Polymorphic sulfide deep removal solvent and application thereof in removal of acid gas in gas

Abstract

The invention provides a polymorphic sulfide deep removal solvent and application of the polymorphic sulfide deep removal solvent in removal of acid gas in gas, and the removal solvent comprises the following components in percentage by mass: 15%-40% of an alcohol amine solvent, 10%-30% of a special-effect solvent, 0.5%-3% of an auxiliary agent and the balance of water, wherein the alcohol amine solvent comprises a combination of N-methyldiethanolamine, tert-butylamine ethoxyethanol and tert-butyl diethanolamine, and the mass ratio of the N-methyldiethanolamine to the tert-butylamine ethoxyethanol to the tert-butyl diethanolamine is (5-8): 1: (1-4); the special effect solvent is N-methyl pyrrolidone and / or polyethylene glycol monomethyl ether. The removal solvent is suitable for deep purification of sulfur-containing natural gas and other sulfur-containing gases, has the advantages of good desulfurization performance, high recycling frequency and the like, and is an important candidate solvent system in the field of gas purification.

Description

Technical Field

[0001] The present invention belongs to the technical field of sulfide removal, and particularly relates to a solvent for deep removal of multi-form sulfides and its application in removing acid gas from gas. Background Art

[0002] Primary energy plays a crucial role in human society. Among them, natural gas is an indispensable energy source and industrial raw material, which is widely used in all aspects of human life and production. In raw natural gas, there are often sulfides in different forms and contents. Sulfides are mainly divided into two categories in terms of physical properties, including inorganic sulfur and organic sulfur. Inorganic sulfur is highly toxic hydrogen sulfide, and organic sulfur includes compounds in various forms such as carbonyl sulfide, mercaptan, thioether, and thiophene.

[0003] Sulfides not only endanger human health, but also cause immeasurable harm and damage to the environment, and will corrode and damage industrial devices and equipment. Therefore, in order to efficiently and cleanly utilize natural gas, it is necessary to deeply remove multi-form sulfides in raw natural gas. With the exploitation of new natural gas blocks, a series of gas fields with complex organic sulfur components have been discovered. Due to the different acidities and large differences in reaction activities of various organic sulfur gases, it is difficult for conventional alkanolamine solvents to achieve deep removal of all components of organic sulfur, resulting in the risk of total sulfur exceeding the standard in the purified gas.

[0004] Therefore, developing a solvent that can adapt to the removal of multi-form organic sulfur is an important way to achieve clean production of natural gas. At present, natural gas purification mainly includes two categories: selective desulfurization technology and organic sulfur removal technology applicable to the removal of carbonyl sulfide and methanethiol. Among them, selective desulfurization technology is mainly aimed at the selective removal of hydrogen sulfide, and tries to retain carbon dioxide in the product gas as much as possible. The desulfurization technology applicable to the removal of carbonyl sulfide and methanethiol is mainly applied to the gas conditions with higher contents of these two organic sulfurs. For acid gases with weaker acidity such as thioether and thiophene, the existing desulfurization technologies are difficult to meet the requirements, and a solvent system that can react well with weak acidic substances needs to be developed. Summary of the Invention

[0005] In order to solve the problems existing in the prior art, the purpose of the present invention is to provide a solvent for deep removal of multi-form sulfides. By compounding different components in a certain proportion and utilizing the synergistic effect among various components, the optimal performance of the compound solvent of the present invention can be exerted. The purpose of the present invention is also to provide a solvent for deep removal of multi-form sulfides and its application in removing acid gas from gas.

[0006] To achieve the above object, the present invention provides a multi-form sulfide deep removal solvent. By mass percentage, the removal solvent comprises the following components: 15%-40% of an alkanolamine solvent, 10%-30% of a special solvent, 0.5%-3% of an auxiliary agent, and the balance is water;

[0007] Among them, the alkanolamine solvent comprises a combination of N-methyldiethanolamine, tert-butylaminoethoxyethanol and tert-butyldiethanolamine, and the mass ratio of N-methyldiethanolamine, tert-butylaminoethoxyethanol and tert-butyldiethanolamine is 5-8:1:1-4;

[0008] The special solvent is N-methylpyrrolidone and / or polyethylene glycol monomethyl ether.

[0009] According to a specific embodiment of the present invention, preferably, the removal solvent comprises the following components: 30%-40% of an alkanolamine solvent, 15%-30% of a special solvent, 1.5%-3% of an auxiliary agent, and the balance is water.

[0010] According to a specific embodiment of the present invention, preferably, the mass ratio of N-methyldiethanolamine, tert-butylaminoethoxyethanol and tert-butyldiethanolamine is 5-7.5:1:1-1.25, and more preferably, the mass ratio is 6:1:1.

[0011] According to a specific embodiment of the present invention, preferably, the auxiliary agent comprises an antifoaming agent and an antioxidant.

[0012] According to a specific embodiment of the present invention, preferably, the antifoaming agent is one or a combination of two or more of polyether-modified silicone, polyvinyl alcohol and fatty alcohol polyoxyethylene ether.

[0013] According to a specific embodiment of the present invention, preferably, the antioxidant is tert-butylphenol and / or propionate.

[0014] According to a specific embodiment of the present invention, preferably, the mass ratio of the antifoaming agent to the antioxidant is 2-8:5, more preferably 2-5:5, and further preferably 2-2.5:5.

[0015] The present invention also provides a preparation method of a multi-form sulfide deep removal solvent, which comprises the following steps: weighing each component in the above weight percentages, adding the alkanolamine solvent and the special solvent to water and mixing evenly, and then adding the antifoaming agent and the antioxidant and mixing evenly to obtain the multi-form sulfide deep removal solvent.

[0016] In the above preparation method, preferably, the method comprises the following steps:

[0017] (1) Weigh water, the alkanolamine solvent and the special solvent into a stirring kettle and mix evenly at room temperature;

[0018] (2) Add the defoamer and antioxidant to the stirring kettle described in step (1), and stir and mix evenly to obtain a solvent for deep removal of multi-morphological sulfides.

[0019] The present invention also provides the application of the above-mentioned solvent for deep removal of multi-morphological sulfides in removing acid gas from gas.

[0020] According to the specific implementation scheme of the present invention, preferably, the total sulfur content of the product gas obtained after removing acid gas using the above-mentioned solvent for deep removal of multi-morphological sulfides is < 20 mg / m 3 .

[0021] The present invention forms a solvent for removing various organic sulfides through high-throughput research, which is applicable to the deep purification of sour natural gas and other sulfur-containing gases. This removal solvent has advantages such as good desulfurization performance and a large number of recycling times, and is an important candidate solvent system in the field of gas purification.

[0022] The technical solution provided by the present invention has the following beneficial effects:

[0023] (1) The solvent for deep removal of multi-morphological sulfides of the present invention is mainly applied to natural gas purification, especially raw natural gas containing complex organic sulfur components, and the removal efficiency of various organic sulfides is much higher than that of traditional desulfurization solvents.

[0024] (2) By adding alkanolamines with steric hindrance effects such as tert-butyl diethanolamine to the solvent for deep removal of multi-morphological sulfides of the present invention, while increasing the removal rate of organic sulfur, the selectivity of carbon dioxide is increased. It can not only make the total organic sulfur removal rate reach more than 96%, but also ensure that the total sulfur content of the purified gas is less than 20 mg / m 3 , realizing that complex sulfur-containing gases can fully meet the total sulfur content requirements specified in the national natural gas standard after purification without using a carbonyl sulfide hydrolysis device.

[0025] (3) The polyethylene glycol monomethyl ether used in the solvent for deep removal of multi-morphological sulfides of the present invention can form intermolecular hydrogen bonds with mercaptan sulfides, enhancing its physical solubility in the solvent. The asymmetric C-O-C structure in the polyethylene glycol monomethyl ether structure also increases its removal ability for other organic sulfides with asymmetric structures. Compared with traditional solvents, the solvent for deep removal of multi-morphological sulfides of the present invention can still greatly reduce hydrocarbon loss in natural gas purification without using the traditional physical solvent sulfolane. Detailed implementation mode

[0026] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will be described in detail below, but it should not be construed as a limitation on the implementable scope of the present invention.

[0027] All the raw materials used in the present invention are commercially available products. Unless otherwise specified, the % used in the present invention represents its mass percentage content, i.e., wt%.

[0028] Example 1

[0029] This example provides a solvent for deep removal of multi-form sulfides, comprising the following components (by mass percentage): N-methyldiethanolamine 24%, tert-butylaminoethoxyethanol 3%, tert-butyldiethanolamine 3%, polyethylene glycol monomethyl ether 25%, polyether-modified silicone 1.5%, tert-butylphenol 1.5%, deionized water 42%.

[0030] The preparation method of this solvent comprises the following steps:

[0031] (1) Weigh the alkanolamine solvent and the special solvent according to the mass percentages of each component, and mix them evenly in a stirring kettle at room temperature;

[0032] (2) Weigh the defoamer and antioxidant and add them to the stirring kettle described in step (1), and stir and mix evenly to obtain the solvent for deep removal of multi-form sulfides.

[0033] Use the above solvent for natural gas purification containing multi-form organic sulfur, and the test process is as follows:

[0034] Fill the solvent for deep removal of multi-form sulfides in an absorption reactor (2L), and introduce the raw material gas from the bottom of the absorption reactor to make the raw material gas contact with the removal solvent for acid gas absorption reaction;

[0035] Discharge the purified gas from the top of the absorption reactor, and detect the remaining components in the purified gas after cooling; stop introducing the raw material gas when the concentration of acid gas in the purified gas reaches the set value; the components of the obtained purified gas comply with the regulations in GB17820-2018.

[0036] Among them, the packing height of the packing tower through which the selective desulfurizer flows is 1 m, the temperature of the removal solvent is 39 - 40 °C, and the flow rate of the raw material gas is 300 L / h. During the reaction process, the reacted removal solvent enters the regeneration tower for heating regeneration, and the regenerated removal solvent returns to the absorption reactor to participate in the reaction; the circulation amount of the selective desulfurizer is controlled by the flow rate of the circulation pump between the absorption reactor and the regeneration tower, and the circulation amount is 3.0 L / h.

[0037] The composition of the raw natural gas includes (by molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm.

[0038] In the purified gas: hydrogen sulfide 3 ppm, carbon dioxide 1.8%, carbonyl sulfide 5.5 ppm, methanethiol 2 ppm, ethanethiol 1.7 ppm, 1-propanethiol 2.1 ppm, dimethyl sulfide 1.1 ppm, carbon disulfide 0 ppm, thiophene 0 ppm, total organic sulfur 12.4 mg / m 3 , and the total removal rate of organic sulfur is 97.52%.

[0039] Example 2

[0040] This example provides a solvent for deep removal of multi-form sulfides, including the following components (by mass percentage): N-methyldiethanolamine 20%, tert-butylaminoethoxyethanol 4%, tert-butyldiethanolamine 6%, polyethylene glycol monomethyl ether 28%, polyether-modified silicone 1%, tert-butylphenol 1.4%, deionized water 39.6%.

[0041] The preparation method of the solvent is the same as that in Example 1.

[0042] The above solvent is used for natural gas purification containing multi-form organic sulfur, and the test process is the same as that in Example 1.

[0043] The composition of the raw natural gas includes (by molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm. In the purified gas: hydrogen sulfide 4 ppm, carbon dioxide 1.87%, carbonyl sulfide 3.3 ppm, methanethiol 2.6 ppm, ethanethiol 1.8 ppm, 1-propanethiol 2.4 ppm, dimethyl sulfide 1.3 ppm, carbon disulfide 0 ppm, thiophene 1.6 ppm, total organic sulfur 13 mg / m 3 , and the total removal rate of organic sulfur is 97.4%.

[0044] Example 3

[0045] This example provides a solvent for deep removal of multi-form sulfides, including the following components (by mass percentage): N-methyldiethanolamine 28%, tert-butylaminoethoxyethanol 4%, tert-butyldiethanolamine 4%, polyethylene glycol monomethyl ether 15%, polyether-modified silicone 0.8%, tert-butylphenol 2%, deionized water 46.2%.

[0046] The preparation method of the solvent is the same as that in Example 1.

[0047] The above solvent is used for natural gas purification containing multi-form organic sulfur, and the test process is the same as that in Example 1.

[0048] The composition of the raw natural gas includes (in molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm. In the purified gas: hydrogen sulfide 3 ppm, carbon dioxide 1.65%, carbonyl sulfide 4.1 ppm, methanethiol 3.3 ppm, ethanethiol 1.5 ppm, 1-propanethiol 0 ppm, dimethyl sulfide 0 ppm, carbon disulfide 2.7 ppm, thiophene 1.6 ppm, and the total organic sulfur is 13.2 mg / m 3 , and the total removal rate of organic sulfur is 97.36%.

[0049] Example 4

[0050] This example provides a solvent for deep removal of multi-form sulfides, which includes the following components (in mass percentage): N-methyldiethanolamine 30%, tert-butylaminoethoxyethanol 5%, tert-butyldiethanolamine 5%, polyethylene glycol monomethyl ether 20%, polyether-modified silicone 1%, tert-butylphenol 2%, and deionized water 37.3%.

[0051] The preparation method of the solvent is the same as that in Example 1.

[0052] The above solvent is used for the purification of natural gas containing multi-form organic sulfur, and the test process is the same as that in Example 1.

[0053] The composition of the raw natural gas includes (in molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm. In the purified gas: hydrogen sulfide 1 ppm, carbon dioxide 1.32%, carbonyl sulfide 3.5 ppm, methanethiol 1.6 ppm, ethanethiol 1.1 ppm, 1-propanethiol 0 ppm, dimethyl sulfide 0 ppm, carbon disulfide 0 ppm, thiophene 0 ppm, and the total organic sulfur is 6.2 mg / m 3 , and the total removal rate of organic sulfur is 98.76%.

[0054] Example 5

[0055] This example provides a solvent for deep removal of multi-form sulfides, which includes the following components (in mass percentage): N-methyldiethanolamine 30%, tert-butylaminoethoxyethanol 5%, tert-butyldiethanolamine 5%, N-methylpyrrolidone 18%, polyether-modified silicone 1%, tert-butylphenol 2%, and deionized water 39%.

[0056] The preparation method of the solvent is the same as that in Example 1.

[0057] The above solvent is used for the purification of natural gas containing multi-morphological organic sulfur, and the test process is the same as that in Example 1.

[0058] The composition of the raw natural gas includes (in molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm. In the purified gas: hydrogen sulfide 2 ppm, carbon dioxide 1.38%, carbonyl sulfide 4.4 ppm, methanethiol 3.8 ppm, ethanethiol 2.7 ppm, 1-propanethiol 1.2 ppm, dimethyl sulfide 0 ppm, carbon disulfide 2.1 ppm, thiophene 2.9 ppm, and the total sulfur of organic sulfur is 17.1 mg / m 3 , and the total removal rate of organic sulfur is 96.58%.

[0059] Example 6

[0060] This example provides a solvent for deep removal of multi-morphological sulfides, which includes the following components (in mass percentage): N-methyldiethanolamine 25%, tert-butylaminoethoxyethanol 5%, tert-butyldiethanolamine 10%, N-methylpyrrolidone 15%, polyether-modified silicone 0.8%, tert-butylphenol 0.8%, and deionized water 43.4%.

[0061] The preparation method of the solvent is the same as that in Example 1.

[0062] The above solvent is used for the purification of natural gas containing multi-morphological organic sulfur, and the test process is the same as that in Example 1.

[0063] The composition of the raw natural gas includes (in molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm. In the purified gas: hydrogen sulfide 3 ppm, carbon dioxide 1.27%, carbonyl sulfide 5.1 ppm, methanethiol 3.1 ppm, ethanethiol 1.5 ppm, 1-propanethiol 0 ppm, dimethyl sulfide 0 ppm, carbon disulfide 2.4 ppm, thiophene 1.8 ppm, and the total sulfur of organic sulfur is 13.9 mg / m 3 , and the total removal rate of organic sulfur is 97.22%.

[0064] Example 7

[0065] This example provides a solvent for deep removal of multi-morphological sulfides, which includes the following components (in mass percentage): N-methyldiethanolamine 26%, tert-butylaminoethoxyethanol 4%, tert-butyldiethanolamine 8%, N-methylpyrrolidone 18%, polyether-modified silicone 0.6%, tert-butylphenol 1.5%, and deionized water 41.9%.

[0066] The preparation method of the solvent is the same as that in Example 1.

[0067] The above solvent is used for the purification of natural gas containing multi-morphological organic sulfur, and the testing process is the same as that in Example 1.

[0068] The composition of the raw natural gas includes (in terms of molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, and thiophene 20 ppm. In the purified gas: hydrogen sulfide 3 ppm, carbon dioxide 1.05%, carbonyl sulfide 3.9 ppm, methanethiol 2.3 ppm, ethanethiol 1.2 ppm, 1-propanethiol 0 ppm, dimethyl sulfide 0 ppm, carbon disulfide 1.7 ppm, thiophene 0 ppm, and the total sulfur of organic sulfur is 9.1 mg / m 3 , and the total removal rate of organic sulfur is 98.18%.

[0069] Example 8

[0070] This example provides a solvent for deep removal of multi-morphological sulfides, which includes the following components (in terms of mass percentage): N-methyldiethanolamine 30%, tert-butylaminoethoxyethanol 4%, tert-butyldiethanolamine 6%, N-methylpyrrolidone 20%, polyether-modified silicone 0.8%, tert-butylphenol 2%, and deionized water 37.2%.

[0071] The preparation method of the solvent is the same as that in Example 1.

[0072] The above solvent is used for the purification of natural gas containing multi-morphological organic sulfur, and the testing process is the same as that in Example 1.

[0073] The composition of the raw natural gas includes (in terms of molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, and thiophene 20 ppm. In the purified gas: hydrogen sulfide 3 ppm, carbon dioxide 1.21%, carbonyl sulfide 3 ppm, methanethiol 1.8 ppm, ethanethiol 1.1 ppm, 1-propanethiol 0 ppm, dimethyl sulfide 0 ppm, carbon disulfide 1.5 ppm, thiophene 0 ppm, and the total sulfur of organic sulfur is 7.4 mg / m 3 , and the total removal rate of organic sulfur is 98.52%.

[0074] Example 9

[0075] This example provides a solvent for deep removal of multi-form sulfides, which comprises the following components (by mass percentage): 25% of N-methyldiethanolamine, 5% of tert-butylaminoethoxyethanol, 10% of tert-butyldiethanolamine, 18% of N-methylpyrrolidone, 1% of polyether-modified silicone, 2% of propionate, and 39% of deionized water.

[0076] The preparation method of the solvent is the same as that in Example 1.

[0077] The above solvent is used for natural gas purification containing multi-form organic sulfur, and the test process is the same as that in Example 1.

[0078] The composition of the raw natural gas includes (by molar ratio): 85% of methane, 2.5% of hydrogen sulfide, 5% of carbon dioxide, 200 ppm of carbonyl sulfide, 150 ppm of methanethiol, 50 ppm of ethanethiol, 20 ppm of 1-propanethiol, 20 ppm of dimethyl sulfide, 40 ppm of carbon disulfide, and 20 ppm of thiophene. In the purified gas: 2 ppm of hydrogen sulfide, 0.97% of carbon dioxide, 3.1 ppm of carbonyl sulfide, 1.1 ppm of methanethiol, 1.7 ppm of ethanethiol, 0 ppm of 1-propanethiol, 0 ppm of dimethyl sulfide, 0 ppm of carbon disulfide, 1.6 ppm of thiophene, and the total sulfur of organic sulfur is 7.5 mg / m 3 , and the total removal rate of organic sulfur is 98.5%.

[0079] Example 10

[0080] This example provides a solvent for deep removal of multi-form sulfides, which comprises the following components (by mass percentage): 30% of N-methyldiethanolamine, 5% of tert-butylaminoethoxyethanol, 5% of tert-butyldiethanolamine, 26% of polyethylene glycol monomethyl ether, 1% of polyether-modified silicone, 2% of propionate, and 31% of deionized water.

[0081] The preparation method of the solvent is the same as that in Example 1.

[0082] The above solvent is used for natural gas purification containing multi-form organic sulfur, and the test process is the same as that in Example 1.

[0083] The composition of the raw natural gas includes (by molar ratio): 85% of methane, 2.5% of hydrogen sulfide, 5% of carbon dioxide, 200 ppm of carbonyl sulfide, 150 ppm of methanethiol, 50 ppm of ethanethiol, 20 ppm of 1-propanethiol, 20 ppm of dimethyl sulfide, 40 ppm of carbon disulfide, and 20 ppm of thiophene. In the purified gas: 2 ppm of hydrogen sulfide, 0.97% of carbon dioxide, 1.7 ppm of carbonyl sulfide, 1.2 ppm of methanethiol, 0 ppm of ethanethiol, 0 ppm of 1-propanethiol, 0 ppm of dimethyl sulfide, 0 ppm of carbon disulfide, 1.3 ppm of thiophene, and the total sulfur of organic sulfur is 4.2 mg / m 3 , and the total removal rate of organic sulfur is 99.16%.

[0084] Comparative Example 1

[0085] This comparative example provides a deep removal solvent for multi-morphological sulfides, comprising the following components (by mass percentage): N-methyldiethanolamine 25%, tert-butylaminoethoxyethanol 5%, tert-butyldiethanolamine 10%, polyether-modified silicone 1%, propionate 2%, deionized water 57%.

[0086] The preparation method of the solvent is the same as that in Example 1.

[0087] The above solvent is used for the purification of natural gas containing multi-morphological organic sulfur, and the test process is the same as that in Example 1.

[0088] The composition of the raw natural gas includes (by molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm. In the purified gas: hydrogen sulfide 2.4 ppm, carbon dioxide 1.57%, carbonyl sulfide 45 ppm, methanethiol 89 ppm, ethanethiol 36 ppm, 1-propanethiol 13 ppm, dimethyl sulfide 15 ppm, carbon disulfide 12 ppm, thiophene 15 ppm, and the total sulfur of organic sulfur is 225 mg / m 3 , and the total removal rate of organic sulfur is 55%.

[0089] Compared with Example 9, in this comparative example, by controlling variables, N-methylpyrrolidone was reduced. Under the condition that other conditions remained unchanged, after reducing N-methylpyrrolidone, the removal rate of organic sulfur dropped sharply from 98.5% to 55%.

[0090] Comparative Example 2

[0091] This comparative example provides a deep removal solvent for multi-morphological sulfides, comprising the following components (by mass percentage): N-methyldiethanolamine 30%, tert-butylaminoethoxyethanol 5%, tert-butyldiethanolamine 5%, polyether-modified silicone 1%, propionate 2%, deionized water 57%.

[0092] The preparation method of the solvent is the same as that in Example 1.

[0093] The above solvent is used for the purification of natural gas containing multi-morphological organic sulfur, and the test process is the same as that in Example 1.

[0094] The composition of the raw natural gas includes (in molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm. In the purified gas: hydrogen sulfide 22 ppm, carbon dioxide 1.3%, carbonyl sulfide 46 ppm, methanethiol 73 ppm, ethanethiol 28 ppm, 1-propanethiol 16 ppm, dimethyl sulfide 15 ppm, carbon disulfide 16 ppm, thiophene 14 ppm, total organic sulfur 208 mg / m 3 , and the total removal rate of organic sulfur is 58.4%.

[0095] Compared with Example 10, in this comparative example, by controlling variables, the polyethylene glycol monomethyl ether was reduced. With the remaining conditions unchanged, after reducing the polyethylene glycol monomethyl ether, the removal rate of organic sulfur dropped sharply from 99.16% to 58.4%.

[0096] Comparative Example 3

[0097] This comparative example provides a solvent for deep removal of multi-morphological sulfides, including the following components (in mass percentage): N-methyldiethanolamine 30%, tert-butylaminoethoxyethanol 5%, tert-butyldiethanolamine 5%, polyethylene glycol dimethyl ether 26%, polyether-modified silicone 1%, propionate 2%, deionized water 31%.

[0098] The preparation method of the solvent is the same as that of Example 1.

[0099] The above solvent was used for the purification of natural gas containing multi-morphological organic sulfur, and the test process was the same as that of Example 1.

[0100] The composition of the raw natural gas includes (in molar ratio): methane 85%, hydrogen sulfide 2.5%, carbon dioxide 5%, carbonyl sulfide 200 ppm, methanethiol 150 ppm, ethanethiol 50 ppm, 1-propanethiol 20 ppm, dimethyl sulfide 20 ppm, carbon disulfide 40 ppm, thiophene 20 ppm. In the purified gas: hydrogen sulfide 2.1 ppm, carbon dioxide 1.01%, carbonyl sulfide 2.2 ppm, methanethiol 1.7 ppm, ethanethiol 2.1 ppm, 1-propanethiol 3.7 ppm, dimethyl sulfide 2.6 ppm, carbon disulfide 1.1 ppm, thiophene 4.3 ppm, total organic sulfur 17.7 mg / m 3 , and the total removal rate of organic sulfur is 96.46%.

[0101] Compared with Example 10, in this comparative example, by controlling variables, the polyethylene glycol monomethyl ether was replaced with polyethylene glycol dimethyl ether. With the remaining conditions unchanged, after replacing the polyethylene glycol monomethyl ether with polyethylene glycol dimethyl ether, the removal rate of organic sulfur dropped from 99.16% to 96.46%.

[0102] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features invented herein.

Claims

1. A multi-morphology sulfide deep removal solvent, by mass percentage, the removal solvent comprises the following components: 15%-40% of an alkanolamine solvent, 10%-30% of a special solvent, 0.5%-3% of an auxiliary agent, and the balance is water; Among them, The alkanolamine solvent comprises a combination of N-methyldiethanolamine, tert-butylaminoethoxyethanol and tert-butyldiethanolamine, and the mass ratio of N-methyldiethanolamine, tert-butylaminoethoxyethanol and tert-butyldiethanolamine is 5-8:1:1-4; The special solvent is N-methylpyrrolidone and / or polyethylene glycol monomethyl ether.

2. The multi-morphology sulfide deep removal solvent according to claim 1, wherein, The removal solvent comprises the following components: 30%-40% of an alkanolamine solvent, 15%-30% of a special solvent, 1.5%-3% of an auxiliary agent, and the balance is water.

3. The multi-morphology sulfide deep removal solvent according to claim 1, wherein, The mass ratio of N-methyldiethanolamine, tert-butylaminoethoxyethanol and tert-butyldiethanolamine is 5-7.5:1:1-1.

25.

4. The multi-morphology sulfide deep removal solvent according to claim 1, wherein, The auxiliary agent comprises an antifoaming agent and an antioxidant.

5. The multi-morphology sulfide deep removal solvent according to claim 4, wherein, The antifoaming agent is one or a combination of two or more of polyether-modified silicone, polyvinyl alcohol and fatty alcohol polyoxyethylene ether.

6. The multi-morphological sulfide deep removal solvent according to claim 4, wherein, The antioxidant is tert-butylphenol and / or propionate.

7. The multi-morphology sulfide deep removal solvent according to claim 4, wherein, The mass ratio of the antifoaming agent to the antioxidant is 2-8:

5.

8. The multi-morphology sulfide deep removal solvent according to claim 4, wherein, The mass ratio of the antifoaming agent to the antioxidant is 2-5:

5.

9. Application of the multi-morphology sulfide deep removal solvent according to any one of claims 1-8 in removing acid gas from gas.

10. The application according to claim 9, wherein, The total sulfur content of the product gas obtained after acid gas removal < 20 mg / m 3 .