Gas separation mercaptan removal tail gas treatment system and method

Abstract

The invention relates to the technical field of waste gas treatment, and particularly discloses a gas-separation mercaptan-removal tail gas treatment system which comprises a tail gas conveying pipe connected with a tail gas exhaust port of a three-phase separation tank, the tail gas conveying pipe is connected with an oil-liquid separator, and the oil-liquid separator is connected with a sulfur production furnace through an oil-liquid-removal tail gas exhaust pipe. The sulfur production furnace is connected with a sulfur production system fan through a pipeline, an oil removal liquid tail gas discharge pipe is provided with an oil removal liquid tail gas branch pipe and a control valve which are sequentially arranged in the tail gas flowing direction, the oil removal liquid tail gas branch pipe is connected to a tail gas furnace, and the oil removal liquid tail gas branch pipe is provided with a control valve. By controlling the opening, closing and opening degrees of the control valves on the oil-removing liquid tail gas discharge pipe and the oil-removing liquid tail gas branch pipe, part of the gas-separating mercaptan-removing tail gas enters the tail gas furnace, so that the load of the sulfur-making furnace is reduced, and the condition of insufficient air supply of a fan of a sulfur-making system is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of waste gas treatment, in particular to a system and method for treating tail gas from gas fraction desulfurization. Background Art

[0002] The liquefied gas sweetening unit is used to process the mixed liquefied gas of DCC, heavy catalyst and coking units. The sulfur-containing substances in the liquefied gas are removed by alkali washing. After the mercaptan reacts with the alkali solution, inorganic sulfur is generated and enters the alkali solution. The sweetening alkali solution regeneration process requires ventilation and oxidation in the alkali solution. After ventilation, some excess oxygen and impurity gases need to be discharged, which is called the gas sweetening tail gas. The regeneration temperature of the sweetening alkali solution regeneration system is about 60℃. The gas sweetening tail gas contains excess oxygen, sulfide, trace hydrocarbons and alkali, which are harmful to safety and environmental protection. Direct discharge does not meet environmental protection requirements. The temperature of the gas sweetening tail gas is 45-55℃, and the medium composition contains nitrogen, oxygen, disulfide, oil and gas, etc. The existing process pipeline is heated, and the tail gas enters the sulfur-making furnace. Due to the intermittent liquid and hydrocarbon, the load of the sulfur-making furnace is high, which causes the sulfur-making system to have production instability problems such as insufficient air supply from the fan and safety hazards. Summary of the invention

[0003] The present invention aims to solve the problem that the exhaust gas from gas desulfurization entering a sulfur-making furnace may cause insufficient air supply from a fan in a sulfur-making system, and provides a system and method for treating exhaust gas from gas desulfurization by incinerating the exhaust gas to avoid insufficient air supply from a fan in a sulfur-making system.

[0004] In order to solve the above technical problems, the present invention includes an exhaust gas delivery pipe connected to the exhaust outlet of the three-phase separation tank, and its structural characteristics are: the exhaust gas delivery pipe is connected to an oil-liquid separator used to separate and remove oil and liquid in the exhaust gas of the gas fraction sweetening alcohol, the exhaust outlet of the oil-liquid separator is connected to the sulfur-making furnace through an oil removal liquid exhaust gas discharge pipe, the sulfur-making furnace is connected to the sulfur-making system fan for supplying air to the sulfur-making furnace through a pipeline, the oil removal liquid exhaust gas discharge pipe is provided with an oil removal liquid exhaust gas branch pipe arranged in sequence along the exhaust gas flow direction and a control valve for controlling the flow rate of the gas fraction sweetening alcohol exhaust gas entering the sulfur-making furnace, the oil removal liquid exhaust gas branch pipe is connected to the exhaust furnace, and the oil removal liquid exhaust gas branch pipe is provided with a control valve for controlling the flow rate of the gas fraction sweetening alcohol exhaust gas entering the exhaust furnace.

[0005] After adopting the above structure, the gas sweetening tail gas discharged from the alkali liquid regeneration waste gas of the liquefied gas sweetening device through the three-phase separation tank enters the oil-liquid separator through the tail gas conveying pipe. The oil-liquid separator separates and removes part of the oil in the tail gas to reduce the air volume consumed by the combustion of organic matter in the oil. The tail gas discharged from the oil-liquid separator enters the sulfur-making furnace through the oil-removing tail gas discharge pipe for treatment. Since the gas sweetening tail gas discharged from the three-phase separation tank may intermittently contain liquid and hydrocarbons, the gas sweetening tail gas entering the sulfur-making furnace may also have an intermittent high hydrocarbon content. When the gas sweetening tail gas with a high hydrocarbon content enters the sulfur-making furnace, the air supply demand increases. In order to prevent the problem of insufficient air supply to the sulfur-making furnace, open the control valve on the deoiling liquid tail gas branch pipe to allow part of the gas sweetening tail gas to enter the tail gas furnace through the deoiling liquid tail gas branch pipe for treatment, adjust the opening of the control valves on the deoiling liquid tail gas discharge pipe and the deoiling liquid tail gas branch pipe, thereby adjusting the flow of the gas sweetening tail gas entering the sulfur-making furnace and the tail gas furnace, reducing the air supply load of the sulfur-making furnace, and preventing the problem of insufficient air supply to the sulfur-making furnace.

[0006] The tail gas delivery pipe is provided with a cooler for cooling the gas desulfurization tail gas, and the cooler is arranged on the tail gas delivery pipe connected to the tail gas inlet of the oil-liquid separator.

[0007] The fan of the sulfur production system is a variable frequency fan with adjustable air supply volume.

[0008] The control valves on the de-oiling liquid tail gas discharge pipe and the de-oiling liquid tail gas branch pipe are electrically controlled valves, and the electrically controlled valves and the sulfur production system fan are all electrically connected to the control system.

[0009] The bottom of the oil separator is connected with a dirty oil discharge pipe for discharging the separated oil.

[0010] A method for treating gas sweetening tail gas, the method is characterized in that: using any of the above-mentioned gas sweetening tail gas treatment systems, the gas sweetening tail gas generated by alkali liquid regeneration of a liquefied gas sweetening device enters an oil-liquid separator through a tail gas conveying pipe, separates and removes part of the oil in the tail gas, and the gas sweetening tail gas after the oil is removed enters a sulfur-making furnace through an oil removal liquid tail gas discharge pipe for treatment, and part of the gas sweetening tail gas can enter the tail gas furnace through an oil removal liquid tail gas branch pipe for incineration treatment, and the flow rate of the gas sweetening tail gas entering the sulfur-making furnace is adjusted by adjusting the control valves on the oil removal liquid tail gas discharge pipe and the oil removal liquid tail gas branch pipe to ensure that the air supply volume of the sulfur-making system fan meets the requirements of the sulfur-making furnace; the oil separated in the oil-liquid separator is discharged through the dirty oil discharge pipe.

[0011] A cooler for cooling the gas sweetening tail gas is provided on the tail gas delivery pipe connected to the tail gas inlet of the oil-liquid separator, so as to improve the removal effect of the oil-liquid separator on the oil in the gas sweetening tail gas.

[0012] The sulfur-making furnace is connected to the variable frequency fan of the sulfur-making system through a pipeline. The control valves on the deoiling liquid tail gas discharge pipe and the deoiling liquid tail gas branch pipe are electric control valves. The variable frequency fan and the electric control valve of the sulfur-making system are electrically connected to the control system. The opening and closing and the opening degree of the electric control valves on the deoiling liquid tail gas discharge pipe and the deoiling liquid tail gas branch pipe are controlled according to the frequency of the variable frequency fan of the sulfur-making system. The flow rate of the gas desulfurization alcohol tail gas entering the sulfur-making furnace and the tail gas furnace is adjusted through cascade control to prevent the air supply of the variable frequency fan of the sulfur-making system from failing to meet the air supply requirement of the sulfur-making furnace.

[0013] The gas desulfurization tail gas treatment system and method of the present invention first cools the gas desulfurization tail gas generated during the alkaline liquid regeneration of the liquefied gas desulfurization device, and then enters the oil-liquid separator to separate and remove part of the oil and liquid in the gas desulfurization tail gas, so as to reduce the air supply demand during the subsequent gas desulfurization tail gas combustion treatment. The gas desulfurization tail gas after the oil and liquid are removed enters the sulfur-making furnace for treatment. When the gas desulfurization tail gas intermittently enters the sulfur-making furnace with liquid and hydrocarbons, the air demand of the sulfur-making furnace will increase, and the air supply load of the fan will increase. In order to prevent the fan of the sulfur-making system from insufficient air supply, the control system opens the electric control valve on the desulfurization liquid tail gas branch pipe according to the frequency of the variable frequency fan of the sulfur-making system, and adjusts the opening of the electric control valve of the desulfurization liquid tail gas discharge pipe and the desulfurization liquid tail gas branch pipe, so that part of the gas desulfurization tail gas enters the tail gas furnace for treatment, reduces the flow of the gas desulfurization tail gas entering the sulfur-making furnace, reduces the air supply demand of the sulfur-making furnace, and avoids the problem of insufficient air supply of the fan of the sulfur-making system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the gas fraction desulfurization tail gas treatment system of the present invention; Figure 2 It is a structural schematic diagram of an existing gas fraction desulfurization tail gas treatment system; In the figure: 1. tail gas conveying pipe; 11. cooler; 111. cooling medium inlet pipe; 112. cooling medium outlet pipe; 2. oil-liquid separator; 3. air supply pipe; 21. de-oiling liquid tail gas discharge pipe; 211. first electric control valve; 212. de-oiling liquid tail gas branch pipe; 213. second electric control valve; 22. dirty oil discharge pipe; 221. conveying pump; 100. control system; 200. three-phase separation tank; 300. sulfur making furnace; 400. variable frequency fan of sulfur making system; 500. tail gas furnace. DETAILED DESCRIPTION

[0015] Figure 2The figure shows an existing gas desulfurization tail gas treatment system, including a tail gas delivery pipe 1, the tail gas delivery pipe 1 is connected to the tail gas outlet of the three-phase separation tank 200, the gas desulfurization tail gas is discharged from the tail gas outlet of the three-phase separation tank 200, the tail gas delivery pipe 1 is provided with a control valve group, the tail gas delivery pipe 1 is connected to the sulfur making furnace 300, the sulfur making furnace 300 is connected to the sulfur making system variable frequency fan 400 through the air supply pipe 3, the sulfur making system variable frequency fan 400 provides the air required for sulfur recovery and its air supply volume is adjustable. The problem of this system is that the gas desulfurization tail gas will intermittently carry liquid and hydrocarbons. When the gas desulfurization tail gas containing more hydrocarbons enters the sulfur making furnace 300, the load of the sulfur making furnace 300 increases, the air volume required for combustion increases, and the air supply load of the sulfur making system variable frequency fan 400 is increased. The problem of insufficient air supply of the sulfur making system variable frequency fan 400 will occur, resulting in unstable production.

[0016] Reference Figure 1 A gas fraction desulfurization tail gas treatment system of the present invention comprises a tail gas delivery pipe 1, the tail gas delivery pipe 1 is connected to the tail gas outlet of the three-phase separation tank 200, the tail gas delivery pipe 1 is connected to the oil-liquid separator 2, the oil-liquid separator 2 is used to separate and remove part of the hydrocarbon-containing oil in the gas fraction desulfurization tail gas, reduce the air supply demand of the sulfur-making furnace 300, the trapped droplets are acidic and contain part of the sulfur-containing substances, and the tail gas outlet of the oil-liquid separator 2 is connected to the sulfur-making furnace 300 through the oil-removing tail gas outlet pipe 21. The tail gas outlet of the oil-liquid separator 2 is located at the top of the separator, and the gas-fractionated sweetening tail gas flows from bottom to top in the oil-liquid separator 2; the sulfur-making furnace 300 is connected to the sulfur-making system fan through the air supply pipe 3, and the sulfur-making system fan provides the sulfur-making furnace 300 with the air required for combustion. The oil-removing liquid tail gas outlet pipe 21 is provided with an oil-removing liquid tail gas branch pipe 212 and a control valve arranged in sequence along the tail gas flow direction. The control valve is used to control the flow rate of the gas-fractionated sweetening tail gas entering the sulfur-making furnace 300. The oil-removing liquid tail gas branch pipe 21 2 is connected to the tail gas furnace 500, and the de-oiling liquid tail gas branch pipe 212 is provided with a control valve for controlling the flow rate of the gas sweetening tail gas entering the tail gas furnace 500. The gas sweetening tail gas can enter the sulfur-making furnace 300 for treatment through the de-oiling liquid tail gas discharge pipe 21, and can also enter the tail gas furnace 500 for treatment through the de-oiling liquid tail gas branch pipe 212. When the gas sweetening tail gas carries little liquid and hydrocarbon, it enters the sulfur-making furnace 300 for treatment. When the gas sweetening tail gas carries more liquid and hydrocarbon, if all of it enters the sulfur-making furnace The processing in the sulfur furnace 300 will cause a higher load on the sulfur making furnace 300 and increase the required air volume. The sulfur making system fan will have a problem of insufficient air supply. At this time, open the control valve on the deoiling liquid tail gas branch pipe 212, adjust the opening of the control valves on the deoiling liquid tail gas discharge pipe 21 and the deoiling liquid tail gas branch pipe 212, and then adjust the flow of the gas desulfurization tail gas entering the sulfur making furnace 300 and the tail gas furnace 500, so that the air supply of the sulfur making system fan meets the requirements of the sulfur making furnace 300, thereby preventing the occurrence of insufficient air supply.

[0017] Reference Figure 1 A control valve group and a cooler 11 are provided on the tail gas conveying pipe 1. The cooler 11 is arranged on the tail gas conveying pipe 1 connected to the tail gas inlet of the oil-liquid separator 2. The tail gas inlet is arranged at the lower part of the oil-liquid separator 2. The cooler 11 cools the gas fraction sweetening tail gas. After cooling, some hydrocarbons in the gas fraction sweetening tail gas will condense and are easy to be removed in the oil-liquid separator 2, thereby improving the removal effect of oil in the tail gas, reducing the oil entering the sulfur-making furnace 300, and reducing the load and required air volume of the sulfur-making furnace 300. The cooler 11 is connected with a cooling medium inlet pipe 111 and a cooling medium outlet pipe 112. The principle is a heat exchange device. The cooling medium can be cooling water, and of course, air cooling or other cooling methods can also be used. The bottom of the oil separator 2 is connected to a dirty oil discharge pipe 22, through which the separated acidic oil is discharged. A delivery pump 221 is provided on the dirty oil discharge pipe 22. The delivery pump 221 is a corrosion-resistant chemical pump, which is a conventional equipment in the field. After the separated oil is discharged, it can be sent to an acidic water stripping device for treatment.

[0018] Reference Figure 1 The sulfur-making system fan is a sulfur-making system variable frequency fan 400 with adjustable air supply volume. The sulfur-making system variable frequency fan 400 is electrically connected to the control system 100. The control system 100 can adopt a DCS or PLC system, which is the prior art in the field; the control valve on the deoiling liquid tail gas discharge pipe 21 is a first electric control valve 211, and the control valve on the deoiling liquid tail gas branch pipe 212 is a second electric control valve 213. The electric control valve can adopt a corrosion-resistant electric ball valve or other electric valves. The first electric control valve 211 and the second electric control valve 213 are both electrically connected to the control system 100. The control system 100 automatically controls the opening and closing of the first electric control valve 211 and the second electric control valve 213 according to the frequency of the sulfur-making system variable frequency fan 400, and adjusts the flow rate of the gas fraction sweetening tail gas entering the sulfur-making furnace 300 and the tail gas furnace 500, so that the air supply of the sulfur-making system variable frequency fan 400 meets the requirements of the sulfur-making furnace 300 to prevent insufficient air supply.

[0019] It should be noted that the actual tank body is also equipped with instruments, valves, inspection ports and other accessories, and the pipeline is also equipped with pumps, fans, valves, filters, detection and metering instruments, heating equipment and other accessories, which belong to the conventional settings in this field and are not shown in the drawings or text. Among the equipment involved above, the three-phase separation tank 200 is an existing equipment, which belongs to the liquefied gas desulfurization device and is used to treat the waste gas generated during the regeneration of alkali solution. The sulfur making furnace 300 (i.e., sulfur making combustion furnace) is an existing equipment, which belongs to the sulfur recovery device and is used to recover sulfur. The sulfur making system variable frequency fan 400 is a supporting equipment of the sulfur making furnace 300. The tail gas furnace 500 (i.e., tail gas incinerator) is an existing equipment, which oxidizes and decomposes combustible harmful gases. The acid water stripping device is an existing device, which is used to treat the acid waste water generated by the device. The structures and principles of the above-mentioned existing equipment and devices are all prior art and are not described in detail here. The structural principle of the oil-liquid separator 2 is similar to that of the degassing tank and other equipment in the prior art. The exhaust gas flows from bottom to top in the separator. A wire mesh, filler or other form of demister is arranged on the upper part of the separator to intercept and remove droplets in the exhaust gas.

[0020] A method for treating gas fraction sweetening tail gas, using Figure 1The gas sweetening tail gas treatment system, the gas sweetening tail gas discharged from the alkali liquid regeneration waste gas of the liquefied gas sweetening device through the three-phase separation tank 200 enters the oil-liquid separator 2 through the tail gas conveying pipe 1, and the tail gas conveying pipe 1 connected to the tail gas inlet of the oil-liquid separator 2 is provided with a cooler 11. The gas sweetening tail gas is cooled by the cooler 11 before entering the oil-liquid separator 2. The temperature of the gas sweetening tail gas discharged is 45-55°C, which is conducive to the separation and removal of oil in the tail gas in the oil-liquid separator 2 after cooling. The separated oil is discharged through the dirty oil discharge pipe 22 and can be sent to the acidic water stripping device for treatment. The gas sweetening tail gas after the oil is removed enters the sulfur-making furnace 300 for treatment through the oil removal tail gas discharge pipe 21. The sulfur-making furnace 30 0 is connected to the variable frequency blower 400 of the sulfur making system through a pipeline, and the variable frequency blower 400 of the sulfur making system provides the sulfur making furnace 300 with the air required for combustion, and part of the gas sweetening tail gas can enter the tail gas furnace 2 for incineration through the oil removal liquid tail gas branch pipe 21, and the oil removal liquid tail gas discharge pipe 21 is provided with a first electric control valve 211 for controlling the flow rate of the gas sweetening tail gas entering the sulfur making furnace 300, and the oil removal liquid tail gas branch pipe 212 is provided with a second electric control valve 213 for controlling the flow rate of the gas sweetening tail gas entering the tail gas furnace 500, and the flow rate of the gas sweetening tail gas entering the sulfur making furnace 300 is adjusted by controlling the opening and closing of the first electric control valve 211 and the second electric control valve 213, so as to ensure that the air supply of the variable frequency blower 400 of the sulfur making system meets the requirements of the sulfur making furnace 300. 00, because the gas-fractionated sweetening tail gas will intermittently carry liquid and hydrocarbons. When the gas-fractionated sweetening tail gas carries liquid and hydrocarbons, even after passing through the oil-liquid separator 2, the hydrocarbon content in the tail gas is still high. If all the gas-fractionated sweetening tail gas enters the sulfur-making furnace 300, the load and air supply of the sulfur-making furnace 300 will increase, and the sulfur-making system variable frequency fan 400 will have the problem of insufficient air supply, resulting in unstable production. In order to solve the problem of insufficient air supply of the sulfur-making system variable frequency fan 400, when the gas-fractionated sweetening tail gas carries liquid and hydrocarbons, the second electric control valve 213 is opened to allow part of the gas-fractionated sweetening tail gas to enter the tail gas furnace 500 for incineration treatment, thereby reducing the flow of the gas-fractionated sweetening tail gas entering the sulfur-making furnace 300, so that the air supply of the sulfur-making system variable frequency fan 400 meets the requirements of the sulfur-making system. The requirements of the sulfur furnace 300 are specifically adjusted by cascade control to adjust the flow rate of the gas-fractionated sweetening alcohol tail gas entering the sulfur-making furnace 300 and the tail gas furnace 500, so as to prevent the air supply of the variable frequency fan 400 of the sulfur-making system from failing to meet the air supply requirements of the sulfur-making furnace. Specifically, the variable frequency fan 400 of the sulfur-making system, the first electrically controlled valve 211, and the second electrically controlled valve 213 are all electrically connected to the control system 100. The control system 100 controls the opening and closing and the opening degree of the first electrically controlled valve 211 and the second electrically controlled valve 213 according to the frequency of the variable frequency fan 400 of the sulfur-making system. For example, when the frequency of the variable frequency fan 400 of the sulfur-making system is 95%, the control system 100 controls to gradually open the second electrically controlled valve 213, so that part of the gas-fractionated sweetening alcohol tail gas enters the tail gas furnace 500 for incineration treatment;When the frequency of the variable frequency fan 400 of the sulfur-making system reaches 100%, the second electric control valve 213 is fully opened, and the opening of the first electric control valve 211 is reduced, further reducing the flow rate of the gas fraction desulfurization tail gas entering the sulfur-making furnace 300, reducing the load of the sulfur-making furnace 300, and making the air supply volume of the variable frequency fan 400 of the sulfur-making system meet the requirements of the sulfur-making furnace 300. ;

[0021] The present invention sends the gas desulfurization tail gas into the sulfur-making furnace for treatment, adds a de-oiling liquid tail gas branch pipe to the de-oiling liquid tail gas discharge pipe, so that part of the gas desulfurization tail gas enters the tail gas furnace for incineration treatment. When the gas desulfurization tail gas carries liquid and hydrocarbons, the load of the sulfur-making furnace will be increased, resulting in insufficient air supply from the fan of the sulfur-making system. In order to overcome the problem of insufficient air supply from the fan of the sulfur-making system, the control valve of the de-oiling liquid tail gas branch pipe is opened, so that part of the gas desulfurization tail gas enters the tail gas furnace for incineration treatment, thereby reducing The flow rate of the gas sweetening tail gas entering the sulfur-making furnace reduces the load of the sulfur-making furnace and enables the sulfur-making system fan to meet the air supply requirement of the incinerator; the gas sweetening tail gas first passes through the oil-liquid separator to separate and remove the oil in the tail gas before entering the sulfur-making furnace, reducing the organic hydrocarbon substances in the gas sweetening tail gas, thereby reducing the load of the sulfur-making furnace; the gas sweetening tail gas is cooled before entering the oil-liquid separator, which is beneficial to the separation and removal of the oil in the gas sweetening tail gas in the oil-liquid separator.

Claims

1. A gas separation and desulfurization tail gas treatment system, comprising a tail gas delivery pipe (1) connected to the tail gas outlet of a three-phase separation tank (200), characterized in that: The tail gas delivery pipe (1) is connected to an oil-liquid separator (2) for separating and removing oil from the gas fraction sweetening tail gas; the tail gas outlet of the oil-liquid separator (2) is connected to the sulfur-making furnace (300) via an oil-removing tail gas discharge pipe (21); the sulfur-making furnace (300) is connected to a sulfur-making system fan for supplying air to the sulfur-making furnace (300) via a pipeline; the oil-removing tail gas discharge pipe (21) is provided with an oil-removing tail gas branch pipe (212) sequentially arranged along the tail gas flow direction and a control valve for controlling the flow rate of the gas fraction sweetening tail gas entering the sulfur-making furnace (300); the oil-removing tail gas branch pipe (212) is connected to the tail gas furnace (500); the oil-removing tail gas branch pipe (212) is provided with a control valve for controlling the flow rate of the gas fraction sweetening tail gas entering the tail gas furnace (500).

2. The gas desulfurization tail gas treatment system according to claim 1 is characterized in that: The tail gas delivery pipe (1) is provided with a cooler (11) for cooling the gas desulfurization tail gas, and the cooler (11) is arranged on the tail gas delivery pipe (1) connected to the tail gas inlet of the oil-liquid separator (2).

3. The gas desulfurization tail gas treatment system according to claim 1 is characterized in that: The fan of the sulfur production system is a variable frequency fan with adjustable air supply volume.

4. The gas desulfurization tail gas treatment system according to claim 3 is characterized in that: The control valves on the deoiling liquid tail gas discharge pipe (21) and the deoiling liquid tail gas branch pipe (212) are electrically controlled valves, and the electrically controlled valves and the sulfur production system fan are both electrically connected to the control system (100).

5. The gas desulfurization tail gas treatment system according to claim 1 is characterized in that: The bottom of the oil-liquid separator (2) is connected to a dirty oil discharge pipe (22) for discharging the separated oil.

6. A method for treating gas desulfurization tail gas, characterized in that: The gas desulfurization tail gas treatment system according to any one of claims 1 to 5 is adopted, the gas desulfurization tail gas generated by the alkaline liquid regeneration of the liquefied gas desulfurization device enters the oil-liquid separator (2) through the tail gas conveying pipe (1), and a part of the oil and liquid in the tail gas is separated and removed. The gas desulfurization tail gas after the oil and liquid are removed enters the sulfur-making furnace (300) for treatment through the oil removal liquid tail gas discharge pipe (21), and a part of the gas desulfurization tail gas can enter the tail gas furnace (500) for incineration treatment through the oil removal liquid tail gas branch pipe (212). The flow rate of the gas desulfurization tail gas entering the sulfur-making furnace (300) is adjusted by adjusting the control valves on the oil removal liquid tail gas discharge pipe (21) and the oil removal liquid tail gas branch pipe (212), so as to ensure that the air supply volume of the sulfur-making system fan meets the requirements of the sulfur-making furnace (300); the oil separated in the oil-liquid separator (2) is discharged through the dirty oil discharge pipe (22).

7. The method for treating tail gas from gas desulfurization according to claim 6, wherein: A cooler (11) for cooling the gas sweetening tail gas is provided on the tail gas delivery pipe (1) connected to the tail gas inlet of the oil-liquid separator (2), so as to improve the effect of the oil-liquid separator (2) in removing oil from the gas sweetening tail gas.

8. The method for treating tail gas from gas desulfurization according to claim 7, wherein: The sulfur-making furnace (300) is connected to the variable frequency blower (400) of the sulfur-making system through a pipeline. The control valves on the de-oiling liquid tail gas discharge pipe (21) and the de-oiling liquid tail gas branch pipe (212) are electrically controlled valves. The variable frequency blower (400) and the electrically controlled valves of the sulfur-making system are electrically connected to the control system (100). The opening and closing and the opening degree of the electrically controlled valves on the de-oiling liquid tail gas discharge pipe (21) and the de-oiling liquid tail gas branch pipe (212) are controlled according to the frequency of the variable frequency blower (400) of the sulfur-making system. The flow rate of the gas fraction desulfurization alcohol tail gas entering the sulfur-making furnace (300) and the tail gas furnace (500) is adjusted through cascade control to prevent the air supply volume of the variable frequency blower (400) of the sulfur-making system from failing to meet the air supply requirement of the sulfur-making furnace (300).

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