Aromatic hydrocarbon sulfonation method and system using sulfur trioxide

Abstract

The invention relates to an aromatic hydrocarbon sulfonation method and system using sulfur trioxide, and relates to the technical field of fine chemical raw material synthesis, and the aromatic hydrocarbon sulfonation method using sulfur trioxide comprises the steps of reactant pumping, main reaction, temperature judgment, ambient temperature judgment I and ambient temperature judgment II. The reaction temperature can be adjusted under different temperature conditions, the probability of byproducts is gradually reduced in the reaction process, and then the generation of the byproducts is reduced after the reaction is finished.

Description

Technical Field

[0001] This invention relates to the technical field of fine chemical raw material synthesis, and in particular to a method and system for the sulfonation of aromatic hydrocarbons using sulfur trioxide. Background Technology

[0002] The main component of an industrial sulfonation reactor is a stirred tank reactor. Due to the critical safety of alkylbenzenes and the difficulty in achieving effective mixing and good thermal control in conventional reactors, the sulfonation reaction of alkylbenzenes is limited to low temperatures. Despite this, accidents caused by the sulfonation reaction still occur frequently. Furthermore, uneven heat distribution within the reactor can lead to the formation of undesirable byproducts and low yields. Microreactors are a new type of reactor with advantages such as small channel size and large specific surface area. They can effectively improve the energy transfer rate within the reactor, save energy, and increase internal production efficiency. Microreactors are suitable for high-temperature SO3 sulfonation reactions with instantaneous and strongly exothermic processes.

[0003] An article in the *Journal of Chemical Industry and Engineering*, with DOI 10.11949 / 0438-1157.20211523 and Xu Yiming as the first author, proposes a study on the continuous synthesis process of industrial mixed linear alkylbenzene sulfonates in a microchannel reactor. The article discloses a microreactor for the continuous sulfonation of alkylbenzene, consisting of two horizontal flow pumps, a three-way micromixer, stainless steel tubing, and a water bath. A check valve is installed before the micromixer to prevent backflow of reactants, maintaining a constant volumetric flow rate within the mixer. The stainless steel tubing reactor has an inner diameter of 0.6 mm, and the residence time of the reactants is adjusted by changing the length of the reaction tube.

[0004] The study investigated process conditions, such as reaction temperature, feed molar ratio, and sulfonating agent concentration, to elucidate their effects on the yield of linear alkylbenzene sulfonic acid. These process conditions were optimized to achieve the desired high-quality product specifications and maximize product yield.

[0005] Regarding the above technical solutions, although this type of microreactor uses a water bath for temperature control, the water bath can only increase the water temperature. At the same time, SO3 sulfonation is a large exothermic process, so the temperature of the water bath will rise during the reaction. The increased temperature will affect the color of the product and may even exceed the detection limit of the instrument. Summary of the Invention

[0006] In order to increase the reaction rate and thus increase the yield while maintaining the purity of the reaction products, the present invention provides a method and system for the sulfonation of aromatic hydrocarbons using sulfur trioxide.

[0007] In a first aspect, the present invention provides a method for sulfonating aromatic hydrocarbons using sulfur trioxide, which employs the following technical solution: A method for sulfonating aromatic hydrocarbons using sulfur trioxide includes the following steps: Reactant pumping: The dichloroethane solution containing dissolved SO3 and the dichloroethane solution containing dissolved linear alkylbenzene are pumped to the inlet of the main reactor for mixing according to a set rate threshold. Main reaction: SO3 reacts with linear alkylbenzene in the main reactor in a sulfonation reaction, and the main reactor is kept at an ambient temperature with a set temperature threshold. Temperature judgment: If the temperature of the reaction product at the outlet of the main reactor is greater than the first temperature threshold, then execute the ambient temperature judgment step I; if the temperature of the reaction product at the outlet of the main reactor is less than the second temperature threshold, then execute the ambient temperature judgment step II; if the temperature of the reaction product at the outlet of the main reactor is less than or equal to the first temperature threshold and greater than or equal to the second temperature threshold, then continue to execute the reactant pumping step; the second temperature threshold is less than the first temperature threshold. Ambient temperature judgment I: If the ambient temperature has dropped to the lowest value of the set range, the pumping speed in the reactant pumping step is restored to the set speed threshold, and the ambient temperature in the main reaction step is restored to the set temperature threshold; otherwise, the ambient temperature reduction step is executed. Ambient Temperature Judgment II: If the ambient temperature has risen to the highest value of the set range, proceed with the material feeding step; otherwise, proceed with the ambient temperature increase step. Feeding: Increase the pumping speed of the dichloroethane solution dissolving SO3 and the dichloroethane solution dissolving straight-chain alkylbenzenes in proportion; Lower the ambient temperature: Lower the ambient temperature of the main reaction. Increase ambient temperature: Increase the ambient temperature of the main reaction.

[0008] By adopting the above technical solution, SO3 sulfonation is a large-scale exothermic reaction. During the reaction, the temperature at the back of the reactor is higher than that at the front. If the temperature is too high, by-products are easily generated, which increases the color of the product. By judging the temperature, the reaction temperature is reduced during the synthesis process to reduce the impact on the color of the product.

[0009] Simultaneously, by judging the ambient temperature (I), the control of reaction cooling can be adjusted more precisely. When the temperature rises, cooling is performed. When the temperature is too high and the cooling cannot reach the first temperature threshold, the pumping speed and temperature are restored. The excessive reaction temperature is due to the excessively fast pumping speed causing violent collisions of reactants. Therefore, the pumping speed is incorrect and is accelerated. Restoring the pumping speed and temperature helps to quickly restore the predetermined values ​​of the entire system, with less impact on the overall product and reducing the degree of impact on the affected parts.

[0010] By using ambient temperature judgment II, the control of reaction temperature rise can be adjusted more precisely. When the temperature rises, a heating process is performed first. If the heating process cannot meet the ambient temperature requirements, a feeding step is performed. By increasing the feeding rate of the materials, the mixing uniformity of the two reactants can be improved, thereby increasing the reaction rate and increasing the rate at which the reactants heat up, so that the temperature can quickly return to the ambient temperature.

[0011] Optionally, the aromatic sulfonation method using sulfur trioxide further includes a compensation reaction I step; Compensation Reaction I: The sulfonation products from the main reactor are transported to the compensation reactor to continue the sulfonation reaction. The ambient temperature of the compensation reactor is the same as that of the main reactor, and the length of the compensation reactor is shorter than that of the main reactor.

[0012] In the ambient temperature judgment step II, if the ambient temperature has risen to the highest value of the set range, the compensation reaction step is executed simultaneously with the feeding step.

[0013] By adopting the above technical solution, after the feeding step in ambient temperature judgment II, the pumping speed and flow rate of the dichloroethane solution dissolving SO3 and the dichloroethane solution dissolving straight-chain alkylbenzene are increased. Under these conditions, the residence time cannot ensure the completion of the reaction. At this time, by compensating for reaction step I, the residence time is increased, thereby improving the conversion rate of the product.

[0014] Optionally, the aromatic sulfonation method using sulfur trioxide further includes a dichloromethane pumping step.

[0015] Dichloromethane pumping: Obtain the flow rate of the mixed reactants at the inlet of the main reactor at the current moment, and record it as the first flow rate; stop the reactant pumping step, and pump dichloromethane into the inlet of the main reactor at a rate greater than the first flow rate.

[0016] In the ambient temperature judgment step I, if the ambient temperature has dropped to the lowest value of the set range, the dichloromethane pumping step is executed first for the first duration, and then the reactant pumping step is resumed.

[0017] By adopting the above technical solution, the superheated solution is promptly emptied through a rapid dichloromethane pumping step. After the superheated solution is removed, new material is added without affecting the generation of subsequent products. In addition, the added solution is dichloroethane, which will not generate impurities.

[0018] Optionally, the aromatic sulfonation method using sulfur trioxide further includes a compensation reaction II step.

[0019] Simultaneously, compensation reaction II is performed during the dichloromethane pumping step. Compensation Reaction II: The sulfonation products from the main reactor are transported to the compensation reactor to continue the sulfonation reaction. The ambient temperature of the compensation reactor is lower than that of the main reactor, and the length of the compensation reactor is shorter than that of the main reactor.

[0020] By adopting the above technical solution, after the dichloromethane pumping step, the superheated solution flows out too quickly. Under such circumstances, the residence time cannot ensure the completion of the reaction. At this time, by compensating for the reaction in step II, the ambient temperature of the compensation reactor is reduced, the reactants are further cooled, the temperature reduction rate is increased, the generation of by-products is reduced, and the residence time is increased to improve the conversion rate of the product.

[0021] Optionally, the aromatic sulfonation method using sulfur trioxide includes an experimental data acquisition step before the pumping step; Experimental data acquisition: The main reactor was placed at an ambient temperature equal to the third temperature threshold. A dichloroethane solution containing dissolved SO3 and a dichloroethane solution containing dissolved linear alkylbenzenes were pumped to the inlet of the main reactor for mixing. The temperature at which the reactants flowed to a distance l from the reactor inlet after mixing, when the flow rate of the reactants in the main reactor was v, was recorded. ; An over-temperature prediction step is included concurrently with the main reaction step. Overtemperature prediction: Obtaining the actual temperature at which the reactants reach a distance l from the reactor inlet when the flow rate is v in the main reaction step. And obtain the temperature difference between the ambient temperature of the main reaction step and the third temperature threshold. ,like ≥ If the temperature of the reaction product at the outlet of the main reactor is greater than the first temperature threshold, then L is the total length of the main reactor.

[0022] By adopting the above technical solution, the standard temperature is calculated from experimental data. The actual temperature is monitored in real time during the reaction process. ,Will and By making comparisons, the reaction temperature can be adjusted in a timely manner during the reaction process, and at the same time The introduction of [the technology] further refined [the technology]. Adjusting the reaction temperature under varying ambient temperatures is beneficial for regulating the reaction temperature under different conditions, gradually reducing the probability of byproducts during the reaction, and thus reducing the formation of byproducts after the reaction is complete.

[0023] Secondly, the present invention provides an aromatic hydrocarbon sulfonation system using sulfur trioxide, which adopts the following technical solution: An aromatic hydrocarbon sulfonation system using sulfur trioxide includes a first feed tank, a first horizontal flow pump, a second feed tank, a second horizontal flow pump, a main reactor, a first temperature sensor, a first insulation device, a finished product tank, and a main control system. The inlet of the first horizontal flow pump is connected to the first material tank, the outlet of the first horizontal flow pump is connected to the inlet of the main reactor, the inlet of the second horizontal flow pump is connected to the second material tank, the outlet of the second horizontal flow pump is connected to the inlet of the main reactor, and the outlet of the main reactor is connected to the finished product tank. The first temperature sensor is located at the outlet of the main reactor. The first insulation device includes a first insulation pipe, a first hot water pipe, a first cold water pipe, a first outlet pipe, and a first regulating valve. The first insulation pipe is coaxially sleeved on the main reactor. The outlets of the first hot water pipe and the first cold water pipe are connected to the inside of the first insulation pipe. The inlet of the first outlet pipe is connected to the inside of the first insulation pipe. The first regulating valve is located on the first cold water pipe. The first temperature sensor is electrically connected to the main control system, and the main control system is electrically connected to the first flow pump, the second flow pump, and the first regulating valve.

[0024] By adopting the above technical solution, the dichloroethane solution dissolving SO3 and the dichloroethane solution dissolving linear alkylbenzene are stored in the first and second tanks, respectively. The first and second horizontal flow pumps pump the dichloroethane solutions dissolving SO3 and linear alkylbenzene to the inlet of the main reactor, respectively, where they are mixed by flow impact. The mixture then flows into the main reactor for the sulfonation reaction. During the sulfonation reaction, the first hot water pipe supplies hot water to the first insulation pipe, thereby providing the main reactor with the ambient temperature required for the sulfonation reaction.

[0025] When the temperature monitored by the first temperature sensor is higher than the first temperature threshold, the main control system controls the first regulating valve to increase its opening, and the first cold water pipe flows cold water into the first insulation pipe to lower the ambient temperature inside the first insulation pipe, thereby cooling the reactants in the main reactor. If the opening of the first regulating valve is at its maximum but the temperature monitored by the first temperature sensor is still higher than the set threshold, the main control system controls the first and second parallel flow pumps to return to their initial pumping speeds and controls the first regulating valve to close, thereby restoring the ambient temperature inside the first insulation pipe and reducing the generation of by-product impurities.

[0026] If the temperature monitored by the first temperature sensor is lower than the second set threshold, the main control system controls the first regulating valve to reduce its opening, and the first cold water pipe to reduce the amount of cold water flowing into the first insulation pipe, thereby increasing the ambient temperature inside the first insulation pipe and providing sufficient reaction temperature for the reactants in the main reactor. If the first regulating valve is completely closed but the temperature monitored by the first temperature sensor is still lower than the second temperature threshold, the main control system controls the first and second parallel flow pumps to increase their pumping speed proportionally, thereby improving the mixing uniformity of the reactants and improving the completeness of the sulfonation reaction.

[0027] Optionally, the aromatic sulfonation system using sulfur trioxide further includes a compensation reactor, a connecting pipe, a first control valve, and a second insulation device.

[0028] The inlet of the connecting pipe is connected to the outlet of the main reactor, the outlet of the connecting pipe is connected to the inlet of the compensation reactor, and the outlet of the compensation reactor is connected to the finished product tank. A first control valve is installed on the connecting pipe. The first control valve is used to control whether the outlet of the main reactor is connected to the inlet of the compensation reactor or to the finished product tank. The second insulation device includes a second insulation pipe, a second hot water pipe, a second cold water pipe, a second outlet pipe, and a second regulating valve. The second insulation pipe is coaxially sleeved on the compensation reactor. The outlets of the second hot water pipe and the second cold water pipe are both connected to the inside of the second insulation pipe, and the inlet of the second outlet pipe is connected to the inside of the second insulation pipe. The second regulating valve is installed on the second cold water pipe, and the temperature of the cold water in the second cold water pipe is lower than the temperature of the cold water in the first cold water pipe. The main control system is connected to the electrical signals of the first control valve and the second regulating valve.

[0029] By adopting the above technical solution, if the first regulating valve is completely closed but the temperature monitored by the first temperature sensor is still lower than the second temperature threshold, the reactants in the main reactor will have incomplete reactions. At this time, the main control system controls the control valve to connect the outlet of the main reactor to the inlet of the compensation reactor, and at the same time controls the first and second parallel flow pumps to increase the pumping speed proportionally. In this way, the incompletely reacted reactants can flow into the compensation reactor to continue the reaction, thereby improving the yield and reducing the content of incompletely reacted reactants in the finished product.

[0030] Optionally, the aromatic sulfonation system using sulfur trioxide further includes a third feed tank, a third horizontal flow pump, and a second control valve.

[0031] The inlet of the third horizontal flow pump is connected to the third material tank, and the outlet of the third horizontal flow pump is connected to the inlet of the main reactor through the second control valve. The second control valve is used to connect the outlet of the first horizontal flow pump, the outlet of the second horizontal flow pump to the inlet of the main reactor, or the outlet of the third horizontal flow pump to the inlet of the main reactor.

[0032] The main control system is electrically connected to the third horizontal flow pump and the second control valve.

[0033] By adopting the above technical solution, if the opening of the first regulating valve is maximized but the temperature monitored by the first temperature sensor is still higher than the set threshold, it proves that the reactants are reacting too fast in the main reactor. When the reactants leave the main reactor, they will produce byproducts. At this time, the main control system controls the second control valve to connect the outlet of the third horizontal flow pump with the inlet of the main reactor. At the same time, the third horizontal flow pump starts and introduces dichloromethane into the main reactor. In this way, the reactants that are about to react into byproducts in the main reactor can be quickly pushed away from the main reactor to reduce the content of byproducts in the finished product.

[0034] Optionally, the aromatic sulfonation system using sulfur trioxide also includes multiple second temperature sensors.

[0035] Multiple sets of second temperature sensors are evenly distributed along the length of the main reactor on the main reactor.

[0036] The second temperature sensor is electrically connected to the main control system.

[0037] By adopting the above technical solution, the temperature sensor group can monitor the reaction temperature of each part in real time. The real-time temperature monitoring can predict the temperature of the reactants when they reach the outlet of the main reactor. If the predicted temperature is higher than the first temperature threshold, the main control system controls the first regulating valve to increase its opening, and the first cold water pipe to introduce cold water into the first insulation pipe to reduce the ambient temperature inside the first insulation pipe, thereby cooling the reactants in the main reactor. If the predicted temperature is lower than the second set threshold, the main control system controls the first regulating valve to decrease its opening, and the first cold water pipe to reduce the amount of cold water introduced into the first insulation pipe to increase the ambient temperature inside the first insulation pipe, thereby providing sufficient reaction temperature for the reactants in the main reactor. If the first regulating valve is completely closed but the temperature monitored by the first temperature sensor is still lower than the second temperature threshold, the main control system controls the first and second parallel flow pumps to increase their pumping speed proportionally, thereby improving the mixing uniformity of the reactants and improving the completeness of the sulfonation reaction. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the overall system structure of the present invention; Figure 2 This is a partial view of the main reactor and the compensation reactor of the present invention.

[0039] Explanation of reference numerals in the attached drawings: 11. First material tank; 12. First horizontal flow pump; 13. Second material tank; 14. Second horizontal flow pump; 15. Main reactor; 16. First temperature sensor; 17. First insulation device; 171. First insulation pipe; 172. First hot water pipe; 173. First cold water pipe; 174. First outlet pipe; 175. First regulating valve; 18. Compensating reactor; 19. Connecting pipe; 20. First control valve; 21. Second insulation device; 211. Second insulation pipe; 212. Second hot water pipe; 213. Second cold water pipe; 214. Second outlet pipe; 215. Second regulating valve; 22. Third material tank; 23. Third horizontal flow pump; 24. Second control valve; 25. Second temperature sensor; 26. Finished product tank. Detailed Implementation

[0040] The present invention will be further described in detail below with reference to the embodiments.

[0041] In a specific embodiment of the present invention, the linear alkylbenzene is selected as hexadecylbenzene, and in other embodiments it may be other linear alkylbenzenes such as dodecylbenzene.

[0042] Example 1: This example discloses a method for sulfonating aromatic hydrocarbons using sulfur trioxide, comprising the following steps.

[0043] Experimental data acquisition: The main reactor was placed at an ambient temperature equal to a third temperature threshold. In this embodiment, the third temperature threshold was 50°C. A dichloroethane solution containing dissolved SO3 and a dichloroethane solution containing dissolved linear alkylbenzene were pumped to the inlet of the main reactor for mixing. In this embodiment, the molar ratio of SO3 to linear alkylbenzene was 1.1:1. The temperature at which the reactants reached a distance l from the reactor inlet after mixing, when the flow rate of the reactants in the main reactor was v, was recorded. .

[0044] The experiment was repeated 5 times for each flow rate, and the average value was taken.

[0045] Reactant pumping: The dichloroethane solution containing dissolved SO3 and the dichloroethane solution containing dissolved linear alkylbenzene are pumped to the inlet of the main reactor for mixing according to a set rate threshold. In this embodiment, the molar ratio of SO3 to linear alkylbenzene is 1.1:1 and the rate threshold is 8 mL / min.

[0046] Main reaction: SO3 reacts with linear alkylbenzene in the main reactor to undergo sulfonation. The main reactor is kept at an ambient temperature with a set temperature threshold. In this embodiment of the application, the ambient temperature is 50°C.

[0047] An overtemperature prediction step is performed simultaneously with the main reaction step.

[0048] Overtemperature prediction: Obtaining the actual temperature at which the reactants reach a distance l from the reactor inlet when the flow rate is v in the main reaction step. And obtain the temperature difference between the ambient temperature of the main reaction step and the third temperature threshold. ,like ≥ If the temperature of the reaction product at the outlet of the main reactor is greater than the first temperature threshold, then L is determined to be the total length of the main reactor. In this embodiment of the application, the first temperature threshold is 60°C.

[0049] Temperature determination: If the temperature of the reaction product at the outlet of the main reactor is greater than the first temperature threshold, then perform the ambient temperature determination step I; if the temperature of the reaction product at the outlet of the main reactor is less than the second temperature threshold, then perform the ambient temperature determination step II; if the temperature of the reaction product at the outlet of the main reactor is less than or equal to the first temperature threshold and greater than or equal to the second temperature threshold, then continue to perform the reactant pumping step; the second temperature threshold is less than the first temperature threshold. In this embodiment, the second temperature threshold is 45°C.

[0050] Ambient temperature judgment I: If the ambient temperature has dropped to the lowest value of the set range, the dichloromethane pumping step and the compensation reaction II step are executed first, with an execution time of the first duration. Then the reactant pumping step is resumed, so that the pumping speed in the reactant pumping step is restored to the set speed threshold, and the ambient temperature in the main reaction step is restored to the set temperature threshold. Otherwise, the ambient temperature reduction step is executed.

[0051] Ambient temperature judgment II: If the ambient temperature has risen to the highest value of the set range, then execute the feeding step and simultaneously execute the compensation reaction I step; otherwise, execute the step of increasing the ambient temperature.

[0052] Lower the ambient temperature: Lower the ambient temperature of the main reaction.

[0053] Increase ambient temperature: Increase the ambient temperature of the main reaction.

[0054] Compensation Reaction I: The sulfonation products from the main reactor are transported to the compensation reactor to continue the sulfonation reaction. The ambient temperature of the compensation reactor is the same as that of the main reactor, and the length of the compensation reactor is shorter than that of the main reactor.

[0055] Dichloromethane pumping: Obtain the flow rate of the mixed reactants at the inlet of the main reactor at the current moment, and record it as the first flow rate; stop the reactant pumping step, and pump dichloromethane into the inlet of the main reactor at a rate greater than the first flow rate.

[0056] Compensation Reaction II: Obtain the current ambient temperature of the main reactor. The sulfonation products from the main reactor are transported to the compensation reactor to continue the sulfonation reaction. The ambient temperature of the compensation reactor is lower than that of the main reactor, and the length of the compensation reactor is shorter than that of the main reactor.

[0057] Feeding: Increase the pumping speed of the dichloroethane solution dissolving SO3 and the dichloroethane solution dissolving straight-chain alkylbenzenes in proportion.

[0058] The implementation principle of an aromatic sulfonation method using sulfur trioxide in this application embodiment is as follows: Before production, data on the temperature rise trend of the reactants at various mixing rates are collected for use during production.

[0059] During production, raw materials are first pumped at a set rate to mix the two materials, which then undergo a sulfonation reaction in the main reactor. Temperature monitoring is performed at various locations within the main reactor during the sulfonation reaction to determine the temperature of the reactants.

[0060] If the raw material addition rate increases due to pumping errors during the pumping process, the raw materials will be mixed more evenly due to the stronger impact, thus accelerating the sulfonation reaction. Since sulfonation is an exothermic reaction, this will cause the reactant temperature to rise too quickly. In this case, the potential for overheating can be predicted based on the temperature of the reactants in the main reactor and the temperature rise trend of the reactants at various mixing rates.

[0061] If the reactants may overheat, first lower the ambient temperature of the main reactor to reduce the reaction rate of the sulfonation reaction and the probability of a side reaction producing sulfone. If the reactants may still overheat after the ambient temperature is lowered, stop pumping raw materials into the main reactor and instead pump dichloromethane at a rate greater than the rate at which the raw materials were pumped before the pumping of raw materials was stopped. This allows the reactants in the main reactor to be pushed into the compensation reactor at a faster rate, reducing the probability of overheating in the main reactor.

[0062] Because the reactants leave the main reactor quickly, some reactants do not react. At this time, the reactants undergo compensation reaction II in the compensation reactor, and the ambient temperature of the compensation reactor is lower than that of the main reactor. This can reduce the probability of side reactions of the reactants, while increasing the reaction rate of the reactants and reducing impurities in the products.

[0063] If the feed rate decreases due to pumping errors during the pumping process, the feed will be mixed less evenly due to the gentler impact, leading to a slower sulfonation reaction rate and incomplete reaction. In this case, the temperature of the reactants in the main reactor and the temperature rise trend of the reactants at various mixing rates can be used to predict whether the reactants will experience "supercooling".

[0064] If the reactants may become supercooled, the ambient temperature of the main reactor is first increased to accelerate the sulfonation reaction rate and reduce the probability of incomplete reaction. If supercooling still occurs after increasing the ambient temperature, the rate at which raw materials are pumped into the main reactor is increased to improve the mixing uniformity of the reactants, thereby increasing the reaction rate. Simultaneously, the exothermic rate is increased to accelerate the rise in the ambient temperature within the main reactor. The supercooled reactants are then transferred to a compensation reactor to continue the reaction, further reducing the probability of incomplete reaction.

[0065] Example 2: This example discloses an aromatic sulfonation system using sulfur trioxide.

[0066] An aromatic sulfonation system using sulfur trioxide includes a first feed tank 11, a first horizontal flow pump 12, a second feed tank 13, a second horizontal flow pump 14, a main reactor 15, a first temperature sensor 16, a first insulation device 17, a compensation reactor 18, a connecting pipe 19, a first control valve 20, a second insulation device 21, a third feed tank 22, a third horizontal flow pump 23, a second control valve 24, multiple second temperature sensors 25, a finished product tank 26, and a main control system.

[0067] The inlet of the first horizontal flow pump 12 is connected to the first feed tank 11, and the outlet of the first horizontal flow pump 12 is connected to the inlet of the main reactor 15. The inlet of the second horizontal flow pump 14 is connected to the second feed tank 13, and the outlet of the second horizontal flow pump 14 is connected to the inlet of the main reactor 15. The inlet of the third horizontal flow pump 23 is connected to the third feed tank 22, and the outlet of the third horizontal flow pump 23 is connected to the inlet of the main reactor 15 through a second control valve 24. The second control valve 24 is used to connect the outlets of the first horizontal flow pump 12 and the second horizontal flow pump 14 to... The inlet of the main reactor 15 is connected, or the outlet of the third horizontal flow pump 23 is connected to the inlet of the main reactor 15. The inlet of the connecting pipe 19 is connected to the outlet of the main reactor 15, and the outlet of the connecting pipe 19 is connected to the inlet of the compensation reactor 18. The outlet of the compensation reactor 18 is connected to the finished product tank 26. The first control valve 20 is installed on the connecting pipe 19. The first control valve 20 is used to control whether the outlet of the main reactor 15 is connected to the inlet of the compensation reactor 18 or the outlet of the main reactor 15 is connected to the finished product tank 26.

[0068] The first temperature sensor 16 is located at the outlet of the main reactor 15, and multiple sets of second temperature sensors 25 are evenly distributed along the length of the main reactor 15.

[0069] The first heat preservation device 17 includes a first heat preservation pipe 171, a first hot water pipe 172, a first cold water pipe 173, a first water outlet pipe 174, and a first regulating valve 175. The first heat preservation pipe 171 is coaxially sleeved on the main reactor 15. The outlets of the first hot water pipe 172 and the first cold water pipe 173 are both connected to the inside of the first heat preservation pipe 171. The inlet of the first water outlet pipe 174 is connected to the inside of the first heat preservation pipe 171. The first regulating valve 175 is installed on the first cold water pipe 173.

[0070] The second heat preservation device 21 includes a second heat preservation pipe 211, a second hot water pipe 212, a second cold water pipe 213, a second outlet pipe 214, and a second regulating valve 215. The second heat preservation pipe 211 is coaxially sleeved on the compensation reactor 18. The outlets of the second hot water pipe 212 and the second cold water pipe 213 are both connected to the inside of the second heat preservation pipe 211. The inlet of the second outlet pipe 214 is connected to the inside of the second heat preservation pipe 211. The second regulating valve 215 is installed on the second cold water pipe 213. The temperature of the cold water in the second cold water pipe 213 is lower than the temperature of the cold water in the first cold water pipe 173.

[0071] The first temperature sensor 16 and the second temperature sensor 25 are electrically connected to the main control system.

[0072] The main control system is electrically connected to the first horizontal flow pump 12, the second horizontal flow pump 14, the first regulating valve 175, the first control valve 20, the second regulating valve 215, the third horizontal flow pump 23, and the second control valve 24.

[0073] The implementation principle of an aromatic sulfonation system using sulfur trioxide in this application embodiment is as follows: The dichloroethane solution for dissolving SO3 and the dichloroethane solution for dissolving linear alkylbenzene are stored in the first tank 11 and the second tank 13, respectively. The first horizontal flow pump 12 and the second horizontal flow pump 14 pump the dichloroethane solution for dissolving SO3 and the dichloroethane solution for dissolving linear alkylbenzene to the inlet of the main reactor 15, respectively, and mix them by flow impact. Then they flow into the main reactor 15 for sulfonation reaction.

[0074] During the sulfonation reaction, the first hot water pipe 172 supplies hot water to the first heat insulation pipe 171, thereby providing the main reactor 15 with the ambient temperature required for the sulfonation reaction.

[0075] When the temperature monitored by the first temperature sensor 16 is higher than the first temperature threshold, the main control system controls the first regulating valve to increase its opening, and the first cold water pipe 173 introduces cold water into the first insulation pipe 171 to reduce the ambient temperature inside the first insulation pipe 171, thereby cooling the reactants in the main reactor 15. If the opening of the first regulating valve 175 is maximized but the temperature monitored by the first temperature sensor 16 is still higher than the set threshold, the main control system controls the first parallel flow pump 12 and the second parallel flow pump 14 to return to their initial pumping speeds, and controls the first regulating valve 175 to close, thereby restoring the ambient temperature inside the first insulation pipe 171 and reducing the generation of by-product impurities.

[0076] If the first regulating valve 175 is opened to its maximum but the temperature monitored by the first temperature sensor 16 is still higher than the set threshold, it proves that the reactants are reacting too fast in the main reactor 15. When the reactants leave the main reactor 15, they will produce byproducts. At this time, the main control system controls the second control valve 24 to connect the outlet of the third horizontal flow pump 23 with the inlet of the main reactor 15. At the same time, the third horizontal flow pump 23 is started to introduce dichloromethane into the main reactor 15. In this way, the reactants that are about to react into byproducts in the main reactor 15 can be quickly pushed away from the main reactor 15 to reduce the content of byproducts in the finished product.

[0077] At the same time, the main control system controls the first control valve 20 and the second regulating valve 215 to connect the outlet of the main reactor 15 to the inlet of the compensation reactor 18. The second cold water pipe 213 introduces cold water into the second insulation pipe 211 to reduce the ambient temperature inside the second insulation pipe 211, thereby cooling the reactants inside the compensation reactor 18.

[0078] The unreacted reactants can then flow into the compensation reactor 18 to continue the reaction, while the reactants are further cooled, which increases the yield and reduces the generation of by-products.

[0079] If the temperature monitored by the first temperature sensor 16 is lower than the second set threshold, the main control system controls the first regulating valve to reduce its opening, and the first cold water pipe 173 reduces the amount of cold water flowing into the first insulation pipe 171, thereby increasing the ambient temperature inside the first insulation pipe 171 and providing sufficient reaction temperature for the reactants in the main reactor 15. If the first regulating valve 175 is completely closed but the temperature monitored by the first temperature sensor 16 is still lower than the second temperature threshold, the main control system controls the first parallel flow pump 12 and the second parallel flow pump 14 to increase their pumping speed proportionally, thereby improving the mixing uniformity of the reactants.

[0080] At the same time, the main control system controls the control valve to connect the outlet of the main reactor 15 to the inlet of the compensation reactor 18. In this way, the unreacted reactants can flow into the compensation reactor 18 to continue the reaction, which improves the yield and reduces the content of unreacted reactants in the finished product.

[0081] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for sulfonating aromatic hydrocarbons using sulfur trioxide, characterized in that, Includes the following steps: Reactant pumping: The dichloroethane solution containing dissolved SO3 and the dichloroethane solution containing dissolved linear alkylbenzene are pumped to the inlet of the main reactor for mixing according to a set rate threshold. Main reaction: SO3 reacts with linear alkylbenzene in the main reactor in a sulfonation reaction, and the main reactor is kept at an ambient temperature with a set temperature threshold. Temperature judgment: If the temperature of the reaction product at the outlet of the main reactor is greater than the first temperature threshold, then execute the ambient temperature judgment step I; if the temperature of the reaction product at the outlet of the main reactor is less than the second temperature threshold, then execute the ambient temperature judgment step II; if the temperature of the reaction product at the outlet of the main reactor is less than or equal to the first temperature threshold and greater than or equal to the second temperature threshold, then continue to execute the reactant pumping step; the second temperature threshold is less than the first temperature threshold. Ambient temperature judgment I: If the ambient temperature has dropped to the lowest value of the set range, the pumping speed in the reactant pumping step is restored to the set speed threshold, and the ambient temperature in the main reaction step is restored to the set temperature threshold; otherwise, the ambient temperature reduction step is executed. Ambient Temperature Judgment II: If the ambient temperature has risen to the highest value of the set range, proceed with the material feeding step; otherwise, proceed with the ambient temperature increase step. Feeding: Increase the pumping speed of the dichloroethane solution dissolving SO3 and the dichloroethane solution dissolving straight-chain alkylbenzenes in proportion; Lower the ambient temperature: Lower the ambient temperature of the main reaction. Increase ambient temperature: Increase the ambient temperature of the main reaction.

2. The method for sulfonating aromatic hydrocarbons using sulfur trioxide according to claim 1, characterized in that: The aromatic sulfonation method using sulfur trioxide further includes a compensation reaction I step; Compensation Reaction I: The sulfonation products from the main reactor are transported to the compensation reactor to continue the sulfonation reaction. The ambient temperature of the compensation reactor is the same as that of the main reactor, and the length of the compensation reactor is shorter than that of the main reactor. In the ambient temperature judgment step II, if the ambient temperature has risen to the highest value of the set range, the compensation reaction step is executed simultaneously with the feeding step.

3. The method for sulfonating aromatic hydrocarbons using sulfur trioxide according to claim 1, characterized in that: The aromatic sulfonation method using sulfur trioxide also includes a dichloromethane pumping step; Dichloromethane pumping: Obtain the flow rate of the mixed reactants at the inlet of the main reactor at the current moment, and record it as the first flow rate; stop the reactant pumping step, and pump dichloromethane into the inlet of the main reactor at a rate greater than the first flow rate. In the ambient temperature judgment step I, if the ambient temperature has dropped to the lowest value of the set range, the dichloromethane pumping step is executed first for the first duration, and then the reactant pumping step is resumed.

4. The method for sulfonating aromatic hydrocarbons using sulfur trioxide according to claim 3, characterized in that: The aromatic sulfonation method using sulfur trioxide further includes a compensation reaction II step; Simultaneously, compensation reaction II is performed during the dichloromethane pumping step. Compensation Reaction II: The sulfonation products from the main reactor are transported to the compensation reactor to continue the sulfonation reaction. The ambient temperature of the compensation reactor is lower than that of the main reactor, and the length of the compensation reactor is shorter than that of the main reactor.

5. The method for sulfonating aromatic hydrocarbons using sulfur trioxide according to claim 1, characterized in that: The aromatic sulfonation method using sulfur trioxide includes an experimental data acquisition step before the pumping step and an over-temperature prediction step before the main reaction step. Experimental data acquisition: The main reactor was placed at an ambient temperature equal to the third temperature threshold. A dichloroethane solution containing dissolved SO3 and a dichloroethane solution containing dissolved linear alkylbenzenes were pumped to the inlet of the main reactor for mixing. The temperature at which the reactants flowed to a distance l from the reactor inlet after mixing, when the flow rate of the reactants in the main reactor was v, was recorded. ; Overtemperature prediction: Obtaining the actual temperature at which the reactants reach a distance l from the reactor inlet when the flow rate is v in the main reaction step. And obtain the temperature difference between the ambient temperature of the main reaction step and the third temperature threshold. ,like ≥ If the temperature of the reaction product at the outlet of the main reactor is greater than the first temperature threshold, then L is the total length of the main reactor.

6. An aromatic sulfonation system using sulfur trioxide, employing an aromatic sulfonation method using sulfur trioxide as described in any one of claims 1-5, characterized in that, It includes a first material tank (11), a first horizontal flow pump (12), a second material tank (13), a second horizontal flow pump (14), a main reactor (15), a first temperature sensor (16), a first heat preservation device (17), a finished product tank (26), and a main control system; The inlet of the first horizontal flow pump (12) is connected to the first material tank (11), the outlet of the first horizontal flow pump (12) is connected to the inlet of the main reactor (15), the inlet of the second horizontal flow pump (14) is connected to the second material tank (13), the outlet of the second horizontal flow pump (14) is connected to the inlet of the main reactor (15), and the outlet of the main reactor (15) is connected to the finished product tank (26). The first temperature sensor (16) is located at the outlet of the main reactor (15). The first heat preservation device (17) includes a first heat preservation pipe (171), a first hot water pipe (172), a first cold water pipe (173), a first outlet pipe (174), and a first regulating valve (175). The first heat preservation pipe (171) is coaxially sleeved on the main reactor (15). The outlets of the first hot water pipe (172) and the first cold water pipe (173) are connected to the inside of the first heat preservation pipe (171). The inlet of the first outlet pipe (174) is connected to the inside of the first heat preservation pipe (171). The first regulating valve (175) is located on the first cold water pipe (173). The first temperature sensor (16) is electrically connected to the main control system, and the main control system is electrically connected to the first advection pump (12), the second advection pump (14), and the first regulating valve (175).

7. An aromatic sulfonation system using sulfur trioxide according to claim 6, characterized in that: The aromatic sulfonation system using sulfur trioxide also includes a compensation reactor (18), a connecting pipe (19), a first control valve (20), and a second heat preservation device (21). The inlet of the connecting pipe (19) is connected to the outlet of the main reactor (15), the outlet of the connecting pipe (19) is connected to the inlet of the compensation reactor (18), the outlet of the compensation reactor (18) is connected to the finished product tank (26), and the first control valve (20) is installed on the connecting pipe (19). The first control valve (20) is used to control the connection between the outlet of the main reactor (15) and the inlet of the compensation reactor (18), or to connect the outlet of the main reactor (15) to the finished product tank (26). The second heat preservation device (21) includes a second heat preservation pipe (211), a second hot water pipe (212), a second cold water pipe (213), a second outlet pipe (214), and a second regulating valve (215). The second heat preservation pipe (211) is coaxially sleeved on the compensation reactor (18). The outlets of the second hot water pipe (212) and the second cold water pipe (213) are connected to the inside of the second heat preservation pipe (211). The inlet of the second outlet pipe (214) is connected to the inside of the second heat preservation pipe (211). The second regulating valve (215) is set on the second cold water pipe (213). The temperature of the cold water in the second cold water pipe (213) is lower than the temperature of the cold water in the first cold water pipe (173). The main control system is connected to the electrical signal of the first control valve (20) and the electrical signal of the second regulating valve (215); The main control system is electrically connected to the third horizontal flow pump (23) and the second control valve (24).

8. An aromatic sulfonation system using sulfur trioxide according to claim 6, characterized in that: The aromatic sulfonation system using sulfur trioxide also includes a third tank (22), a third horizontal flow pump (23), and a second control valve (24). The inlet of the third horizontal flow pump (23) is connected to the third material tank (22), and the outlet of the third horizontal flow pump (23) is connected to the inlet of the main reactor (15) through the second control valve (24). The second control valve (24) is used to connect the outlet of the first horizontal flow pump (12), the outlet of the second horizontal flow pump (14) to the inlet of the main reactor (15), or the outlet of the third horizontal flow pump (23) to the inlet of the main reactor (15).

9. An aromatic sulfonation system using sulfur trioxide according to claim 6, characterized in that: The aromatic sulfonation system using sulfur trioxide also includes multiple second temperature sensors (25). Multiple sets of second temperature sensors (25) are evenly distributed along the length of the main reactor (15) on the main reactor (15); The second temperature sensor (25) is electrically connected to the main control system.

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