A method and apparatus for treating regenerated flue gas from an SZorb unit.

Abstract

This invention relates to a method and apparatus for treating regenerated flue gas from an SZorb unit, comprising: (1) conveying the regenerated flue gas from the SZorb unit to a pretreatment unit, the pretreatment unit including cooling-compression-condensation treatment; (2) conveying the pretreated flue gas to an adsorption unit for adsorbing SO2 in the flue gas, and the purified gas after adsorption being reused in the SZorb unit; (3) performing desorption after adsorption, using a stable vacuum desorption gas volume unit for regulation, and stably conveying the vacuum desorption gas to a sulfur recovery device, thereby achieving near-zero emissions of the regenerated flue gas from the SZorb unit. This invention uses adsorption to recover SO2 from the regenerated flue gas of the SZorb unit, and the purified gas after adsorption is reused in the SZorb unit. The desorbed gas is stabilized before sulfur recovery, avoiding the impact of fluctuations in desorbed gas concentration and volume on the sulfur recovery device, and achieving near-zero emissions of the regenerated flue gas from the SZorb unit.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of environmental protection waste gas treatment, and particularly relates to a treatment method and device for regenerative flue gas of a SZorb device. BACKGROUND

[0002] SO2 is one of the main atmospheric pollutants, and is the main cause of global acid rain, haze and other environmental problems. Its emission sources include thermal power generation, metallurgical production, industrial boilers, chemical industry, petrochemical industry, transportation and other fields, and mainly come from fossil fuel combustion and chemical fuel desulfurization process. According to the Environmental Statistics Yearbook, the SO2 emission in recent years in China shows a downward trend, which shows that China has begun to strengthen the control and management, but the annual emission is still about 20 million tons, and the total amount control task is still very difficult. Therefore, the state has strictly controlled the emission concentration of SO2 in flue gas, generally required to be less than 100 mg / m 3 , and ultra-low emission required to be less than 30 mg / m 3 .

[0003] The SZorb device is mainly used for catalytic gasoline adsorption desulfurization. The SZorb device includes four parts of feed and adsorption desulfurization reaction, adsorbent regeneration, adsorbent circulation and product stabilization. In the adsorbent regeneration process, regenerative flue gas needs to be treated, which has high SO2 concentration and large concentration change range, and the gas amount is generally 1000-3000 Nm 3 / h, the SO2 volume concentration is generally 0.5%-7%, and the N2 volume concentration is greater than 85%. For the regenerative flue gas of the SZorb device, the alkali absorption method is generally used for treatment, but due to the high SO2 concentration, the reagent consumption is large, the operation cost is high, and the salt-containing wastewater is formed to cause secondary pollution. Enterprises with conditions can send the regenerative flue gas of the SZorb device to the sulfur production device in the plant for treatment, which mainly includes three process routes. The first is mixed with raw acid gas and then enters the sulfur production combustion furnace; the second is mixed with the process gas after the sulfur production combustion furnace and then enters the sulfur production reactor, which will have a certain impact on the normal operation of the sulfur production device, especially for small-scale devices; the third is mixed with the sulfur production tail gas and then enters the hydrogenation reactor for hydrogenation to produce hydrogen sulfide, and then organic amine absorption is used to obtain hydrogen sulfide to return as raw material of the sulfur production device. The process has large hydrogen consumption and high operation cost.

[0004] CN201510639559.3 discloses a treatment method of sulfur-containing waste gas, which is to introduce one or both of sulfur recovery unit flue gas or SZorb unit regeneration flue gas and catalytic cracking unit regeneration air into the regeneration unit of the catalytic cracking unit for coking reaction, and then the unreacted SO2-containing gas and the flue gas generated by the coking reaction are sequentially subjected to separation and heat exchange before entering the desulfurization and denitrification unit of the catalytic cracking unit for treatment, and the purified tail gas is discharged after being treated. However, this method ultimately relies on the desulfurization unit of the catalytic cracking unit to achieve desulfurization, which will consume a large amount of desulfurization reagent and generate a large amount of desulfurization waste liquid at the same time.

[0005] CN201010269123.7 discloses a treatment method of gasoline adsorption desulfurization regeneration flue gas, which is to introduce the SZorb unit regeneration flue gas into the tail gas hydrogenation unit of the sulfur recovery unit and mix with the Claus tail gas, and then use a special tail gas hydrogenation catalyst for treatment. The hydrogenated tail gas is subjected to solvent absorption-regeneration, hydrogen sulfide is returned to the Claus unit for sulfur recovery, and the purified tail gas is incinerated in an incinerator before being discharged. This method can recover sulfur resources and avoid environmental pollution. The special tail gas hydrogenation catalyst is prepared by using the titanium-aluminum composite dry gel as the main raw material, adding additives, and then extruding, drying and calcining to prepare the carrier. The catalyst uses ternary metals of group ⅥB and group Ⅷ as active components and is prepared by the impregnation method. The catalyst has high activity at low temperature and is resistant to oxygen. It can be used for hydrogenation reaction of the SZorb unit regeneration flue gas and the Claus tail gas at 230-250℃. The activity of the catalyst is 30% higher than that of the conventional Claus tail gas hydrogenation catalyst, and the use temperature is 60℃ lower than that of the conventional catalyst. However, the hydrogen consumption is large and the operation cost is high when hydrogenation treatment is performed on SO2 in the SZorb unit regeneration flue gas.

[0006] CN201520627122.3 discloses a sulfur recovery unit, which comprises a sulfur production unit with a combustion furnace and a hydrogenation unit with a hydrogenation furnace, an inlet for SZorb device regeneration flue gas, an inlet for hydrogen sulfide-containing acid gas, and an inlet for Claus tail gas of the sulfur production unit. A pipeline is configured to split the regeneration flue gas entering from the inlet for SZorb device regeneration flue gas. Part of the regeneration flue gas is mixed with the hydrogen sulfide-containing acid gas entering from the inlet for hydrogen sulfide-containing acid gas and enters the combustion furnace. Part of the regeneration flue gas is mixed with the Claus tail gas entering from the inlet for Claus tail gas of the sulfur production unit and enters the hydrogenation furnace. By using the above-mentioned sulfur recovery unit, the sulfur-containing substance emission of the sulfur recovery unit can be reduced under the condition of using conventional hydrogenation catalyst. However, due to the fluctuation of SZorb regeneration flue gas, the normal operation of the sulfur production combustion furnace will be affected. In addition, the hydrogen consumption is large and the operation cost is high when hydrogenation treatment is performed on SO2 in the SZorb regeneration flue gas. SUMMARY

[0007] In view of the deficiencies of the prior art, the present application provides a treatment method and device for SZorb device regeneration flue gas.

[0008] The treatment method for SZorb device regeneration flue gas provided by the present application comprises the following contents:

[0009] (1) The SZorb device regeneration flue gas is transported to a pretreatment unit, and the pretreatment unit comprises cooling-compression-condensation treatment;

[0010] (2) After pretreatment, the flue gas is transported to an adsorption unit to adsorb SO2 in the flue gas, and the purified gas after adsorption is reused in the SZorb device;

[0011] (3) After adsorption, desorption is carried out, and a stable vacuum desorption gas amount unit is used for regulation and control, and the vacuum desorption gas is stably transported to a sulfur recovery device, so as to realize near-zero emission of the SZorb device regeneration flue gas.

[0012] In the present application, the SZorb device regeneration flue gas is the flue gas generated in the adsorbent regeneration process of the SZorb catalytic gasoline adsorption desulfurization production device, the volume content of SO2 in the flue gas is 0.5% to 7%, the volume content of N2 is more than 85%, the volume content of H2O is 2% to 4%, the volume content of CO2 is 1% to 4%, and the volume content of O2 is less than 0.5%.

[0013] In the present application, the initial temperature of the SZorb device regeneration flue gas is generally above 150℃, and after cooling in the pretreatment unit, the temperature is reduced to below 80℃, preferably 40 to 60℃; after cooling, the flue gas is compressed to increase the pressure to 0.1 to 1.5MPaG, preferably 0.2 to 0.8MPaG; after pressurization, the flue gas is condensed to reduce the temperature to 5 to 50℃, preferably 10 to 45℃.

[0014] In the present application, after pretreatment, the regeneration flue gas is transported to the adsorption unit to adsorb SO2 in the flue gas, and the adsorption unit is composed of two or more adsorption tanks and operates alternately.

[0015] In the present application, the adsorption conditions of the adsorption unit are as follows: the adsorption temperature is 10 to 40℃; the adsorption pressure is 0.1 to 1.5MPaG, and the volume space velocity of adsorption is 50 to 1000h -1 .

[0016] In the application, the adsorption tank is filled with SO2 adsorption material, which can be at least one of activated carbon, silica gel, molecular sieve, etc., preferably the SO2 adsorption material described in CN201811651651.1, CN201811651640.3, CN202011166063.6, CN201811651667.2, etc.

[0017] In the application, when the SO2 adsorbent adsorbs breakthrough, the adsorption-desorption switching operation is performed. Desorption can use vacuum desorption, vacuum thermal desorption, etc., preferably vacuum desorption combined with periodic vacuum thermal desorption. The switching control of adsorption-desorption is double controlled according to time and SO2 adsorption breakthrough concentration. The normal adsorption-desorption switching is performed by setting time, and the SO2 adsorption breakthrough concentration is set to 5-100 mg / m 3 , preferably 10-50 mg / m 3 When the set adsorption-desorption switching time is not reached, but the SO2 concentration of the purified gas is monitored to exceed the set breakthrough concentration, switching is performed, and the switching time is optimized according to the breakthrough time.

[0018] In the application, vacuum desorption is specifically divided into three steps: the first step is to release the pressure of the adsorption tank, and the released gas is mixed with the SZorb device regeneration flue gas for adsorption treatment; the second step is to start the vacuum pump to perform vacuum desorption on the adsorption material, and recover SO2 resources; the third step is to use purge gas to purge the adsorption material after vacuum desorption, and the pressure of the adsorption tank during purging is 10-110 KPaA. If necessary, increase the temperature of the purge gas source to 50-80℃ to improve the purging effect. The purge discharge gas is mixed with the SZorb device regeneration flue gas for adsorption treatment. The purge gas can use nitrogen, etc., preferably the adsorption purified gas.

[0019] In the present application, the desorption gas generated by vacuum desorption is transported to a sulfur recovery device. In order to reduce the impact of the desorption gas on the sulfur recovery device, the following desorption method is adopted: a frequency conversion vacuum device is used for regeneration, a pressure gauge is arranged at the inlet and outlet of the vacuum device, a communication side line is arranged between the pipelines in front of the inlet and outlet pressure gauges, a regulating valve I is arranged on the side line, a regulating valve II and a flow limiting device are connected in parallel after the outlet pressure gauge, a concentration analyzer and a flow meter are sequentially arranged, a communication cross line is arranged between the pipelines in front of the adsorption device and the concentration analyzer, a regulating valve III is arranged on the cross line, and the outlet gas volume is controlled through the flow meter; before starting vacuum desorption, the regulating valves I and III are opened, and the regulating valve II is closed; after starting, a three-stage control mode is adopted to keep the outlet concentration and gas volume stable, the first-stage control is realized by forming a closed-loop control through the association of the concentration analyzer, the regulating valve II and the flow limiting device, the second-stage control is realized by forming a closed-loop control through the association of the concentration analyzer and the regulating valve I, and the third-stage control is realized by forming a closed-loop control through the association of the concentration analyzer and the vacuum device; when the frequency of the vacuum device reaches 100% of the maximum frequency, and the outlet SO2 concentration still cannot be maintained, the vacuum desorption operation is stopped; at this time, the gas volume is maintained through the regulating valve III and the flow meter, and the above process is repeated in the next regeneration cycle.

[0020] In the above-mentioned vacuum desorption method, before starting vacuum desorption, the regulating valve I and the regulating valve III are opened, and the regulating valve II is closed; the opening degree of the regulating valve I is controlled to be 10% to 100%, and is preferably 60% to 80%.

[0021] In the above-mentioned vacuum desorption method, before starting vacuum desorption, the frequency conversion of the vacuum device is set to 10% to 90% of the total frequency, and is preferably 40% to 60%.

[0022] In the above-mentioned vacuum desorption method, after starting vacuum desorption, the first-stage control is performed, the regulating valve II is gradually opened to stabilize the outlet SO2 concentration, when the regulating valve II is close to full opening, the second-stage control is started because the SO2 concentration still cannot be maintained; in the second-stage control, the regulating valve I is gradually closed, and when the regulating valve I is close to full closing, the third-stage control is started; in the third-stage control, the frequency of the vacuum device is gradually increased, and when the frequency reaches 100% of the maximum frequency, the vacuum desorption operation is stopped because the SO2 concentration still cannot be stabilized.

[0023] In the above-mentioned vacuum desorption method, in the first-stage control, the outlet pressure of the vacuum device is limited to 1 to 30 KPaG by the flow limiting device, and is preferably 2 to 10 KPaG. The opening degree of the regulating valve II is controlled through the concentration analyzer, that is, according to the preset SO2 concentration, a signal is transmitted to the regulating valve II to control the opening degree, so as to stabilize the SO2 concentration in the vacuum desorption gas. When the regulating valve II is close to full opening, that is, the opening degree is not less than 90%, the second-stage control is started because the preset SO2 concentration still cannot be maintained.

[0024] In the above vacuum desorption method, in the second stage regulation, in order to stabilize the SO2 concentration at the outlet, the valve I is gradually closed, and when it is close to full closing, the third stage regulation is started.

[0025] In the above vacuum desorption method, in the third stage regulation, in order to stabilize the SO2 concentration at the outlet and ensure the vacuum desorption effect, the frequency of the vacuum equipment reaches 100% of the maximum frequency, the vacuum pump inlet pressure gauge reaches 0-8KPaA, preferably 2-6KPaA, and still maintains until the end of the vacuum desorption.

[0026] In the above vacuum desorption method, according to the requirements of the sulfur recovery device, the preset range of gas amount is determined, and when the gas amount is insufficient during the vacuum desorption process, the SZorb regeneration flue gas is introduced into the vacuum desorption system under the regulation of the flow meter and the regulating valve III, the gas amount is controlled within the preset range, the stability of the subsequent gas amount entering the sulfur recovery device is ensured, and the above process is repeated in the next regeneration cycle.

[0027] In the present application, the multi-adsorption tank operation mode is preferred, the overall vacuum desorption time is less than or equal to the adsorption time, the purification effect of high-concentration SO2 is ensured, and the vacuum desorption process is continuous, so that the continuous and stable operation of the vacuum regeneration equipment and the stability of the vacuum desorption gas amount and concentration are ensured.

[0028] In the present application, after the adsorption material is adsorbed and desorbed for multiple times, when the breakthrough adsorption amount of the adsorption material is reduced to below 85% of the initial breakthrough adsorption amount, the adsorption material is subjected to vacuum thermal desorption, and the adsorption purified gas or nitrogen gas is used as the gas source, the temperature is 80-300℃, and the desorption gas is mixed with the SZorb device regeneration flue gas for treatment.

[0029] In the present application, the SO2 concentration in the adsorbed purified gas meets the emission requirements, the nitrogen gas volume concentration is greater than 95%, and the rest is CO2 and H2O, preferably the nitrogen gas required for SZorb device regeneration, and can also be used as a refinery storage tank protection gas. When used in the SZorb device, the purified gas is first heat-exchanged with the SZorb flue gas to be treated, on the one hand to reduce the temperature of the SZorb flue gas, and on the other hand to increase the temperature of the purified gas, so as to achieve the purpose of energy saving.

[0030] In the present application, through the reuse between the purified gas and the SZorb device in the system, the CO2 in the purified gas is enriched after circulation, and the concentration can reach more than 10%, which can be captured by adsorption method, membrane method and organic amine adsorption method, thereby reducing the capture cost and reducing CO2 emission.

[0031] The application also provides a device for the above-mentioned flue gas treatment method for regeneration of the SZorb device, mainly comprising a pretreatment unit, an adsorption unit and a stable vacuum desorption gas amount unit, wherein the pretreatment unit is used for cooling-compression-condensation of the flue gas, the adsorption unit mainly comprises two or more adsorption tanks and can be operated alternately and is used for adsorption of SO2 in the flue gas; the purified gas after adsorption is used for the SZorb device; the stable vacuum desorption gas amount unit mainly comprises a variable frequency vacuum device and a three-stage control system, pressure gauges are arranged at the inlet and outlet of the vacuum device, a communication side line is arranged between the pipelines in front of the inlet and outlet pressure gauges, an adjusting valve I is arranged on the side line, adjusting valves II and flow limiting devices are arranged in parallel after the outlet pressure gauge, a concentration analyzer and a flow meter are arranged in sequence, a communication cross line is arranged between the pipeline in front of the adsorption tower and the concentration analyzer, an adjusting valve III is arranged on the cross line, and the outlet gas amount is controlled through the flow meter; the three-stage control system is adopted to keep the outlet SO2 concentration and gas amount stable, the first-stage control system mainly comprises the concentration analyzer, the adjusting valve II, the flow limiting device and the closed-loop control pipeline formed by the three; the second-stage control system mainly comprises the concentration analyzer and the adjusting valve I and the closed-loop control pipeline formed by the two; the third-stage control system mainly comprises the concentration analyzer and the vacuum device and the closed-loop control pipeline formed by the two; and the high-concentration SO2 gas generated by vacuum desorption is sent to a sulfur recovery device after the concentration and gas amount are stabilized.

[0032] Further, the device of the application comprises a CO2 capture unit, which is captured by an adsorption method, a membrane method or an organic amine adsorption method, so as to reduce the capture cost and reduce CO2 emission.

[0033] Compared with the prior art, the application has the following beneficial effects:

[0034] (1) According to the characteristics of the flue gas for regeneration of the SZorb device, a cooling-compression-condensation-adsorption-desorption process is adopted, the purified gas after adsorption is used for the SZorb device, and the desorption gas is transported to a sulfur recovery device, so as to avoid the impact of the fluctuation of the desorption gas concentration and gas amount on the sulfur recovery device, realize near-zero emission of the flue gas for regeneration of the SZorb device, and significantly improve the environmental protection and economic benefits.

[0035] (2) Generally, when the adsorbent is desorbed and regenerated, the gas amount and concentration of the vacuum desorption process fluctuate greatly, which will cause great impact on the subsequent sulfur recovery device. In order to avoid the use of compression and buffer facilities, the inventors of the application adopt a variable frequency vacuum desorption combined with a three-stage control mode, and introduce the SZorb regeneration flue gas into the vacuum desorption gas to control the gas amount, so as to linearize the nonlinear desorption process to the greatest extent, thereby ensuring the stability of the vacuum desorption gas concentration and gas amount, reducing the impact on the subsequent sulfur recovery device without increasing the buffer facilities.

[0036] (3) The combination of vacuum desorption and periodic vacuum thermal desorption is adopted. The depressurization gas, purging gas and thermal regeneration tail gas during vacuum desorption are all returned to the SZorb unit for regeneration flue gas to be mixed and treated, thus realizing the effective treatment of the waste gas emitted by the entire process.

[0037] (4) Based on the control of concentration and gas volume, the S Zorb regenerated flue gas is introduced into the vacuum desorption gas pipeline to control the gas volume, thereby increasing the vacuum desorption gas temperature, avoiding the generation of free water, and preventing corrosion of pipelines and equipment. In addition, the introduction of S Zorb regenerated flue gas into the vacuum desorption gas to control the gas volume recovers some heat and saves fuel consumption for the sulfur recovery unit.

[0038] (5) The purified gas after SO2 adsorption is recycled back to the S Zorb device. The CO2 concentration can be enriched to more than 10%, which helps to reduce the cost of CO2 capture and reduce CO2 emissions. Attached Figure Description

[0039] Figure 1 This is a flowchart illustrating one aspect of the processing method of the present invention.

[0040] Wherein: a-cooler, b-compressor, c-condenser, d-adsorption tank group, e-vacuum equipment, f-heater, g-SZorb adsorbent regenerator, h-SO2 online monitor, i-CO2 capture unit, j-stabilized vacuum desorption gas volume unit; 1-1-SZorb device regeneration flue gas to be treated, 1-2-SZorb device regeneration flue gas with stable flow rate, 2-cooled flue gas, 3-pressurized flue gas, 4-condensed flue gas, 5-condensate, 6-purified gas after adsorption, 7-depressurization gas, 8-vacuum desorption gas, 9-purge gas, 10-purge gas after heating (during thermal regeneration), 11-purge exhaust gas, 12-thermal regeneration tail gas, 13-purified gas after CO2 capture, 14-purified gas after heat recovery, 15-purified gas directly discharged.

[0041] Figure 2 This is a schematic flowchart of the stable vacuum desorption gas volume unit of the present invention;

[0042] Wherein: J1-Connecting side line, J2-Regulating valve I, J3-Inlet pressure gauge, e-Vacuum pump, J4-Vacuum pump frequency converter, J5-Outlet pressure gauge, J6-Regulating valve II, J7-Flow limiting device, J8-SO2 concentration analyzer, J9-Flow meter, J10-Regulating valve III, 16-Vacuum desorption gas sent to the desulfurization recovery unit; 101-First-stage control system, 102-Second-stage control system, 103-Third-stage control system, 104-Gas volume control. Detailed Implementation

[0043] The technical solution and its effects of the present invention will be further described in detail below with reference to specific embodiments. The embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following embodiments.

[0044] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments were purchased from conventional biochemical reagent stores. In this invention, v% refers to volume fraction.

[0045] The concentrations of SO2 and CO2 in the gas of this invention are detected using a flue gas analyzer.

[0046] The processing device of the present invention is as follows Figure 1 As shown, it mainly includes a cooling-compression-condensation unit, an adsorption unit, and a stable vacuum desorption gas volume unit. The cooling-compression-condensation unit mainly includes a cooler (a), a compressor (b), and a condenser (c). The adsorption unit mainly includes two or more adsorption tank groups (d), each filled with SO2 selective adsorption material. An online SO2 monitor (h) is installed at the outlet of the adsorption tank. The adsorption tank desorption and regeneration equipment mainly includes a desorption vacuum pump (e) and a heater (f). A circulating heating fan can be installed if necessary. The stable vacuum desorption gas volume unit (J) consists of a side line connecting the inlet and outlet of the vacuum pump (J1), regulating valve I (J2), vacuum pump inlet and outlet pressure gauges (J3 and J5), vacuum pump frequency converter (J4), flow limiting device bypass regulating valve II (J6), flow limiting device (J7), SO2 concentration analyzer (J8), flow meter (J9), and regulating valve III (J10). The vacuum desorption gas flow rate and concentration are stably regulated through the first-stage control system (101), the second-stage control system (102), the third-stage control system (103), and the gas volume control system (104).

[0047] The regenerated flue gas 1-1 from the SZorb unit first passes through cooler a, reducing its temperature to below 80℃. After cooling, flue gas 2 is pressurized by compressor b. The pressurized flue gas 3 then enters condenser c for condensation, controlling the flue gas temperature below 50℃. The condensate 5 is neutralized and discharged to the wastewater treatment plant. The condensed flue gas 4 then enters adsorption tank group d. The purified gas 6 after adsorption enters the online SO2 detector h, controlling the SO2 concentration in the purified gas to not exceed 50 mg / m³. 3The purified gas 6 mainly contains nitrogen, which meets the requirements of the purified gas 15. It is preferably returned to the SZorb unit regenerator g after heat exchange with the regenerated flue gas 1-1 of the SZorb unit. When the CO2 in the purified gas is enriched to a certain concentration, it is captured by the CO2 capture unit i. The adsorption tank group d is operated by switching multiple adsorption tanks. The adsorption tanks that have been penetrated are desorbed and regenerated at regular intervals. First, the pressure is released, and the depressurized gas 7 is returned to be mixed with the regenerated flue gas 1-1 of the SZorb unit for further treatment. After depressurization, the vacuum pump e is used to draw a vacuum for desorption. After the desorbed gas is stabilized by the stable vacuum desorption gas volume unit J, SO2 is recovered (for sulfur recovery devices, such as sulfur production devices or sulfuric acid production devices). Finally, nitrogen or the purified gas from the adsorption tank is used as the purging gas 9 to purge the adsorbent after vacuum desorption. If necessary, the heater f is started to heat the purging gas to improve the desorption effect. The purging exhaust gas 11 is returned to be mixed with the regenerated flue gas 1-1 of the SZorb unit for further treatment. When the adsorbent's adsorption capacity decreases, the adsorbent undergoes thermal regeneration. The thermal regeneration tail gas 12 is returned to be mixed with the regenerated flue gas 1-1 from the SZorb unit for further treatment.

[0048] A schematic flowchart of the control method for the vacuum desorption gas inlet sulfur recovery device of the present invention is attached. Figure 2 As shown, the system mainly includes a vacuum pump e (including a vacuum pump frequency converter J4) and a three-stage control system 101, 102, and 103. An inlet pressure gauge J3 and an outlet pressure gauge J5 are installed on the inlet and outlet pipelines of the vacuum pump, respectively. A connecting line J1 is installed between the pipelines before the inlet and outlet pressure gauges. A regulating valve I (J2) is installed on the connecting line J1. A regulating valve II (J6) and a flow restrictor J7 are connected in parallel after the outlet pressure gauge J5. Following these, an SO2 concentration analyzer J8 and a flow meter J9 are installed sequentially. A regulating valve III (J10) is installed on the S Zorb regeneration flue gas cross-line. The gas flow is regulated by the flow meter J9. Before vacuum desorption starts, regulating valves I and III are open, and regulating valve II is closed. The flow meter J9 and regulating valve III regulate the gas flow to keep it within a preset range. The vacuum pump frequency converter J4 is set to its initial frequency. After vacuum desorption starts, the three-stage control system and gas flow regulation maintain stable outlet SO2 concentration and gas flow.

[0049] The first-stage control system 101 mainly achieves closed-loop control through the interconnection of regulating valve II, flow limiting device J7, and SO2 concentration analyzer J8. The flow limiting device 8 limits the vacuum pump outlet pressure to 1–30 kPaG, preferably 2–10 kPaG. The SO2 concentration analyzer J8 regulates the opening of regulating valve II; that is, based on the preset SO2 concentration, a signal is transmitted to regulating valve II to control its opening, thereby stabilizing the SO2 sulfur concentration in the vacuum desorbed gas. When regulating valve II is nearly fully open (i.e., the opening is not less than 90%), and the preset SO2 concentration still cannot be maintained, the second-stage control system is activated.

[0050] The second-level control system 102 achieves closed-loop control by linking the regulating valve I and the SO2 concentration analyzer J8. To stabilize the SO2 concentration, the regulating valve I is gradually closed by automatic control. When the regulating valve I is close to being fully closed, the third-level control system is activated.

[0051] The third-level control system 103 is achieved through a closed-loop control formed by the SO2 concentration analyzer J8 and the vacuum pump frequency conversion component J4 of the frequency conversion vacuum pump e. In order to stabilize the SO2 concentration, the frequency of the vacuum equipment is gradually increased automatically. When the vacuum pump frequency gradually reaches 100% of the maximum frequency, the vacuum pump inlet pressure gauge J3 finally reaches 0-8 kPaA and is maintained until the vacuum regeneration operation ends.

[0052] During the vacuum desorption process, the gas flow is stabilized by flow meter J9 and regulating valve Ⅲ. When the gas flow is insufficient, the flow rate of S Zorb regeneration flue gas 1-2 is adjusted to maintain the preset gas flow rate and ensure that the gas flow rate entering the sulfur recovery unit is stable. The above process is repeated in the next regeneration cycle.

[0053] In this embodiment of the invention, the regenerated flue gas of the SZorb unit originates from the flue gas generated during the regeneration of the adsorbent in the SZorb catalytic gasoline adsorption desulfurization unit of a refinery. The flue gas contains 2%-5% SO2 by volume, 2%-4% CO2 by volume, less than 0.2% O2 by volume, 2%-4% H2O by volume, with N2 as the main component. The flue gas temperature is approximately 180℃, the pressure is 120 kPaG, and the flue gas volume is 1500-2500 Nm³. 3 / h.

[0054] Example 1

[0055] Using the appendix of this invention Figure 1 The process described above includes an adsorption unit comprising five parallel adsorption tanks, filled with SO2 adsorption material prepared according to Example CN201811651651.1.

[0056] The SZorb device regenerates flue gas using the method described in this invention. Figure 1 The process involves first cooling to 50°C, pressurizing to approximately 0.8 MPaG, then condensing and cooling to 15°C before entering the adsorption tank assembly. The adsorption temperature is 15–30°C, the adsorption pressure is 0.7–0.8 MPaG, and the volumetric hourly space velocity (HSV) is approximately 200 h⁻¹. -1 The adsorption switching time was set to 15 minutes, and the SO2 concentration in the purified gas at the adsorption outlet was monitored to ensure that the breakthrough concentration did not exceed 50 mg / m³. 3The adsorption tank that has penetrated the adsorption is desorbed. First, the pressure is released, and the depressurized gas is returned to be mixed with the regeneration flue gas of the SZorb unit for further treatment. Then, vacuum desorption is performed. After the vacuum desorption gas has been stabilized at a certain flow rate and concentration, it is sent to the sulfur recovery workshop to produce sulfur. Finally, purging is performed using adsorption purified gas at a controlled temperature of 50-60℃. The purging exhaust gas is returned to be mixed with the regeneration flue gas of the SZorb unit for further treatment.

[0057] Using the appendix of this invention Figure 2 The control method stabilizes the flow rate and concentration of the vacuum desorption gas from the adsorbent. This desorption gas then enters the downstream sulfur production unit, requiring a stable flow rate of 200–300 Nm³. 3 The adsorption rate is [ / h], and the SO2 concentration needs to be as stable as possible. The vacuum desorption time for a single adsorption tank is 15 minutes.

[0058] A vacuum pump is used, and the flow limiting device is a pressure reducing valve. Before vacuum desorption starts, the initial opening of regulating valve I is 70%, regulating valve II is closed, and the outlet gas flow of the vacuum pump is regulated to 200 Nm³ using regulating valve III and a flow meter. 3 The vacuum pump frequency converter is set to 50% of the total frequency. After vacuum desorption starts, a three-stage control method is used to maintain stable SO2 concentration and flow rate at the outlet. The first stage control limits the vacuum pump outlet pressure to 5 kPaG through a flow limiting device, and controls the opening of regulating valve II through an SO2 concentration analyzer to stabilize the concentration at around 50% v%. When the opening of regulating valve II reaches 95%, it is still unable to maintain the SO2 concentration at the vacuum pump outlet, so the second stage control is activated. In the second stage control, to stabilize the SO2 concentration, regulating valve I is gradually closed from an initial 70% opening. When it is close to fully closed, the third stage control is activated. In the second stage control, to stabilize the SO2 concentration, the vacuum pump frequency converter gradually reaches 100% of the maximum frequency through automatic control, and finally the vacuum pump inlet pressure gauge reaches 2-6 kPaA until vacuum desorption ends. Throughout the regeneration process, the flow rate of gas entering the sulfur production unit is stabilized by appropriately introducing S Zorb flue gas. The basic control of the vacuum desorption gas flow rate sent to the sulfur production unit is 200-300 Nm³. 3 The SO2 volume concentration remained stable at 40%–50% per hour.

[0059] Monitoring with an online SO2 analyzer at the adsorption tank outlet showed that when the SO2 concentration in the purified gas exceeded 50 mg / m³... 3 If the adsorption tank fails to achieve effective desorption, it should be disconnected for vacuum thermal desorption. After thermal regeneration, the five adsorption tanks will resume alternating adsorption-desorption operation. Under normal circumstances, the five adsorption tanks will switch operation. If the SO2 concentration in the purified gas at the outlet of a particular adsorption tank exceeds 15 mg / m³ for five consecutive times, this indicates that the adsorption tank has failed to achieve effective desorption. 3When the process is complete, the adsorption tank is disconnected for one vacuum thermal desorption operation, while the remaining four adsorption tanks continue to operate in alternating adsorption-desorption mode. Thermal regeneration uses the purified gas as the gas source, with a desorption temperature of 150–180°C. The thermal desorption exhaust gas is returned to be mixed with the regeneration flue gas from the SZorb unit for further treatment. After thermal regeneration, the alternating adsorption-desorption operation of the five adsorption tanks is resumed.

[0060] The purified flue gas from the S Zorb unit after adsorption and desulfurization using this method is returned to the S Zorb unit for regeneration. After a period of accumulation, the CO2 concentration can reach more than 10%, at which point an organic amine absorber is used for CO2 capture.

[0061] After one month of operation, the hourly average concentration of SO2 in the purified gas remained below 20 mg / m³. 3 With an N2 concentration exceeding 95%, the purified gas is used as a nitrogen resource. Part of it is returned to the SZorb unit's regeneration unit after heat exchange with the flue gas, while the remainder is used as inert protective gas in the storage tank. Simultaneously, SO2 resources are recovered, and CO2 is captured, achieving near-zero emissions from the SZorb unit's regeneration flue gas.

[0062] Example 2

[0063] Using the appendix of this invention Figure 1 The process described above includes an adsorption unit comprising five parallel adsorption tanks, filled with SO2 adsorption material prepared in Example 1 of CN201811651651.1.

[0064] The SZorb device regenerates flue gas using the method described in this invention. Figure 1 The process involves first cooling to 50°C, pressurizing to approximately 0.4 MPaG, then condensing and cooling to 15°C before entering the adsorption tank assembly. The adsorption temperature is 15–25°C, the adsorption pressure is 0.3–0.4 MPaG, and the volumetric hourly space velocity (VHSV) is approximately 100 h⁻¹. -1 The adsorption switching time was set to 10 minutes, and the SO2 concentration in the purified gas at the adsorption outlet was monitored to ensure that the breakthrough concentration did not exceed 50 mg / m³. 3 The adsorption tank that has penetrated the adsorption is desorbed. First, the pressure is released, and the depressurized gas is returned to be mixed with the regeneration flue gas of the SZorb unit for further treatment. Then, vacuum desorption is performed. After the vacuum desorption gas has been stabilized at a certain flow rate and concentration, it is sent to the sulfur recovery workshop to produce sulfur. Finally, purging is performed using adsorption purified gas, with the temperature controlled at 50-60℃. The purging exhaust gas is returned to be mixed with the regeneration flue gas of the SZorb unit for further treatment.

[0065] Using the appendix of this invention Figure 2 The control method stabilizes the flow rate and concentration of the vacuum desorption gas from the adsorbent. The vacuum desorption gas is then fed into the downstream sulfur production unit, where the gas flow rate is required to be stable at 200–300 Nm³. 3The adsorption rate is [ / h], and the SO2 concentration needs to be as stable as possible. The vacuum desorption time for a single adsorption tank is 10 minutes.

[0066] A vacuum pump is used, and the flow limiting device is a pressure reducing valve. Before vacuum desorption starts, the initial opening of regulating valve I is 60%, regulating valve II is closed, and the outlet gas flow of the vacuum pump is regulated to 200 Nm³ using regulating valve III and a flow meter. 3 The vacuum pump frequency converter is set to 60% of the total frequency. After vacuum desorption starts, a three-stage control method is used to maintain stable SO2 concentration and flow rate at the outlet. The first stage control limits the vacuum pump outlet pressure to 5 kPaG through a flow limiting device, and controls the opening of regulating valve II through an SO2 concentration analyzer to stabilize the concentration at around 50% v%. When the opening of regulating valve II reaches 90%, it is still unable to maintain the SO2 concentration at the vacuum pump outlet, so the second stage control is activated. In the second stage control, to stabilize the SO2 concentration, regulating valve I is gradually closed from the initial 60% opening. When it is close to fully closed, the third stage control is activated. In the second stage control, to stabilize the SO2 concentration, the vacuum pump frequency converter gradually reaches 100% of the maximum frequency through automatic control, and finally the vacuum pump inlet pressure gauge reaches 2-6 kPaA until vacuum desorption ends. Throughout the desorption process, the flow rate of gas entering the sulfur production unit is stabilized by appropriately introducing S Zorb flue gas. The basic control is that the flow rate of vacuum desorption gas sent to the sulfur production unit is 200-300 Nm³. 3 The SO2 volume concentration remained stable at 40%–50% per hour.

[0067] Monitoring with an online SO2 analyzer at the adsorption tank outlet showed that when the SO2 concentration in the purified gas exceeded 50 mg / m³... 3 If the adsorption tank fails to achieve effective desorption, it indicates that the adsorption tank has not been effectively desorbed. The adsorption tank should then be disconnected for vacuum thermal desorption. After thermal desorption, the alternating adsorption-desorption operation of the five adsorption tanks should be resumed. Under normal circumstances, the five adsorption tanks should be switched on. If the SO2 concentration in the purified gas at the outlet of any adsorption tank exceeds 15 mg / m³ for five consecutive times... 3 When the process is complete, the adsorption tank is disconnected for one vacuum thermal desorption operation, while the remaining four adsorption tanks continue to operate in alternating adsorption-desorption mode. Thermal desorption uses the purified gas as the gas source, with a desorption temperature of 180–200°C. The thermal desorption exhaust gas is returned to be mixed with the regeneration flue gas from the S Zorb unit for further treatment. After thermal desorption is completed, the alternating adsorption-desorption operation of the five adsorption tanks is resumed.

[0068] After the flue gas from the S Zorb unit is purified by adsorption and desulfurization using this method, it is returned to the S Zorb unit as regeneration gas for reuse. After a period of accumulation, the CO2 concentration can reach more than 10%, and CO2 is captured by using an organic amine absorber.

[0069] After one month of operation, the hourly average SO2 concentration in the purified gas remained below 35 mg / m³. 3The N2 concentration can reach over 95%. The purified gas is used as a nitrogen resource. Part of it is returned to the SZorb unit regeneration unit after heat exchange with the flue gas, and part of it is used as inert protective gas in the storage tank. At the same time, SO2 resources are recovered and CO2 is captured, achieving near-zero emissions of regeneration flue gas from the SZorb unit.

[0070] Example 3

[0071] Using the appendix of this invention Figure 1 The process described above includes an adsorption unit comprising five parallel adsorption tanks filled with SO2 adsorption material prepared in Example CN201811651640.3.

[0072] The SZorb device regenerates flue gas using the method described in this invention. Figure 1 The process involves first cooling to 50°C, pressurizing to approximately 0.8 MPaG, then condensing and cooling to 30°C before entering the adsorption tank assembly. The adsorption temperature is 30–40°C, the adsorption pressure is 0.7–0.8 MPaG, and the volumetric hourly space velocity (HSV) is approximately 150 h⁻¹. -1 The adsorption switching time was set to 15 minutes, and the SO2 concentration in the purified gas at the adsorption outlet was monitored to ensure that the breakthrough concentration did not exceed 50 mg / m³. 3 The adsorption tank that has penetrated the adsorption is desorbed. First, the pressure is released, and the depressurized gas is returned to be mixed with the regeneration flue gas of the SZorb unit for further treatment. Then, vacuum desorption is performed. After the vacuum desorption gas has been stabilized at a certain flow rate and concentration, it is sent to the sulfur recovery workshop to produce sulfur. Finally, purging is performed using adsorption purified gas at a controlled temperature of 50-60℃. The purging exhaust gas is returned to be mixed with the regeneration flue gas of the SZorb unit for further treatment.

[0073] Using the appendix of this invention Figure 2 The control method stabilizes the flow rate and concentration of the vacuum desorption gas from the adsorbent. This desorption gas then enters the downstream sulfur production unit, requiring a stable flow rate of 200–300 Nm³. 3 The adsorption rate is [ / h], and the SO2 concentration needs to be as stable as possible. The vacuum desorption time for a single adsorption tank is 15 minutes.

[0074] A vacuum pump is used, and the flow limiting device is a pressure reducing valve. Before vacuum desorption starts, the initial opening of regulating valve I is 60%, regulating valve II is closed, and the outlet gas flow of the vacuum pump is regulated to 200 Nm³ using regulating valve III and a flow meter. 3The vacuum pump frequency converter is set to 60% of the total frequency. After vacuum desorption starts, a three-stage control method is used to maintain stable outlet SO2 concentration and flow rate. The first stage control limits the vacuum pump outlet pressure to 5 kPaG through a flow limiting device, and controls the opening of regulating valve II through an SO2 concentration analyzer to stabilize the concentration at around 50% v%. When the opening of regulating valve II reaches 90%, it is still unable to maintain the SO2 concentration at the vacuum pump outlet, so the second stage control is activated. In the second stage control, to stabilize the SO2 concentration, regulating valve I is gradually closed from the initial 60% opening. When it is close to fully closed, the third stage control is activated. In the second stage control, to stabilize the SO2 concentration, the vacuum pump frequency converter gradually reaches 100% of the maximum frequency through automatic control, and finally the vacuum pump inlet pressure gauge reaches 2-6 kPa until vacuum desorption ends. Throughout the regeneration process, the flow rate of gas entering the sulfur production unit is stabilized by appropriately introducing S Zorb flue gas. The basic control of the vacuum desorption gas flow rate sent to the sulfur production unit is 200-300 Nm³. 3 The SO2 volume concentration remained stable at 40%–50% per hour.

[0075] Monitoring with an online SO2 analyzer at the adsorption tank outlet showed that when the SO2 concentration in the purified gas exceeded 50 mg / m³... 3 If the adsorption tank fails to achieve effective desorption, it indicates that the adsorption tank has not been effectively desorbed. The adsorption tank should then be disconnected for vacuum thermal desorption. After thermal desorption, the alternating adsorption-desorption operation of the five adsorption tanks should be resumed. Under normal circumstances, the five adsorption tanks should be switched on. If the SO2 concentration in the purified gas at the outlet of any adsorption tank exceeds 15 mg / m³ for three consecutive times... 3 When the process is complete, the adsorption tank is disconnected for one vacuum thermal desorption operation, while the remaining four adsorption tanks continue to operate in alternating adsorption-desorption mode. Thermal desorption uses the purified gas as the gas source, with a desorption temperature of 180–200°C. The thermal desorption exhaust gas is returned to be mixed with the regeneration flue gas from the SZorb unit for further treatment. After thermal desorption is completed, the alternating adsorption-desorption operation of the five adsorption tanks is resumed.

[0076] After the flue gas from SZorb undergoes adsorption and desulfurization using this method, the purified gas is returned to the SZorb unit for regeneration and reuse. After a period of accumulation, the CO2 concentration can reach more than 10%, at which point an organic amine absorber is used for CO2 capture.

[0077] After one month of operation, the hourly average SO2 concentration in the purified gas remained below 30 mg / m³. 3 The N2 concentration can reach over 95%. The purified gas is used as a nitrogen resource. Part of it is returned to the SZorb unit regeneration unit after heat exchange with the flue gas, and part of it is used as inert protective gas in the storage tank. At the same time, SO2 resources are recovered and CO2 is captured. Near-zero emissions of regeneration flue gas from the SZorb unit are achieved.

[0078] Example 4

[0079] Same as Example 1, except that: ordinary activated carbon is used as the adsorbent, and the volume hourly space velocity of the adsorbent is not greater than 100 h⁻¹. -1 The SO2 concentration in the purified gas at the adsorption tank outlet will exceed 50 mg / m³. 3 After one month of operation, the hourly average SO2 concentration in the purified gas remained consistently between 40 and 60 mg / m³. 3 .

[0080] Comparative Example 1

[0081] Similar to Example 1, but with the difference that only the adsorption-desorption switching operation of the adsorption tank is performed according to time, without online monitoring of the SO2 concentration in the purified gas. Because the adsorption tanks that failed to desorb effectively cannot be switched out and processed in a timely manner, the purified gas concentration cannot be consistently below 50 mg / m³. 3 The purification requirements.

[0082] Comparative Example 2

[0083] Similar to Example 1, but with the difference that the switching operation of the adsorption tank is only based on the online monitoring of the SO2 concentration in the adsorbed purified gas, instead of using a time-based adsorption-desorption switching operation. Because the switching time varies significantly each time, the vacuum desorption time also varies, sometimes resulting in a long desorption time and unstable desorbed gas concentration, and sometimes insufficient desorption time, preventing the adsorbent from being fully desorbed, thus hindering the long-term stable operation of the device.

[0084] Comparative Example 3

[0085] Similar to Example 1, but with the difference that: no stable vacuum desorption gas flow unit was set up to regulate the vacuum desorption gas, resulting in large fluctuations in the vacuum desorption gas, with SO2 concentration fluctuating between 20% and 80% and gas flow rate between 20 and 250 Nm³. 3 Fluctuations in the hourly rate affect the stable operation of the sulfur production unit.

Claims

1. A method for treating a regeneration flue gas of a SZorb unit, characterized in that The application relates to a method for recycling SZorb device regeneration flue gas. The method comprises the following steps: (1) the SZorb device regeneration flue gas is transported to a pretreatment unit, and the pretreatment unit comprises a cooling-compression-condensation treatment; (2) the pretreated flue gas is transported to an adsorption unit, and SO2 in the flue gas is adsorbed, and the purified gas is reused in the SZorb device; (3) desorption is carried out after adsorption, a stable vacuum desorption gas amount unit is adopted for regulation and control, the vacuum desorption gas is stably transported to a sulfur recovery device, and near-zero emission of the SZorb device regeneration flue gas is realized. In order to reduce the impact of the desorption gas on the sulfur recovery device, the following desorption method is adopted: a variable frequency vacuum device is adopted for regeneration, pressure gauges are arranged at the inlet and outlet of the vacuum device, a communication side line is arranged between the pipelines in front of the inlet and outlet pressure gauges, an adjusting valve I is arranged on the side line, an adjusting valve II and a flow limiting device are connected in parallel after the outlet pressure gauge, a concentration analyzer and a flowmeter are sequentially arranged, a communication cross line is arranged between the pipelines in front of the adsorption device and the concentration analyzer, an adjusting valve III is arranged on the cross line, and the outlet gas amount is regulated and controlled through the flowmeter; before starting the vacuum desorption, the adjusting valves I and III are opened, and the adjusting valve II is closed; the opening degree of the adjusting valve I is controlled to be 10%-100%; the variable frequency of the vacuum device is set to be 10%-90% of the total frequency; after starting, a three-stage regulation and control mode is adopted to keep the outlet concentration and gas amount stable, first-stage regulation and control is realized through the correlation of the concentration analyzer, the adjusting valve II and the flow limiting device, the outlet pressure of the vacuum device is limited to be 1-30KPaG through the flow limiting device, and the opening degree of the adjusting valve II is regulated and controlled through the concentration analyzer, that is, according to the preset SO2 concentration, a signal is transmitted to the adjusting valve II to control the opening degree, so that the SO2 concentration in the vacuum desorption gas is stabilized; in order to stabilize the outlet SO2 concentration, the adjusting valve II is gradually opened, when the adjusting valve II is close to full opening, that is, the opening degree is not less than 90%, the SO2 concentration still cannot be kept, the second-stage regulation and control is started; the second-stage regulation and control is realized through the correlation of the concentration analyzer and the adjusting valve I, in order to stabilize the outlet SO2 concentration, the adjusting valve I is gradually closed, when the adjusting valve I is close to full closing, the third-stage regulation and control is started; the third-stage regulation and control is realized through the correlation of the concentration analyzer and the vacuum device, in order to stabilize the outlet SO2 concentration and ensure the vacuum desorption effect, the frequency of the vacuum device is gradually increased, when the frequency of the vacuum device reaches 100% of the maximum frequency, the inlet pressure gauge of the vacuum pump reaches 0-8KPaA, and the outlet SO2 concentration still cannot be kept, the vacuum desorption operation is stopped; according to the requirement of the sulfur recovery device, the preset range of the gas amount is determined, when the gas amount is insufficient in the vacuum desorption process, the gas amount is maintained under the regulation and control of the flowmeter and the adjusting valve III, the SZorb regeneration flue gas is introduced into the vacuum desorption system, the gas amount is controlled in the preset range, the stability of the gas amount entering the sulfur recovery device is ensured, and the above process is repeated in the next regeneration period.

2. The method of claim 1, wherein: The regeneration flue gas of SZorb device is the flue gas generated in the regeneration process of the adsorbent of the SZorb catalytic gasoline adsorption desulfurization production device, the volume content of SO2 in the flue gas is 0.5%-7%, the volume content of H2O is 2%-4%, the volume content of CO2 is 1%-4%, the volume content of O2 is less than 0.5%, and the volume content of N2 is more than 85%.

3. The method of claim 1, wherein: The initial temperature of the regeneration flue gas of the SZorb device is above 150 DEG C, and the temperature is reduced to below 80 DEG C in the pretreatment unit through cooling; after cooling, the flue gas is compressed to be pressurized to 0.1-1.5 MPaG; after pressurization, the flue gas is condensed to reduce the temperature of the flue gas to 5-50 DEG C.

4. The method of claim 3, wherein: The temperature is reduced to 40-60 DEG C in the pretreatment unit through cooling; after cooling, the flue gas is compressed to be pressurized to 0.2-0.8 MPaG; after pressurization, the flue gas is condensed to reduce the temperature of the flue gas to 10-45 DEG C.

5. The method of claim 1, wherein: The adsorption unit is composed of two or more adsorption tanks, which are operated alternately. The adsorption conditions of the adsorption unit are as follows: adsorption temperature is 10-40℃; adsorption pressure is 0.1-1.5MPaG; and the volume space velocity of adsorption is 50-1000h -1 .

6. The method of claim 5, wherein: The SO2 adsorption material filled in the adsorption tank is at least one of activated carbon, silica gel and molecular sieve.

7. The method of claim 1, wherein: When the SO2 adsorbent is adsorbed to be penetrated, the adsorption-desorption switching operation is carried out; the desorption adopts vacuum desorption or / and vacuum thermal desorption.

8. The method of claim 1, wherein: The desorption adopts vacuum desorption and periodic vacuum thermal desorption in combination.

9. The method of claim 1 or 7, wherein: The switch control of adsorption-desorption is double controlled according to time and SO2 adsorption breakthrough concentration. The adsorption-desorption switch is normally carried out by setting time, and the SO2 adsorption breakthrough concentration is set to be 5-100 mg / m 3 When the SO2 concentration of the purified gas exceeds the set breakthrough concentration before the set adsorption-desorption switch time, the switch is carried out, and the switch time is optimized according to the breakthrough time.

10. The method of claim 9, wherein: The SO2 adsorption breakthrough concentration was set to 10-50 mg / m 3 .

11. The method of claim 1, wherein: The vacuum desorption is specifically divided into three steps: in the first step, the adsorption tank is depressurized, the depressurization gas is mixed with the regeneration flue gas of the SZorb device to carry out adsorption treatment; in the second step, the vacuum pump is started to carry out vacuum desorption on the adsorption material to recover SO2 resources; in the third step, the adsorption material after vacuum desorption is purged by using purge gas, and the pressure of the adsorption tank is 10-110 KPaA during purging.

12. The method of claim 11, wherein: The temperature of the purge gas is increased to 50-80 DEG C.

13. The method of claim 1, wherein: Before the vacuum desorption is started, the regulating valve I and the regulating valve III are opened, and the regulating valve II is closed; the opening degree of the regulating valve I is controlled to be 60%-80%.

14. The method of claim 1, wherein: Before the vacuum desorption is started, the frequency conversion of the vacuum equipment is set to be 40%-60% of the total frequency.

15. The method of claim 1, wherein: In the first level regulation, the outlet pressure of the vacuum equipment is limited to be 2-10 KPaG by using the flow limiting equipment.

16. The method of claim 1, wherein: In the third level regulation, the inlet pressure table of the vacuum pump reaches 2-6 KPaA.

17. The method of claim 1, wherein: The adsorption unit adopts a multi-adsorption tank operation mode, and the overall vacuum desorption time is less than or equal to the adsorption time.

18. The method of claim 1, wherein: After the adsorption material is adsorbed-desorbed for multiple times, when the penetrated adsorption amount is reduced to be below 85% of the initial penetrated adsorption amount, the adsorption material is subjected to vacuum thermal desorption, the temperature of the adsorption purified gas or nitrogen gas is 80-300 DEG C, and the desorption gas is mixed with the regeneration flue gas of the SZorb device to carry out treatment.

19. The method of claim 1, wherein: The SO2 concentration in the purified gas after adsorption meets the emission requirement, the purified gas is used as the nitrogen gas required by the regeneration of the SZorb device, or is used as the protection gas of the storage tank of the refinery; When the purified gas is used in the SZorb device, the purified gas is first heat-exchanged with the SZorb flue gas to be treated.

20. The method of claim 1, wherein: Through the reuse between the purified gas and the SZorb device, the CO2 in the purified gas is enriched after circulation, and the concentration reaches more than 10%, and the CO2 is captured by using the adsorption method, the membrane method or the organic amine adsorption method.

21. An apparatus for a flue gas treatment process for regenerating a SZorb unit as defined in any one of claims 1-20, characterized by: It mainly comprises a pretreatment unit, an adsorption unit and a stable vacuum desorption gas quantity unit, wherein the pretreatment unit is used for cooling-compression-condensation of flue gas, the adsorption unit mainly comprises two or more adsorption tanks which are alternately operated and used for SO2 adsorption in flue gas, and the purified gas after adsorption is used for an SZorb device; the stable vacuum desorption gas quantity unit mainly comprises a variable frequency vacuum device and a three-stage control system, the first-stage control system mainly comprises a concentration analyzer, a regulating valve II, a flow limiting device and a closed-loop control pipeline formed by the three, the second-stage control system mainly comprises a concentration analyzer and a regulating valve I and a closed-loop control pipeline formed by the two, and the third-stage control system mainly comprises a concentration analyzer and a vacuum device and a closed-loop control pipeline formed by the two.

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