Sulfur recovery system and process for production process of rubber accelerator M

Abstract

The invention provides a sulfur recovery system and process for a rubber accelerator M. The sulfur recovery system comprises an acidic gas generation unit, a sulfur recovery unit and a sulfur recovery unit which are connected in sequence, the acidic gas generation unit comprises a high-pressure reaction kettle, aniline, CS2, sulfur and H2O are added into the high-pressure reaction kettle, and acidic gas is generated when a rubber accelerator is produced at a certain temperature; the acid gas pressure stabilizing unit at least comprises a first buffer assembly and a second buffer assembly which are connected in sequence, and the operating pressure of the acid gas in the first buffer assembly and the second buffer assembly is reduced in sequence; the acid gas combustion unit comprises a combustion furnace and a combustion waste heat boiler which are connected in sequence; the tail gas treatment unit comprises a condenser assembly, a reheater assembly, a reactor assembly, a trap, an incinerator, an incineration waste boiler and a tail gas purification assembly; through the pressure and flow stabilization operation of the acid gas pressure stabilization unit, the stable pressure of acid gas is ensured, accurate air distribution is realized, and the sulfur recovery efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sulfur recovery of rubber accelerators, and in particular to a sulfur recovery system and process for a rubber accelerator M production process. Background Art

[0002] Rubber accelerator M, chemical name 2-mercaptobenzothiazole, is mainly produced under high temperature and high pressure conditions with aniline, carbon disulfide and sulfur as raw materials. During the production process of vulcanization accelerator M, there is a large amount of tail gas, the main component of which is hydrogen sulfide. If the hydrogen sulfide in the tail gas is directly incinerated, it will not only cause a large amount of sulfur resources to be wasted, but also consume a large amount of alkali solution and produce wastewater containing sodium sulfate and sodium sulfite, increasing the operating burden of the enterprise.

[0003] In the prior art, the acid gas generated in the high-pressure reactor for producing rubber accelerators directly passes through the converter of the sulfur recovery device for reaction, and then forms gas-liquid separation, where the liquid is liquid sulfur, and the gas is directly discharged; since the acid gas fluctuates greatly when it passes through the converter directly, it is difficult to operate the air volume in the acid gas combustion furnace; most importantly, since the pressure of the acid gas in the high-pressure reactor is relatively high, directly passing the acid gas into the converter will cause the acid gas to carry a large amount of organic matter such as carbon disulfide, aniline, and sulfur into the converter, which not only leads to a low sulfur yield and causes excessive tail gas, but also carries a large amount of organic matter such as carbon disulfide, aniline, and sulfur into the combustion furnace for a long time in actual production, seriously affecting the normal operation of the sulfur recovery system. Summary of the invention

[0004] In view of this, the present invention aims to propose a sulfur recovery system and process for the production process of rubber accelerator M. In order to solve the problem in the prior art that the acid gas fluctuates greatly when it passes directly through the converter, so it is difficult to operate the air volume in the acid gas combustion furnace; most importantly, due to the high pressure of the acid gas in the high-pressure reactor, directly passing the acid gas into the combustion furnace will cause the acid gas to carry a large amount of carbon disulfide, aniline, sulfur and other organic substances into the combustion furnace, which not only leads to a low sulfur yield and excessive tail gas, but also carries a large amount of carbon disulfide, aniline, sulfur and other organic substances into the combustion furnace for a long time in actual production, seriously affecting the normal operation of the sulfur recovery system.

[0005] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0006] A sulfur recovery system for a rubber accelerator M production process, comprising:

[0007] An acid gas generating unit, including a high pressure reactor, generates acid gas when producing a rubber accelerator at a certain temperature by adding aniline, CS2, sulfur, and H2O in the high pressure reactor;

[0008] An acid gas pressure stabilizing unit, the acid gas pressure stabilizing unit comprising at least a first buffer component and a second buffer component connected in sequence, the operating pressure of the acid gas in the first buffer component and the second buffer component being reduced in sequence;

[0009] An acid gas combustion unit, the acid gas combustion unit comprising a combustion furnace and a combustion waste boiler connected in sequence;

[0010] The tail gas treatment unit comprises a condenser assembly, a reheater assembly, a reactor assembly, a collector, an incinerator, a waste incineration pot and a tail gas purification assembly.

[0011] This setting ensures the relative stability of the acid gas pressure and concentration during the pressure relief process of the high-pressure reactor by setting an acid gas pressure stabilizing unit between the high-pressure reactor and the acid gas combustion unit. It not only reduces the difficulty of operating the air volume of the combustion furnace, but also realizes precise air distribution and improves the sulfur recovery efficiency.

[0012] Furthermore, the first buffer assembly includes a plurality of acid gas buffer tanks, at least one of which is a spare acid gas buffer tank and at least one is a working acid gas buffer tank.

[0013] This setting ensures that there is enough buffer space for acid gas and can effectively achieve pressure stabilization for acid gas coming from upstream intermittent operations.

[0014] Furthermore, the first buffer assembly at least includes a tank A and a tank B, the tank A and the tank B are connected in parallel, the tank A is provided with a first valve, and the tank B is provided with a second valve.

[0015] In this arrangement, the A / B tank and the first valve / second valve are arranged at both ends of the A / B tank. By controlling the opening of the first valve / second valve, the operating pressure of the A / B tank is reduced, which plays a primary pressure stabilization role. The A / B tank can buffer the acid gas and reduce the fluctuation of the acid gas concentration during the nitrogen replacement of the autoclave.

[0016] Furthermore, the second buffer assembly includes a C tank, the A tank / B tank and the C tank are connected in series, and the C tank is provided with a third valve.

[0017] In this arrangement, the C tank and the third valve are arranged after the acid gas comes out of the C tank to further reduce the pressure, thereby playing a secondary pressure stabilization role for the acid gas. The acid gas flow entering the sulfur recovery unit can be adjusted in real time, and the air flow can be adjusted according to the air distribution rules to ensure the stability of the air distribution operation of the acid gas combustion furnace of the sulfur recovery unit.

[0018] Furthermore, the structures of tanks A, B and C are the same. Tank A is provided with an air inlet, an air outlet and a baffle structure. The air inlet is located on the side wall of tank A, and the air outlet is located at the upper end of tank A. The baffle structure allows the acid gas to take a U-shaped route in tank A.

[0019] The provision of the baffle structure can increase the residence time of the acid gas in tank A and improve the pressure stabilization effect of the acid gas.

[0020] Furthermore, the A tank is also provided with a wire mesh demister and a gas purge port, the wire mesh demister is located at the upper end of the baffle structure, and the gas purge port is located at the bottom end of the A tank.

[0021] Furthermore, the condenser assembly includes a primary condenser, a secondary condenser, a tertiary condenser, a fourth condenser, and a fifth condenser; the reheater assembly includes a primary reheater, a secondary reheater, a tertiary reheater, and a fourth reheater; and the reactor assembly includes a primary reactor, a secondary reactor, a tertiary reactor, and a selective oxidation reactor.

[0022] This setting can improve the sulfur recovery efficiency.

[0023] Furthermore, the first-stage condenser and the second-stage condenser, the third-stage condenser and the fourth-stage condenser are all combined structures, and the first-stage reactor and the second-stage reactor, the third-stage reactor and the selective oxidation reactor are all combined structures.

[0024] A sulfur recovery process for the production process of rubber accelerator M, characterized in that the sulfur recovery process uses the above-mentioned sulfur recovery system, and the sulfur recovery process comprises the following steps:

[0025] S100: producing rubber accelerator M in a high-pressure reactor according to the process ratio, generating acid gas;

[0026] S200: The acid gas generated in step S100 enters tank A / tank B and tank C in sequence, and then enters the combustion furnace for combustion. The high-temperature process gas generated by the combustion is condensed in a combustion waste boiler to obtain liquid sulfur and is recovered;

[0027] S300: the process gas condensed from the combustion waste boiler in step S200 enters various condensers, various reheaters, and various reactors, and Claus reaction is carried out in the reactor to recover liquid sulfur, and the generated process gas is condensed by the condenser, and the deeply condensed process gas is separated from sulfur by a collector;

[0028] S400: the tail gas after passing through the collector in step S300 is sent to the incinerator for incineration. The flue gas after incineration in the incinerator is cooled by the waste incineration boiler and then sent to the desulfurization system. At the same time, medium-pressure saturated steam is generated and connected to the plant steam network.

[0029] In this setting, the conversion efficiency of H2S and CS2 in the acid gas in the high-pressure reactor into liquid sulfur is significantly improved through the pressure and flow stabilization of tanks A / B and C and the four-stage Claus sulfur recovery process of "three-stage Claus + selective oxidation", and the SO2-containing flue gas after the tail gas incinerator is sent to the desulfurization boundary area for further desulfurization before meeting the emission standards.

[0030] Furthermore, step S200 further includes the following steps:

[0031] S201: Detect the acid gas flow rate P1 of tank B at t1, and detect the acid gas flow rate P2 of tank B at t2, ΔP = |P2-P1|;

[0032] S202: Determine ΔP>0.01, if yes, proceed to step S203, if no, proceed to step S204;

[0033] S203: adjusting the opening of the first valve / the second valve and the third valve in sequence; then returning to step S201;

[0034] S204: According to the acid gas flow rate P2 of tank B, the main control gas flow rate P3 is adjusted to make P2 / P3 = 2 to 2.5;

[0035] S205: Detecting H2S concentration m1 and SO2 concentration m2 at the outlet of the fourth-stage sulfur condenser;

[0036] S206: Determine if 1.0>m1>0.6, 0.2>m1>0, if so, keep P2 and P3 running, if not, proceed to step S203.

[0037] This setting can improve the pressure and flow stability of acid gas, reduce the difficulty of air distribution operation of the combustion furnace, and improve sulfur recovery efficiency.

[0038] Further, step S400 specifically includes the following steps: the acid gas sequentially enters a primary condenser, a primary reheater, a primary reactor, a secondary condenser, a secondary reheater, a secondary reactor, a tertiary condenser, a tertiary reheater, a tertiary reactor, a quaternary condenser, a quaternary reheater, a selective oxidation reactor, and a quintuple condenser.

[0039] Compared with the prior art, the sulfur recovery system and process for the production process of rubber accelerator M described in the present invention have the following advantages:

[0040] (1) The present invention provides an acid gas pressure stabilizing unit between the high-pressure reactor and the acid gas combustion unit, thereby ensuring the relative stability of the pressure and concentration of the acid gas during the pressure relief process of the high-pressure reactor, thereby reducing the difficulty of operating the air volume of the combustion furnace, achieving accurate air distribution, and improving the sulfur recovery efficiency;

[0041] (2) The present invention arranges A tank / B tank and arranges the first valve / second valve at both ends of the A tank / B tank, and controls the opening of the first valve / second valve to reduce the operating pressure of the A tank / B tank, thereby playing a primary pressure stabilization role. The A tank / B tank can buffer the acid gas and reduce the fluctuation of the acid gas concentration during the nitrogen replacement of the autoclave;

[0042] (3) The present invention provides a C tank and a third valve after the acid gas comes out of the C tank to further reduce the pressure, thereby playing a secondary pressure stabilization role for the acid gas. The flow rate of the acid gas entering the sulfur recovery device can be adjusted in real time, and the air flow rate can be adjusted according to the air distribution rules to ensure the stability of the air distribution operation of the acid gas combustion furnace of the sulfur recovery device; through the two pressure stabilizations and the buffering of the acid gas buffer tank, the relative stability of the pressure and concentration of the acid gas during the pressure relief process of the autoclave can be ensured, thereby ensuring the normal operation of the sulfur recovery device;

[0043] (4) The present invention provides a baffle structure on tank A / tank B / tank C. After the acid gas enters the tank, it is baffled by the baffle structure and follows a U-shaped route, thereby further increasing the residence time of the acid gas in the buffer tank and improving the pressure and flow stabilization effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the flow structure of the sulfur recovery system of Example 1 of the present invention;

[0045] Figure 2 This is a flow chart of the acid gas pressure stabilizing unit according to Example 1 of the present invention;

[0046] Figure 3 This is a process flow chart of the rubber accelerator production process of Example 1 of the present invention;

[0047] Figure 4 This is a schematic diagram of the overall structure of tank A according to Example 1 of the present invention;

[0048] Figure 5 This is a schematic diagram of the overall structure of a tank A according to another embodiment of the present invention;

[0049] Figure 6 This is a flowchart of step S200 of embodiment 2 of the present invention.

[0050] Description of reference numerals:

[0051] 1-high pressure reactor, 2-acid gas buffer tank, 21-tank A, 211-first valve, 212-air inlet, 213-air outlet, 214-baffle structure, 215-wire mesh demister, 216-gas purge port, 217-flow direction of acid gas, 22-tank B, 221-second valve, 23-tank C, 231-third valve, 3-combustion furnace, 4-combustion waste pot, 5-condenser assembly, 51-primary condenser , 52-secondary condenser, 53-third-stage condenser, 54-fourth-stage condenser, 55-fifth-stage condenser, 6-reheater assembly, 61-first-stage reheater, 62-secondary reheater, 63-third-stage reheater, 64-fourth-stage reheater, 7-reactor assembly, 71-first-stage reactor, 72-secondary reactor, 73-third-stage reactor, 74-selective oxidation reactor, 8-collector, 9-incinerator, 10-waste incineration pot. DETAILED DESCRIPTION

[0052] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The descriptions of "first", "second", etc. mentioned in the embodiments of the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0053] Example 1

[0054] This embodiment provides a sulfur recovery system for the production process of rubber accelerator M, such as Figure 1-2 As shown, it includes: an acid gas generating unit, an acid gas pressure stabilizing unit, an acid gas combustion unit, and an exhaust gas treatment unit connected in sequence; the acid gas generating unit includes a high-pressure reactor 1, and acid gas is generated when a rubber accelerator is produced at a certain temperature by adding aniline, CS2, sulfur, and H2O into the high-pressure reactor 1; the acid gas pressure stabilizing unit includes at least a first buffer component and a second buffer component connected in sequence, and the operating pressure of the acid gas in the first buffer component and the second buffer component is reduced in sequence; the acid gas combustion unit includes a combustion furnace 3 and a combustion waste boiler 4 connected in sequence; the exhaust gas treatment unit includes a condenser component 5, a reheater component 6, a reactor component 7, a collector 8, an incinerator 9, an incineration waste boiler 10, and an exhaust gas purification component (not shown in the figure).

[0055] The sulfur recovery system for the rubber accelerator M production process described in this embodiment can meet the requirements of sulfur recovery when the H2S concentration in the acid gas is 85-95% and the CS2 concentration is 5-15%, and the sulfur recovery rate is high.

[0056] Specifically, the first buffer assembly and the second buffer assembly are both acid gas buffer tanks 2, and the first buffer assembly includes 2 or more acid gas buffer tanks 2 connected in parallel, such as 2 acid gas buffer tanks, 1 of which is used and 1 is used as a spare, or 2 are used and 1 is used as a spare, or more are used and more are used. The acid gas buffer tank ensures that there is enough buffer space for the acid gas, and can effectively achieve a pressure stabilization effect for the acid gas from the upstream intermittent operation. In addition, the design pressure of the acid gas buffer tank can be increased to 1.2-1.5MpaG. When the sulfur recovery unit fails or the upstream acid gas volume increases sharply, the acid gas can be temporarily buffered to avoid the risk of acid gas leakage. When the sulfur recovery unit is operational, the acid gas is discharged into the sulfur recovery unit in an orderly manner to achieve safe and stable acid production.

[0057] More specifically, the first buffer assembly includes an A tank 21 and a B tank 22, which are connected in parallel, and the A tank 21 is provided with a first valve 211, and the B tank 22 is provided with a second valve 221. The pressure of the acid gas produced by the high-pressure reactor in the prior art affects the entire sulfur recovery system, so by providing the A tank and the B tank, the pressure stabilization process can be performed at a higher acid gas concentration, ensuring that the acid gas has a stable pressure after entering the combustion furnace, and avoiding large fluctuations in the acid gas pressure.

[0058] More specifically, the second buffer assembly includes a C tank 23 , the A tank 21 / B tank 22 and the C tank 23 are connected in series, and the C tank 23 is provided with a third valve 231 .

[0059] More specifically, each of the A tank 21 , the B tank 22 , and the C tank 23 is provided with a pressure sensor (not shown in the figure).

[0060] More specifically, the A tank 21, the B tank 22, and the C tank 23 have the same structure. The A tank 21 is provided with an air inlet 212, an air outlet 213, and a baffle structure 214. The air inlet 212 is located on the side wall of the A tank, and the air outlet 213 is located at the upper end of the A tank. The baffle structure 214 allows the acid gas to take a U-shaped route in the A tank 21. The baffle structure can increase the residence time of the acid gas in the A tank and improve the pressure stabilization effect of the acid gas.

[0061] As an embodiment of the present application, the baffle structure 214 is a baffle, which clamps the air inlet 212 and is fixed on tank A. After the acid gas enters and is baffled by the baffle, the acid gas takes a U-shaped route, thereby increasing the residence time of the acid gas in the buffer tank.

[0062] Specifically, the baffle includes a horizontal plate and a vertical plate that are connected to each other. The horizontal plate is located at the upper end of the air inlet and extends toward the center of tank A. The vertical plate extends toward the bottom end of tank A, and the lowest end of the vertical plate is lower than the height of the air inlet.

[0063] As another embodiment of the present application, the baffle structure is a bend pipe, which is connected to the gas inlet. After the acid gas enters, it first flows to the bottom of the buffer tank, then bends to the top of the acid gas buffer tank and then exits the buffer tank. The acid gas takes a U-shaped route, which increases the residence time of the acid gas in the buffer tank.

[0064] Specifically, the baffle includes a horizontal tube and a vertical tube that are interconnected. The horizontal tube is connected to the air inlet and extends toward the center of tank A, and the vertical tube extends toward the bottom end of tank A.

[0065] More specifically, the A tank 21 is also provided with a wire mesh demister 215 and a gas purge port 216. The wire mesh demister 215 is located at the upper end of the baffle structure 214, and the gas purge port 216 is located at the bottom end of the A tank 21. The gas purge port 216 facilitates the cleaning of the interior of the acid gas buffer tank and timely pressurizes the liquid in the acid gas buffer tank. The wire mesh demister 215 can capture the liquid substances carried in the acid gas in a timely manner to prevent the liquid from entering the subsequent system, blocking the acid gas pipeline, and affecting the normal operation of the sulfur recovery device. In addition, the acid gas takes a U-shaped route in the acid gas buffer tank, which is also conducive to the separation of the liquid substances carried in the acid gas.

[0066] Specifically, the acid gas is burned with a certain amount of air in the combustion furnace 3, and the process gas from the combustion furnace 3 sequentially enters the reactors at each stage to perform the Claus reaction. The reaction products are cooled by condensers adapted to the reactors at each stage, and the liquid sulfur product is recovered.

[0067] More specifically, the condenser assembly includes a primary condenser 51, a secondary condenser 52, a third condenser 53, a fourth condenser 54, and a fifth condenser 55 which are connected in sequence. Sulfur is condensed and produced in each condenser, and low-pressure steam is produced as a by-product for heating the liquid sulfur pipeline.

[0068] More specifically, the first-stage condenser 51 and the second-stage condenser 52 , and the third-stage condenser 53 and the fourth-stage condenser 54 are all combined and share a shell side, thereby reducing the control and regulation loops on the cold side.

[0069] More specifically, the reheater assembly 6 includes a primary reheater 61, a secondary reheater 62, a tertiary reheater 63, and a quaternary reheater 64 connected in sequence, and the reheater assembly is used to control the temperature of the process gas entering the reactor.

[0070] More specifically, the by-product medium-pressure steam in the combustion waste boiler is used for each stage of reheater.

[0071] More specifically, the reactor assembly 7 includes a primary reactor 71, a secondary reactor 72, a tertiary reactor 73, and a selective oxidation reactor 74; the primary reactor 71 and the secondary reactor 72, and the tertiary reactor 73 and the selective oxidation reactor 74 are all combined structures.

[0072] More specifically, Figure 1 As shown, the first-stage condenser is arranged after the combustion waste boiler, the first-stage reheater is arranged after the first-stage condenser, the first-stage reactor is arranged after the first-stage reheater, the second-stage condenser is arranged after the first-stage reactor, the second-stage reheater is arranged after the second-stage condenser, the second-stage reactor is arranged after the second-stage reheater, the third-stage condenser is arranged after the third-stage condenser, the third-stage reactor is arranged after the third-stage reheater, the fourth-stage condenser is arranged after the fourth-stage condenser, the fourth-stage reheater is arranged after the fourth-stage condenser, the selective oxidation reactor is arranged after the fourth-stage reheater, the fifth-stage condenser is arranged after the selective oxidation reactor, the collector is arranged after the fifth-stage condenser, the incinerator is arranged after the collector, the incineration waste boiler is arranged after the incinerator, and the exhaust gas purification component is arranged after the incineration waste boiler.

[0073] The catalyst loading of the first-stage reactor adopts the upper / lower part, the upper part adopts the oxygen leakage protection catalyst to remove the leaked trace oxygen of the combustion furnace (free oxygen will cause the temperature of the catalyst bed in the reactor to rise sharply, the elemental sulfur of the residual oxygen will be oxidized or even burned, and the existence of the catalyst will also accelerate the sulfation of the catalyst, making the device unable to operate normally) to eliminate the influence on the lower reactor; the lower part adopts the hydrolysis catalyst to completely hydrolyze the sulfides such as COS / CS2 produced as by-products in the sulfur-making combustion furnace to prevent COS / CS2 from penetrating the subsequent reactor and causing unqualified emissions;

[0074] The catalyst loading of the three-stage reactor also uses the upper / lower part. The upper part uses the sulfur recovery catalyst, and the lower part uses the selective hydrogenation catalyst. The selective hydrogenation catalyst selectively hydrogenates SO2 into S, controlling the H2S concentration at the outlet of the three-stage reactor to not exceed 0.8%, thereby ensuring the efficiency of the selective oxidation reactor;

[0075] The selective oxidation reactor is loaded with a selective oxidation catalyst to convert H2S into S (based on the premise that the inlet concentration of H2S does not exceed 0.8%), ensuring that the sulfur recovery rate reaches the designed value.

[0076] More specifically, Figure 1As shown in the figure, the acid gas and air entering the combustion furnace are proportioned and adjusted by a ratio regulator, and an H2S / SO2 ratiometer is set between the four-stage condenser and the four-stage reheater. The fine-tuning air circuit adjusts the amount of air / oxygen-deficient air entering the combustion furnace according to the H2S concentration signal output by the online analyzer. Through the main air adjustment circuit and the fine-tuning air circuit, precise control is achieved, so that the oxygen-deficient combustion in the combustion furnace is more complete and the occurrence of side reactions is reduced.

[0077] Specifically, an O2 analyzer is set after the selective oxidation reactor, and the amount of air blown in is cascade-regulated in combination with the reactor bed temperature (an air-process gas mixer is provided), and under the action of the selective oxidation catalyst, H2S is basically completely oxidized to S, ensuring a total S recovery rate of more than 99%;

[0078] More specifically, the collector, the incinerator and the waste incineration pot are connected in sequence.

[0079] Specifically, the exhaust gas purification component includes a dynamic wave scrubber and a desulfurization tower (not shown in the figure); the specific method of use is: the sulfur recovery exhaust gas is first cooled to about 65°C by a dynamic wave scrubber (equipped with a plate heat exchanger and a circulating water cooling system), and then enters the packed desulfurization tower. The circulating liquid is pumped to the spray system in the tower through the desulfurization tower circulating pump. After the gas and liquid are absorbed by the countercurrent contact reaction in the packing layer, the liquid phase falls to the circulation tank at the bottom of the tower. The gas phase is removed from the acid mist by the wire mesh demister installed at the top of the tower and then discharged to the exhaust chimney, thereby constituting a continuous circulation absorption of SO2 exhaust gas to ensure that the exhausted exhaust gas meets the emission standard requirements.

[0080] The transportation and circulation of the absorption reagent solution are as follows: the purchased 27.5% concentration industrial-grade hydrogen peroxide is transported to the hydrogen peroxide storage system through the unloading pump. The hydrogen peroxide in the hydrogen peroxide storage system is added to the spray pipe as needed through the hydrogen peroxide pressure delivery pump under the control of the flow meter and mixed with the desulfurization circulating liquid. After passing through the spray layer and the packing layer, the SO2 in the flue gas is fully reacted and the utilization rate of hydrogen peroxide is ensured to reach more than 99%. The amount of hydrogen peroxide added is automatically adjusted according to the molar flow rate of SO2 in the exhaust gas at the outlet of the desulfurization system. After the circulating absorption liquid removes SO2 from the flue gas, it generates dilute sulfuric acid, which falls to the circulation tank at the bottom of the tower by gravity. The circulating absorption liquid in the circulation tank is then sent to the spray absorption layer of the desulfurization tower for circulation and absorption through the circulation pump. After absorbing SO2, the density of the circulating absorption liquid gradually increases. When it reaches the set value (corresponding to 30% concentration), it is discharged to the dilute sulfuric acid storage tank through the spray branch pipe; the use of hydrogen peroxide for desulfurization has high desulfurization efficiency and can ensure that the SO2 content in the exhaust gas is less than 50mg / Nm 3 The by-product dilute acid is used in other devices in the factory, and no other waste liquid is generated.

[0081] As a preferred embodiment of the present application, the circulation tank of the power wave scrubber and the desulfurization tower is designed as an independent circulation tank outside the tower, and the tower and the tank are separated. The circulation tank is provided with an independent circulation system, and each system is equipped with a submerged circulation pump and a built-in PP adsorption filler. After the main circulation system has been running for a period of time (the running time depends on the start-up status), it is switched to the standby circulation system; at this time, the state of the adsorption filler of the main circulation system can be checked, and the main system and the filler can be cleaned for standby, and the two independent circulation systems are standby for each other. Because of the fluctuation of the acid gas flow rate and the change of H2S concentration during the pressure relief of the high-pressure reactor, despite the use of pressure and flow stabilization measures and the four-stage Claus sulfur recovery process of "three-stage Claus + selective oxidation", when the acid gas buffer component is in the device load fluctuation or start-up and shutdown, the acid gas furnace cannot accurately distribute the air, and the content of sulfur-containing substances such as S / H2S in the process gas entering the tail gas incinerator will increase, and the incinerator cannot complete the incineration of S / H2S into SO2, especially the S element will enter the desulfurization unit with the flue gas, causing the plate heat exchanger to be blocked, affecting the normal operation of the desulfurization device.

[0082] As a preferred embodiment of the present application, a flame arrester, an oxygen content analyzer, and a VOCs concentration analyzer are installed on the pipeline through which the VOCs gas enters the exhaust gas incinerator. When the VOCs concentration is high or the oxygen content changes greatly and is at the explosion limit, the VOCs gas is cut off and does not enter the incinerator for incineration to ensure safety.

[0083] Specifically, before the VOCs gas enters the incinerator, an exhaust gas buffer tank and an exhaust gas booster fan are set up to detect the pressure and flow of the VOCs gas entering the exhaust gas incinerator in real time to prevent the gas fluctuation from affecting the normal operation of the exhaust gas incinerator.

[0084] Example 2

[0085] This embodiment proposes a sulfur recovery process for the production process of rubber accelerator M. The sulfur recovery process uses the sulfur recovery system described in Example 1. The sulfur recovery process includes the following steps:

[0086] S100: rubber accelerator M is produced in a high pressure reactor according to the process ratio, and the H2S concentration in the produced gas is 85-95%, and the CS2 concentration is 5-15%;

[0087] S200: The acid gas generated in step S100 enters tank A and / or tank B and tank C in sequence, and then enters the combustion furnace for combustion. The high-temperature process gas generated by the combustion is condensed in a combustion waste boiler to obtain liquid sulfur and is recovered;

[0088] S300: the process gas condensed from the combustion waste boiler in step S200 enters various condensers, various reheaters, and various reactors, and Claus reaction is carried out in the reactor to recover liquid sulfur, and the generated process gas is condensed by the condenser, and the deeply condensed process gas is separated from sulfur by a collector;

[0089] S400: the tail gas after passing through the collector in step S300 is sent to the incinerator for incineration. The flue gas after incineration in the incinerator is cooled by the waste incineration boiler and then sent to the desulfurization system. At the same time, medium-pressure saturated steam is generated and connected to the plant steam network.

[0090] Specifically, step S100 includes the following steps:

[0091] Rubber Accelerator M Production Process Figure 2 As shown, aniline, CS2 and sulfur are pumped into a high-pressure reactor according to the process ratio, and the high-pressure reactor is heated by a thermal oil furnace (electrically heated thermal oil furnace) and the reaction temperature is controlled. The high-pressure reactor is controlled at a reaction temperature of 250-270°C, a reaction pressure of 8.0-9.8MpaG, and a reaction time of 3-4h. The total yield of M in the reaction is 85%. When the pressure rises to the highest temperature and drops by 5-20°C, the pressure is released (manually operated), hydrogen sulfide gas is released, and sulfur is recovered through a sulfur recovery device. The reactants are extracted with toluene, and the extracted waste liquid is distilled to recover toluene. The toluene is recycled, and the refined M is centrifuged, washed, dried, crushed, packaged, and finally stored.

[0092] Specifically, step S200 also includes the following steps:

[0093] S201: Detect the acid gas flow rate P1 of tank B at t1, and detect the acid gas flow rate P2 of tank B at t2, ΔP = |P2-P1|; wherein the unit of the acid gas flow rate is MPa;

[0094] S202: Determine ΔP>0.01, if yes, proceed to step S203, if no, proceed to step S204, wherein t2-t1=1~5min;

[0095] S203: adjusting the opening of the first valve / the second valve and the third valve in sequence; then returning to step S201;

[0096] S204: According to the acid gas flow rate P2 of tank B, the main air flow rate P3 is adjusted so that P2 / P3=2-2.5; wherein the unit of the main air flow rate is MPa;

[0097] S205: Detecting H2S concentration m1 and SO2 concentration m2 at the outlet of the fourth-stage sulfur condenser, wherein the unit of concentration is mol%;

[0098] S206: Determine if 1.0>m1>0.6, 0.2>m1>0, if so, keep P2 and P3 running, if not, proceed to step S203.

[0099] Specifically, step S203 also includes the following steps: the acid gas generated by the high-pressure reactor can selectively flow through tank A and tank B, and then flow through tank C, wherein the acid gas flow rate (operating pressure) P4 in tank A / tank B is controlled at 0.1-0.15Mpa, and the acid gas flow rate (operating pressure) P5 in tank C is controlled at 0.05-0.07Mpa. Wherein, selectively flowing through tank A and tank B means that the acid gas can flow through one of tank A or tank B, or the acid gas flows through both tank A and tank B, and the operating pressures in tank A, tank B, and tank C need to be met.

[0100] More specifically, the reactions in the combustion furnace 2 are mainly as follows:

[0101] H2S+3 / 2O2→SO2+H2O

[0102] H2S+1 / 2SO2→H2O+3 / 4S2

[0103] CS2+3O2→CO2+2SO2

[0104] The process gas after combustion is cooled to 320℃ in the combustion waste boiler and then enters the primary sulfur cooler to cool to 170℃. The recovered liquid sulfur enters the sulfur sealing tank.

[0105] The medium-pressure steam produced as a by-product of the steam generator of combustion furnace 2 is partially used for heating process gas, acid gas and air, and the excess steam is decompressed and then sent to the plant steam pipeline network.

[0106] The process gas from the primary condenser enters the primary reheater and is heated to 240°C by medium-pressure steam before entering the primary reactor for Claus reaction. The primary reactor is filled with a deoxidation protection titanium-based catalyst and a sulfur recovery (hydrolysis) titanium-based catalyst. The main chemical reactions in the primary reactor are:

[0107] 2H2S+SO2→3 / xSx+2H2O

[0108] COS+H2O→H2S+CO2

[0109] CS2+2H2O→2H2S+CO2

[0110] The process gas from the primary reactor enters the secondary condenser at 240℃ and is cooled to 170℃ to recover liquid sulfur. After recovering liquid sulfur, the process gas enters the secondary reheater and is heated to about 220℃ by medium-pressure steam before entering the secondary reactor. The secondary reactor is filled with sulfur recovery catalyst. The main chemical reactions in the secondary reactor are:

[0111] 2H2S+SO2→3 / xSx+2H2O

[0112] The process gas after the reaction enters the three-stage condenser at 220℃ and cools down to 170℃ to recover liquid sulfur. After recovering liquid sulfur, the process gas enters the three-stage reheater and is heated to about 200℃ by medium-pressure steam before entering the three-stage reactor. The three-stage reactor is respectively filled with sulfur recovery catalyst and selective hydrogenation catalyst. The main chemical reactions in the three-stage reactor are:

[0113] 2H2S+SO2→3 / xSx+2H2O

[0114] SO2+2H2→1 / x Sx+2H2O

[0115] The process gas from the third-stage reactor enters the fourth-stage sulfur condenser to cool down to 170°C. The process gas from the fourth-stage condenser is mixed with the quantitative air from the combustion fan and enters the fourth-stage reheater to be heated to 195°C with medium-pressure steam before entering the selective oxidation reactor, which is filled with a selective oxidation catalyst. The main chemical reactions in the selective oxidation reactor are:

[0116] 2H2S+SO2→3 / xSx+2H2O

[0117] 2H2S+O2→2 / x Sx+2H2O

[0118] The gas coming out of the selective oxidation reactor is cooled to about 135°C by a five-stage condenser, and low-pressure saturated steam of 0.10MpaG is generated. The deeply condensed process gas is separated from sulfur by a high-efficiency collector. All the condensed and separated liquid sulfur flows into the liquid sulfur seal, and then into the liquid sulfur pool, and is pressurized by the liquid sulfur pump and sent to the subsequent device for use.

[0119] The tail gas after the collector enters the incinerator for incineration. The flue gas from the incinerator enters the incinerator steam generator to cool down to 260℃ and then is sent to the desulfurization system. At the same time, medium-pressure saturated steam is generated and sent to the plant steam network. The main reactions in the incinerator are:

[0120] H2S+3 / 2O2→SO2+H2O

[0121] 1 / x Sx+O2→SO2

[0122] COS+3 / 2O2→SO2+CO2

[0123] The 0.45MPaG steam produced as by-product by the first-stage condenser, second-stage condenser, third-stage condenser and fourth-stage condenser is sent to the 0.4MPaG steam network as the heating steam for the system liquid sulfur pipeline and other pipelines. The 0.1MPaG low-pressure saturated steam produced as by-product by the fourth-stage condenser.

[0124] In this embodiment, the relevant parameters in the sulfur recovery system are as follows: the temperature of the acid gas before entering the combustion furnace is 200°C and the pressure is 0.08MPa(g); the furnace temperature of the combustion furnace is 1300°C; the steam pressure generated by burning the waste boiler is 4.4MPa(g); the process gas outlet temperature of the combustion furnace steam generator is 320°C; the steam pressure generated by the first / second, third / fourth stage sulfur condenser is 0.45MPa(g); the process gas inlet / outlet temperature of the first reactor is 240°C / 305°C; the first / secondary sulfur condenser tube side gas outlet temperature is 170°C; the second reactor inlet / outlet temperature is 220°C / 241°C; the third reactor process gas inlet / outlet temperature is 200°C / 208°C; the third / fourth stage sulfur condenser tube side gas outlet temperature is 170℃; the inlet / outlet temperature of the selective oxidation reactor is 195℃ / 235℃; the steam pressure generated by the five-stage condenser is 0.10MPa(g); the furnace temperature of the tail gas incinerator is 650℃; the process gas outlet temperature of the incinerator steam generator is 260℃; through the acid gas pressure stabilization operation, when the flow ratio of the main air to the acid gas is between 2-2.5, the ratiometer on the process gas pipeline at the outlet of the four-stage sulfur condenser shows that the H2S concentration is controlled at 0.6-1.0mol%, and the SO2 concentration is controlled at 0-0.2mol%, and the fine-tuning air flow is precisely adjusted through the concentration of the above ratiometer; through pressure stabilization and precise air distribution, a sulfur recovery rate of 99% can be achieved, and the SO2 concentration in the flue gas entering the tail gas desulfurization is 5000-6000mg / Nm 3 .

[0125] Comparative Example 1

[0126] The difference between this comparative example and Example 1-2 is that the acid gas generated from the production of rubber accelerator is directly fed into the combustion furnace. Due to the large fluctuation of the acid gas flow rate, the air supply must be irregular, which makes the operation more difficult. Under the same reaction order, the sulfur recovery rate can only reach 96%-97%, and the SO2 content in the flue gas entering the tail gas desulfurization is 15000-20000mg / Nm 3 The subsequent flue gas desulfurization load is large, which affects the desulfurization system's emission standards.

[0127] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

Claims

1. A sulfur recovery system for the production process of rubber accelerator M, characterized in that: Including sequential connections: The acid gas generating unit comprises a high pressure reactor (1), and generates acid gas when producing a rubber accelerator at a certain temperature by adding aniline, CS2, sulfur, and H2O into the high pressure reactor (1); An acid gas pressure stabilizing unit, the acid gas pressure stabilizing unit comprising at least a first buffer component and a second buffer component connected in sequence, the operating pressure of the acid gas in the first buffer component and the second buffer component being reduced in sequence; An acid gas combustion unit, the acid gas combustion unit comprising a combustion furnace (3) and a combustion waste boiler (4) connected in sequence; A tail gas treatment unit, comprising a condenser assembly (5), a reheater assembly (6), a reactor assembly (7), a collector (8), an incinerator (9), an incineration waste pot (10), and a tail gas purification assembly.

2. The sulfur recovery system according to claim 1, characterized in that: The first buffer assembly comprises two or more acid gas buffer tanks (2) connected in parallel, of which at least one is a spare acid gas buffer tank (2) and at least one is an active acid gas buffer tank (2).

3. The sulfur recovery system according to claim 1, characterized in that: The first buffer assembly comprises at least an A tank (21) and a B tank (22), wherein the A tank (21) and the B tank (22) are connected in parallel, and the A tank (21) is provided with a first valve (211), and the B tank (22) is provided with a second valve (221).

4. The sulfur recovery system according to claim 3, characterized in that: The second buffer assembly comprises a C tank (23), the A tank (21) / B tank (22) and the C tank (23) are connected in series, and the C tank (23) is provided with a third valve (231).

5. The sulfur recovery system according to claim 4, characterized in that: The A tank (21), the B tank (22), and the C tank (23) have the same structure. The A tank (21) is provided with an air inlet (212), an air outlet (213), and a baffle structure (214). The air inlet (212) is located on the side wall of the A tank, and the air outlet (213) is located at the upper end of the A tank. The baffle structure (214) enables the acid gas to follow a U-shaped route in the A tank (21).

6. The sulfur recovery system according to claim 5, characterized in that: The A tank (21) is also provided with a wire mesh demister (215) and a gas purge port (216); the wire mesh demister (215) is located at the upper end of the baffle structure (214), and the gas purge port (216) is located at the bottom end of the A tank (21).

7. The sulfur recovery system according to claim 1, characterized in that: The condenser assembly (5) includes a primary condenser (51), a secondary condenser (52), a tertiary condenser (53), a fourth condenser (53), and a fifth condenser (54); the reheater assembly (6) includes a primary reheater (61), a secondary reheater (61), a tertiary reheater (62), and a fourth reheater (63); the reactor assembly (7) includes a primary reactor (71), a secondary reactor (72), a tertiary reactor (73), and a selective oxidation reactor (74).

8. The sulfur recovery system according to claim 7, characterized in that: The first-stage condenser (51) and the second-stage condenser (52), the third-stage condenser (73) and the fourth-stage condenser (54) are all combined structures, and the first-stage reactor (71) and the second-stage reactor (72), the third-stage reactor (73) and the selective oxidation reactor (74) are all combined structures.

9. A sulfur recovery process for the production of rubber accelerator M, characterized in that: The sulfur recovery process uses the sulfur recovery system according to any one of claims 1 to 8, and the sulfur recovery process comprises the following steps: S100: producing rubber accelerator M in a high-pressure reactor according to the process ratio to generate acid gas; S200: The acid gas generated in step S100 enters tank A and / or tank B and tank C in sequence, and then enters the combustion furnace for combustion. The high-temperature process gas generated by the combustion is condensed in a combustion waste boiler to obtain liquid sulfur and is recovered; S300: the process gas condensed from the combustion waste boiler in step S200 enters various condensers, various reheaters, and various reactors, and Claus reaction is carried out in the reactor to recover liquid sulfur, and the generated process gas is condensed by the condenser, and the deeply condensed process gas is separated from sulfur by a collector; S400: the tail gas after passing through the collector in step S300 is sent to the incinerator for incineration. The flue gas after incineration in the incinerator is cooled by the waste incineration boiler and then sent to the desulfurization system. At the same time, medium-pressure saturated steam is generated and connected to the plant steam network.

10. The sulfur recovery process according to claim 9, characterized in that: Step S200 also includes the following steps: S201: Detect the acid gas flow rate P1 of tank B at t1, and detect the acid gas flow rate P2 of tank B at t2, ΔP = |P2-P1|; S202: Determine ΔP>0.01, if yes, proceed to step S203, if no, proceed to step S204; S203: adjusting the opening of the first valve / the second valve, and the third valve in sequence; then returning to step S201; S204: According to the acid gas flow rate P2 of tank B, the main air flow rate P3 is adjusted to make P2 / P3 = 2 to 2.5; S205: Detecting H2S concentration m1 and SO2 concentration m2 at the outlet of the fourth-stage sulfur condenser; S206: Determine if 1.0>m1>0.6, 0.2>m1>0, if so, keep P2 and P3 running, if not, proceed to step S203.

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