Low-energy-consumption epoxy resin production process

Abstract

The invention belongs to the technical field of epoxy resin production, and particularly relates to a low-energy-consumption epoxy resin production process. The method comprises the following steps: firstly, mixing bisphenol A with epoxy chloropropane, and dissolving the bisphenol A by utilizing high-temperature steam and hot water linkage heating; then heating and adding a sodium hydroxide solution for pre-reaction; controlling pressure and temperature, and adding a sodium hydroxide solution for main reaction; after the reaction is completed, under different pressure and temperature conditions, recovering epichlorohydrin by using high-temperature steam, finally, ending recovery through low-temperature steam bubbling, cooling, then heating, adding benzyltriethylammonium chloride and a sodium hydroxide solution for reaction, carrying out water washing and liquid separation twice, and pumping residual toluene resin into a debenzolization kettle. And finally, debenzolization: completing toluene recovery and water removal by using low-temperature steam bubbling to obtain the product. According to the production technology, steam heat in the production process is fully utilized to obtain hot water for heat recycling, the energy utilization rate is greatly increased, operation is easy, and safety is high.

Description

Technical Field

[0001] The invention belongs to the technical field of epoxy resin production, and in particular relates to a production process for low-energy consumption epoxy resin. Background Art

[0002] As a high-performance polymer material, epoxy resin has extensive and critical applications in many fields such as aerospace, electronics, and building materials. Its unique chemical structure gives the product good mechanical properties, chemical corrosion resistance, and excellent bonding properties. Therefore, the production process of epoxy resin has always been a research focus in the field of materials science.

[0003] At present, the industrial production process of epoxy resin mainly includes six key processes: dissolution, pre-reaction, main reaction, recovery of epichlorohydrin, refining and debenzening. In the dissolution process, raw materials such as bisphenol A and epichlorohydrin are added to the dissolution kettle. After being treated in a specific way, heating is used to make bisphenol A fully dissolved, laying the foundation for subsequent reactions; the pre-reaction and main reaction processes gradually generate epoxy resin through a series of complex chemical reactions; the refining process aims to remove impurities in the product and improve the purity of the product; and the recovery of epichlorohydrin and debenzening processes are also crucial for resource recycling and product quality improvement.

[0004] However, in the recovery of epichlorohydrin and debenzenization, the existing process has significant defects. The current process converts epichlorohydrin and toluene into high-temperature steam by reducing pressure and raising temperature, and then directly condenses them into low-temperature liquid through a condenser, thereby realizing the recovery of epichlorohydrin and toluene. However, this direct condensation method will cause a large amount of heat to be wasted. At a time when energy is becoming increasingly scarce and energy conservation and emission reduction requirements are becoming more stringent, this energy waste increases production costs. In addition, excessive energy consumption also limits the economic benefits and market competitiveness of enterprises. Therefore, the development of an epoxy resin production process that can effectively reduce heat waste and improve energy utilization efficiency has become a key issue that needs to be urgently solved in the industry.

[0005] The existing technology, such as the production process mentioned in CN114671998A, mainly reduces the energy waste caused by the recovery of epichlorohydrin by reducing the feed of epichlorohydrin, strictly limits the feed ratio of bisphenol A and epichlorohydrin, and ultimately limits the product epoxy equivalent index, and the process applicability is not strong; the production process mentioned in CN118085229A mainly changes the refining process to avoid the generation of a large amount of refining wastewater, and increases the energy consumption of the later wastewater treatment to achieve the purpose of reducing energy consumption, but still cannot solve the energy consumption when recovering epichlorohydrin and toluene. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art, provide a low-energy consumption epoxy resin production process, make full use of the heat of epichlorohydrin and toluene vapor in the production process to obtain hot water for heat reuse, greatly improve energy utilization, and be simple to operate and highly safe.

[0007] The production process of the low-energy consumption epoxy resin of the present invention comprises the following steps: (1) Dissolution: Mix and dissolve bisphenol A and epichlorohydrin, and use 160-180°C high-temperature steam and 60-90°C hot water to heat the dissolution system to 40-50°C until bisphenol A is completely dissolved; (2) Pre-reaction: Continue to use 160-180℃ high-temperature steam and 60-90℃ hot water to heat the reaction system to 50-60℃, add sodium hydroxide solution, and react for 2-4h to obtain a pre-reaction solution; (3) Main reaction: Control the pressure of the reaction system to 15-30 kPa, use 160-180 °C high-temperature steam to raise the temperature of the system to 60-65 °C, add sodium hydroxide solution and react for 2-4 hours to obtain a reaction solution; (4) Recovering epichlorohydrin: The pressure of the reaction system is controlled at 15-30 kPa, and at the same time, the system is heated to 100-120°C using 160-180°C high-temperature steam to recover epichlorohydrin under low vacuum. The pressure of the system is then reduced to below 3 kPa, and at the same time, the system is heated to 130-140°C using 160-180°C high-temperature steam to recover epichlorohydrin under high vacuum. Finally, epichlorohydrin is recovered by bubbling with 130-140°C low-temperature steam. After the reaction system is cooled to 80-100°C, the reaction solution is pumped into a refining kettle filled with toluene. The epichlorohydrin recovery method comprises the following steps: heating water with epichlorohydrin vapor through a heat exchanger to obtain hot water with a temperature of 60-90° C., condensing the hot water into epichlorohydrin liquid, and pumping the hot water into an epichlorohydrin recovery tank; and directing excess epichlorohydrin vapor to a condenser to condense the hot water into epichlorohydrin liquid, and pumping the hot water into an epichlorohydrin recovery tank; the water with a temperature of 60-90° C. obtained is used in steps (1), (2), and (5); (5) Refining: Use 160-180℃ high temperature steam to raise the temperature of the refining system to 70-90℃, add benzyltriethylammonium chloride and sodium hydroxide solution, react for 1-2h, then add water for the first and second washing and separation. During the first and second washing, use 160-180℃ high temperature steam and 60-90℃ hot water to heat, maintain the system temperature at 60-70℃, stir for 20-40min, stand for 20-40min to separate the liquids, and adjust the pH to 6.5-7 during the second washing, and put the remaining toluene resin into the debenzening kettle; (6) Debenzening: Use 160-180℃ high temperature steam to raise the temperature of the refining system to 110-130℃ for atmospheric pressure debenzening, then reduce the system pressure to below 3kPa and use 160-180℃ high temperature steam to raise the system temperature to 140-160℃ for reduced pressure debenzening, and finally use 130-140℃ low temperature steam bubbling to complete toluene recovery and water removal to obtain product resin; The debenzening is carried out in a manner of removing toluene vapor. The toluene vapor is used to heat water through a heat exchanger to obtain hot water with a temperature of 60-90° C., which is condensed into toluene liquid and pumped into a toluene storage tank. Excess toluene vapor is directly passed to a condenser to be condensed into toluene liquid and pumped into a toluene storage tank. The obtained water with a temperature of 60-90° C. is supplied to steps (1), (2) and (5).

[0008] The mass ratio of bisphenol A to epichlorohydrin in step (1) is 1:1-3.

[0009] The concentration of the sodium hydroxide solution in step (2) is 30-50wt%, and the mass ratio of bisphenol A to sodium hydroxide is 20-40:1.

[0010] The concentration of the sodium hydroxide solution in step (3) is 30-50wt%, and the mass ratio of bisphenol A to sodium hydroxide is 1:0.3-0.4.

[0011] The steam bubbling flow rate in step (4) is 20-40 Nm 3 / Hr, bubbling time is 20-30min.

[0012] The pH in step (5) is adjusted using sodium dihydrogen phosphate.

[0013] The mass ratio of bisphenol A to toluene in step (5) is 1:1.9-2.2, the mass ratio of benzyltriethylammonium chloride to bisphenol A is 0.05-0.1%, and the mass ratio of bisphenol A to sodium hydroxide is 1:0.01-0.02.

[0014] The mass ratio of bisphenol A to the first washing pure water in step (5) is 1:1-1.5, and the mass ratio of bisphenol A to the second washing pure water is 1:0.4-0.7.

[0015] The steam bubbling flow rate in step (6) is 20-40 Nm 3 / Hr, bubbling time is 30-60min.

[0016] The water removal in step (6) is carried out by using nitrogen at 20-40 Nm 3 / Hr flow rate for 30-60min to remove water from the system. Specifically, the production process of the low-energy consumption epoxy resin comprises the following steps: (1) Dissolution: Add bisphenol A and epichlorohydrin into a dissolution kettle, evacuate and seal with nitrogen to remove oxygen, start dissolution stirring, use high-temperature steam and hot water to heat the dissolution system to 40-50°C, stir until bisphenol A is completely dissolved, and then pump the dissolution system materials into the pre-reactor (the mass ratio of bisphenol A to epichlorohydrin is 1:1-3); (2) Pre-reaction: Start the pre-reaction kettle for stirring, evacuate and seal with nitrogen to remove oxygen, use high-temperature steam and hot water to raise the temperature of the pre-reaction system to 50-60°C, add 30-50wt% sodium hydroxide solution, maintain the temperature stable, react for 2-4h, and then pump the materials into the main reaction kettle (the mass ratio of bisphenol A to sodium hydroxide is 20-40:1); (3) Main reaction: Start the main reactor and stir, evacuate the system to reduce the pressure to 15-30 kPa, and use high-temperature steam to heat the system to 60-65 ° C, maintain constant temperature and pressure, and then add 30-50wt% sodium hydroxide solution to the system within 2-4 hours to complete the reaction. Finally, replace the system with nitrogen to normal pressure and pump it into the recovery kettle for epichlorohydrin. During the reaction, use a water separator to remove water from the system in time, and reflux epichlorohydrin to the main reactor (the mass ratio of bisphenol A to sodium hydroxide is 1:0.3-0.4); (4) Recovery of epichlorohydrin: Start the recovery kettle of epichlorohydrin and stir, evacuate the system to reduce the pressure to 15-30 kPa and use high-temperature steam to raise the system temperature to 100-120°C for low-vacuum recovery of epichlorohydrin, then reduce the system pressure to below 3 kPa and use high-temperature steam to raise the system temperature to 130-140°C for high-vacuum recovery of epichlorohydrin, and finally use low-temperature steam at 20-40 Nm 3 / Hr flow rate steam bubbling for 20-30min to complete epichlorohydrin recovery. After cooling the system to 80-100℃, replace it with nitrogen to normal pressure and pump it into a refining kettle filled with toluene. Epichlorohydrin steam heats water through a heat exchanger to obtain hot water with a temperature of 60-90℃ and condenses it into epichlorohydrin and pumps it into a storage tank for recovering epichlorohydrin. When the water temperature is heated to 60-90℃, the excess epichlorohydrin steam is directly passed to the condenser to condense it into epichlorohydrin and pump it into a storage tank for recovering epichlorohydrin; (wherein the mass ratio of bisphenol A to toluene is 1:1.9-2.2); (5) Refining: Start the refining kettle and stir, use high-temperature steam to raise the temperature of the refining system to 70-90°C, add benzyltriethylammonium chloride and 10-20wt% sodium hydroxide solution, keep warm for reaction for 1-2h, then add pure water twice for water washing and liquid separation, use high-temperature steam and hot water to heat each time, maintain the system temperature between 60-70°C, stir for 20-40min, let stand for 20-40min and then separate the liquid, wherein sodium dihydrogen phosphate is added to adjust the pH of the system to between 6.5-7 during the second water washing, and finally filter the remaining toluene resin through a filter and put it into the debenzene kettle (the mass of benzyltriethylammonium chloride added is 0.05-0.1% of the mass of bisphenol A, the mass ratio of bisphenol A to sodium hydroxide is 1:0.01-0.02, the mass ratio of bisphenol A to the mass of pure water for the first water washing is 1:1-1.5, and the mass ratio of bisphenol A to the mass of pure water for the second water washing is 1:0.4-0.7); (6) Debenzening: Start the debenzening kettle and stir. Use high-temperature steam to raise the temperature of the debenzening system to 110-130°C for atmospheric debenzening. Then reduce the system pressure to below 3 kPa and use high-temperature steam to raise the system temperature to 140-160°C for debenzening. Then use low-temperature steam at 20-40 Nm 3 / Hr flow rate steam bubbling 30-60min to complete toluene recovery, and finally use nitrogen at 20-40Nm 3 / Hr flow rate bubbling for 30-60min to remove the system moisture to obtain the product resin. Toluene vapor heats water through another set of heat exchangers to obtain hot water with a temperature of 60-90°C and condenses into toluene and pumps into the toluene storage tank. When the water temperature is heated to 60-90°C, the excess toluene vapor is directly passed to the condenser to be condensed into toluene and pumped into the toluene storage tank.

[0017] The schematic diagram of energy recovery in the production process of epoxy resin of the present invention is as follows Figure 1 As shown, the present invention obtains hot water with a temperature of 60-90°C by heating water with high-temperature epichlorohydrin steam and high-temperature toluene steam obtained in the epichlorohydrin section and the debenzening section. The hot water meets the heating requirements of the dissolution section, the pre-reaction section and the refined water washing section. Therefore, the energy of the epichlorohydrin steam and toluene steam recovered in the epichlorohydrin section and the debenzening section can be transferred to the dissolution section, the pre-reaction section and the refined water washing section using hot water as a medium to realize energy recovery and utilization.

[0018] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention fully utilizes the heat of epichlorohydrin and toluene vapor in the production process, greatly improving energy utilization.

[0019] (2) The present invention is simple to operate and easy to modify, and the heat transfer medium is water, which is highly safe.

[0020] (3) In the present invention, high-temperature steam and hot water can be switched during heating in the dissolution, pre-reaction and refining stages, which has strong flexibility and adjustability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of energy recovery in the production process of epoxy resin of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with specific embodiments.

[0023] The raw materials and additives used in the following examples and comparative examples are all commercially available products.

[0024] Example 1 The production process of the low-energy consumption epoxy resin comprises the following steps: (1) Dissolution: Add 10t bisphenol A and 30t epichlorohydrin into a dissolution kettle, evacuate and seal with nitrogen to remove oxygen, start dissolution stirring, use 160℃ high-temperature steam and 60℃ hot water to heat the dissolution system to 40℃, stir until bisphenol A is completely dissolved, and then pump the dissolution system materials into the pre-reactor; (2) Pre-reaction: Start the pre-reaction kettle for stirring, evacuate and seal with nitrogen to remove oxygen, use 160°C high-temperature steam and 60°C hot water to raise the temperature of the pre-reaction system to 50°C, add 1670kg of 30% sodium hydroxide solution, maintain the temperature stable, react for 2h, and then pump the materials into the main reaction kettle; (3) Main reaction: Start the main reactor and stir, evacuate the system to reduce the pressure to 15kPa, and use 160℃ high-temperature steam to raise the temperature of the system to 60℃, maintain the temperature and pressure constant, and then add 10t of 30% sodium hydroxide solution to the system within 4 hours to complete the reaction. Finally, replace the system with nitrogen to normal pressure and pump it into the recovery kettle for epichlorohydrin. During the reaction, use a water separator to remove water from the system in time, and reflux epichlorohydrin to the main reactor; (4) Recovery of epichlorohydrin: Start the recovery kettle of epichlorohydrin and stir, evacuate the system to reduce the pressure to 15 kPa and use 160 °C high temperature steam to raise the system temperature to 100 °C for low vacuum recovery of epichlorohydrin, then reduce the system pressure to below 3 kPa and use 160 °C high temperature steam to raise the system temperature to 130 °C for high vacuum recovery of epichlorohydrin, finally use 130 °C low temperature steam at 20 Nm 3 / Hr flow rate steam bubbling for 20min to complete epichlorohydrin recovery. After cooling the system to 80℃, replace it with nitrogen to normal pressure and pump it into a refining kettle filled with 19t toluene. Epichlorohydrin vapor heats water through a heat exchanger to obtain hot water at a temperature of 60℃ and condenses it into epichlorohydrin, which is pumped into a storage tank for recovering epichlorohydrin. When the water temperature is heated to 60℃, the excess epichlorohydrin vapor is directly passed to the condenser to be condensed into epichlorohydrin and pumped into a storage tank for recovering epichlorohydrin; (5) Refining: Start the refining kettle and stir, use 160℃ high-temperature steam to raise the temperature of the refining system to 70℃, add 5kg benzyltriethylammonium chloride and 1000kg sodium hydroxide solution with a mass concentration of 10%, keep warm for 1h, then add pure water twice for water washing and liquid separation. Use 160℃ high-temperature steam and 60℃ hot water to heat each time, maintain the system temperature at 60℃, stir for 20min, let stand for 20min and then separate the liquid. During the second water washing, add sodium dihydrogen phosphate to adjust the pH of the system to 6.5. Finally, filter the remaining toluene resin through a filter and put it into the debenzene kettle (the mass of pure water for the first water washing is 10t, and the mass of pure water for the second water washing is 4t); (6) Debenzening: Start the debenzening kettle and stir. Use 160℃ high-temperature steam to raise the temperature of the debenzening system to 110℃ for atmospheric pressure debenzening. Then reduce the system pressure to below 3kPa and use 160℃ high-temperature steam to raise the system temperature to 140℃ for reduced pressure debenzening. Then use 130℃ low-temperature steam at 20Nm 3 / Hr flow rate steam bubbling 30min to complete toluene recovery, and finally nitrogen was used at 20Nm 3 / Hr flow rate bubbling for 30min to remove water from the system to obtain product resin. Toluene vapor heats water through another set of heat exchangers to obtain hot water at a temperature of 60°C and condenses into toluene, which is pumped into a toluene storage tank. When the water temperature is heated to 60°C, the excess toluene vapor is directly passed to the condenser to be condensed into toluene, which is pumped into a toluene storage tank.

[0025] Example 2 The production process of the low-energy consumption epoxy resin comprises the following steps: (1) Dissolution: 11.5t bisphenol A and 28.6t epichlorohydrin are added to a dissolution kettle, vacuumed and nitrogen-sealed to remove oxygen, dissolution stirring is started, 165°C high-temperature steam and 68°C hot water are used to heat the dissolution system to 43°C, stirred until bisphenol A is completely dissolved, and then the dissolution system materials are pumped into the pre-reactor; (2) Pre-reaction: Start the pre-reaction kettle for stirring, evacuate and seal with nitrogen to remove oxygen, use 165°C high-temperature steam and 68°C hot water to raise the temperature of the pre-reaction system to 53°C, add 1300kg of 35% sodium hydroxide solution, maintain the temperature stable, react for 2.5h, and then pump the materials into the main reaction kettle; (3) Main reaction: Start the main reactor for stirring, evacuate the system to reduce the pressure to 19 kPa, and use 165 ° C high-temperature steam to raise the temperature of the system to 62 ° C, maintain the temperature and pressure constant, and then add 10.8 tons of 35% sodium hydroxide solution to the system within 3.5 hours to complete the reaction. Finally, replace the system with nitrogen to normal pressure and pump it into the recovery kettle for epichlorohydrin. During the reaction, use a water separator to remove water from the system in time, and reflux epichlorohydrin to the main reactor; (4) Recovery of epichlorohydrin: Start the recovery kettle of epichlorohydrin and stir, evacuate the system to reduce the pressure to 19 kPa and use 165 °C high temperature steam to raise the system temperature to 105 °C for low vacuum recovery of epichlorohydrin, then reduce the system pressure to below 3 kPa and use 165 °C high temperature steam to raise the system temperature to 133 °C for high vacuum recovery of epichlorohydrin, finally use 133 °C low temperature steam at 25 Nm 3 Epichlorohydrin recovery is completed by steam bubbling at a flow rate of / Hr for 23min. After the system is cooled to 85°C, it is replaced with nitrogen to normal pressure and pumped into a refining kettle filled with 22.6t of toluene. Epichlorohydrin vapor heats water through a heat exchanger to obtain hot water at a temperature of 68°C and condenses into epichlorohydrin, which is pumped into a storage tank for recovering epichlorohydrin. When the water temperature is heated to 68°C, the excess epichlorohydrin vapor is directly passed to the condenser to be condensed into epichlorohydrin and pumped into a storage tank for recovering epichlorohydrin; (5) Refining: Start the refining kettle and stir, use 165℃ high-temperature steam to raise the temperature of the refining system to 75℃, add 7kg benzyltriethylammonium chloride and 1140kg sodium hydroxide solution with a mass concentration of 13%, keep warm for 1.3h, then add pure water twice for water washing and liquid separation. Use 165℃ high-temperature steam and 68℃ hot water to heat each time, maintain the system temperature at 63℃, stir for 25min, let stand for 25min and then separate the liquid. During the second water washing, add sodium dihydrogen phosphate to adjust the pH of the system to 6.7. Finally, filter the remaining toluene resin through a filter and put it into the debenzene kettle (the mass of pure water for the first water washing is 13.5t, and the mass of pure water for the second water washing is 5.5t); (6) Debenzening: Start the debenzening kettle and stir. Use 165℃ high-temperature steam to raise the temperature of the debenzening system to 115℃ for atmospheric pressure debenzening. Then reduce the system pressure to below 3kPa and use 165℃ high-temperature steam to raise the system temperature to 145℃ for reduced pressure debenzening. Then use 133℃ low-temperature steam at 25Nm 3 / Hr flow rate steam bubbling 38min to complete toluene recovery, and finally nitrogen was used at 25Nm 3 / Hr flow rate bubbling for 38min to remove water from the system to obtain product resin. Toluene vapor heats water through another set of heat exchangers to obtain hot water with a temperature of 68°C and condenses into toluene, which is pumped into a toluene storage tank. When the water temperature is heated to 68°C, the excess toluene vapor is directly passed to the condenser to be condensed into toluene, which is pumped into a toluene storage tank.

[0026] Example 3 The production process of the low-energy consumption epoxy resin comprises the following steps: (1) Dissolution: 13.4t bisphenol A and 26.7t epichlorohydrin are added to a dissolution kettle, vacuumed and nitrogen sealed to remove oxygen, dissolution stirring is started, and the dissolution system is heated to 45°C using 170°C high-temperature steam and 75°C hot water in conjunction with heating, and stirred until bisphenol A is completely dissolved, and then the dissolution system materials are pumped into the pre-reactor; (2) Pre-reaction: Start the pre-reaction kettle for stirring, evacuate and seal with nitrogen to remove oxygen, use 170°C high-temperature steam and 75°C hot water to raise the temperature of the pre-reaction system to 55°C, add 830kg of 40% sodium hydroxide solution, maintain the temperature stable, react for 3 hours, and then pump the materials into the main reaction kettle; (3) Main reaction: Start the main reactor for stirring, evacuate the system to reduce the pressure to 23 kPa, and use 170 °C high-temperature steam to raise the temperature of the system to 63 °C, maintain the temperature and pressure constant, and then add 11.7 tons of 40% sodium hydroxide solution to the system within 3 hours to complete the reaction. Finally, replace the system with nitrogen to normal pressure and pump it into the recovery kettle for epichlorohydrin. During the reaction, use a water separator to remove water from the system in time, and reflux epichlorohydrin to the main reactor; (4) Recovery of epichlorohydrin: Start the recovery kettle of epichlorohydrin and stir, evacuate the system to reduce the pressure to 23 kPa and use 170 °C high temperature steam to raise the system temperature to 110 °C for low vacuum recovery of epichlorohydrin, then reduce the system pressure to below 3 kPa and use 170 °C high temperature steam to raise the system temperature to 135 °C for high vacuum recovery of epichlorohydrin, finally use 135 °C low temperature steam at 30 Nm 3 Epichlorohydrin recovery is completed by steam bubbling at a flow rate of / Hr for 25min. After the system is cooled to 90℃, it is replaced with nitrogen to normal pressure and pumped into a refining kettle filled with 23.7t of toluene. Epichlorohydrin vapor heats water through a heat exchanger to obtain hot water at a temperature of 75℃ and condenses into epichlorohydrin, which is pumped into a storage tank for recovering epichlorohydrin. When the water temperature is heated to 75℃, the excess epichlorohydrin vapor is directly passed to the condenser to be condensed into epichlorohydrin and pumped into a storage tank for recovering epichlorohydrin; (5) Refining: Start the refining kettle and stir, use 170℃ high-temperature steam to raise the temperature of the refining system to 80℃, add 10kg benzyltriethylammonium chloride and 1330kg 15% sodium hydroxide solution, keep warm for 1.5h, then add pure water twice for water washing and liquid separation, use 170℃ high-temperature steam and 75℃ hot water to heat each time, maintain the system temperature at 65℃, stir for 30min, let stand for 30min and then separate the liquid, add sodium dihydrogen phosphate for the second water washing to adjust the system pH to 6.8, finally filter the remaining toluene resin through a filter and put it into the debenzene kettle (the mass of pure water for the first water washing is 16.7t, and the mass of pure water for the second water washing is 7.4t); (6) Debenzening: Start the debenzening kettle and stir. Use 170℃ high-temperature steam to raise the temperature of the debenzening system to 120℃ for atmospheric pressure debenzening. Then reduce the system pressure to below 3kPa and use 170℃ high-temperature steam to raise the system temperature to 150℃ for reduced pressure debenzening. Then use 135℃ low-temperature steam at 30Nm 3 / Hr flow rate steam bubbling 45min to complete toluene recovery, and finally nitrogen was used at 30Nm 3 / Hr flow rate bubbling for 45min to remove water from the system to obtain product resin. Toluene vapor heats water through another set of heat exchangers to obtain hot water at a temperature of 75°C and condenses into toluene, which is pumped into a toluene storage tank. When the water temperature is heated to 75°C, the excess toluene vapor is directly passed to the condenser to be condensed into toluene, which is pumped into a toluene storage tank.

[0027] Example 4 The production process of the low-energy consumption epoxy resin comprises the following steps: (1) Dissolution: Add 16 tons of bisphenol A and 24 tons of epichlorohydrin into a dissolution kettle, evacuate and seal with nitrogen to remove oxygen, start dissolution stirring, use 175°C high-temperature steam and 83°C hot water to heat the dissolution system to 48°C, stir until bisphenol A is completely dissolved, and then pump the dissolution system materials into the pre-reactor; (2) Pre-reaction: Start the pre-reaction kettle for stirring, evacuate and seal with nitrogen to remove oxygen, use 175°C high-temperature steam and 83°C hot water to raise the temperature of the pre-reaction system to 58°C, add 1000kg of 45% sodium hydroxide solution, maintain the temperature stable, react for 3.5h, and then pump the materials into the main reaction kettle; (3) Main reaction: Start the main reactor and stir, evacuate the system to reduce the pressure to 27 kPa, and use 175 ° C high-temperature steam to heat the system to 64 ° C, maintain constant temperature and pressure, and then add 13.5 tons of 45% sodium hydroxide solution to the system within 2.5 hours to complete the reaction. Finally, replace the system with nitrogen to normal pressure and pump it into the recovery kettle for epichlorohydrin. During the reaction, use a water separator to remove water from the system in time, and reflux epichlorohydrin to the main reactor; (4) Recovery of epichlorohydrin: Start the recovery kettle of epichlorohydrin and stir, evacuate the system to reduce the pressure to 27 kPa and use 175 °C high temperature steam to raise the system temperature to 115 °C for low vacuum recovery of epichlorohydrin, then reduce the system pressure to below 3 kPa and use 175 °C high temperature steam to raise the system temperature to 138 °C for high vacuum recovery of epichlorohydrin, finally use 138 °C low temperature steam at 35 Nm 3 Epichlorohydrin recovery is completed by steam bubbling at a flow rate of / Hr for 28min. After the system is cooled to 95°C, it is replaced with nitrogen to normal pressure and pumped into a refining kettle containing 34t of toluene. Epichlorohydrin vapor heats water through a heat exchanger to obtain hot water at a temperature of 83°C and condenses into epichlorohydrin, which is pumped into a storage tank for recovering epichlorohydrin. When the water temperature is heated to 83°C, the excess epichlorohydrin vapor is directly passed to the condenser to be condensed into epichlorohydrin and pumped into a storage tank for recovering epichlorohydrin; (5) Refining: Start the refining kettle and stir, use 175℃ high-temperature steam to raise the temperature of the refining system to 85℃, add 14kg benzyltriethylammonium chloride and 1600kg 18% sodium hydroxide solution, keep warm for 1.8h, then add pure water twice for water washing and liquid separation, use 175℃ high-temperature steam and 83℃ hot water to heat each time, maintain the system temperature at 68℃, stir for 35min, let stand for 35min and then separate the liquid, add sodium dihydrogen phosphate for the second water washing to adjust the system pH to 6.9, finally filter the remaining toluene resin through a filter and put it into the debenzene kettle (the mass of pure water for the first water washing is 22t, and the mass of pure water for the second water washing is 10t); (6) Debenzening: Start the debenzening kettle and stir. Use 175℃ high-temperature steam to raise the temperature of the debenzening system to 125℃ for atmospheric debenzening. Then reduce the system pressure to below 3kPa and use 175℃ high-temperature steam to raise the system temperature to 155℃ for debenzening under reduced pressure. Then use 138℃ low-temperature steam at 35Nm 3 / Hr flow rate steam bubbling 53min to complete toluene recovery, and finally nitrogen was used at 35Nm 3 / Hr flow rate bubbling for 53min to remove water from the system to obtain product resin. Toluene vapor heats water through another set of heat exchangers to obtain hot water at a temperature of 83°C and condenses into toluene, which is pumped into a toluene storage tank. When the water temperature is heated to 83°C, the excess toluene vapor is directly passed to the condenser to be condensed into toluene, which is pumped into a toluene storage tank.

[0028] Example 5 The production process of the low-energy consumption epoxy resin comprises the following steps: (1) Dissolution: Add 20 tons of bisphenol A and 20 tons of epichlorohydrin into a dissolution kettle, evacuate and seal with nitrogen to remove oxygen, start dissolution stirring, use 180°C high-temperature steam and 90°C hot water to heat the dissolution system to 50°C, stir until bisphenol A is completely dissolved, and then pump the dissolution system materials into the pre-reactor; (2) Pre-reaction: Start the pre-reaction kettle for stirring, evacuate and seal with nitrogen to remove oxygen, use 180°C high-temperature steam and 90°C hot water to raise the temperature of the pre-reaction system to 60°C, add 1000kg of 50% sodium hydroxide solution, maintain the temperature stable, react for 4 hours, and then pump the materials into the main reaction kettle; (3) Main reaction: Start the main reactor and stir, evacuate the system to reduce the pressure to 30 kPa, and use 180 ° C high-temperature steam to raise the temperature of the system to 65 ° C, maintain constant temperature and pressure, and then add 16 tons of 50% sodium hydroxide solution to the system within 2 hours to complete the reaction. Finally, replace the system with nitrogen to normal pressure and pump it into the recovery kettle of epichlorohydrin. During the reaction, use a water separator to remove water from the system in time, and reflux epichlorohydrin to the main reactor; (4) Recovery of epichlorohydrin: Start the recovery kettle of epichlorohydrin and stir, evacuate the system to reduce the pressure to 30 kPa and use 180 °C high temperature steam to raise the system temperature to 120 °C for low vacuum recovery of epichlorohydrin, then reduce the system pressure to below 3 kPa and use 180 °C high temperature steam to raise the system temperature to 140 °C for high vacuum recovery of epichlorohydrin, finally use 140 °C low temperature steam at 40 Nm 3 Epichlorohydrin recovery is completed by steam bubbling at a flow rate of / Hr for 30 minutes. After the system is cooled to 100°C, it is replaced with nitrogen to normal pressure and pumped into a refining kettle filled with 44t of toluene. Epichlorohydrin vapor heats water through a heat exchanger to obtain hot water at a temperature of 90°C and condenses into epichlorohydrin, which is pumped into a storage tank for recovering epichlorohydrin. When the water temperature is heated to 90°C, the excess epichlorohydrin vapor is directly passed to the condenser to be condensed into epichlorohydrin and pumped into a storage tank for recovering epichlorohydrin; (5) Refining: Start the refining kettle and stir, use 180℃ high-temperature steam to raise the temperature of the refining system to 90℃, add 20kg benzyltriethylammonium chloride and 2000kg sodium hydroxide solution with a mass concentration of 20%, keep warm for 2h, then add pure water twice for water washing and liquid separation, use 180℃ high-temperature steam and 90℃ hot water to heat each time, maintain the system temperature at 70℃, stir for 40min, let stand for 40min and then separate the liquid, add sodium dihydrogen phosphate for the second water washing to adjust the system pH to 7, finally filter the remaining toluene resin through a filter and put it into the debenzene kettle (the mass of pure water for the first water washing is 30t, and the mass of pure water for the second water washing is 14t); (6) Debenzening: Start the debenzening kettle and stir. Use 180℃ high-temperature steam to raise the temperature of the debenzening system to 130℃ for atmospheric pressure debenzening. Then reduce the system pressure to below 3kPa and use 180℃ high-temperature steam to raise the system temperature to 160℃ for reduced pressure debenzening. Then use 140℃ low-temperature steam at 40Nm 3 / Hr flow rate steam bubbling 60min to complete toluene recovery, and finally nitrogen was used at 40Nm 3 / Hr flow rate bubbling for 60min to remove water from the system to obtain product resin. Toluene vapor heats water through another set of heat exchangers to obtain hot water at a temperature of 90°C and condenses into toluene, which is pumped into a toluene storage tank. When the water temperature is heated to 90°C, the excess toluene vapor is directly passed to the condenser to be condensed into toluene, which is pumped into a toluene storage tank.

[0029] Comparative Example 1 Compared with Example 1, only 160° C. high-temperature steam heating is used in the dissolution section, pre-reaction section and refining water washing section.

[0030] Comparative Example 2 Compared with Example 2, only 165° C. high-temperature steam heating is used in the dissolution section, pre-reaction section and refined water washing section.

[0031] Comparative Example 3 Compared with Example 3, only 170° C. high-temperature steam heating is used in the dissolution section, pre-reaction section and refining water washing section.

[0032] Comparative Example 4 Compared with Example 4, only 175° C. high-temperature steam heating is used in the dissolution section, pre-reaction section and refining water washing section.

[0033] Comparative Example 5 Compared with Example 5, only 180° C. high-temperature steam heating is used in the dissolution section, pre-reaction section and refining water washing section.

[0034] The products obtained in each embodiment and comparative example were tested and the steam consumption was calculated. The results are shown in Table 1.

[0035] Table 1 Product indicators and energy consumption results

[0036] As can be seen from the above, by comparing Examples 1-5 with Comparative Examples 1-5, it can be seen that the product indicators are not changed when the present invention is used to produce epoxy resin; the steam unit consumption of Examples 1-5 is significantly reduced relative to Comparative Examples 1-5, and the reduction range is about 4.6-6.5%. Experimental data show that the steam heat of recovered epichlorohydrin and toluene is effectively utilized using the method of the present invention, and when the quality of recovered epichlorohydrin and recovered toluene is higher and the hot water temperature is higher, the proportion of reduced steam unit consumption is greater. The reason is that when more epichlorohydrin and toluene are recovered, more heat will be wasted according to the traditional process operation. When the present invention is used to produce resin, this part of the heat will be converted into the heat of hot water and reused in the production process of the resin, and the higher the hot water temperature, the more heat can be conducted, so the proportion of reduced steam unit consumption is greater.

Claims

1. A production process for low-energy consumption epoxy resin, characterized in that: The following steps are involved: (1) Dissolution: Mix and dissolve bisphenol A and epichlorohydrin, and use 160-180°C steam and 60-90°C water to heat the dissolution system to 40-50°C until bisphenol A is completely dissolved; (2) Pre-reaction: Continue to use 160-180°C steam and 60-90°C water to heat the reaction system to 50-60°C, add sodium hydroxide solution, and react for 2-4 hours to obtain a pre-reaction solution; (3) Main reaction: Control the pressure of the reaction system to 15-30 kPa, use 160-180 °C steam to raise the temperature of the system to 60-65 °C, add sodium hydroxide solution and react for 2-4 hours to obtain a reaction solution; (4) Recovering epichlorohydrin: The pressure of the reaction system is controlled at 15-30 kPa, and at the same time, 160-180°C steam is used to heat the system to 100-120°C to recover epichlorohydrin, and then the system pressure is reduced to below 3 kPa, and at the same time, 160-180°C steam is used to heat the system to 130-140°C to recover epichlorohydrin in vacuum, and finally, 130-140°C steam is used to bubble to complete the recovery of epichlorohydrin, and after the reaction system is cooled to 80-100°C, the reaction solution is pumped into a refining kettle filled with toluene; The epichlorohydrin recovery method comprises heating water with epichlorohydrin vapor through a heat exchanger to obtain water with a temperature of 60-90° C., condensing the water into epichlorohydrin liquid, and pumping the water into an epichlorohydrin recovery tank; the excess epichlorohydrin vapor is directly passed to a condenser to condense the epichlorohydrin liquid, and pumping the epichlorohydrin recovery tank; the obtained water with a temperature of 60-90° C. is used in steps (1), (2), and (5); (5) Refining: Use 160-180℃ steam to raise the temperature of the refining system to 70-90℃, add benzyltriethylammonium chloride and sodium hydroxide solution, react for 1-2h, then add water for the first and second washing and separation. During the first and second washing, use 160-180℃ steam and 60-90℃ hot water to heat, maintain the system temperature at 60-70℃, stir for 20-40min, stand for 20-40min to separate the liquids, and adjust the pH to 6.5-7 during the second washing. Put the remaining toluene resin into the debenzening kettle; (6) Debenzening: Use 160-180°C steam to raise the temperature of the debenzening system to 110-130°C for atmospheric pressure debenzening, then reduce the system pressure to below 3 kPa, and simultaneously use 160-180°C steam to raise the system temperature to 140-160°C for reduced pressure debenzening, and finally use 130-140°C steam bubbling to complete toluene recovery and water removal to obtain the product resin; The debenzening is carried out in a manner of removing toluene vapor. The toluene vapor is used to heat water through a heat exchanger to obtain hot water with a temperature of 60-90° C., which is condensed into toluene liquid and pumped into a toluene storage tank. Excess toluene vapor is directly passed to a condenser to be condensed into toluene liquid and pumped into a toluene storage tank. The obtained water with a temperature of 60-90° C. is supplied to steps (1), (2) and (5).

2. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The mass ratio of bisphenol A to epichlorohydrin in step (1) is 1:1-3.

3. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The concentration of the sodium hydroxide solution in step (2) is 30-50wt%, and the mass ratio of bisphenol A to sodium hydroxide is 20-40:

1.

4. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The concentration of the sodium hydroxide solution in step (3) is 30-50wt%, and the mass ratio of bisphenol A to sodium hydroxide is 1:0.3-0.

4.

5. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The steam bubbling flow rate in step (4) is 20-40 Nm 3 / Hr, bubbling time is 20-30min.

6. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The pH in step (5) is adjusted using sodium dihydrogen phosphate.

7. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The benzyltriethylammonium chloride in step (5) is 0.05-0.1% of the mass of bisphenol A, and the mass ratio of bisphenol A to sodium hydroxide is 1:0.01-0.

02.

8. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The mass ratio of bisphenol A to the first washing pure water in step (5) is 1:1-1.5, and the mass ratio of bisphenol A to the second washing pure water is 1:0.4-0.

7.

9. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The steam bubbling flow rate in step (6) is 20-40 Nm 3 / Hr, bubbling time is 30-60min.

10. The production process of low energy consumption epoxy resin according to claim 1, characterized in that: The water removal in step (6) is carried out by using nitrogen at 20-40 Nm 3 / Hr flow rate for 30-60min to remove water from the system.

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