A control method and device for feeding vacuum regeneration gas into a sulfur production device

Abstract

The present invention relates to a method and device for controlling the flow of vacuum regeneration gas into a sulfur production device. After adsorption, the S Zorb regeneration flue gas is regenerated using a variable frequency vacuum device. Pressure gauges are installed at the inlet and outlet of the vacuum device. A connecting lateral line is provided between the pipelines preceding the inlet and outlet pressure gauges. A regulating valve I is installed on the lateral line. A regulating valve II and a flow limiting device are installed in parallel after the outlet pressure gauge. A concentration analyzer and a flow meter are then installed. A connecting crossover line is provided between the pipelines preceding the adsorption device and the concentration analyzer. A regulating valve III is installed on the crossover line. The outlet gas volume is controlled by the flow meter. After vacuum regeneration is initiated, three-stage control and gas volume control are used to maintain stable concentration and volume. The present invention achieves stable SO2 concentration and volume in the vacuum regeneration gas generated after adsorption of the S Zorb regeneration flue gas without requiring buffer facilities, reducing impact on subsequent sulfur production devices and achieving excellent operational stability.

Description

Technical Field

[0001] The invention belongs to the technical field of air pollution control, and in particular relates to a control method and device for feeding vacuum regeneration gas into a sulfur-making device. Background Art

[0002] S Zorb units are primarily used for catalytic gasoline adsorption desulfurization. Currently, dozens of these units exist in China. These units comprise four components: feed and adsorption desulfurization reaction, adsorbent regeneration, adsorbent circulation, and product stabilization. During the adsorbent air oxidation regeneration process, S Zorb regeneration flue gas, primarily containing sulfur dioxide, requires treatment.

[0003] At present, the widely used desulfurization technologies can be divided into wet desulfurization technology and dry desulfurization technology. Existing desulfurization technologies can be divided into three categories according to the degree of recycling of desulfurization products: the first category is that sulfur dioxide cannot be recycled or is difficult to reuse after removal, such as the gypsum method and the calcium carbide slag method. These methods produce a large amount of liquid or solid waste, causing secondary pollution. The second category is to convert sulfur dioxide into dilute sulfuric acid or sulfate through chemical oxidation or catalytic oxidation, such as the hydrogen peroxide oxidation method, the ammonia oxidation method, the activated carbon wet catalytic method, etc. For example, patent CN105381699A records the use of hydrogen peroxide to remove sulfur dioxide, and patent CN101085410A records the method of converting sulfur dioxide in flue gas into ammonium sulfate. This type of technology requires the continuous consumption of oxidants or catalysts, involves the supply radius and cost of the reagents, and is inconvenient to use in remote areas. The third type is to absorb or adsorb low-concentration sulfur dioxide gas and then desorb and regenerate it to obtain high-concentration sulfur dioxide gas, which can be used to produce liquid sulfur dioxide, enter the acid production section to produce sulfuric acid, or enter the sulfur production device to produce sulfur, etc.

[0004] CN111375274A discloses a method and device for treating SO2-containing gas, which mainly includes a compression unit, an adsorption unit and a regeneration unit, wherein the compression unit mainly includes a compressor for compressing the exhaust gas; the adsorption unit mainly includes two or more adsorption towers filled with modified zinc-based metal organic framework materials for adsorbing SO2; the regeneration unit mainly includes a vacuum pump, a nitrogen heater, etc., for desorption and regeneration to obtain high-concentration SO2. The desorption regeneration adopted in this patent adopts heating regeneration, vacuum regeneration or vacuum thermal regeneration, and the desorbed gas obtained is a high-purity SO2 gas, which can be used in situations where SO2 gas is needed, such as for sulfur recovery equipment to make sulfur, acidification treatment of waste alkali liquor from oil refineries, etc. However, if it is directly fed into the existing recycling device, it will cause a certain impact on it, and buffer facilities need to be added.

[0005] CN102380311A discloses a method for treating flue gas regenerated from gasoline adsorption desulfurization. The regenerated flue gas is introduced into the tail gas hydrogenation unit of a sulfur recovery device and mixed with Claus tail gas. This method uses a dedicated tail gas hydrogenation catalyst for treatment. The hydrogenated tail gas is absorbed and regenerated by a solvent, and the hydrogen sulfide is returned to the Claus unit for sulfur recovery. The purified tail gas is then incinerated in an incinerator and discharged in compliance with emission standards. This method not only recovers sulfur resources but also avoids environmental pollution. It is currently the most ideal treatment method for regenerated flue gas from gasoline adsorption desulfurization. However, introducing the regenerated flue gas directly into the hydrogenation unit, without a buffering facility, results in poor reaction stability due to the influence of the regeneration process.

[0006] After the S Zorb regeneration flue gas is treated by adsorption, the saturated adsorbent is generally regenerated by vacuum regeneration or / and vacuum thermal regeneration. The regeneration gas produced by vacuum regeneration is a gas containing a high concentration of sulfur dioxide. It can usually be fed into the refinery's sulfur production unit to produce sulfur or the acid production section to produce sulfuric acid. However, due to the operating curve and process characteristics of the vacuum pump, the vacuum regeneration gas volume and concentration are difficult to stabilize, and the gas volume fluctuates widely, significantly affecting the stable operation of the subsequent reuse device. To address this problem, in current industrial plant design practice, buffer facilities such as buffer tanks are generally installed after the vacuum regeneration equipment. Due to the low outlet pressure of the vacuum pump, the buffer tank size is large to meet the buffering effect. Some designs require connecting a compressor in series with the vacuum pump outlet to compress the vacuum regeneration gas before entering the buffer tank to reduce the buffer tank size and improve buffering efficiency. However, this will inevitably result in an increase in land occupation, operating costs, and primary investment costs. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention provides a method and apparatus for controlling the flow of vacuum regeneration gas into a sulfur production unit. This method stabilizes the SO2 concentration and volume of the vacuum regeneration gas generated after adsorption regeneration of the S Zorb regeneration flue gas, without requiring buffering facilities. This reduces the impact on subsequent sulfur production units and improves operational stability.

[0008] The first aspect of the present invention provides a method for controlling the feeding of vacuum regeneration gas into a sulfur production device, comprising the following contents:

[0009] After the S Zorb regeneration flue gas is treated by the adsorption equipment, it is regenerated by vacuum equipment. Pressure gauges are set at the inlet and outlet of the vacuum equipment. A connecting side line is set between the pipelines in front of the inlet and outlet pressure gauges. A regulating valve I is set on the side line. A parallel regulating valve II and a flow limiting device are set after the outlet pressure gauge. Then a concentration analyzer and a flow meter are set in sequence. A connecting cross-line is set between the pipelines in front of the adsorption equipment and the concentration analyzer. A regulating valve III is set on the cross-line. The outlet gas volume is regulated by the flow meter. Before the vacuum regeneration is started, regulating valves I and III are opened and regulating valve II is closed. After the vacuum regeneration is started, a three-stage Control is performed to maintain the outlet sulfur dioxide concentration and gas volume stable. The first-level control is achieved by linking the concentration analyzer, regulating valve II and current limiting equipment to form a closed-loop control. The second-level control is achieved by linking the concentration analyzer and regulating valve I to form a closed-loop control. The third-level control is achieved by linking the concentration analyzer and vacuum equipment to form a closed-loop control. When the vacuum equipment frequency reaches 100% of the maximum frequency and still cannot maintain the outlet sulfur dioxide concentration, the vacuum regeneration operation is stopped; at this time, the gas volume is maintained by regulating valve III and the flow meter, and the above process is repeated in the next regeneration cycle.

[0010] In the method of the present invention, the S Zorb regeneration flue gas is the flue gas generated during the adsorbent regeneration process of the S Zorb catalytic gasoline adsorption desulfurization production device, with a SO2 concentration of 0.5v% to 7v%, an O2 volume content of less than 0.5%, and a temperature of 150 to 240°C.

[0011] In the method of the present invention, the S Zorb regeneration flue gas is subjected to adsorption treatment in an adsorption device, the adsorption pressure is 0.3-0.9 MPaG, and the adsorption time is 5-20 minutes.

[0012] In the method of the present invention, before vacuum regeneration is started, regulating valves I and III are opened, and regulating valve II is closed. The opening of regulating valve I is controlled to be 10% to 100%, preferably 60% to 80%.

[0013] In the method of the present invention, before the vacuum regeneration is started, the frequency conversion of the vacuum equipment is set to 10% to 90% of the total frequency, preferably 40% to 60%.

[0014] In the method of the present invention, after vacuum regeneration is started, the first level of regulation is first performed. In order to stabilize the outlet sulfur dioxide concentration, the regulating valve II is gradually opened. When the regulating valve II is close to fully open, the sulfur dioxide concentration cannot be maintained, and the second level of regulation is started; during the second level of regulation, the regulating valve I is gradually closed. When the regulating valve I is close to fully closed, the third level of regulation is started; during the third level of regulation, the frequency of the vacuum equipment is gradually increased. When it reaches 100% of the maximum frequency and the sulfur dioxide concentration cannot be stabilized, the vacuum regeneration operation is stopped.

[0015] In the method of the present invention, during the first stage of control, a flow-limiting device limits the outlet pressure of the vacuum device to 1 to 30 kPaG, preferably 2 to 10 kPaG. A concentration analyzer controls the opening of control valve II. Specifically, a signal is transmitted to control valve II based on a preset sulfur dioxide concentration to control the opening, thereby stabilizing the sulfur dioxide concentration in the vacuum regeneration gas. When control valve II is nearly fully open (i.e., at least 90% open), but still cannot maintain the preset sulfur dioxide concentration, the second stage of control is initiated.

[0016] In the method of the present invention, in the second stage of regulation, in order to stabilize the outlet sulfur dioxide concentration, the regulating valve I is gradually closed, and when it is close to being fully closed, the third stage of regulation is started.

[0017] In the method of the present invention, in the third stage of regulation, in order to stabilize the outlet sulfur dioxide concentration, when the frequency of the vacuum equipment reaches 100% of the maximum frequency, further observation is made on the vacuum degree of the vacuum pump inlet pressure gauge to reach 90 kPa to absolute vacuum, preferably 96 to 99 kPa. If the sulfur dioxide concentration still cannot be maintained, vacuum regeneration is stopped.

[0018] In the method of the present invention, a preset range of gas volume is determined according to the requirements of the sulfur production device. During the vacuum regeneration process, when the gas volume is insufficient, the S Zorb regeneration flue gas is introduced into the vacuum regeneration system through the interconnecting jumper under the control of the flow meter and the regulating valve III, and the gas volume is controlled within the preset range to ensure the stability of the gas volume subsequently entering the sulfur production device. The above process is repeated in the next regeneration cycle.

[0019] In the method of the present invention, in order to stabilize the gas volume and concentration of the vacuum regeneration gas entering the downstream sulfur production device, it is preferred that the SZorb regeneration flue gas adsorption time and the vacuum regeneration time are equal.

[0020] In the method of the present invention, the adsorbent used to fill the S Zorb regeneration flue gas adsorption equipment is various porous adsorbents capable of adsorbing sulfur dioxide, such as at least one of activated carbon, molecular sieve, silica gel, etc.

[0021] In the method of the present invention, after the S Zorb regeneration flue gas is subjected to adsorption treatment in the adsorption equipment, the purified gas meets the emission standards, and the sulfur dioxide concentration in the vacuum regeneration gas generated by regeneration is increased, and the gas can be fed into the subsequent sulfur production device to produce sulfur.

[0022] The second aspect of the present invention provides a device for the control method of the above-mentioned vacuum regeneration gas feeding into the sulfur production device, which mainly includes adsorption equipment, variable frequency vacuum equipment and a three-stage control system. Pressure gauges are provided at the inlet and outlet of the vacuum equipment, and a connecting side line is provided between the pipelines in front of the inlet and outlet pressure gauges. A regulating valve I is provided on the side line. A parallel regulating valve II and a flow limiting device are provided after the outlet pressure gauge. Thereafter, a concentration analyzer and a flow meter are provided in sequence. A connecting cross-line is provided between the pipeline in front of the adsorption tower and the pipeline in front of the concentration analyzer. A regulating valve III is provided on the cross-line. The outlet gas volume is controlled by the flow meter. The three-stage control system is used to maintain the stability of the outlet sulfur dioxide concentration and gas volume. The first-stage control system mainly includes the concentration analyzer, the regulating valve II and the flow limiting device, and a closed-circuit control pipeline formed by the association of the three; the second-stage control system mainly includes the concentration analyzer and the regulating valve I, and a closed-circuit control pipeline formed by the association of the two; the third-stage control system mainly includes the concentration analyzer and the vacuum equipment, and a closed-circuit control pipeline formed by the association of the two.

[0023] In the device of the present invention, the adsorption tower is a packed tower conventionally used in the art, and is filled with a porous adsorbent for adsorbing S Zorb regeneration flue gas, such as at least one of activated carbon, molecular sieve, silica gel, etc.

[0024] In the apparatus of the present invention, the variable frequency vacuum equipment used for vacuum regeneration after S Zorb regeneration flue gas adsorption treatment is selected from a variable frequency vacuum pump capable of generating a vacuum degree of 90 kPa to absolute vacuum, such as, but not limited to, a screw vacuum pump, a liquid ring vacuum pump, a piston vacuum pump, a diaphragm vacuum pump, a rotary vane vacuum pump, and the like. The variable frequency vacuum pump adjusts the vacuum pump's vacuum capacity by adjusting the vacuum pump motor frequency.

[0025] In the device of the present invention, the flow limiting device is a device that can stably adjust the pressure before the valve, such as any one of a process manual valve, a one-way valve, a pressure reducing valve, an orifice plate, etc.

[0026] In the device of the present invention, before vacuum regeneration is started, regulating valves I and III are opened, and regulating valve II is closed; after vacuum regeneration is started, a three-level control system is used to maintain stable outlet sulfur dioxide concentration and gas volume.

[0027] In the device of the present invention, in the first-stage control system, the outlet pressure of the vacuum equipment is limited by the flow limiting device, and the opening of the control valve II is regulated by the concentration analyzer. When the control valve II is close to fully open and still cannot maintain the sulfur dioxide concentration, the second-stage control system is started.

[0028] In the device of the present invention, in the second-stage control system, in order to stabilize the sulfur dioxide concentration, the regulating valve I is gradually closed, and when it is close to being fully closed, the third-stage control system is started.

[0029] In the device of the present invention, in the third-level control system, when the frequency of the vacuum equipment reaches 100% of the maximum frequency, further observation is made on the vacuum degree of the vacuum pump inlet pressure gauge to reach 90 kPa to absolute vacuum, preferably 96 to 99 kPa, and if the sulfur dioxide concentration still cannot be maintained, vacuum regeneration is stopped.

[0030] In the device of the present invention, during the vacuum regeneration process, when the gas volume is insufficient, the S Zorb regeneration flue gas is introduced into the vacuum regeneration pipeline through the connecting jumper under the control of the flow meter and the regulating valve III, and the gas volume is controlled within a preset range to ensure the stability of the gas volume entering the subsequent sulfur production device, and the above process is repeated in the next regeneration cycle.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] (1) During adsorbent regeneration, the gas volume and concentration of vacuum regeneration fluctuate greatly, which can have a significant impact on subsequent recycling equipment. To avoid the use of compression and buffer facilities, the inventors of this application adopted variable frequency vacuum regeneration combined with a three-stage control method, and introduced S Zorb regeneration flue gas into the vacuum regeneration gas to control the gas volume, thereby linearizing the nonlinear regeneration process to the greatest extent possible, thereby ensuring the stability of the vacuum regeneration gas concentration and gas volume. Without adding buffer facilities, the impact on subsequent sulfur production equipment is reduced.

[0033] (2) The present invention maintains a stable sulfur dioxide concentration and gas volume in the vacuum regeneration gas by constructing a three-level closed-loop control method and introducing part of the S Zorb regeneration flue gas to control the gas volume. No additional compression or buffer equipment is required, thus reducing material consumption and investment costs.

[0034] (3) The inventors of this application discovered during experiments that due to the relatively low temperature of the vacuum regeneration gas, some water condensed out, causing air blockage or air hammer in the pipeline, thereby causing corrosion of the pipeline and equipment. To this end, the inventors introduced the S Zorb regeneration flue gas into the vacuum regeneration gas pipeline to control the gas volume, based on the control of concentration and gas volume. This increased the vacuum regeneration gas temperature, avoided the formation of free water, and prevented corrosion of the pipeline and equipment. In addition, by introducing the S Zorb regeneration flue gas into the vacuum regeneration gas to control the gas volume, some heat was recovered, saving fuel consumption entering the sulfur production device. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic flow chart of the method and apparatus of the present invention;

[0036] Among them, 1-Unicom side line, 2-control valve I, 3-inlet pressure gauge, 4-vacuum pump, 5-vacuum pump frequency conversion component, 6-outlet pressure gauge, 7-control valve II, 8-current limiting device, 9-sulfur dioxide concentration analyzer, 10-S Zorb regeneration flue gas, 11-Unicom cross-line, 12-control valve III, 13-flow meter, 14-vacuum regeneration gas from desulfurization device, 15-adsorption tower; 101-first-stage control system, 102-second-stage control system, 103-third-stage control system, 104-gas volume control. DETAILED DESCRIPTION

[0037] The method and apparatus of the present invention are further described in detail below with reference to the accompanying drawings and examples. The examples are based on the technical solutions of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following examples. In the present invention, v% refers to the volume fraction.

[0038] The experimental methods in the following examples, unless otherwise specified, are all conventional methods in the art. The experimental materials used in the following examples, unless otherwise specified, were purchased from conventional biochemical reagent stores.

[0039] The control method and flow diagram of the vacuum regeneration gas feeding sulfur production device of the present invention are shown in the attached figure. Figure 1 As shown, the system primarily comprises an adsorption tower 15, a vacuum pump 4 (including a vacuum pump frequency conversion assembly 5), and three-stage control systems 101, 102, and 103. An inlet pressure gauge 3 and an outlet pressure gauge 6 are installed on the vacuum pump's inlet and outlet pipelines, respectively. A connecting lateral line 1 is installed between the inlet and outlet pressure gauges, with a regulating valve I installed on the connecting lateral line 1. A regulating valve II and a flow limiting device 8 are installed in parallel after the outlet pressure gauge 6. A sulfur dioxide concentration analyzer 9 and a flow meter 13 are then installed. A connecting crossover line 11 is installed between the pipelines upstream of the adsorption tower 15 and upstream of the sulfur dioxide concentration analyzer 9. A regulating valve III is installed on the crossover line, and the gas volume is controlled by the flow meter 13. Before vacuum regeneration is initiated, regulating valves I and III are opened, while regulating valve II is closed. The flow meter 13 and regulating valve III regulate the gas volume to maintain it within a preset range, and the vacuum pump frequency conversion assembly 5 sets the initial frequency. After vacuum regeneration is initiated, the three-stage control system and gas volume control are used to maintain a stable outlet sulfur dioxide concentration and volume.

[0040] The first-stage control system 101 primarily operates through a closed-loop control system consisting of a control valve II, a flow-limiting device 8, and a sulfur dioxide concentration analyzer 9. The flow-limiting device 8 limits the vacuum pump outlet pressure to 1 to 30 kPaG, preferably 2 to 10 kPaG. The sulfur dioxide concentration analyzer 9 controls the opening of the control valve II. Based on the preset sulfur dioxide concentration, a signal is transmitted to the control valve II to control the opening, thereby stabilizing the sulfur dioxide concentration in the vacuum regeneration gas. When the control valve II is nearly fully open (i.e., at least 90% open), but still cannot maintain the preset sulfur dioxide concentration, the second-stage control system is activated.

[0041] The second-level control system 102 is realized by forming a closed-loop control through the association of the control valve I and the sulfur dioxide concentration analyzer 9. In order to stabilize the sulfur dioxide concentration, the control valve I is gradually closed through automatic control. When the control valve I is close to being fully closed, the third-level control system is started.

[0042] The third-level control system 103 is realized by closed-loop control formed by the association of the flow meter 13 and the vacuum pump frequency conversion component 5 of the variable frequency vacuum pump 4. In order to stabilize the sulfur dioxide concentration, the vacuum equipment frequency is automatically increased. When the vacuum pump frequency gradually reaches 100% of the maximum frequency, the vacuum pump inlet pressure gauge 3 is further observed. When the vacuum degree reaches 90KPa~absolute vacuum, the vacuum regeneration operation is stopped.

[0043] During the vacuum regeneration process, the gas volume is controlled by the flow meter 13 and the regulating valve III. When the gas volume is insufficient, the SZorb regeneration flue gas is introduced into the vacuum regeneration pipeline through the connecting jumper 11 to maintain the preset gas volume unchanged, ensuring that the gas volume entering the sulfur production device is stable, and the above process is repeated in the next regeneration cycle.

[0044] During the vacuum adsorption-regeneration process, in order to stabilize the gas volume and concentration of the vacuum regeneration gas entering the sulfur production unit, it is preferred that the adsorption time of the S Zorb regeneration flue gas be equal to the vacuum regeneration time.

[0045] Example 1

[0046] The volume concentration of SO2 in the regeneration flue gas of a certain enterprise's S Zorb device is 2% to 5%, the volume concentration of O2 is less than 0.2%, and the flue gas treatment capacity is about 2900Nm 3 After dust removal, cooling and compression, it enters the adsorption tower for adsorption. The adsorbent is activated carbon, the adsorption pressure is 0.6MPaG, and the adsorption time is 15min. Figure 1 The control device performs adsorption-vacuum regeneration, and the vacuum regeneration gas generated is fed into the downstream sulfur production device to produce sulfur. The sulfur production device requires the gas volume to be stable at 300-400Nm 3 / h, the concentration is stable at 45v%~55v%.

[0047] A liquid ring vacuum pump is used, and the flow limiting device is a pressure reducing valve. Before vacuum regeneration starts, the initial opening of regulating valve I is 70%, regulating valve II is closed, regulating valve III and flow meter are opened, and the vacuum pump outlet gas volume is adjusted to 300Nm 3 / h, and the vacuum pump frequency conversion was set to 50% of the total frequency. After vacuum regeneration was initiated, a three-stage control system was used to maintain stable outlet sulfur dioxide concentration and gas volume. The first stage of control used a flow-limiting device to limit the vacuum pump outlet pressure to 5 kPaG. A sulfur dioxide concentration analyzer was used to control the opening of control valve II, stabilizing the concentration at around 50%. When the opening of control valve II reached 95%, the sulfur dioxide concentration at the vacuum pump outlet could still not be maintained, and the second stage of control was initiated. During the second stage of control, control valve I was gradually closed from an initial opening of 70% to stabilize the sulfur dioxide concentration. When it approached full closure, the third stage of control was initiated. During the second stage of control, the vacuum pump frequency conversion component automatically reached its maximum frequency of 100% to stabilize the sulfur dioxide concentration. Further observation of the vacuum pump inlet pressure gauge revealed that the vacuum reached 96 kPa. When the sulfur dioxide concentration could not be maintained, vacuum regeneration was terminated. At this point, only the gas volume control remained open, and the above process was repeated for the next regeneration cycle. The test results are shown in Table 1.

[0048] Example 2

[0049] The volume concentration of SO2 in the regeneration flue gas of the S Zorb unit of a refinery is 2% to 5%, the volume concentration of O2 is less than 0.2%, and the flue gas treatment capacity is about 1900Nm 3 / h. After dust removal, cooling and compression, it enters the adsorption tower for adsorption. The adsorbent is activated carbon, the adsorption pressure is 0.6MPaG, and the adsorption time is 15min. Figure 1 The vacuum regeneration gas is fed into the downstream sulfur production device to produce sulfur. The sulfur production device requires the gas volume to be stable at 150-250 Nm 3 / h, the concentration is stable at 35v%~45v%.

[0050] A diaphragm vacuum pump is used, and the flow limiting device is a one-way valve. Before vacuum regeneration starts, the initial opening of regulating valve I is 60%, regulating valve II is closed, regulating valve III and flow meter are opened, and the vacuum pump outlet gas volume is adjusted to 200Nm 3 / h, and the vacuum pump frequency conversion was set to 60% of the total frequency. After vacuum regeneration was initiated, a three-stage control system was used to maintain stable outlet sulfur dioxide concentration and gas volume. The first stage of control used a flow-limiting device to limit the vacuum pump outlet pressure to 7 kPaG. A sulfur dioxide concentration analyzer was used to control the opening of control valve II, stabilizing the concentration at around 40%. When the opening of control valve II reached 90%, the sulfur dioxide concentration at the vacuum pump outlet could still not be maintained, and the second stage of control was initiated. During the second stage of control, control valve I was gradually closed from an initial opening of 60% to stabilize the sulfur dioxide concentration. When it approached full closure, the third stage of control was initiated. During the second stage of control, the vacuum pump frequency conversion component automatically reached its maximum frequency of 100% to stabilize the sulfur dioxide concentration. Further observation of the vacuum pump inlet pressure gauge revealed that the vacuum reached 97 kPa. When the sulfur dioxide concentration could not be maintained, vacuum regeneration was terminated. At this point, only the gas volume control remained open, and the above process was repeated for the next regeneration cycle. The test results are shown in Table 1.

[0051] Example 3

[0052] The volume concentration of SO2 in the regeneration flue gas of a certain enterprise's S Zorb device is 2% to 5%, the volume concentration of O2 is less than 0.2%, and the flue gas treatment capacity is about 800Nm 3 / h. After dust removal, cooling and compression, it enters the adsorption tower for adsorption. The adsorbent is activated carbon, the adsorption pressure is 0.4MPaG, and the adsorption time is 15min. Figure 1 The adsorbent is vacuum regenerated as shown in the flow chart. The vacuum regeneration gas is fed into the downstream sulfur production unit to produce sulfur. The sulfur production unit requires a stable gas volume of 50 to 150 Nm 3 / h, the concentration is stable at 30v%-40v%.

[0053] A screw vacuum pump is used, and the flow limiting device is a process hand valve. Before vacuum regeneration starts, the initial opening of regulating valve I is 80%, regulating valve II is closed, regulating valve III and flow meter are opened, and the vacuum pump outlet gas volume is adjusted to 80Nm 3 / h, and the vacuum pump frequency converter was set to 50% of the total frequency. After vacuum regeneration was initiated, a three-stage control system was used to maintain stable outlet sulfur dioxide concentration and gas volume. The first stage of control used a flow-limiting device to limit the vacuum pump outlet pressure to 5 kPaG. The sulfur dioxide concentration analyzer controlled the opening of control valve II, stabilizing the concentration at around 35% v / v. When the opening of control valve II reached 90%, the vacuum pump outlet sulfur dioxide concentration could not be maintained, and the second stage of control was initiated. During the second stage of control, control valve I was gradually closed from an initial opening of 80% to stabilize the sulfur dioxide concentration. When it approached full closure, the third stage of control was initiated. During the second stage of control, the vacuum pump frequency converter component automatically reached its maximum frequency of 100% to stabilize the sulfur dioxide concentration. Further observation of the vacuum pump inlet pressure gauge revealed that the vacuum reached 98 kPa. When the sulfur dioxide concentration could not be maintained, vacuum regeneration was terminated. At this point, only the gas volume control remained open, and the above process was repeated for the next regeneration cycle. The test results are shown in Table 1.

[0054] Example 4

[0055] The same as Example 3, except that molecular sieve was used as the adsorbent instead of activated carbon. The test results are shown in Table 1.

[0056] Comparative Example 1

[0057] The same as Example 1, except that the three-stage control method of the present invention was not used, and only a vacuum pump was used to regenerate the adsorbent in a vacuum state for 15 minutes. The test results are shown in Table 1.

[0058] Comparative Example 2

[0059] The same as Example 1, except that the regulating valve I and the second regulating system are not provided. The test results are shown in Table 1.

[0060] Comparative Example 3

[0061] The same as Example 1, except that no current limiting device is provided in the first control system. The test results are shown in Table 1.

[0062] Comparative Example 4

[0063] The same as Example 1, except that the first control system does not have a regulating valve II. The test results are shown in Table 1.

[0064] Comparative Example 5

[0065] The same as Example 1, except that the third control system was not provided. The test results are shown in Table 1.

[0066] Comparative Example 6

[0067] The same as Example 1, except that no connecting cross-line, regulating valve III and gas volume control are provided. The test results are shown in Table 1.

[0068] After vacuum regeneration in different embodiments and comparative examples, the gas volume and concentration of the vacuum regeneration gas are shown in Table 1. The vacuum regeneration was performed at room temperature.

[0069] Table 1 Changes in the amount and concentration of vacuum regeneration gas in different embodiments and comparative examples

[0070]

[0071] As can be seen from Table 1, the technical solution of the present application can keep the gas volume and concentration of the vacuum regeneration gas stable throughout the entire process, meeting the requirements of the subsequent sulfur production device and greatly reducing the impact on the subsequent sulfur production device.

Claims

1. A method for controlling the flow of vacuum regeneration gas into a sulfur production device, characterized in that Including the following contents: S Zorb regeneration flue gas is regenerated by vacuum equipment after being treated by adsorption equipment, pressure gauges are installed at the inlet and outlet of the vacuum equipment, and a connecting side line is installed between the pipelines in front of the inlet and outlet pressure gauges, and a regulating valve I is installed on the side line, and a regulating valve II and a flow limiting device are installed in parallel after the outlet pressure gauge, and then a concentration analyzer and a flow meter are installed in sequence, and a connecting cross-line is installed between the pipeline in front of the adsorption equipment and the pipeline in front of the concentration analyzer, and a regulating valve III is installed on the cross-line, and the outlet gas volume is regulated by the flow meter; before the vacuum regeneration is started, regulating valves I and III are opened, and regulating valve II is closed; after starting, a three-level control method is used to keep the outlet concentration and gas volume stable. The first-level control is achieved by linking the concentration analyzer, regulating valve II and the flow limiting device to form a closed-loop control. The outlet pressure of the vacuum equipment is limited to 1~30KPaG by the flow limiting device, and the opening of the regulating valve II is regulated by the concentration analyzer. When the regulating valve II is close to fully open, that is, the opening is not less than 90%, it is still impossible to maintain the preset When the sulfur dioxide concentration is low, the second-level control is started; the second-level control is achieved by linking the concentration analyzer and the control valve I to form a closed-loop control. Specifically, the control valve I is gradually closed through automatic control. When the control valve I is close to fully closed, the third-level control is started; the third-level control is achieved by linking the concentration analyzer and the vacuum equipment to form a closed-loop control. The automatic control gradually increases the frequency of the vacuum equipment. When the frequency of the vacuum equipment reaches 100% of the maximum frequency, the vacuum degree of the vacuum pump inlet pressure gauge is further observed to reach 90KPa~absolute vacuum. When the outlet sulfur dioxide concentration still cannot be maintained, the vacuum regeneration operation is stopped; during the vacuum regeneration process, the gas volume is maintained by the control valve III and the flow meter. When the outlet gas volume is insufficient, the SZorb regeneration flue gas is introduced into the vacuum regeneration pipeline through the connecting jump line, and the gas volume is controlled within the preset range to ensure the stability of the gas volume entering the subsequent sulfur production device, and the above process is repeated in the next regeneration cycle.

2. The method according to claim 1, wherein: The S Zorb regeneration flue gas is the flue gas generated during the adsorbent regeneration process of the S Zorb catalytic gasoline adsorption desulfurization production device, with an SO2 concentration of 0.5v% to 7v%, an O2 volume content of less than 0.5%, and a temperature of 150 to 240°C.

3. The method according to claim 1 or 2, wherein: The adsorption pressure of the S Zorb regeneration flue gas in the adsorption equipment is 0.3-0.9 MPaG, and the adsorption time is 5-20 minutes.

4. The method according to claim 1, wherein: Before vacuum regeneration starts, the opening of regulating valve I is 10% to 100%.

5. The method according to claim 4, characterized in that: Before vacuum regeneration starts, the opening of regulating valve I is 60% to 80%.

6. The method according to claim 1, wherein: Before vacuum regeneration starts, the frequency conversion of the vacuum equipment is set to 10% to 90% of the total frequency.

7. The method according to claim 6, characterized in that: Before starting vacuum regeneration, the frequency conversion of the vacuum equipment is set to 40% to 60% of the total frequency.

8. The method according to claim 1, wherein: In the first level of regulation, the outlet pressure of the vacuum equipment is limited to 2-10 kPaG by a flow limiting device.

9. The method according to claim 1, wherein: In the third level of regulation, in order to stabilize the outlet sulfur dioxide concentration, when the frequency of the vacuum equipment reaches 100% of the maximum frequency, further observe the vacuum degree of the vacuum pump inlet pressure gauge to reach 96~99KPa. If the sulfur dioxide concentration still cannot be maintained, stop vacuum regeneration.

10. The method according to claim 1, wherein: In order to stabilize the gas volume and concentration of the vacuum regeneration gas entering the downstream sulfur production unit, the S Zorb regeneration flue gas adsorption time is equal to the vacuum regeneration time.

11. The method according to claim 1, wherein: The adsorbent used for the S Zorb regeneration flue gas adsorption treatment is a porous adsorbent capable of adsorbing sulfur dioxide.

12. The method according to claim 11, wherein: The adsorbent used for S Zorb regeneration flue gas adsorption treatment is at least one of activated carbon, molecular sieve, and silica gel.

13. A device for controlling the feeding of vacuum regeneration gas into a sulfur production device according to any one of claims 1 to 12, characterized in that It includes adsorption equipment, variable frequency vacuum equipment and a three-level control system. Pressure gauges are installed at the inlet and outlet of the vacuum equipment, a connecting side line is installed between the pipelines in front of the inlet and outlet pressure gauges, a regulating valve I is installed on the side line, a parallel regulating valve II and a flow limiting device are installed behind the outlet pressure gauge, and then a concentration analyzer and a flow meter are installed in sequence. A connecting cross-line is installed between the pipeline in front of the adsorption tower and the pipeline in front of the concentration analyzer, a regulating valve III is installed on the cross-line, and the outlet gas volume is controlled by the flow meter; a three-level control system is used to maintain the stability of the outlet sulfur dioxide concentration and gas volume. The first-level control system mainly includes the concentration analyzer, the regulating valve II and the flow limiting device, as well as a closed-circuit control pipeline formed by the association of the three; the second-level control system mainly includes the concentration analyzer and the regulating valve I, as well as a closed-circuit control pipeline formed by the association of the two; the third-level control system mainly includes the concentration analyzer and the vacuum equipment, as well as a closed-circuit control pipeline formed by the association of the two.

14. The device according to claim 13, wherein: The adsorption tower is a packed tower filled with a porous adsorbent for adsorbing S Zorb regeneration flue gas.

15. The device according to claim 14, wherein: The adsorption tower is filled with at least one of activated carbon, molecular sieve and silica gel for adsorbing S Zorb regeneration flue gas.

16. The device according to claim 13, wherein: The variable frequency vacuum equipment is used for vacuum regeneration after S Zorb regeneration flue gas adsorption treatment, and is selected from a variable frequency vacuum pump that can generate a vacuum degree of 90KPa to absolute vacuum.

17. The device according to claim 16, characterized in that: The variable frequency vacuum equipment is selected from any one of a screw vacuum pump, a liquid ring vacuum pump, a piston vacuum pump, a diaphragm vacuum pump, and a rotary vane vacuum pump.

18. The device according to claim 13, characterized in that: The flow limiting device is any one of a process manual valve, a one-way valve, a pressure reducing valve and an orifice plate that can stably adjust the pressure before the valve.

19. The device according to claim 13, characterized in that: Before vacuum regeneration is started, regulating valve I and regulating valve III are opened, and regulating valve II is closed; after vacuum regeneration is started, a three-level control system is used to maintain stable outlet sulfur dioxide concentration and gas volume.

20. The device according to claim 13, characterized in that: In the first-level control system, the outlet pressure of the vacuum equipment is limited by the flow limiting device, and the opening of the control valve II is regulated by the concentration analyzer. When the control valve II is close to fully open and still cannot maintain the sulfur dioxide concentration, the second-level control system is started.

21. The device according to claim 13, characterized in that: In the second-level control system, in order to stabilize the sulfur dioxide concentration, the regulating valve I is gradually closed. When it is close to being fully closed, the third-level control system is started.

22. The device according to claim 13, characterized in that: In the third-level control system, when the frequency of the vacuum equipment reaches 100% of the maximum frequency, further observation shows that the vacuum degree of the vacuum pump inlet pressure gauge reaches 90KPa ~ absolute vacuum, and the sulfur dioxide concentration still cannot be maintained, stop vacuum regeneration.

23. The device according to claim 22, characterized in that: Further observation shows that when the vacuum degree of the vacuum pump inlet pressure gauge reaches 96-99KPa and the sulfur dioxide concentration still cannot be maintained, vacuum regeneration is stopped.

24. The device according to claim 13, wherein: During the vacuum regeneration process, when the outlet gas volume is insufficient, the S Zorb regeneration flue gas is introduced into the vacuum regeneration pipeline through the cross-line under the control of the flow meter and regulating valve III, and the gas volume is controlled within the preset range to ensure the stability of the gas volume entering the subsequent sulfur production device, and the above process is repeated in the next regeneration cycle.

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