Method for continuously synthesizing decabromodiphenylethane by using tubular reactor

Abstract

The invention discloses a method for continuously synthesizing decabromodiphenylethane by using a tubular reactor, and belongs to the technical field of organic synthesis processes. The method comprises the following steps: by taking diphenylethane as a raw material, continuously brominating the diphenylethane and bromine in a tubular reactor at a certain material ratio, retention time and reaction temperature, feeding the reacted material into a gas-liquid separation device for gas-liquid separation, absorbing the gas with water, and carrying out post-treatment such as quenching, bromine steaming, alkali neutralization, washing, suction filtration and drying on the effluent liquid to obtain the product decabromodiphenylethane. According to the process method, a method different from a traditional intermittent synthesis method is adopted, and the synthesis efficiency and safety of decabromodiphenylethane are greatly improved.

Description

TECHNICAL FIELD

[0001] The application relates to a method for continuously synthesizing decabromodiphenyl ethane by using a tubular reactor and belongs to the technical field of organic synthesis processes. TECHNICAL BACKGROUND

[0002] Decabromodiphenyl ethane is an important bromine-based flame retardant. A representative product, decabromodiphenyl ether, is limited due to the risk of generating POPs and dioxins. In response to the environmental protection challenge and the market demand for high-efficiency flame retardants, decabromodiphenyl ethane has become a substitute product. Decabromodiphenyl ethane usually uses an ethane group instead of an ether bond, which significantly reduces the risk of generating toxic dioxins during combustion while maintaining high bromine content and excellent flame retardant performance. However, most current production methods are batch or semi-continuous tank processes.

[0003] The tubular reactor has the characteristics of large specific surface area, good mass and heat transfer effect, continuous process, easy scaling-up, etc. It can realize full-automatic feeding and discharging control, and multiple corrosion-resistant materials can be selected. Based on these characteristics of the tubular reactor, the continuous production of decabromodiphenyl ethane can be realized, thereby shortening the reaction time, improving the single-pass conversion rate, reducing the production of by-products, and improving the production efficiency and safety. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects of the existing intermittent synthesis of decabromodiphenyl ethane, to complete continuous feeding of materials and continuous discharge of products, and to provide a method for continuously synthesizing decabromodiphenyl ethane by using a tubular reactor. The process is simple, the production efficiency is high, the safety is good, the synthesized decabromodiphenyl ethane has good thermal stability, high bromine content and low color.

[0005] The technical solution adopted by the application to solve the above problems is: a method for continuously synthesizing decabromodiphenyl ethane by using a tubular reactor, characterized by comprising the following steps: S01, heating a certain mass of diphenyl ethane to a molten state in a water bath, adding a catalyst to bromine, and pumping part of the bromine and the catalyst into the tubular reactor in advance and filling the tubular reactor; S02, pumping the two reaction liquids in S01 into the tubular reactor through a metering pump, mixing and reacting at a certain temperature, and after the reaction is completed, the material enters a gas-liquid separation device for separation, and the gas is absorbed with water; S03, quenching the liquid separated in S02 in deionized water, adding deionized water for bromine evaporation, and performing solid-liquid separation to obtain a crude product; S04, neutralizing the crude product in S03 to alkaline, washing and suction filtering, and then high-temperature drying to constant weight to obtain a product, and the product is re-dried to obtain data.

[0006] In S01, the water bath temperature of diphenyl ethane is 60 DEG C, in a molten state, with fluidity, the bromine addition amount is 25-40 times of the mass of diphenyl ethane, the moisture of bromine is less than 200 ppm, the catalyst addition amount is 10-20% of the mass of diphenyl ethane, here the catalyst is aluminum bromide, the bromine mixed with the catalyst is pumped into the reactor, and fills the entire reactor, and all air in the reactor is excluded.

[0007] In S02, the reaction temperature is 45-65 DEG C, the residence time is 10-30 min, and the flow rate is calculated according to the residence time.

[0008] In S03, the bromine evaporation temperature is 90-100 DEG C, and the mass ratio of the reaction solution to deionized water is 1:1.2-1.5.

[0009] In S04, the alkali solution for adjusting pH is one or both of sodium hydroxide and sodium carbonate, the pH range is 8-11, the drying temperature is 120-140 DEG C, the drying time is 1-2 h, the re-drying temperature is 230-250 DEG C, and the re-drying time is 1-2 h.

[0010] Compared with the prior art, the present application has the following advantages: The method for continuously synthesizing decabromodiphenyl ethane by using a tubular reactor according to the present application is to take diphenyl ethane as raw material, control the reaction temperature by water bath, continuously brominate diphenyl ethane and bromine through the tubular reactor, and directly react in one step, so that the synthesis efficiency and safety of decabromodiphenyl ethane are greatly improved. The synthesized decabromodiphenyl ethane has the characteristics of good thermal stability, high bromine content and low colority. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 The synthesis route of decabromodiphenyl ethane according to the present application is shown in the following figure. Figure 2 The process flow chart for continuously synthesizing decabromodiphenyl ethane by using a tubular reactor according to the present application is shown in the following figure. DETAILED DESCRIPTION

[0012] The present application will be further described below in combination with examples, and the examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0013] Example 1: 18 g of diphenylmethane was charged into a jacketed reaction bottle A and heated to 60 ℃, 2.7 g of aluminum bromide and 540 g of bromine (moisture less than 200 ppm) were added into reaction bottle B, the bromine pump was started to pump the bromine mixed with aluminum bromide into the tubular reactor until the reactor was filled, and the pump was stopped. The reactor temperature was set to 50 ℃, and the temperature was waited to be in place, the reactor outlet valve was opened, and the two metering pumps were started to adjust the pumping speed to meet the requirement of 20 min residence time. The material entered the gas-liquid separation device for gas-liquid separation, the gas was introduced into the absorption device, and the reaction liquid was introduced into water for quenching.

[0014] Post-processing method: the above reaction liquid was transferred into a distillation device, heated to 96±1 ℃, and the evaporated bromine was recovered, and the crude product 96 g was obtained by solid-liquid separation, the crude product and deionized water 120 g were added into a four-necked flask with zirconium beads, stirring was started, 8% sodium carbonate aqueous solution was added to adjust the pH of the system to 10 based on pH test paper, 1 h after stirring, water was added to wash the material out of the zirconium beads, filtration was performed to obtain a solid, the wet product was dried at 130 ℃ for 2 h, 94.08 g of decabromodiphenylmethane product was obtained, the whiteness, 1% TG, and bromine content data were detected, the remaining sample was continuously dried at 240 ℃ for 2 h, and the thermal stability data was detected.

[0015] The whiteness of the product was 86.7, the 1% TG was 339.5 ℃, the bromine content was 81.6%, and the thermal stability was 86.1.

[0016] Example 2: 18 g of diphenylmethane was charged into a jacketed reaction bottle A and heated to 60 ℃, 1.8 g of aluminum bromide and 630 g of bromine (moisture less than 200 ppm) were added into reaction bottle B, the bromine pump was started to pump the bromine mixed with aluminum bromide into the tubular reactor until the reactor was filled, and the pump was stopped. The reactor temperature was set to 50 ℃, and the temperature was waited to be in place, the reactor outlet valve was opened, and the two metering pumps were started to adjust the pumping speed to meet the requirement of 20 min residence time. The material entered the gas-liquid separation device for gas-liquid separation, the gas was introduced into the absorption device, and the reaction liquid was introduced into water for quenching.

[0017] Post-processing method: the above reaction liquid was transferred into a distillation device, heated to 96±1 ℃, and the evaporated bromine was recovered, and the crude product 96 g was obtained by solid-liquid separation, the crude product and deionized water 120 g were added into a four-necked flask with zirconium beads, stirring was started, 8% sodium carbonate aqueous solution was added to adjust the pH of the system to 10 based on pH test paper, 1 h after stirring, water was added to wash the material out of the zirconium beads, filtration was performed to obtain a solid, the wet product was dried at 130 ℃ for 2 h, 94.08 g of decabromodiphenylmethane product was obtained, the whiteness, 1% TG, and bromine content data were detected, the remaining sample was continuously dried at 240 ℃ for 2 h, and the thermal stability data was detected.

[0018] The product has a whiteness of 86.7, a 1% TG temperature of 327.9 ℃, a bromine content of 81.6%, and a thermal stability of 86.

[0019] Example 3: 18 g of diphenyl ethane was placed in a jacketed reaction flask A and heated to 60 °C. 2.7 g of aluminum bromide and 720 g of bromine (moisture content less than 200 ppm) were added to reaction flask B. The bromine pump was started to pump the bromine mixed with aluminum bromide into a tubular reactor until the reactor was full, then the pump was stopped. The reactor temperature was set to 50 °C, and after the temperature reached the set point, the reactor outlet valve was opened. Simultaneously, two metering pumps were started to adjust the pumping rate to achieve the required residence time of 20 min. The material entered a gas-liquid separator for gas-liquid separation. The gas was passed into an absorption device, and the reaction liquid was quenched in water.

[0020] Post-processing: The above reaction solution was transferred to a distillation apparatus and heated to 96±1 ℃ to recover the evaporated bromine. Solid-liquid separation yielded 96.1 g of crude product. The crude product and 120 g of deionized water were added to a four-necked flask containing zirconium beads. Stirring was started, and 8% sodium carbonate aqueous solution was added to adjust the pH of the system to 8 according to pH paper. After stirring for 1 h, water was added to wash the material out of the zirconium beads. The solid was filtered off, and the wet product was dried at 130 ℃ for 2 h to obtain 93.71 g of decabromodiphenyl ethane product. The whiteness, 1% TG, and bromine content were measured. The remaining sample was dried at 240 ℃ for another 2 h, and the thermal stability data were measured.

[0021] The product has a whiteness of 87.6, a 1% TG temperature of 336.2 ℃, a bromine content of 81.7%, and a thermal stability of 86.9.

[0022] Example 4: 18 g of diphenyl ethane was placed in a jacketed reaction flask A and heated to 60 °C. 1.8 g of aluminum bromide and 450 g of bromine (moisture content less than 200 ppm) were added to reaction flask B. The bromine pump was started to pump the bromine mixed with aluminum bromide into a tubular reactor until the reactor was full, then the pump was stopped. The reactor temperature was set to 50 °C, and after the temperature reached the set point, the reactor outlet valve was opened. Simultaneously, two metering pumps were started to adjust the pumping rate to achieve the required residence time of 20 min. The material entered a gas-liquid separator for gas-liquid separation. The gas was passed into an absorption device, and the reaction liquid was quenched in water.

[0023] Post-processing method: the above reaction liquid is transferred into a distillation device, heated to 96±1 ℃, and the evaporated bromine is recovered. Solid-liquid separation is performed to obtain 94.7 g of a crude product. The crude product and 120 g of deionized water are added into a four-necked flask with zirconium beads pre-placed therein. Stirring is started, 8% sodium carbonate aqueous solution is added to adjust the pH of the system to 10 based on pH test paper, and stirring is performed for 1 h. Then, water is added to wash the material out of the zirconium beads. Filtration is performed to obtain a solid. The wet product is dried at 130 ℃ for 2 h to obtain 92.33 g of decabromodiphenylethane product. The whiteness, 1% TG, and bromine content data are detected. The remaining sample is continuously dried at 240 ℃ for 2 h, and the thermal stability data are detected.

[0024] The whiteness of the product is 86.5, the 1% TG is 330.6 ℃, the bromine content is 81.5%, and the thermal stability is 85.8.

[0025] Example 5: 18 g of diphenylethane is loaded into a jacketed reaction bottle A, heated to 60 ℃, 1.8 g of aluminum bromide and 540 g of bromine (moisture less than 200 ppm) are added into reaction bottle B, the bromine pump is started to pump the bromine mixed with aluminum bromide into the tubular reactor, until the reactor is filled, and the pump is stopped. The reactor temperature is set to 55 ℃, and waiting for the temperature to rise in place, the reactor outlet valve is opened, and the two metering pumps are started to adjust the pumping speed to meet the requirement of 20 min residence time. The material enters the gas-liquid separation device for gas-liquid separation, the gas is introduced into the absorption device, and the reaction liquid is introduced into water for quenching.

[0026] Post-processing method: the above reaction liquid is transferred into a distillation device, heated to 96±1 ℃, and the evaporated bromine is recovered. Solid-liquid separation is performed to obtain 94.7 g of a crude product. The crude product and 120 g of deionized water are added into a four-necked flask with zirconium beads pre-placed therein. Stirring is started, 8% sodium carbonate aqueous solution is added to adjust the pH of the system to 10 based on pH test paper, and stirring is performed for 1 h. Then, water is added to wash the material out of the zirconium beads. Filtration is performed to obtain a solid. The wet product is dried at 130 ℃ for 2 h to obtain 92.33 g of decabromodiphenylethane product. The whiteness, 1% TG, and bromine content data are detected. The remaining sample is continuously dried at 240 ℃ for 2 h, and the thermal stability data are detected.

[0027] The whiteness of the product is 87.1, the 1% TG is 328.6 ℃, the bromine content is 81.5%, and the thermal stability is 86.3.

[0028] Example 6: 18 g of diphenyl ethane was placed in a jacketed reaction flask A and heated to 60 °C. 1.8 g of aluminum bromide and 540 g of bromine (moisture content less than 200 ppm) were added to reaction flask B. The bromine pump was started to pump the bromine mixed with aluminum bromide into a tubular reactor until the reactor was full, then the pump was stopped. The reactor temperature was set to 50 °C, and after the temperature reached the set point, the reactor outlet valve was opened. Simultaneously, two metering pumps were started to adjust the pumping rate to achieve the required residence time of 10 min. The material entered a gas-liquid separator for gas-liquid separation. The gas was passed into an absorption device, and the reaction liquid was quenched in water.

[0029] Post-processing: The above reaction solution was transferred to a distillation apparatus and heated to 96±1 ℃ to recover the evaporated bromine. Solid-liquid separation yielded 94.2 g of crude product. The crude product and 120 g of deionized water were added to a four-necked flask containing zirconium beads. Stirring was started, and 8% sodium carbonate aqueous solution was added to adjust the pH of the system to 9 according to pH paper. After stirring for 1 h, water was added to wash the material out of the zirconium beads. The solid was filtered off, and the wet product was dried at 130 ℃ for 2 h to obtain 91.85 g of decabromodiphenyl ethane product. The whiteness, 1% TG, and bromine content were measured. The remaining sample was dried at 240 ℃ for another 2 h, and the thermal stability data were measured.

[0030] The product has a whiteness of 87.5, a 1% TG temperature of 336.5 ℃, a bromine content of 81.5%, and a thermal stability of 86.7.

[0031] Example 7: 18 g of diphenyl ethane was placed in a jacketed reaction flask A and heated to 60 °C. 1.8 g of aluminum bromide and 540 g of bromine (moisture content less than 200 ppm) were added to reaction flask B. The bromine pump was started to pump the bromine mixed with aluminum bromide into a tubular reactor until the reactor was full, then the pump was stopped. The reactor temperature was set to 65 °C, and after the temperature reached the set point, the reactor outlet valve was opened. Simultaneously, two metering pumps were started to adjust the pumping rate to achieve the required residence time of 10 min. The material entered a gas-liquid separator for gas-liquid separation. The gas was passed into an absorption device, and the reaction liquid was quenched in water.

[0032] Post-processing: The above reaction solution was transferred to a distillation apparatus and heated to 96±1 ℃ to recover the evaporated bromine. Solid-liquid separation yielded 93.8 g of crude product. The crude product and 120 g of deionized water were added to a four-necked flask containing zirconium beads. Stirring was started, and 8% sodium carbonate aqueous solution was added to adjust the pH of the system to 11 according to pH paper. After stirring for 1 h, water was added to wash the material out of the zirconium beads. The solid was filtered off, and the wet product was dried at 130 ℃ for 2 h to obtain 91.46 g of decabromodiphenyl ethane product. The whiteness, 1% TG, and bromine content were measured. The remaining sample was dried at 240 ℃ for another 2 h, and the thermal stability data were measured.

[0033] The whiteness of the product was 86.6, the 1% TG was 333.6 °C, the bromine content was 81.5%, and the thermal stability was 86.2.

[0034] Comparative Example 1: Based on Example 1, the only difference between this comparative example and Example 1 was that the temperature of the reactor was set to 85 °C.

[0035] The results were that the reaction was incomplete, and part of the reactants did not participate in the reaction. The whiteness of the product was 80.1, the 1% TG was 330.3, the bromine content was 81.4%, and the thermal stability was 78.3. The whiteness and thermal stability were lower than those of Example 1.

[0036] Comparative Example 2: The only difference between this comparative example and Example 1 was that the residence time was 5 min.

[0037] The results were that the reaction was incomplete, and part of the reactants did not participate in the reaction. The whiteness of the product was 78.4, the 1% TG was 312.4, the bromine content was 65.6%, and the thermal stability was 70.3. The data obtained were all lower than those of Example 1.

[0038] Comparative Example 3: The only difference between this comparative example and Example 1 was that the amount of aluminum bromide was 1.0 g.

[0039] The results were that the reaction was incomplete, and part of the reactants did not participate in the reaction. The whiteness of the product was 80.5, the 1% TG was 320.9, the bromine content was 60.2%, and the thermal stability was 75.1. The data obtained were all lower than those of Example 1.

[0040] The above are only specific application examples of the present application, and do not constitute any limitation on the scope of protection of the present application. Any technical solutions formed by equivalent transformation or equivalent replacement fall within the scope of protection of the present application.

Claims

1. A method for the continuous synthesis of decabromodiphenyl ethane using a tubular reactor, characterized in that: Includes the following steps: S01, a certain mass of diphenyl ethane is heated to a molten state in a water bath to form molten reaction solution A, and the catalyst is added to bromine and mixed to form reaction solution B; reaction solution B is pumped into the tubular reactor in advance and filled. S02: The two reaction liquids in S01 are pumped into the tubular reactor through a metering pump and mixed and reacted at a certain temperature. After the reaction is complete, the material enters the gas-liquid separation device for separation, and the gas is absorbed by water. SO3, the liquid separated from SO2 is sent to deionized water for quenching, deionized water is added to distill bromine, and solid-liquid separation is performed to obtain crude product. SO4: The crude SO3 product is adjusted to alkalinity by adding alkali, washed and filtered, and then dried at high temperature to constant weight to obtain the decabromodiphenyl ethane product.

2. The method for continuous synthesis of decabromodiphenyl ethane using a tubular reactor according to claim 1, characterized in that: In SO1, the water bath temperature of diphenyl ethane is 60 ℃; the amount of bromine added is 25 to 40 times the mass of diphenyl ethane, the moisture content of bromine is less than 200 ppm, the amount of catalyst added is 10 to 20% of the mass of diphenyl ethane, and aluminum bromide is used as the catalyst.

3. The method for continuous synthesis of decabromodiphenyl ethane using a tubular reactor according to claim 1, characterized in that: In SO2, the reaction temperature is 45~65 ℃, and the residence time of the mixed reaction in the tubular reactor is 10~30 min.

4. The method for continuous synthesis of decabromodiphenyl ethane using a tubular reactor according to claim 1, characterized in that: In SO3, the bromine distillation temperature is 90~100 ℃, and the mass ratio of the liquid separated from S2 to deionized water during bromine distillation is 1:1.2~1.

5.

5. The method for continuous synthesis of decabromodiphenyl ethane using a tubular reactor according to claim 1, characterized in that: In SO4, the alkaline solution used to adjust the pH is one or both of sodium hydroxide and sodium carbonate, with a pH range of 8 to 11. The drying temperature is 120-140 ℃, and the drying time is 1-2 h.

6. A method for the continuous synthesis of decabromodiphenyl ethane using a tubular reactor, characterized in that: Thermal stability data for product S04 was obtained by re-drying. The re-drying temperature was 230-250 ℃ and the re-drying time was 1-2 h.

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