor. When released into the atmosphere, H2S not only causes severe pollution, acid rain, and damages factory equipment and crops, but also poses a significant threat to human health. Furthermore, if H2S is not completely removed from natural gas, it can cause corrosion of equipment and pipelines during extraction, processing, and storage, leading to safety hazards. Therefore, extracted natural gas must undergo desulfurization before processing in transportation equipment.

[0003] Existing desulfurization technologies mainly include dry desulfurization, wet desulfurization, membrane separation, biological desulfurization, and amine-based desulfurization. Among them, amine-based desulfurization technology has evolved to its third generation after about a century of development. This generation utilizes sterically hindered amines, which are designed and synthesized based on MDEA and exhibit high selectivity. Stericly hindered amines offer advantages in removing acidic gases, such as faster absorption rates, higher absorption capacity, superior selectivity for H2S absorption, and lower energy consumption. However, with increasingly stringent environmental requirements, the total sulfur content of natural gas is subject to stricter controls, and higher demands are placed on the removal of impurities such as carbon dioxide. Therefore, the search for and development of novel amines with high activity and selectivity has become a research hotspot in amine-based desulfurization technology. Summary of the Invention

[0004] One aspect of the present invention provides a sterically hindered amine desulfurizer for natural gas, the chemical structural formula of which is shown in Formula I):

[0005]

[0006] The second aspect of the present invention provides a method for preparing the natural gas steric hindrance amine desulfurizer as described in claim 1, comprising the following steps:

[0007] 1) Dissolve tert-butylamine and ethylene glycol diglycidyl ether in a solvent and react them at a first temperature to obtain a reaction solution;

[0008] 2) Add alkali to the reaction solution, reflux the reaction at a second temperature, filter the solution to obtain a filtrate, and distill the filtrate to obtain the natural gas steric amine desulfurizer.

[0009] In one specific embodiment, the molar ratio of the tert-butylamine to the ethylene glycol diglycidyl ether is 1:(2-4).

[0010] In one specific embodiment, the first temperature is 120 to 180°C, and the reaction is carried out at the first temperature for 2 to 5 hours;

[0011] The second temperature is 60 to 75°C, and the reaction is refluxed at the second temperature for 0.5 to 2 hours.

[0012] In one specific embodiment, the alkali is sodium hydroxide and / or potassium hydroxide.

[0013] In one specific embodiment, in step 2), the pH value of the reaction solution after adding the alkali is 11 to 12.

[0014] In one specific embodiment, the solvent is at least one selected from ethanol, acetone, glycerol, and benzene.

[0015] In one specific embodiment, the distillation is vacuum distillation.

[0016] The third invention provides the application of the natural gas hindered amine desulfurizer according to the first invention or the natural gas hindered amine desulfurizer prepared by the method according to any one of the second invention in desulfurization.

[0017] The beneficial effects of this invention are:

[0018] The natural gas hindered amine desulfurizer provided by this invention is a novel desulfurizer with fast absorption rate, high absorption capacity, and good selectivity for hydrogen sulfide. It is also simple and convenient to prepare, and easy to use in production. The natural gas hindered amine desulfurizer prepared by this invention can achieve a desulfurization efficiency of over 96%, and its absorption rate can reach 6.86 × 10⁻⁶. -6 kmol / sm 3 Therefore, it can be seen that the natural gas steric amine desulfurizer prepared by this invention has good desulfurization performance and good application prospects. Detailed Implementation

[0019] The present invention will be further described below with reference to the embodiments. However, the embodiments of the present invention are merely illustrative examples and should not be construed as limiting the present invention under any circumstances.

[0020] Unless otherwise specified, all reagents used in the following examples are commercially available.

[0021] Example 1

[0022] 1) Dissolve tert-butylamine and ethylene glycol diglycidyl ether in ethanol at a molar ratio of 1:2, heat to 120°C and allow them to react spontaneously for 5 hours. After the reaction is complete, cool to obtain the reaction solution.

[0023] 2) Add 10wt% sodium hydroxide aqueous solution to the reaction solution until the pH value is 11, and reflux the reaction at 60℃ for 2 hours. Filter the solution to obtain the filtrate, and perform vacuum distillation to obtain the natural gas sterically hindered amine desulfurizer, the chemical structural formula of which is shown below:

[0024]

[0025] Example 2

[0026] 1) Dissolve tert-butylamine and ethylene glycol diglycidyl ether in ethanol at a molar ratio of 1:4, heat to 180℃ and allow them to react spontaneously for 2 hours. After the reaction is complete, cool to obtain the reaction solution.

[0027] 2) Add 10wt% sodium hydroxide aqueous solution to the reaction solution until the pH value is 12, and reflux the reaction at 75℃ for 0.5h. Filter the solution to obtain the filtrate, and perform vacuum distillation to obtain the natural gas hindered amine desulfurizer, the chemical structure of which is shown below:

[0028] Example 3

[0029] 1) Dissolve tert-butylamine and ethylene glycol diglycidyl ether in ethanol at a molar ratio of 1:3, heat to 150°C and allow them to react spontaneously for 3 hours. After the reaction is complete, cool to obtain the reaction solution.

[0030] 2) Add 10wt% sodium hydroxide aqueous solution to the reaction solution until the pH value is 11, and reflux the reaction at 70℃ for 1 hour. Filter the solution to obtain the filtrate, and perform vacuum distillation to obtain the natural gas sterically hindered amine desulfurizer, the chemical structural formula of which is shown below:

[0031] Example 4

[0032] 1) Dissolve tert-butylamine and ethylene glycol diglycidyl ether in ethanol at a molar ratio of 1:3, heat to 100℃ and allow them to react spontaneously for 3 hours. After the reaction is complete, cool to obtain the reaction solution.

[0033] 2) Add 10wt% sodium hydroxide aqueous solution to the reaction solution until the pH value is 11, and reflux the reaction at 60℃ for 2 hours. Filter the solution to obtain the filtrate, and perform vacuum distillation to obtain the natural gas sterically hindered amine desulfurizer, the chemical structural formula of which is shown below:

[0034] Performance testing

[0035] The natural gas steric amine desulfurizers prepared in Examples 1 to 4 were formulated into a 30 wt% aqueous solution and desulfurization tests were performed using the iodometric method. The results are shown in Table 1.

[0036] Table 1

[0037]

[0038] While the present invention has been described with reference to specific embodiments, those skilled in the art will understand that various changes can be made without departing from the true spirit and scope of the invention. Furthermore, numerous modifications can be made to the subject, spirit, and scope of the invention to suit specific situations, materials, material compositions, and methods. All such modifications are included within the scope of the claims of the present invention.

Claims

1. A natural gas hindered amine desulfurizer, whose chemical structure is shown as formula I): ###0001### Formula I); A method for preparing the natural gas hindered amine desulfurizer comprises the following steps: 1) dissolving t-butylamine and ethylene glycol diglycidyl ether in a solvent, and reacting at a first temperature to obtain a reaction solution; 2) adding a base to the reaction solution, refluxing at a second temperature, and after suction filtration, obtaining a filtrate, distilling the filtrate to obtain the natural gas hindered amine desulfurizer.

2. The natural gas hindered amine desulfurizer of claim 1, wherein, The molar ratio of the t-butylamine to the ethylene glycol diglycidyl ether is 1: (2-4).

3. The natural gas steric amine desulfurizer of claim 1, wherein, The first temperature is 120-180°C, and the reaction is carried out at the first temperature for 2-5 hours. The second temperature is 60-75°C, and the refluxing is carried out at the second temperature for 0.5-2 hours.

4. The natural gas hindered amine desulfurizer of claim 1, wherein, The base is sodium hydroxide and / or potassium hydroxide.

5. The natural gas hindered amine desulfurizer of claim 1, wherein, In step 2), the pH value after adding the base to the reaction solution is 11-12.

6. The natural gas hindered amine desulfurizer of claim 1, wherein, The solvent is at least one of ethanol, acetone, glycerol and benzene.

7. The natural gas hindered amine desulfurizer of claim 1, wherein, The distillation is reduced pressure distillation.

8. Use of the natural gas hindered amine desulfurizer according to any one of claims 1-7 in desulfurization.

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