Ionic liquid desulfurization method and equipment for sulfur-containing gas

Abstract

The embodiment of the present invention provides an ionic liquid desulfurization method for sulfur-containing gas, which relates to the technical field of sulfur-containing gas processing. Before regenerating the rich liquid, the rich liquid is first filtered to separate the sulfur therein, thereby avoiding the problems of subsequent pipeline blockage and scaling, and improving the regeneration efficiency of the ionic liquid. The embodiment of the present invention also provides an ionic liquid desulfurization device for sulfur-containing gas, which includes a pre-separation system, an absorption system, a filtration system, and a regeneration system connected in sequence; the liquid outlet of the regeneration system is connected to the feed end of the absorption system through a lean liquid circulation pump. A filtration system is provided before the regeneration system to separate the sulfur in the rich liquid, effectively avoiding the problems of pipeline blockage, scaling, difficulty in sulfur separation, slow regeneration of ionic liquid, etc. during the transportation and regeneration of the rich liquid.

Description

Technical Field

[0001] The present invention relates to the technical field of sulfur-containing gas processing, and in particular to an ionic liquid desulfurization method and equipment for sulfur-containing gas. Background Art

[0002] Sulfur-containing gases usually refer to gases containing a small amount of acidic components such as H2S and organic sulfur, such as natural gas, associated gas, biogas, and some industrial waste gas. Natural gas, associated gas, and biogas can be used as energy, but they must be desulfurized before use, otherwise they will not only harm people's health, but also cause corrosion of pipelines, equipment, instruments, and catalyst poisoning during use. As for industrial waste gas, it must also be desulfurized before it can be discharged, otherwise it will cause atmospheric pollution.

[0003] The existing desulfurization process is generally divided into dry desulfurization and wet desulfurization according to the type of desulfurizer. In dry desulfurization, solid adsorbents such as iron oxide, activated carbon, and molecular sieves are often used for adsorption desulfurization. However, solid adsorbents have problems such as low sulfur capacity, high cost of regeneration and replacement of adsorbents. Therefore, dry desulfurization is often used in occasions with extremely small potential sulfur content. Wet desulfurization can be divided into chemical absorption, physical absorption, and direct oxidation-reduction according to the different absorption methods of the desulfurization liquid. The chemical and physical absorption methods based on the alcohol amine method and the sulfone amine method absorb and desorb H2S by solvents to make the purified gas meet the standards and obtain acid gas with a high H2S content, which enters the Claus unit for sulfur recovery. However, the process is complex, technically demanding, and requires a large investment. In addition, the energy consumption during use is high, and it is often used in large-scale natural gas desulfurization units with high potential sulfur content. For small gas wells with low potential sulfur content, the economic efficiency of using the amine method in series with the Claus process is poor, and the direct oxidation-reduction method based on complex iron is still mainly used. H2S is absorbed by solvents and oxidized into elemental sulfur, so that the purified gas meets the standards and sulfur is recovered. The process is simple and the investment is low, but the process has a series of problems such as small sulfur capacity, large circulation volume, high power consumption, long regeneration time, easy blockage of pipeline equipment and easy loss of solvent.

[0004] The introduction of ionic liquid desulfurization overcomes a series of problems in the process of desulfurization of natural gas resources with medium and low sulfur potential, such as small sulfur capacity, large circulation volume, high power consumption, and easy loss of solvent. However, due to its own characteristics of large sulfur capacity, high viscosity, strong corrosiveness, and good water absorption, ionic liquid desulfurization liquid has the disadvantages of difficult sulfur separation, easy accumulation of impurities brought into the solution by the raw gas, slow regeneration rate of rich liquid, and easy dilution of desulfurization liquid by water, which leads to a series of problems such as equipment pipeline blockage, scaling, solution foaming, deterioration, and difficulty in meeting the standards for purified gas during operation. Therefore, the equipment and process of traditional direct oxidation-reduction desulfurization method are difficult to be directly applied to ionic liquid desulfurization. Summary of the invention

[0005] The object of the present invention is to provide an ionic liquid desulfurization method for sulfur-containing gas, which is simple and convenient to operate, can quickly and efficiently remove sulfides in the sulfur-containing gas, and quickly achieve sulfur separation and ionic liquid regeneration.

[0006] Another object of the present invention is to provide an ionic liquid desulfurization device for sulfur-containing gas, which has a simple structure and is easy to use, and can well solve the mismatch of equipment in the current ionic liquid desulfurization process.

[0007] The embodiment of the present invention is achieved as follows:

[0008] An ionic liquid desulfurization method for sulfur-containing gas, comprising:

[0009] Pre-separate the sulfur-containing gas to separate the impurities therein;

[0010] The sulfur-containing gas from which impurities have been separated is subjected to ionic liquid to absorb sulfides therein, thereby obtaining a sulfur-rich liquid and purified gas;

[0011] Filter the rich liquid to separate the sulfur therein;

[0012] The rich liquid after separation of sulfur is regenerated to obtain lean liquid.

[0013] Furthermore, in other preferred embodiments of the present invention, the rich liquid is filtered using a plate and frame filter press, and the inlet pressure of the plate and frame filter press is 0.1~1 MPaG.

[0014] Furthermore, in other preferred embodiments of the present invention, the absorption of sulfur-containing gas by ionic liquid is carried out by using a dynamic wave washing absorption tower, the temperature during absorption is 20~80°C, the pressure is 0.1~1 MPaG, and the gas-liquid ratio is 20~100.

[0015] Furthermore, in other preferred embodiments of the present invention, the rich liquid is regenerated by using a Venturi regeneration tower, the regeneration pressure is 0.1-2 MPaG, the temperature is 40-100° C., and the gas-liquid ratio is 50-150.

[0016] Furthermore, in other preferred embodiments of the present invention, the rich liquid is regenerated using dry hot air, and the temperature of the hot air is 60-100°C.

[0017] Furthermore, in other preferred embodiments of the present invention, the sulfur-containing gas is pre-separated by using a supersonic separator, and the inlet pressure of the supersonic separator is ≥1 MPaG.

[0018] An ionic liquid desulfurization device for sulfur-containing gas comprises a pre-separation system, an absorption system, a filtration system and a regeneration system which are connected in sequence; the liquid outlet of the regeneration system is connected to the liquid feed end of the absorption system through a lean liquid circulation pump.

[0019] Furthermore, in other preferred embodiments of the present invention, the filtration system includes a plate and frame filter press, the liquid inlet end of the plate and frame filter press is connected to the liquid outlet end of the absorption system, and the liquid outlet end of the plate and frame filter press is connected to the liquid inlet end of the regeneration system.

[0020] Furthermore, in other preferred embodiments of the present invention, the filtration system also includes a filter cloth filter, which is located between the plate and frame filter press and the regeneration system, the liquid inlet end of the filter cloth filter is connected to the liquid outlet end of the plate and frame filter press, and the liquid outlet end of the filter cloth filter is connected to the liquid inlet end of the regeneration system.

[0021] Furthermore, in other preferred embodiments of the present invention, the absorption system is a dynamic wave washing absorption tower, and the gas feed end of the absorption system is connected to the gas outlet end of the pre-separation system.

[0022] Furthermore, in other preferred embodiments of the present invention, a sedimentation tank is also provided at the liquid outlet of the absorption system, the liquid inlet of the sedimentation tank is connected to the liquid outlet of the absorption system, and the liquid outlet of the sedimentation tank is connected to the liquid inlet of the plate and frame filter press.

[0023] Furthermore, in other preferred embodiments of the present invention, the regeneration system is a Venturi regeneration tower, the air inlet end of the regeneration system is connected to the air inlet pipe, the air inlet pipe is provided with an air heater, the liquid inlet end of the regeneration system is provided with a rich liquid heater, the liquid inlet end of the rich liquid heater is connected to the liquid outlet end of the plate and frame filter press, and the liquid outlet end of the rich liquid heater is connected to the liquid inlet end of the regeneration system.

[0024] Furthermore, in other preferred embodiments of the present invention, the pre-separation system includes a supersonic separator, and the air inlet end of the supersonic separator is connected to the raw gas inlet pipe.

[0025] Furthermore, in other preferred embodiments of the present invention, the pre-separation system also includes a pre-cooling separator, the air inlet end of the pre-cooling separator is connected to the raw gas inlet pipe, and the air outlet end of the pre-cooling separator is connected to the air inlet end of the supersonic separator.

[0026] The beneficial effects of the embodiments of the present invention are:

[0027] The embodiment of the present invention provides an ionic liquid desulfurization method for sulfur-containing gas, which filters the rich liquid before regenerating it to separate the sulfur therein, avoid subsequent pipeline blockage and scaling problems, and improve the regeneration efficiency of the ionic liquid.

[0028] The embodiment of the present invention also provides an ionic liquid desulfurization device for sulfur-containing gas, which includes a pre-separation system, an absorption system, a filtration system and a regeneration system connected in sequence; the liquid outlet of the regeneration system is connected to the liquid feed end of the absorption system through a lean liquid circulation pump. A filtration system is provided before the regeneration system to separate sulfur from the rich liquid, effectively avoiding problems such as pipeline blockage and scaling, difficulty in sulfur separation, and slow regeneration of ionic liquid during transportation and regeneration of the rich liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 A schematic diagram of an ionic liquid desulfurization device for sulfur-containing gas provided in an embodiment of the present invention.

[0031] Icons: 100-ionic liquid desulfurization equipment; 110-pre-separation system; 111-supersonic separator; 112-pre-cooling separator; 113-raw gas inlet pipe; 114-cyclone separator; 115-pre-filter; 116-heat exchanger; 120-absorption system; 121-dynamic wave washing absorption tower; 122-purified gas gas-liquid separator; 123-sedimentation tank; 124-sulfur slurry pump; 130-filtration system; 131-plate and frame filter press; 132-filter cloth filter; 140-regeneration system; 141-Venturi regeneration tower; 142-air inlet pipe; 143-air heater; 144-rich liquid heater; 145-rich liquid pump; 146-waste air gas-liquid separator; 147-lean liquid storage tank; 148-lean liquid circulation pump. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0033] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0037] The following is a detailed description of an ionic liquid desulfurization method and device for sulfur-containing gas according to an embodiment of the present invention.

[0038] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0039] Example 1

[0040] This embodiment provides an ionic liquid desulfurization device 100 for sulfur-containing gas, referring to Figure 1 As shown, it includes a pre-separation system 110, an absorption system 120, a filtering system 130 and a regeneration system 140 connected in sequence; the liquid outlet of the regeneration system 140 is connected to the feed end of the absorption system 120 through a lean liquid circulation pump 148. When the ionic liquid desulfurization equipment 100 is in operation, the sulfur-containing gas first enters the pre-separation system 110 to separate the impurities therein, and then enters the absorption system 120 to absorb the sulfide by the ionic liquid therein, and the purified gas is discharged from the top of the absorption system 120, and the sulfur-rich rich liquid is separated from the sulfur by the filtering system 130, and then enters the regeneration system 140 to complete the regeneration of the ionic liquid.

[0041] The filtration system 130 includes a plate-frame filter press 131, the liquid inlet of the plate-frame filter press 131 is connected to the liquid outlet of the absorption system 120, and the liquid outlet of the plate-frame filter press 131 is connected to the liquid inlet of the regeneration system 140. The plate-frame filter press 131 can fully separate the rich liquid, and the separated sulfur enters the sulfur purification section in the form of filter cake for recovery.

[0042] Furthermore, if Figure 1As shown, the filtration system 130 further includes a filter cloth filter 132, which is located between the plate-frame filter press 131 and the regeneration system 140, and the liquid inlet end of the filter cloth filter 132 is connected to the liquid outlet end of the plate-frame filter press 131, and the liquid outlet end of the filter cloth filter 132 is connected to the liquid inlet end of the regeneration system 140. The clear liquid discharged from the plate-frame filter press 131 can enter the filter cloth filter 132 for deeper filtration, so as to avoid sulfur residue as much as possible, thereby preventing sulfur powder from affecting the regeneration efficiency of the ionic liquid and preventing subsequent pipelines and equipment from clogging, scaling and other problems.

[0043] In this embodiment, the absorption system 120 includes a dynamic wave washing absorption tower 121, and the feed end of the dynamic wave washing absorption tower 121 is connected to the gas outlet end of the pre-separation system 110. The sulfur-containing gas and the desulfurized lean liquid refluxed from the regeneration system 140 are reversely contacted in the dynamic wave washing absorption tower 121. The acidic components in the sulfur-containing gas are fully absorbed by the lean liquid, and the formed purified gas is discharged from the purified gas outlet at the top of the dynamic wave washing absorption tower 121 to the subsequent process section, while the desulfurized lean liquid that absorbs the acidic components becomes a rich liquid rich in sulfur, which is discharged from the rich liquid outlet at the bottom of the dynamic wave washing absorption tower 121 and enters the subsequent regeneration process. The dynamic wave washing absorption tower 121 utilizes the foam washing principle and the anti-blocking characteristics of the equipment itself, which can enhance the gas-liquid mass transfer efficiency while avoiding the blockage of the equipment by sulfur solids, thereby achieving effective removal of acidic gases. It is particularly suitable for high-viscosity ionic liquids to remove sulfides in high-sulfur gases.

[0044] The purified gas outlet of the dynamic wave washing absorption tower 121 is also connected to a purified gas-liquid separator 122, which can effectively remove the liquid components entrained in the purified gas, and recycle the liquid components while further purifying the purified gas.

[0045] In addition, if Figure 1 As shown, the liquid outlet of the power wave washing absorption tower 121 is also provided with a settling tank 123, the liquid inlet of the settling tank 123 is connected to the liquid outlet of the power wave washing absorption tower 121, and the liquid outlet of the settling tank 123 is connected to the liquid inlet of the plate-frame filter press 131. The power wave washing absorption tower 121 and the settling tank 123 adopt an integrated tower arranged up and down, which has the characteristics of high integration and small footprint. The settling tank 123 can perform preliminary sedimentation of sulfur in the rich liquid, further improving the efficiency of sulfur separation. The liquid outlet of the settling tank 123 is provided with a sulfur slurry pump 124, which is used to transport the sulfur slurry from the settling tank 123 to the plate-frame filter press 131.

[0046] Further, the regeneration system 140 includes a venturi regeneration tower 141, the air inlet end of the venturi regeneration tower 141 is connected to the air inlet pipe 142, the air inlet pipe 142 is provided with an air heater 143, the liquid inlet end of the venturi regeneration tower 141 is provided with a rich liquid heater 144, the liquid inlet end of the rich liquid heater 144 is connected to the liquid outlet end of the filter cloth filter 132, and the liquid outlet end of the rich liquid heater 144 is connected to the liquid inlet end of the venturi regeneration tower 141. The rich liquid is in countercurrent contact with the hot dry air entering the bottom of the tower in the venturi regeneration tower 141 to achieve oxidative regeneration of the rich liquid. The rich liquid heater 144 can heat the rich liquid before it enters the venturi regeneration tower 141, increase the effective collision between gas and liquid molecules, and remove the moisture generated in the ionic liquid during the absorption process by using high-temperature dry air through the air stripping principle. A rich liquid pump 145 is provided at the liquid inlet end of the rich liquid heater 144 for conveying the rich liquid discharged from the filter cloth filter 132 to the rich liquid heater 144 .

[0047] In addition, Figure 1 As shown, the gas outlet at the top of the Venturi regeneration tower 141 is connected to the waste air gas-liquid separator 146, which is used to separate the waste gas discharged from the Venturi regeneration tower 141 before discharging it, recover the liquid therein, and prevent the ionic liquid and other impurity components from being brought out to pollute the atmosphere. The liquid phase outlet at the bottom of the Venturi regeneration tower 141 is connected to the feed end of the power wave washing absorption tower 121 through the lean liquid circulation pump 148, so as to transport the lean liquid obtained after regeneration back to the power wave washing absorption tower 121 for reuse. A lean liquid storage tank 147 is also provided at the liquid phase outlet of the Venturi regeneration tower 141 for temporary storage of the lean liquid.

[0048] The pre-separation system 110 includes a supersonic separator 111, and the air inlet end of the supersonic separator 111 is connected to the raw gas inlet pipe 113. The supersonic separator 111 can effectively perform deep separation of liquid impurities such as water and heavy hydrocarbons in the sulfur-containing gas, and play a role in purifying the sulfur-containing gas to improve the efficiency of subsequent treatment. Further, the pre-separation system 110 also includes a pre-cooling separator 112, and the air inlet end of the pre-cooling separator 112 is connected to the raw gas inlet pipe 113, and the air outlet end of the pre-cooling separator 112 is connected to the air inlet end of the supersonic separator 111. The pre-cooling separator 112 can pre-separate the sulfur-containing gas before the supersonic separator 111, preliminarily treat the liquid impurities, and achieve a certain degree of recovery.

[0049] On this basis, if Figure 1As shown, a cyclone separator 114, a pre-filter 115, etc. can also be added before the pre-cooling separator 112, so that the solid impurities such as gravel and rock debris that may be contained in the sulfur-containing gas can be removed before the liquid phase impurity separation. A heat exchanger 116 is arranged between the pre-filter 115 and the pre-cooling separator 112, and the hot flow side inlet of the heat exchanger 116 is connected to the pre-filter 115, and the hot flow side outlet is connected to the pre-cooling separator 112; the cold flow side inlet of the heat exchanger 116 is connected to the supersonic separator 111, and the cold flow side outlet is connected to the absorption system 120. The gas output from the supersonic separator 111 has a low temperature, which is not conducive to improving the absorption efficiency of the absorption system 120. By exchanging heat with the sulfur-containing gas discharged from the pre-filter 115 through a heat exchange method, its temperature can be effectively increased, thereby improving the absorption efficiency of the ionic liquid for the acidic gas. On the other hand, the temperature of the sulfur-containing gas discharged from the pre-filter 115 is reduced after heat exchange, which can also improve the separation efficiency in the pre-cooling separator 112, thereby achieving optimal energy allocation.

[0050] Example 2

[0051] This embodiment provides an ionic liquid desulfurization method for sulfur-containing gas, which uses the ionic liquid desulfurization device 100 for sulfur-containing gas provided in Example 1 to treat the sulfur-containing associated natural gas of a high-sulfur associated gas processing plant. The hydrogen sulfide content in the sulfur-containing associated natural gas is 3.4%, and the hydrogen sulfide content after desulfurization is required to be ≤20mg / m 3 , requiring that the processed natural gas meet the technical indicators of Class II gas in "Natural Gas" (GB17820-2018).

[0052] The specific operations include:

[0053] S1. Associated natural gas with a pressure of 4.0 MPa, a temperature of 40°C and a hydrogen sulfide content of 3.4% is passed through a cyclone separator 114 and a pre-filter 115 in sequence to remove solid impurities such as sand and rock fragments and some liquid impurities in the associated natural gas.

[0054] S2. The associated natural gas output from the pre-filter 115 is subjected to heat exchange in the heat exchanger 116 to reduce the temperature of the associated gas, and then passes through the pre-cooling separator 112 and the supersonic separator 111 in sequence to perform deep separation of liquid impurities such as water and heavy hydrocarbons in the associated gas.

[0055] S3. The associated natural gas output from the supersonic separator 111 is heat exchanged through the heat exchanger 116 to increase the temperature, and then enters the dynamic wave washing absorption tower 121, where it is mixed with the iron-based ionic liquid lean liquid from the venturi regeneration tower 141 under the operating conditions of 50°C and 0.5 MPaG, and the gas-liquid ratio is controlled to be 50 by adjusting the flow rate of the lean liquid circulation pump 148. The obtained purified gas is discharged from the top and enters the purified gas-liquid separator 122 to remove the entrained liquid and then enter the next stage. Analysis shows that the H2S content in the purified gas is 16 ppm; the obtained sulfur-rich rich liquid is discharged into the settling tank 123.

[0056] S4. After the rich liquid is initially settled in the settling tank 123 and stays there for 10 minutes, it is pumped to the plate and frame filter press 131 through the sulfur slurry pump 124 to separate the sulfur, and then enters the filter cloth filter 132 for secondary separation.

[0057] S5. The rich liquid output from the filter cloth filter 132 is pumped to the rich liquid heater 144 by the rich liquid pump 145 and heated to 80°C, and then enters the venturi regeneration tower 141. In the venturi regeneration tower 141, it is reversely contacted with the dry air heated to 80°C by the air heater 143 to remove a large amount of water produced in the ionic liquid during the absorption process, while improving the regeneration efficiency of the ionic liquid. The regenerated lean liquid is transported from the bottom to the lean liquid storage tank 147, and then pumped to the power wave washing absorption tower 121 by the lean liquid circulation pump 148. The regenerated waste air is discharged from the top to the waste air gas-liquid separator 146 to separate the entrained liquid and then emptied.

[0058] Comparative Example 1

[0059] This comparative example provides an ionic liquid desulfurization method for sulfur-containing gas. The equipment and process parameters used are basically the same as those in Example 2, except that unheated room temperature wet air is used instead of high temperature dry air to regenerate the desulfurized rich liquid, and the purified gas at the top of the absorption tower is sampled, and 500 ppm of hydrogen sulfide is measured.

[0060] Comparative Example 2

[0061] This comparative example provides an ionic liquid desulfurization method for sulfur-containing gas, and the equipment and process parameters used are basically the same as those of Example 2, except that the filter system 130 is removed. After the equipment has been running for 1 hour, the pipeline between the power wave washing absorption tower 121 and the venturi regeneration tower 141 is obviously blocked, and the equipment begins to alarm and cannot work normally. The rich liquid after running for 1 hour is separated from sulfur by the filter system 130, and only a small amount of sulfur solids are separated. The liquid at the outlet of the filter system still contains a large amount of sulfur in the form of slurry and cannot be separated.

[0062] In summary, the embodiments of the present invention provide an ionic liquid desulfurization method for sulfur-containing gas, which filters the rich liquid before regenerating it to separate the sulfur therein, thereby avoiding subsequent pipeline blockage and scaling problems and improving the regeneration efficiency of the ionic liquid.

[0063] The embodiment of the present invention also provides an ionic liquid desulfurization device for sulfur-containing gas, which includes a pre-separation system, an absorption system, a filtration system and a regeneration system connected in sequence; the liquid outlet of the regeneration system is connected to the liquid feed end of the absorption system through a lean liquid circulation pump. A filtration system is provided before the regeneration system to separate sulfur from the rich liquid, effectively avoiding problems such as pipeline blockage and scaling, difficulty in sulfur separation, and slow regeneration of ionic liquid during transportation and regeneration of the rich liquid.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for desulfurization of sulfur-containing gas using ionic liquids, characterized in that: include: Pre-separate the sulfur-containing gas to separate the impurities therein; Absorbing sulfides in the sulfur-containing gas from which impurities have been separated using ionic liquid to obtain a sulfur-rich liquid and purified gas; filtering the rich liquid to separate the sulfur therein; regenerating the rich liquid after separation of sulfur to obtain lean liquid; The rich liquid is filtered by a plate-and-frame filter press, and the inlet pressure of the plate-and-frame filter press is 0.1-1 MPaG; The ionic liquid is used to absorb the sulfur-containing gas by using a dynamic wave washing absorption tower, the temperature during absorption is 20-80° C., the pressure is 0.1-1 MPaG, and the gas-liquid ratio is 20-100; The rich liquid is regenerated by using a Venturi regeneration tower, with a regeneration pressure of 0.1-2 MPaG, a temperature of 40-100°C, and a gas-liquid ratio of 50-150; The rich liquid is dehydrated and regenerated by using dry hot air, and the temperature of the hot air is 60-100°C.

2. The ionic liquid desulfurization method according to claim 1, characterized in that: The sulfur-containing gas is pre-separated by using a supersonic separator, and the inlet pressure of the supersonic separator is ≥1 MPaG.

3. An ionic liquid desulfurization device for sulfur-containing gas, characterized in that: It comprises a pre-separation system, an absorption system, a filtration system and a regeneration system connected in sequence; the liquid outlet end of the regeneration system is connected to the liquid feed end of the absorption system through a lean liquid circulation pump; The filtration system comprises a plate-frame filter press, the liquid inlet end of the plate-frame filter press is connected to the liquid outlet end of the absorption system, and the liquid outlet end of the plate-frame filter press is connected to the liquid inlet end of the regeneration system; The absorption system comprises a dynamic wave washing absorption tower, and the gas feed end of the absorption system is connected to the gas outlet end of the pre-separation system; The regeneration system includes a Venturi regeneration tower, the air inlet end of the regeneration system is connected to the air inlet pipe, the air inlet pipe is provided with an air heater, the liquid inlet end of the regeneration system is provided with a rich liquid heater, the liquid inlet end of the rich liquid heater is connected to the liquid outlet end of the plate and frame filter press, and the liquid outlet end of the rich liquid heater is connected to the liquid inlet end of the regeneration system.

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