Epoxy resin production process for graded utilization of toluene steam heat

Abstract

The invention belongs to the technical field of epoxy resin production, and particularly relates to an epoxy resin production process for toluene steam heat graded utilization. The production process comprises the following steps: pumping toluene resin into a debenzolization kettle, reducing the pressure to 1kPa-5kPa, raising the temperature to 110-130 DEG C, when a temperature monitor I monitors that the temperature of toluene steam generated by the debenzolization kettle is 90-110 DEG C, sending the toluene steam to a steam coil pipe of a refining kettle, raising the temperature of the refining kettle, and pumping toluene into a toluene storage tank II; when a temperature monitor I monitors that the temperature of methylbenzene steam generated by the debenzolization kettle is 70-90 DEG C, the methylbenzene steam is sent to a reaction kettle steam coil pipe, the reaction kettle is heated, and methylbenzene is pumped into a methylbenzene storage tank III; when the temperature monitor I monitors that the toluene steam generated by the debenzolization kettle is 50-70 DEG C, the dissolving kettle is heated to 40-45 DEG C, and the toluene steam is directly recovered to the toluene storage tank I. The epoxy resin production process for graded utilization of toluene steam heat provided by the invention has the advantages of energy conservation, consumption reduction and strong operability.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy resin production, and in particular relates to an epoxy resin production process by graded utilization of toluene vapor heat. Background Art

[0002] In the field of epoxy resin production, the existing technical process is mainly divided into four stages: dissolution, reaction, refining and debenzenization. Each stage plays an indispensable role in the entire production process. However, the existing process still has some problems that need to be solved.

[0003] In the dissolution stage, key raw materials such as bisphenol A and ECH are usually mixed in a certain proportion. In order to fully dissolve bisphenol A, a more traditional heating method is generally used, such as using ordinary steam heating equipment. Although this method can achieve the purpose of dissolution, it is not ideal in terms of energy utilization efficiency. There is a certain degree of heat loss during the heating process, resulting in energy waste.

[0004] During the reaction phase, by precisely controlling the temperature and pressure and adding reagents such as sodium hydroxide solution, the raw materials are prompted to undergo a chemical reaction and the epoxy resin reaction product is initially generated. In this process, the control of reaction conditions is crucial, and even a slight deviation may affect the quality and yield of the product. However, the existing reaction equipment and control technology make it difficult to achieve efficient use of energy and have the problem of high energy consumption.

[0005] During the refining stage, specific reagents such as benzyltriethylammonium chloride need to be added, and a series of operations such as water washing and liquid separation are performed to remove impurities and improve the purity of the product. However, the water washing process at this stage consumes a large amount of water resources, and there is also low energy utilization efficiency when heating to maintain the system temperature.

[0006] Focusing on the debenzenization stage, the existing process generally adopts direct cooling recovery when recovering toluene. In this process, a special refrigeration device, such as a compression refrigerator, must be equipped. The operation of the refrigerator consumes a lot of electricity. According to relevant statistics, in the entire epoxy resin production process, the electricity consumption of the refrigerator in the debenzenization stage accounts for a considerable proportion of the total energy consumption. What is more serious is that toluene vapor contains a lot of heat at high temperature, and direct cooling recovery means that these high heats are completely wasted. If these heats can be effectively utilized, it can not only reduce the energy consumption of other heating links, but also reduce production costs. This recovery method, which consumes a lot of electricity and wastes steam heat, not only causes a huge waste of energy resources, but also increases the production cost of the enterprise. At the same time, it does not conform to the current energy-saving and environmental protection concept advocated. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art and provide an epoxy resin production process using toluene steam heat in a graded manner, which is energy-saving and consumption-reducing and has strong operability.

[0008] The epoxy resin production process using heat graded toluene steam of the present invention comprises the following steps: injecting toluene resin into a debenzening kettle, reducing the pressure to 1 kPa-5 kPa, and heating the temperature to 110-130° C., when the temperature monitor 1 detects that the temperature of toluene steam generated by the debenzening kettle is 90-110° C., sending the toluene steam to a refining kettle steam coil, heating the refining kettle to 70-90° C., and injecting toluene into a toluene storage tank 2; When the temperature monitor detects that the toluene vapor produced by the debenzene kettle is 70-90°C, it is sent to the reactor steam coil to heat the reactor to 50-70°C and pump the toluene into the toluene storage tank three; When the temperature monitor detects that the toluene vapor produced by the debenzene kettle is 50-70°C, it is sent to the steam coil of the dissolving kettle, and after the dissolving kettle is heated to 40-45°C, it is directly recovered to the toluene storage tank one.

[0009] The process also includes a dissolution stage: using 50-70°C toluene vapor and 120-130°C steam to heat the dissolution kettle to 40-45°C, adding bisphenol A, and then adding epichlorohydrin, keeping the temperature and stirring for 20-40 minutes in an anaerobic state, and reacting to obtain system 1.

[0010] The mass ratio of bisphenol A to epichlorohydrin is 1:2.0~3.0.

[0011] The method also includes a reaction stage 1: adding system 1 into a reactor, heating the reactor to 50-70°C using 70-90°C toluene vapor and 120-130°C steam, adding 30%-50% by mass of liquid alkali, reacting for 1-3 hours, and obtaining system 2.

[0012] The mass ratio of bisphenol A to liquid alkali is 1:0.06~0.07.

[0013] The second reaction stage is as follows: the reactor is heated to 50-70°C by using 70-90°C toluene and 120-130°C steam, and liquid alkali with a mass fraction of 30%-50% is added dropwise under the condition of 15kPa-25kPa, and the addition time is controlled within 3h-5h. After the addition is completed, the temperature is kept for 30min-60min to obtain system 3; The mass ratio of bisphenol A to liquid alkali is 1:0.5~0.6; after the reaction, epichlorohydrin is recovered: the pressure of the system is reduced to 1kPa~5kPa, and the reactor is heated to 110℃~130℃ with 150~170℃ steam, and then steam is bubbled, and the steam bubbling flow rate is 30~60Nm 3 / Hr, lasting 30min~60min.

[0014] It also includes a refining stage: the system three is put into a refining kettle, toluene is added, the temperature is raised to 70-90°C by using 90-110°C toluene vapor and 120-130°C steam, benzyltriethylammonium chloride and 10%-15% by mass liquid alkali are added, the reaction is stirred for 2-3 hours, the mixture is allowed to stand for separation, a 1%-2% by mass aqueous solution of disodium hydrogen phosphate is added, the mixture is stirred for 10-30 minutes and then allowed to stand for separation, pure water is added for the first time, the mixture is stirred for 10-30 minutes and then allowed to stand for separation, pure water is added for the second time, the mixture is stirred for 10-30 minutes and then allowed to stand for separation, and toluene resin is obtained.

[0015] The mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, disodium hydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.2~1.4:0.001~0.002:0.3~0.4:0.6~0.8:1~1.5:1~1.5.

[0016] It also includes the debenzenization stage: the toluene resin is pumped into the debenzenization kettle and the pressure is reduced to 1kPa~5kPa, the temperature is raised to 110~130℃, toluene is directly recovered or the waste heat of toluene is used to heat other stages (refining reaction stage, reaction stage, dissolution stage), and then steam is bubbled, and the steam bubbling flow rate is 30~60Nm 3 / Hr, last for 60min~90min, then nitrogen bubbling, nitrogen bubbling flow rate is 10~30Nm 3 / Hr, continue for 30min~60min, and obtain epoxy resin.

[0017] Specifically, the epoxy resin production process using toluene steam heat graded utilization comprises the following steps: (1) Dissolution stage: According to the production arrangement, 50-70°C toluene and 120-130°C steam are used to heat the reactor to 40-45°C, bisphenol A is added, and epichlorohydrin is added to the reactor. The mixture is stirred for 20-40 minutes under an anaerobic condition to obtain system 1. The mass ratio of bisphenol A to epichlorohydrin is 1:2.0-3.0. (2) Reaction stage 1: Use 70-90°C toluene and 120-130°C steam to raise the system temperature to 50-70°C, add 30%-50% liquid alkali by mass into system 1, and react for 1-3 hours to obtain system 2: the mass ratio of bisphenol A to liquid alkali is 1:0.06-0.07; (3) Reaction stage 2: According to the production arrangement, the system temperature is raised to 50-70°C by using 70-90°C toluene and 120-130°C steam. Under the condition of 15kPa-25kPa, liquid alkali with a mass fraction of 30%-50% is added dropwise to system 2. The addition time is controlled at 3h-5h and the temperature is kept for 30min-60min to obtain system 3. The mass ratio of bisphenol A to liquid alkali is 1:0.5-0.6. After the reaction is completed, epichlorohydrin is recovered: the pressure of system 3 is reduced to 1kPa-5kPa, and at the same time, the reactor is heated to 110°C-130°C with 150-170°C steam, and then steam is bubbled. The steam bubbling flow rate is 30-60Nm 3 / Hr, lasting 30min~60min; (4) Refining stage: put system 3 into the refining kettle, add toluene, and heat to 70~90℃ with 90~110℃ toluene vapor and 120~130℃ steam according to the production arrangement, add benzyltriethylammonium chloride and 10%~15% liquid alkali, stir and react for 2~3h, let stand and separate, add 1%~2% disodium hydrogen phosphate aqueous solution, stir for 10~30min, let stand and separate, add pure water, stir for 10~30min, let stand and separate, add pure water again, stir for 10~30min, let stand and separate, and obtain toluene resin; the mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, disodium hydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.2~1.4:0.001~0.002:0.3~0.4:0.6~0.8:1~1.5:1~1.5; (5) Debenzening stage: The toluene resin is pumped into the debenzening kettle and depressurized to 1kPa~5kPa, and the temperature is raised to 110~130℃. According to the production arrangement, toluene is directly recovered or the waste heat of toluene is used to heat other stages, and then steam is bubbled. The steam bubbling flow rate is 30~60Nm 3 / Hr, last for 60min~90min, then nitrogen bubbling, nitrogen bubbling flow rate is 10~30Nm 3 / Hr, continue for 30min~60min, and obtain epoxy resin.

[0018] During the operation of the above five steps, the steps for graded utilization of toluene vapor are as follows: injecting toluene resin into the debenzening kettle to reduce the pressure to 1kPa~5kPa and heating it to 110~130℃; when the temperature monitor 1 detects that the debenzening kettle produces toluene vapor of 90~110℃, the 90~110℃ toluene vapor is sent to the refining kettle coil according to the production arrangement, the refining kettle is heated to 70~90℃, and toluene is injected into toluene storage tank 2; when the temperature monitor 1 detects that the toluene temperature is 70~90℃, the 70~90℃ liquid toluene is sent to the reactor coil according to the production arrangement, the reactor is heated to 50~70℃, and toluene is injected into toluene storage tank 3; when the temperature monitor 1 detects that the toluene temperature is 50~70℃, the 50~70℃ liquid toluene is sent to the dissolving kettle steam coil according to the production arrangement, the dissolving kettle is heated to 40~45℃ and then directly recovered to the toluene storage tank; if there is no production arrangement, the toluene vapor enters the condenser section for cooling and recovery to the toluene storage tank 1.

[0019] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention adopts energy graded utilization to improve the energy utilization rate of toluene vapor.

[0020] (2) The present invention introduces a temperature monitor to facilitate toluene vapor at different temperature stages to heat reactors with different temperature requirements.

[0021] (3) The present invention adopts toluene coil and steam coil in combination, which has strong operability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The present invention is a schematic diagram of an epoxy resin production device using toluene vapor heat fractionation.

[0023] In the figure: 1. debenzene kettle; 2. temperature monitor 1; 3. regulating valve 1; 4. regulating valve 2; 5. regulating valve 3; 6. refining kettle steam coil; 7. reaction kettle steam coil; 8. dissolving kettle steam coil; 9. temperature monitor 2; 10. condenser; 11. toluene storage tank 1; 12. refining kettle; 13. reaction kettle; 14. dissolving kettle; 15. regulating valve 4; 16. toluene storage tank 2; 17. toluene storage tank 3; 18. temperature monitor 3. DETAILED DESCRIPTION

[0024] The present invention will be further described below in conjunction with specific embodiments.

[0025] The raw materials and additives used in the following examples and comparative examples are all commercially available.

[0026] like Figure 1As shown, the epoxy resin production device using toluene steam heat graded utilization comprises a refining kettle 12, a reactor 13 and a dissolving kettle 14, wherein a refining kettle steam coil 6 is arranged in the refining kettle 12, a steam inlet of the refining kettle steam coil 6 is connected to a debenzening kettle 1 through a steam pipeline, a temperature monitor 2 is arranged on the steam outlet of the debenzening kettle 1, three pipelines are branched from the steam pipeline of the temperature monitor 2, a regulating valve 3 is arranged on the first pipeline, the regulating valve 3 is connected to the refining kettle steam coil 6, a regulating valve 2 is arranged on the second pipeline, the regulating valve 24 is connected to the reactor steam coil 7, a regulating valve 3 5 is arranged on the third pipeline, the regulating valve 3 5 is connected to the dissolving kettle steam coil 8; The reactor steam coil 7 is arranged in the reactor 13, and the dissolving reactor steam coil 8 is arranged in the dissolving reactor 14; The outlet of the condensate of the refining kettle steam coil 6 is connected to the second toluene storage tank 16, the gas outlet of the second toluene storage tank 16 is provided with a temperature monitor 29, the outlet pipeline of the temperature monitor 29 is connected to the third toluene storage tank 17, the gas outlet of the third toluene storage tank 17 is provided with a temperature monitor 3 18, the outlet pipeline of the temperature monitor 3 18 is connected to the dissolving kettle 14, the gas outlet of the dissolving kettle 14 is connected to the condenser 10, and the gas outlet of the reaction kettle 13 is connected to the condenser 10; The debenzene kettle 1 is also provided with other gas outlets, and a regulating valve 4 15 is provided on the outlet pipeline, and the pipeline passing through the regulating valve 4 15 is connected to the condenser 10; The condenser 10 is connected to a toluene storage tank 11.

[0027] The reactor 13 is also provided with other gas outlets, and the outlet pipelines are directly connected to the toluene storage tank 3 17.

[0028] The debenzene kettle 1 has heating, stirring and decompression functions and is used to generate toluene vapor; the temperature monitor 2 is mainly used to measure the temperature of toluene vapor; the regulating valve 3 is mainly used to open and close the toluene vapor going to the refining kettle 12; the regulating valve 4 is mainly used to open and close the toluene vapor going to the reactor 13; the regulating valve 3 5 is mainly used to open and close the toluene vapor going to the dissolving kettle 14; the refining kettle steam coil 6 provides heat for the refining reaction to ensure the reaction temperature; the reactor steam coil 7 provides heat for the main reaction to ensure the reaction temperature; the dissolving kettle steam coil 8 provides heat for the dissolving reaction to ensure the reaction temperature; the temperature monitor 9 is mainly used to open and close the toluene vapor going to the reactor 13; the regulating valve 10 is mainly used to open and close the toluene vapor going to the dissolving kettle 14; the refining kettle steam coil 6 provides heat for the refining reaction to ensure the reaction temperature; the reactor steam coil 7 provides heat for the main reaction to ensure the reaction temperature; the dissolving kettle steam coil 8 provides heat for the dissolving reaction to ensure the reaction temperature; the temperature monitor 10 ... regulating valve 10 is mainly used to open and close the toluene vapor going to the reactor 13; the regulating valve 10 is mainly used to open It is used to measure the temperature of toluene; the condenser 10 is mainly used to liquefy and reduce the temperature of toluene; the toluene storage tank 11 is mainly used to store toluene; the refining kettle 12 has heating and stirring functions, and is mainly used for further processing of epoxy resin; the reactor 13 has heating, stirring and decompression functions, and is mainly used for the main synthesis of epoxy resin; the dissolving kettle 14 has heating and stirring functions, and is mainly used for the dissolution of reaction materials; the regulating valve 4 15 is mainly used to adjust the opening degree of toluene vapor that needs to be directly cooled; the toluene storage tank 2 16 is mainly used to store toluene after heating the refining kettle 12; the toluene storage tank 3 17 is mainly used to store toluene after heating the reactor 13.

[0029] The following embodiments are all completed by using the above device, and the relevant steam pipelines and valves are common knowledge in this field and are not further described.

[0030] Example 1 The epoxy resin production process using the toluene steam heat graded utilization comprises the following steps: (1) Dissolution stage: Use 50°C toluene and 120°C steam to heat the reactor to 40°C, add bisphenol A, add epichlorohydrin into the reactor, keep warm and stir for 20 minutes under anaerobic conditions, and react to obtain system 1; the mass ratio of bisphenol A to epichlorohydrin is 1:2.0; (2) Reaction stage 1: The system temperature is raised to 50°C using 70°C toluene and 120°C steam, and 30% by mass of liquid alkali is added to system 1. The reaction is continued for 1 h to obtain system 2: the mass ratio of bisphenol A to liquid alkali is 1:0.06; (3) Reaction stage 2: The system temperature was raised to 50°C by using 70°C toluene and 120°C steam. Under the condition of 15 kPa, 30% liquid alkali was added dropwise to system 2. The addition time was controlled at 3 h and the temperature was kept at 30 min to obtain system 3. The mass ratio of bisphenol A to liquid alkali was 1:0.5. After the reaction, epichlorohydrin was recovered: the pressure of system 3 was reduced to 1 kPa. At the same time, the reactor was heated to 110°C with 150°C steam, and then steam was bubbled. The steam bubbling flow rate was 30 Nm 3 / Hr, lasting 30min; (4) Refining stage: the system 3 is put into the refining kettle, toluene is added, and the temperature is raised to 70°C by combining 90°C toluene vapor and 120°C steam, and benzyltriethylammonium chloride and 10% by mass liquid alkali are added, stirred for 2 hours, and the mixture is allowed to stand for separation, and a 1% by mass aqueous solution of disodium hydrogen phosphate is added, stirred for 10 minutes, and the mixture is allowed to stand for separation, and pure water is added, stirred for 10 minutes, and the mixture is allowed to stand for separation, and pure water is added again, stirred for 10 minutes, and the mixture is allowed to stand for separation to obtain toluene resin; the mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, disodium hydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.2:0.001:0.3:0.6:1:1; (5) Debenzening stage: Toluene resin is pumped into the debenzening kettle and depressurized to 1 kPa, heated to 110 °C, and the waste heat of toluene is used to heat the other stages. Then steam is bubbled at a flow rate of 30 Nm 3 / Hr, continued for 60min, then nitrogen bubbling, nitrogen bubbling flow rate was 10Nm 3 / Hr, continue for 30min, and obtain epoxy resin.

[0031] During the operation of the above five steps, the steps for graded utilization of toluene vapor are as follows: injecting toluene resin into the debenzening kettle, reducing the pressure to 1 kPa, and heating to 110°C; when the temperature monitor 1 detects that the debenzening kettle produces 90°C toluene vapor, the 90°C toluene vapor is sent to the refining kettle coil, the refining kettle is heated to 70°C, and toluene is injected into toluene storage tank 2; when the temperature monitor 1 detects that the toluene temperature is 70°C, the 70°C liquid toluene is sent to the reactor coil, the reactor is heated to 50°C, and toluene is injected into toluene storage tank 3; when the temperature monitor 1 detects that the toluene temperature is 50°C, the 50°C liquid toluene is sent to the dissolving kettle steam coil, the dissolving kettle is heated to 40°C and then directly recovered to the toluene storage tank.

[0032] Example 2 The epoxy resin production process using the toluene steam heat graded utilization comprises the following steps: (1) Dissolution stage: Use 60°C toluene and 125°C steam to heat the reactor to 42°C, add bisphenol A, add epichlorohydrin into the reactor, keep warm and stir for 30 minutes under anaerobic conditions, and react to obtain system 1; the mass ratio of bisphenol A to epichlorohydrin is 1:2.5; (2) Reaction stage 1: Use 80°C toluene and 125°C steam to raise the system temperature to 60°C, add 40% liquid alkali by mass into system 1, and react for 2 hours to obtain system 2: the mass ratio of bisphenol A to liquid alkali is 1:0.065; (3) Reaction stage 2: The system temperature was raised to 60°C by using 80°C toluene and 125°C steam. Under the condition of 20 kPa, 40% liquid alkali was added dropwise to system 2. The addition time was controlled at 4 h and the temperature was kept at 40 min to obtain system 3. The mass ratio of bisphenol A to liquid alkali was 1:0.55. After the reaction, epichlorohydrin was recovered: the pressure of system 3 was reduced to 3 kPa. At the same time, the reactor was heated to 120°C with 160°C steam, and then steam was bubbled. The steam bubbling flow rate was 40 Nm 3 / Hr, lasting 40min; (4) Refining stage: the system 3 is put into the refining kettle, toluene is added, and the temperature is raised to 80°C by using 100°C toluene vapor and 125°C steam, and benzyltriethylammonium chloride and 13% by mass liquid alkali are added, stirred for 2.5 hours, and the mixture is allowed to stand for separation, and an aqueous solution of 1.5% by mass disodium hydrogen phosphate is added, stirred for 20 minutes, and the mixture is allowed to stand for separation, and pure water is added, stirred for 20 minutes, and the mixture is allowed to stand for separation, and pure water is added again, stirred for 20 minutes, and the mixture is allowed to stand for separation to obtain toluene resin; the mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, disodium hydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.3:0.0015:0.35:0.7:1.3:1.3; (5) Debenzening stage: The toluene resin is pumped into the debenzening kettle and depressurized to 3 kPa, and the temperature is raised to 120 °C. The toluene waste heat is used to heat the refining reaction stage, the reaction stage, and the dissolution stage. Then, steam is bubbled. The steam bubbling flow rate is 40 Nm 3 / Hr, continued for 70min, then nitrogen bubbling, nitrogen bubbling flow rate was 20Nm 3 / Hr, continue for 40min, and obtain epoxy resin.

[0033] During the operation of the above five steps, the steps for graded utilization of toluene vapor are as follows: injecting toluene resin into the debenzening kettle, reducing the pressure to 3kPa, and heating to 120°C; when the temperature monitor 1 detects that the debenzening kettle produces toluene vapor at 100°C, the 100°C toluene vapor is sent to the refining kettle coil, the refining kettle is heated to 80°C, and toluene is injected into toluene storage tank 2; when the temperature monitor 1 detects that the toluene temperature is 80°C, the 80°C liquid toluene is sent to the reactor coil, the reactor is heated to 60°C, and toluene is injected into toluene storage tank 3; when the temperature monitor 1 detects that the toluene temperature is 60°C, the 60°C liquid toluene is sent to the dissolving kettle steam coil, the dissolving kettle is heated to 42°C and then directly recovered to the toluene storage tank; Example 3 The epoxy resin production process using the toluene steam heat graded utilization comprises the following steps: (1) Dissolution stage: Use 70°C toluene and 130°C steam to heat the reactor to 45°C, add bisphenol A, add epichlorohydrin into the reactor, keep warm and stir for 40 minutes under anaerobic conditions, and react to obtain system 1; the mass ratio of bisphenol A to epichlorohydrin is 1:3.0; (2) Reaction stage 1: The system temperature is raised to 70°C by using 90°C toluene and 130°C steam, and 50% by mass of liquid alkali is added to system 1. The system is reacted for 3 hours to obtain system 2: the mass ratio of bisphenol A to liquid alkali is 1:0.07; (3) Reaction stage 2: The system temperature was raised to 70°C by using 90°C toluene and 130°C steam. Under the condition of 25 kPa, 50% liquid alkali was added dropwise to system 2. The addition time was controlled at 5 h and the temperature was kept at 60 min to obtain system 3. The mass ratio of bisphenol A to liquid alkali was 1:0.6. After the reaction, epichlorohydrin was recovered: the pressure of system 3 was reduced to 5 kPa. At the same time, the reactor was heated to 130°C with 170°C steam, and then steam was bubbled. The steam bubbling flow rate was 60 Nm 3 / Hr, lasting 60min; (4) Refining stage: the system 3 is put into the refining kettle, toluene is added, and the temperature is raised to 90°C by combining 110°C toluene vapor and 130°C steam, and benzyltriethylammonium chloride and 15% by mass liquid alkali are added, stirred for 3 hours, and the mixture is allowed to stand for separation, and a 2% by mass aqueous solution of disodium hydrogen phosphate is added, stirred for 30 minutes, and the mixture is allowed to stand for separation, and pure water is added, stirred for 30 minutes, and the mixture is allowed to stand for separation, and pure water is added again, stirred for 30 minutes, and the mixture is allowed to stand for separation to obtain toluene resin; the mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, disodium hydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.4:0.002:0.4:0.8:1.5:1.5; (5) Debenzening stage: Toluene resin is pumped into the debenzening kettle and depressurized to 5 kPa, heated to 130 °C, and the waste heat of toluene is used to heat the other stages, and then steam is bubbled. The steam bubbling flow rate is 60 Nm 3 / Hr, continued for 90min, then nitrogen bubbling, nitrogen bubbling flow rate was 30Nm 3 / Hr, continued for 60min, to obtain epoxy resin.

[0034] During the operation of the above five steps, the steps for graded utilization of toluene vapor are as follows: injecting toluene resin into the debenzening kettle, reducing the pressure to 5 kPa, and heating to 130°C; when the temperature monitor 1 detects that the debenzening kettle produces toluene vapor at 110°C, the 110°C toluene vapor is sent to the refining kettle coil, the refining kettle is heated to 90°C, and toluene is injected into toluene storage tank 2; when the temperature monitor 1 detects that the toluene temperature is 90°C, the 90°C liquid toluene is sent to the reactor coil, the reactor is heated to 70°C, and toluene is injected into toluene storage tank 3; when the temperature monitor 1 detects that the toluene temperature is 70°C, the 70°C liquid toluene is sent to the dissolving kettle steam coil, the dissolving kettle is heated to 45°C and then directly recovered to the toluene storage tank.

[0035] Comparative Example 1 The epoxy resin production process comprises the following steps: (1) Dissolution stage: Use 120°C steam to heat the reactor to 40°C, add bisphenol A, add epichlorohydrin into the reactor, keep warm and stir for 20 minutes under anaerobic conditions, and react to obtain system 1; the mass ratio of bisphenol A to epichlorohydrin is 1:2.0; (2) Reaction stage 1: Use 120°C steam to raise the system temperature to 50°C, add 30% by mass of liquid alkali to system 1, and react for 1 hour to obtain system 2: the mass ratio of bisphenol A to liquid alkali is 1:0.06; (3) Reaction stage 2: Use 120℃ steam to raise the system temperature to 50℃. Under the condition of 15kPa, add 30% liquid alkali by mass into system 2. The adding time is controlled at 3h and the temperature is kept for 30min to obtain system 3. The mass ratio of bisphenol A to liquid alkali is 1:0.5. After the reaction, recover epichlorohydrin: reduce the pressure of system 3 to 1kPa, and at the same time, use 150℃ steam to raise the temperature of the reactor to 110℃, and then steam bubble. The steam bubbling flow rate is 30Nm 3 / Hr, lasting 30min; (4) Refining stage: put system 3 into the refining kettle, add toluene, heat it to 70°C with 120°C steam, add benzyltriethylammonium chloride and 10% by mass liquid alkali, stir and react for 2h, let stand and separate, add 1% by mass sodium dihydrogen phosphate aqueous solution, stir for 10min, let stand and separate, add pure water, stir for 10min, let stand and separate, add pure water again, stir for 10min, let stand and separate, and obtain toluene resin; the mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, sodium dihydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.2:0.001:0.3:0.6:1:1; (5) Debenzening stage: The toluene resin is pumped into the debenzening kettle and depressurized to 1 kPa, heated to 110 °C, and toluene is directly recovered. Then steam is bubbled at a flow rate of 30 Nm 3 / Hr, continued for 60min, then nitrogen bubbling, nitrogen bubbling flow rate was 10Nm 3 / Hr, continue for 30min, and obtain epoxy resin.

[0036] Comparative Example 2 The epoxy resin production process using toluene steam heat in a graded manner comprises the following steps: (1) Dissolution stage: Use 125°C steam to heat the reactor to 42°C, add bisphenol A, add epichlorohydrin into the reactor, keep warm and stir for 30 minutes under anaerobic conditions, and react to obtain system 1; the mass ratio of bisphenol A to epichlorohydrin is 1:2.5; (2) Reaction stage 1: Use 125°C steam to raise the system temperature to 60°C, add 40% liquid alkali by mass into system 1, and react for 2 hours to obtain system 2: the mass ratio of bisphenol A to liquid alkali is 1:0.065; (3) Reaction stage 2: Use 125℃ steam to raise the system temperature to 60℃. Under the condition of 20kPa, add 40% liquid alkali by mass into system 2. The adding time is controlled at 4h and the temperature is kept for 40min to obtain system 3. The mass ratio of bisphenol A to liquid alkali is 1:0.55. After the reaction, recover epichlorohydrin: reduce the pressure of system 3 to 3kPa, and at the same time, use 160℃ steam to raise the temperature of the reactor to 120℃, and then steam bubble. The steam bubbling flow rate is 40Nm 3 / Hr, lasting 40min; (4) Refining stage: put system 3 into the refining kettle, add toluene, heat it to 80°C with 125°C steam, add benzyltriethylammonium chloride and 13% by mass liquid alkali, stir and react for 2.5h, let stand and separate, add 1.5% by mass sodium dihydrogen phosphate aqueous solution, stir for 20min, let stand and separate, add pure water, stir for 20min, let stand and separate, add pure water again, stir for 20min, let stand and separate, and obtain toluene resin; the mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, sodium dihydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.3:0.0015:0.35:0.7:1.3:1.3; (5) Debenzening stage: The toluene resin is pumped into the debenzening kettle and depressurized to 3 kPa, heated to 120 °C, and toluene is directly recovered. Then steam is bubbled at a flow rate of 40 Nm 3 / Hr, continued for 70min, then nitrogen bubbling, nitrogen bubbling flow rate was 20Nm 3 / Hr, continue for 40min, and obtain epoxy resin.

[0037] Comparative Example 3 The epoxy resin production process using toluene steam heat in a graded manner comprises the following steps: (1) Dissolution stage: Use 130°C steam to heat the reactor to 45°C, add bisphenol A, add epichlorohydrin into the reactor, keep warm and stir for 40 minutes under anaerobic conditions, and react to obtain system 1; the mass ratio of bisphenol A to epichlorohydrin is 1:3.0; (2) Reaction stage 1: Use 130°C steam to raise the system temperature to 70°C, add 50% by mass of liquid alkali to system 1, and react for 3 hours to obtain system 2: the mass ratio of bisphenol A to liquid alkali is 1:0.07; (3) Reaction stage 2: Use 130°C steam to raise the system temperature to 70°C. Under the condition of 25kPa, add 50% liquid alkali by mass into system 2. The adding time is controlled at 5h and the temperature is kept for 60min to obtain system 3. The mass ratio of bisphenol A to liquid alkali is 1:0.6. After the reaction, recover epichlorohydrin: reduce the pressure of system 3 to 5kPa, and at the same time use 170°C steam to raise the temperature of the reactor to 130°C, and then steam bubble. The steam bubbling flow rate is 60Nm 3 / Hr, lasting 60min; (4) Refining stage: put system 3 into the refining kettle, add toluene, heat it to 90°C with 130°C steam, add benzyltriethylammonium chloride and 15% by mass liquid alkali, stir and react for 3h, let stand and separate, add 2% by mass sodium hydrogen phosphate aqueous solution, stir for 30min, let stand and separate, add pure water, stir for 30min, let stand and separate, add pure water again, stir for 30min, let stand and separate, to obtain toluene resin; the mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, sodium hydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.4:0.002:0.4:0.8:1.5:1.5; (5) Debenzening stage: The toluene resin is pumped into the debenzening kettle and depressurized to 5 kPa, heated to 130 °C, and toluene is directly recovered. Then steam is bubbled at a flow rate of 60 Nm 3 / Hr, continued for 90min, then nitrogen bubbling, nitrogen bubbling flow rate was 30Nm 3 / Hr, continued for 60min, to obtain epoxy resin.

[0038] The epoxy resins prepared in the above examples and comparative examples were subjected to performance testing and process energy consumption monitoring, and the test results are shown in Table 1.

[0039] Table 1 Test results

[0040] Compared with comparative example 1, embodiment 1 saves 0.017 t / t of steam unit consumption and 5.167 degrees / t of electricity unit consumption; compared with comparative example 2, embodiment 2 saves 0.018 t / t of steam unit consumption and 5.189 degrees / t of electricity unit consumption; compared with comparative example 3, embodiment 3 saves 0.019 t / t of steam unit consumption and 2.82 degrees / t of electricity unit consumption. In summary, the use of toluene waste heat in the production of epoxy resin can save 0.017-0.019 t / t of steam unit consumption and 2.82-5.189 degrees / t of electricity unit consumption, without affecting the yield of epoxy resin and the quality of epoxy resin products.

Claims

1. A process for producing epoxy resin by utilizing heat from toluene vapor in a graded manner, characterized in that: The following steps are involved: The toluene resin is pumped into the debenzening kettle (1), the pressure is reduced to 1 kPa~5 kPa, and the temperature is raised to 110~130°C. When the temperature monitor 1 (2) detects that the toluene vapor generated by the debenzening kettle (1) is 90~110°C, it is sent to the refining kettle steam coil (6), the refining kettle (12) is heated to 70~90°C, and the toluene is pumped into the toluene storage tank 2 (16); when the temperature monitor 1 (2) detects that the toluene vapor generated by the debenzening kettle (1) is 70~90°C, it is sent to the reaction kettle steam coil (7), the reaction kettle (13) is heated to 50~70°C, and the toluene is pumped into the toluene storage tank 3 (17); when the temperature monitor 1 (2) detects that the toluene vapor generated by the debenzening kettle (1) is 50~70°C, it is sent to the dissolving kettle steam coil (8), the dissolving kettle (14) is heated to 40~45°C, and then directly recovered to the toluene storage tank 1 (11).

2. The epoxy resin production process using toluene vapor heat graded according to claim 1, characterized in that: The process also includes a dissolving stage: using 50-70°C toluene vapor and 120-130°C steam to heat the dissolving kettle (14) to 40-45°C, adding bisphenol A, and then adding epichlorohydrin, and stirring for 20-40 minutes under an anaerobic state to obtain system 1.

3. The epoxy resin production process using toluene vapor heat graded according to claim 2, characterized in that: The mass ratio of bisphenol A to epichlorohydrin is 1:2.0~3.

0.

4. The epoxy resin production process using toluene vapor heat graded utilization according to claim 2, characterized in that: The method further comprises a reaction stage 1: adding system 1 into a reaction kettle (13), heating the reaction kettle (13) to 50-70°C by using toluene vapor at 70-90°C and steam at 120-130°C, adding liquid alkali with a mass fraction of 30%-50%, reacting for 1-3 hours, and obtaining system 2.

5. The epoxy resin production process using toluene vapor heat fractionation according to claim 4 is characterized in that: The mass ratio of bisphenol A to liquid alkali is 1:0.06~0.

07.

6. The epoxy resin production process using toluene vapor heat fractionation according to claim 4 is characterized in that: The process also includes a second reaction stage: continuing to use 70-90°C toluene and 120-130°C steam to heat the reactor (13) to 50-70°C, and under the condition of 15kPa-25kPa, dripping 30%-50% of liquid alkali, the dripping time is controlled at 3h-5h, and after the dripping is completed, the temperature is kept for 30min-60min to obtain system three.

7. The epoxy resin production process using toluene vapor heat fractionation according to claim 6 is characterized in that: The mass ratio of bisphenol A to liquid alkali is 1:0.5~0.6; the pressure of system 3 is reduced to 1kPa~5kPa, and at the same time, the temperature of the reactor (13) is raised to 110℃~130℃ with 150~170℃ steam, and then steam is bubbled, and the steam bubbling flow rate is 30~60Nm 3 / Hr, lasting 30min~60min.

8. The epoxy resin production process using toluene vapor heat fractionation according to claim 6 is characterized in that: The process also includes a refining stage: injecting system three into a refining kettle (12), adding toluene, raising the temperature to 70-90°C by using toluene vapor at 90-110°C and steam at 120-130°C, adding benzyltriethylammonium chloride and 10%-15% by mass of liquid alkali, stirring for 2-3 hours, standing for separation, adding a 1%-2% by mass of sodium dihydrogen phosphate aqueous solution, stirring for 10-30 minutes and then standing for separation, adding pure water for the first time, stirring for 10-30 minutes and then standing for separation, adding pure water for the second time, stirring for 10-30 minutes and then standing for separation, to obtain a toluene resin.

9. The epoxy resin production process using toluene vapor heat fractionation according to claim 8, characterized in that: The mass ratio of bisphenol A, toluene, benzyltriethylammonium chloride, liquid alkali, disodium hydrogen phosphate aqueous solution, first pure water, and second pure water is 1:1.2~1.4:0.001~0.002:0.3~0.4:0.6~0.8:1~1.5:1~1.

5.

10. The epoxy resin production process using toluene vapor heat fractionation according to claim 8, characterized in that: It also includes a debenzening stage: the toluene resin is pumped into a debenzening kettle (1) and depressurized to 1 kPa~5 kPa, heated to 110~130°C, to directly recover toluene or waste heat, and then steam bubbling, with a steam bubbling flow rate of 30~60 Nm 3 / Hr, last for 60min~90min, then nitrogen bubbling, nitrogen bubbling flow rate is 10~30Nm 3 / Hr, continue for 30min~60min, and obtain epoxy resin.

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