Green acid-base chemical production system

Abstract

The utility model discloses a green acid-alkali chemical production system which comprises a saline refining system, an ionic membrane electrolytic cell, a liquid alkali storage tank and an evaporative crystallization drying system which are sequentially connected, a gas outlet of the ionic membrane electrolytic cell is connected with a hydrogen chloride synthesis furnace, and a gas outlet of the hydrogen chloride synthesis furnace is connected with a hydrochloric acid absorption tower. A jacket type heat exchanger is arranged in the hydrogen chloride synthesis furnace, a liquid inlet of the jacket type heat exchanger is connected with a hot water tank, a liquid outlet of the jacket type heat exchanger is connected with a flash tank, a gas outlet of the flash tank is connected with an evaporative crystallization drying system through a steam compressor, and a liquid outlet of the evaporative crystallization drying system is connected with a condensate water tank. The condensate water tank is connected with the brine refining system, and the whole system is powered by the multi-energy complementary system. According to the utility model, heat released by the hydrogen chloride synthetic furnace is used in the evaporative crystallization drying process of the caustic soda solution through heat exchange, flash evaporation and compression processes, so that the heat recovery and gradient utilization in acid-base production are realized, the energy waste is reduced, and the problem of'green electricity 'consumption is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of green chemical industry, and relates to a production system for green acid and base chemical products. Background Art

[0002] Caustic soda (NaOH) and hydrochloric acid (HCl) are important general basic chemical raw materials, which are widely used in various heavy and light industries. The ion-exchange membrane electrolysis method for producing caustic soda with by-product hydrochloric acid is the current mainstream production process, which can obtain high-purity acid and base products. However, the ion-exchange membrane electrolysis method belongs to a high-energy-consuming industry. For every 1 ton of caustic soda produced, the direct current power consumption is about 2100 - 2200 kWh, accounting for about 60% of the total production cost of caustic soda. At the same time, a large amount of carbon emissions are also generated during the preparation of caustic soda. During the power generation process of renewable energy such as wind power and photovoltaic power, no carbon emissions and pollutants are produced, that is, "green electricity". However, at the same time, due to the geographical imbalance and spatio-temporal imbalance factors of the supply and demand of wind power and photovoltaic power, there are problems in the large-scale consumption of "green electricity" in some regions, and there is a phenomenon of abandoning wind and light, which restricts the development of renewable energy power generation.

[0003] At present, when using the ion-exchange membrane electrolysis method to prepare caustic soda, the refined brine is first electrolyzed to generate caustic soda solution, chlorine and hydrogen. A large amount of heat is released during the reaction of chlorine and hydrogen to form hydrogen chloride. Most of this heat is directly discharged into the atmosphere, which not only affects the surrounding environment but also causes energy waste. In view of the above problems, using renewable energy power generation such as wind power and photovoltaic power in the process of producing caustic soda with by-product hydrochloric acid by ion-exchange membrane electrolysis can not only solve the problem of consumption of "green electricity" but also greatly reduce the electricity cost and carbon emissions during the production process. Content of the Utility Model

[0004] The purpose of the utility model is to provide a production system for green acid and base chemical products, which solves the problems of high carbon emissions and serious energy waste in the existing production system of acid and base chemical products.

[0005] The technical solution adopted by the utility model is that the production system for green acid and base chemical products includes a brine purification system, an ion-exchange membrane electrolyzer, a liquid caustic soda storage tank, an evaporation crystallization and drying system, and a finished product bin connected in sequence. The gas outlet of the ion-exchange membrane electrolyzer is connected to a hydrogen chloride synthesis furnace, the gas outlet of the hydrogen chloride synthesis furnace is connected to a hydrochloric acid absorption tower, a jacketed heat exchanger is arranged inside the hydrogen chloride synthesis furnace, the liquid inlet of the jacketed heat exchanger is connected to a hot water tank, the liquid outlet is connected to a flash tank, the gas outlet of the flash tank is connected to the evaporation crystallization and drying system through a steam compressor, the liquid outlet of the evaporation crystallization and drying system is connected to a condensate tank, and the condensate tank is connected to the brine purification system.

[0006] A brine dissolving tank is connected between the water outlet of the condensate tank and the brine purification system. The feeding port of the brine dissolving tank is connected to a raw salt bin through a belt conveyor mechanism.

[0007] There is a refined brine storage tank connected between the brine purification system and the ion-exchange membrane electrolyzer, and a brine pump is installed at the liquid outlet of the refined brine storage tank.

[0008] A salt dissolving and dosing pump is installed at the water outlet of the condensate tank. The water inlet of the condensate tank is connected to a process water storage tank through pipeline B, and a water valve is installed in the middle of pipeline B.

[0009] The ion-exchange membrane electrolyzer and the hydrogen chloride synthesis furnace are respectively connected with a chlorine gas buffer tank and a hydrogen gas buffer tank through pipelines.

[0010] A cooler is connected between the hydrogen chloride synthesis furnace and the hydrochloric acid absorption tower through a pipeline. A spraying layer is installed at the top inside the hydrochloric acid absorption tower. The water inlet of the spraying layer is connected to a circulation water tank through pipeline C, and a circulation water pump is installed in the middle of pipeline C. The hydrochloric acid absorption tower is provided with a liquid outlet A and a liquid outlet B. The liquid outlet A is connected to the circulation water tank through a pipeline, and the liquid outlet B is connected to a hydrochloric acid storage tank through a pipeline. Valves are installed at both the liquid outlet A and the liquid outlet B.

[0011] The hot water tank and the hydrogen chloride synthesis furnace are connected through pipeline D, and a hot water circulation pump is installed in the middle of pipeline D.

[0012] The liquid caustic soda storage tank and the evaporation, crystallization and drying system are connected through pipeline A, and a liquid caustic soda pump is installed in the middle of pipeline A.

[0013] It also includes a multi-energy complementary power supply module. The multi-energy complementary power supply module includes a power distribution cabinet, which is respectively connected with a wind power station, a photovoltaic power station, the power grid and an energy storage battery. The photovoltaic power station is connected to the power distribution cabinet through a busbar trunking system and a photovoltaic inverter. The power grid is connected to the power distribution cabinet through a transformer. The energy storage battery is respectively connected with the wind power station and the photovoltaic power station.

[0014] The brine pump, the ion-exchange membrane electrolyzer, the liquid caustic soda pump, the evaporation, crystallization and drying system, the circulation water pump, the flash tank, the hot water circulation pump, the steam compressor and the salt dissolving and dosing pump are respectively electrically connected to the power distribution cabinet.

[0015] The beneficial effects of the present utility model are as follows: by arranging a jacket type heat exchanger inside the hydrogen chloride synthesis furnace, the liquid inlet of the jacket type heat exchanger is connected to a hot water tank, the liquid outlet is connected to a flash tank, and the gas outlet of the flash tank is connected to the evaporation, crystallization and drying system through a steam compressor. The heat released by the hydrogen chloride synthesis furnace is used to heat the hot water into saturated water, and saturated steam is obtained after flash evaporation. Then, the superheated steam obtained after compressing the saturated steam is used for the evaporation and crystallization process of the caustic soda solution. The condensed water after the superheated steam releases heat is used for preparing brine, realizing the recovery and cascade utilization of heat in the acid-base production process and reducing energy waste. By adopting the multi-energy complementary power supply module, the wind power station and the photovoltaic power station are used to supply power to each electrical equipment in the production system, which is green and environmentally friendly, and also solves the problem that it is difficult to consume the wind power and photovoltaic power, and greatly reduces the carbon emission in the production process of acid-base chemical products. Brief Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the production system of green acid-base chemical products of the present utility model.

[0017] In the figure, 1-1. Raw salt bin, 1-2. Salt dissolving tank, 1-3. Brine refining system, 1-4. Refined brine storage tank, 1-5. Brine pump, 1-6. Ion-exchange membrane electrolyzer, 1-7. Liquid caustic soda storage tank, 1-8. Liquid caustic soda pump, 1-9. Evaporation crystallization drying system, 1-10. Finished product bin, 2-1. Chlorine buffer tank, 2-2. Hydrogen buffer tank, 2-3. Hydrogen chloride synthesis furnace, 2-4. Cooler, 2-5. Hydrochloric acid absorption tower, 2-6. Hydrochloric acid storage tank, 2-7. Circulation water tank, 2-8. Circulation water pump, 2-9. Spray layer, 2-10. Flash tank, 2-11. Hot water tank, 2-12. Hot water circulation pump, 2-13. Steam compressor, 2-14. Condensate tank, 2-15. Salt dissolving and water distribution pump, 2-16. Process water storage tank, 2-17. Water valve, 3-1. Wind power station, 3-2. Photovoltaic power station, 3-3. Power grid, 3-4. Energy storage battery, 3-5. Combiner box, 3-6. Photovoltaic inverter, 3-7. Power distribution cabinet, 3-8. Transformer. Detailed Description of the Preferred Embodiments

[0018] The present utility model will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0019] Embodiment 1

[0020] A production system of green acid-base chemical products, referring to Figure 1 , includes a brine refining system 1-3, an ion-exchange membrane electrolyzer 1-6, a liquid caustic soda storage tank 1-7, an evaporation crystallization drying system 1-9, and a finished product bin 1-10 connected in sequence. The liquid caustic soda storage tank 1-7 is connected to the evaporation crystallization drying system 1-9 through pipeline A. A liquid caustic soda pump 1-8 is installed in the middle of pipeline A. The gas outlet of the ion-exchange membrane electrolyzer 1-6 is connected to a hydrogen chloride synthesis furnace 2-3. The gas outlet of the hydrogen chloride synthesis furnace 2-3 is connected to a hydrochloric acid absorption tower 2-5. A jacketed heat exchanger is arranged inside the hydrogen chloride synthesis furnace 2-3. The inlet of the jacketed heat exchanger is connected to the hot water tank 2-11 (the range of the hot water temperature should be given in the dependent claim), and the outlet is connected to a flash tank 2-10. The gas outlet of the flash tank 2-10 is connected to the evaporation crystallization drying system 1-9 through a steam compressor 2-13. The liquid outlet of the evaporation crystallization drying system 1-9 is connected to a condensate tank 2-14, and the condensate tank 2-14 is connected to the brine refining system 1-3.

[0021] There is a salt dissolving tank 1-2 connected between the outlet of the condensate water tank 2-14 and the brine refining system 1-3. The inlet of the salt dissolving tank 1-2 is connected to the raw salt bin 1-1 through a belt conveyor. Solid sodium chloride is stored in the raw salt bin 1-1 and transported to the salt dissolving tank 1-2 through the belt conveyor. The solid sodium chloride is mixed with the process water transported by the condensate water tank 2-14 to form brine. The prepared brine enters the brine refining system 1-3 to remove suspended solids and Ca 2+ 、Mg 2+ 、SO4 2- and other impurity ions, so that the NaCl concentration in the refined brine is maintained at 280-320 g / L, the water temperature is maintained at 60-65 °C, the suspended solids ≤ 3 ppm, Ca 2+ +Mg 2+ ≤ 10.0 mg / L, SO4 2- ≤ 5.0 g / L to meet the index requirements of the ion-exchange membrane electrolytic cell for brine.

[0022] The main equipment of the brine refining system 1-3 includes a clarifying tank, a dosing device, a filter and a resin tower. Among them, the clarifying tank uses the principle of precipitation to remove insoluble substances and flocculants; the dosing device is used to add agents such as Na2CO3 and NaOH to the brine to make Ca 2+ 、Mg 2+ form insoluble substances; the filter is used to further remove impurities in the brine; the resin tower is used to further remove Ca 2+ 、Mg 2+ in the brine; preferably, the brine refining system can also select a ceramic membrane and supporting components to replace the clarifying tank, the dosing device and the filter, with better effect and simpler process.

[0023] The ion-exchange membrane electrolytic cell electrolyzes the refined brine prepared by the brine refining system to generate caustic soda NaOH, chlorine gas Cl2 and hydrogen gas H2. The cation exchange membrane in the ion-exchange membrane electrolytic cell separates the cathode and anode of the electrolytic cell. This exchange membrane only allows cations to pass through, and anions and gases cannot pass through; during operation, the refined brine enters the anode chamber, pure water enters the cathode chamber, the electrolytic cell is powered on, NaOH and H2 are generated at the cathode, and diluted brine and Cl2 are generated at the anode, and then discharged from different outlets of the ion-exchange membrane electrolytic cell. The chemical reaction equation in the ion-exchange membrane electrolytic cell is: 2NaCl + 2H2O → 2NaOH + H2↑ + Cl2↑.

[0024] The concentration of the caustic soda solution generated in the ion-exchange membrane electrolytic cell is 32%, which is stored in the liquid caustic soda storage tank 1-7. In order to further increase the concentration of caustic soda, the caustic soda solution is sent to the evaporation crystallization drying system 1-9 through the liquid caustic soda pump 1-8, and liquid caustic soda with a concentration of 50% and dry solid caustic soda (flake soda) with a purity of 98% can be obtained.

[0025] The evaporation crystallization drying system uses the method of evaporation crystallization. External steam enters the evaporation crystallizer, and the heat of the steam is used to raise the temperature of the caustic soda solution, evaporate water, and increase the concentration of caustic soda. Double-effect evaporation crystallization or triple-effect evaporation crystallization can be adopted. The 50% concentrated caustic soda obtained can be directly sold as a product. When using the 50% caustic soda solution to continue making solid caustic soda, the evaporation crystallization drying system will further evaporate and crystallize the caustic soda solution to remove water and obtain a dry caustic soda product. The pot caustic method or the cooling crystallization method can be adopted for this process. The obtained caustic soda product is stored in the finished product warehouse 1-10.

[0026] The steam used in the evaporation crystallization drying system is provided by the steam compressor 2-13. After the heat of the steam is released, it condenses into liquid water, flows out of the evaporation crystallization drying system, and is stored in the condensate tank 2-14.

[0027] Example 2

[0028] A green acid-base chemical production system includes a brine refining system 1-3, an ion-exchange membrane electrolyzer 1-6, a liquid caustic soda storage tank 1-7, an evaporation crystallization drying system 1-9, and a finished product warehouse 1-10 connected in sequence. The gas outlet of the ion-exchange membrane electrolyzer 1-6 is connected to a hydrogen chloride synthesis furnace 2-3, the gas outlet of the hydrogen chloride synthesis furnace 2-3 is connected to a hydrochloric acid absorption tower 2-5. A jacketed heat exchanger is arranged inside the hydrogen chloride synthesis furnace 2-3. The inlet of the jacketed heat exchanger is connected to a hot water tank 2-11, and the outlet is connected to a flash tank 2-10. The gas outlet of the flash tank 2-10 is connected to the evaporation crystallization drying system 1-9 through a steam compressor 2-13. The liquid outlet of the evaporation crystallization drying system 1-9 is connected to a condensate tank 2-14, and the condensate tank 2-14 is connected to the brine refining system 1-3.

[0029] A salt dissolving tank 1-2 is connected between the water outlet of the condensate tank 2-14 and the brine refining system 1-3. The feeding port of the salt dissolving tank 1-2 is connected to a raw salt bin 1-1 through a belt conveyor mechanism. A refined brine storage tank 1-4 is connected between the brine refining system 1-3 and the ion-exchange membrane electrolyzer 1-6, and a brine pump 1-5 is installed at the liquid outlet of the refined brine storage tank 1-4.

[0030] A salt dissolving and dosing pump 2-15 is installed at the water outlet of the condensate tank 2-14. The water inlet of the condensate tank 2-14 is connected to a process water storage tank 2-16 through a pipeline B, and a water valve 2-17 is installed in the middle of the pipeline B.

[0031] A chlorine buffer tank 2-1 and a hydrogen buffer tank 2-2 are respectively connected between the ion-exchange membrane electrolyzer 1-6 and the hydrogen chloride synthesis furnace 2-3 through pipelines. The hot water tank 2-11 and the hydrogen chloride synthesis furnace 2-3 are connected through a pipeline D, and a hot water circulation pump 2-12 is installed in the middle of the pipeline D. The liquid caustic soda storage tank 1-7 and the evaporation crystallization drying system 1-9 are connected through a pipeline A, and a liquid caustic soda pump 1-8 is installed in the middle of the pipeline A.

[0032] There is a cooler 2-4 connected by a pipeline between the hydrogen chloride synthesis furnace 2-3 and the hydrochloric acid absorption tower 2-5. At the top inside the hydrochloric acid absorption tower 2-5, a spray layer 2-9 is installed. The water inlet of the spray layer 2-9 is connected to a circulation water tank 2-7 through pipeline C. In the middle of pipeline C, a circulation water pump 2-8 is installed. The hydrochloric acid absorption tower 2-5 is provided with a liquid outlet A and a liquid outlet B. The liquid outlet A is connected to the circulation water tank 2-7 through a pipeline, and the liquid outlet B is connected to a hydrochloric acid storage tank 2-6 through a pipeline. Valves are installed at both the liquid outlet A and the liquid outlet B.

[0033] After chlorine is generated in the ion-exchange membrane electrolyzer, it enters the chlorine buffer tank 2-1; after hydrogen is generated in the ion-exchange membrane electrolyzer, it enters the hydrogen buffer tank 2-2; chlorine and hydrogen enter the hydrogen chloride synthesis furnace 2-3, and after ignition and combustion, hydrogen chloride HCl is generated, and a large amount of heat is released at the same time. The purities of chlorine and hydrogen are ≥90% and ≥98% respectively, and the volume ratio is chlorine:hydrogen = 1:(1.05 - 1.1).

[0034] The HCl discharged from the hydrogen chloride synthesis furnace enters the hydrochloric acid absorption tower 2-5 after being cooled by the cooler 2-4. The circulation water tank 2-7, the circulation water pump 2-8, and the spray layer 2-9 form a circulating spray system to improve the absorption effect. The pure water sprayed out from the spray layer 2-9 at the upper part of the hydrochloric acid absorption tower 2-5 comes into contact with the HCl gas, making the HCl dissolve in water to form a hydrochloric acid solution. Through detection, when the concentration of the hydrochloric acid discharged from the hydrochloric acid absorption tower < 30%, the valve on the liquid outlet A is opened, and at the same time, the valve on the liquid outlet B is closed. The hydrochloric acid with a lower concentration enters the circulation water tank and is then sent to the spray layer 2-9 by the circulation water pump 2-8 to contact the HCl gas again. During multiple cycles, the concentration of the hydrochloric acid solution continuously increases, thus forming a finished hydrochloric acid with a qualified concentration. The concentration of the finished hydrochloric acid ≥ 30%, that is, when the concentration of the hydrochloric acid discharged from the hydrochloric acid absorption tower ≥ 30%, the valve on the liquid outlet A is closed, and at the same time, the valve on the liquid outlet B is opened. The finished hydrochloric acid enters the hydrochloric acid storage tank 2-6 for storage. Since the HCl gas will escape from the water at a higher temperature, during the operation, it is necessary to keep the temperature of the hydrochloric acid solution in the hydrochloric acid absorption tower 2-5 below <80°C.

[0035] Hot water with a temperature higher than 90°C is stored in the hot water tank 2-11 and is sent to the hydrogen chloride synthesis furnace by the hot water circulation pump 2-12. Since a large amount of heat is released during the combustion reaction in the hydrogen chloride synthesis furnace, the hot water can be heated into saturated water with a pressure reaching 0.6 MPa, and then it enters the flash tank; the flash tank is a device for generating steam. The saturated water enters the tank, the air pressure drops suddenly, a part of the saturated water turns into saturated steam and is discharged from the top of the flash tank 2-10; the remaining saturated water turns into hot water with a lower temperature and is discharged from the bottom of the flash tank 2-10 and returns to the hot water tank 2-11 for recycling.

[0036] The saturated steam discharged from the top of the flash tank 2-10 enters the steam compressor 2-13. The steam compressor 2-13 is a mechanical device that consumes electrical energy to increase the gas pressure. It can compress the saturated steam generated by the flash tank 2-10 into superheated steam, with the steam temperature ≥ 160 °C and the steam pressure ≥ 0.6 MPa. The form of the steam compressor 2-13 is selected from centrifugal, roots, and screw types. Preferably, when the temperature difference between the inlet and outlet steam exceeds 50 °C, a screw-type saturated steam compressor is used.

[0037] The superheated steam discharged from the steam compressor 2-13 enters the evaporation crystallization drying system 1-9 and is used for the evaporation crystallization process of the caustic soda solution, thereby realizing the recovery and utilization of high-grade heat.

[0038] The superheated steam releases heat and condenses into liquid water in the evaporation crystallization drying system and is discharged into the condensate tank 2-14. The water temperature is maintained at ≥ 80 °C. The condensate tank 2-14 supplies hot water to the brine dissolving tank 1-2 through the brine dissolving water pump 2-15 for preparing brine; since the temperature of the refined brine needs to be maintained at 60 - 65 °C, the water temperature is adjusted by mixing low-temperature water into the condensate tank 2-14. The low-temperature water is provided by the process water storage tank 2-16, and the flow rate is controlled by the water valve 2-17, thereby realizing the recovery and utilization of low-grade heat.

[0039] Example 3

[0040] A green acid-base chemical production system includes a brine purification system 1-3, an ion-exchange membrane electrolyzer 1-6, a liquid caustic soda storage tank 1-7, an evaporation crystallization drying system 1-9, and a finished product warehouse 1-10 connected in sequence, and also includes a multi-energy complementary power supply module. Among them, the gas outlet of the ion-exchange membrane electrolyzer 1-6 is connected to a hydrogen chloride synthesis furnace 2-3, the gas outlet of the hydrogen chloride synthesis furnace 2-3 is connected to a hydrochloric acid absorption tower 2-5. A jacketed heat exchanger is arranged inside the hydrogen chloride synthesis furnace 2-3. The inlet of the jacketed heat exchanger is connected to a hot water tank 2-11 (the hot water temperature range should be given in the dependent claims), and the outlet is connected to a flash tank 2-10. The gas outlet of the flash tank 2-10 is connected to the evaporation crystallization drying system 1-9 through a steam compressor 2-13. The liquid outlet of the evaporation crystallization drying system 1-9 is connected to a condensate tank 2-14, and the condensate tank 2-14 is connected to the brine purification system 1-3.

[0041] A brine dissolving tank 1-2 is connected between the water outlet of the condensate water tank 2-14 and the brine purification system 1-3. The feeding port of the brine dissolving tank 1-2 is connected to a raw salt bin 1-1 through a belt conveyor mechanism. A refined brine storage tank 1-4 is connected between the brine purification system 1-3 and the ion-exchange membrane electrolyzer 1-6. A brine pump 1-5 is installed at the liquid outlet of the refined brine storage tank 1-4. A brine dissolving and dosing pump 2-15 is installed at the water outlet of the condensate water tank 2-14. The water inlet of the condensate water tank 2-14 is connected to a process water storage tank 2-16 through a pipeline B, and a water valve 2-17 is installed in the middle of the pipeline B.

[0042] A chlorine gas buffer tank 2-1 and a hydrogen gas buffer tank 2-2 are respectively connected between the ion-exchange membrane electrolyzer 1-6 and the hydrogen chloride synthesis furnace 2-3 through pipelines. A cooler 2-4 is connected between the hydrogen chloride synthesis furnace 2-3 and the hydrochloric acid absorption tower 2-5 through a pipeline. A spray layer 2-9 is installed at the top inside the hydrochloric acid absorption tower 2-5. The water inlet of the spray layer 2-9 is connected to a circulation water tank 2-7 through a pipeline C, and a circulation water pump 2-8 is installed in the middle of the pipeline C. The hydrochloric acid absorption tower 2-5 is provided with a liquid outlet A and a liquid outlet B. The liquid outlet A is connected to the circulation water tank 2-7 through a pipeline, and the liquid outlet B is connected to a hydrochloric acid storage tank 2-6 through a pipeline. Valves are installed at both the liquid outlet A and the liquid outlet B. A hot water tank 2-11 is communicated with the hydrogen chloride synthesis furnace 2-3 through a pipeline D, and a hot water circulation pump 2-12 is installed in the middle of the pipeline D. A liquid caustic soda storage tank 1-7 is communicated with an evaporation, crystallization and drying system 1-9 through a pipeline A, and a liquid caustic soda pump 1-8 is installed in the middle of the pipeline A.

[0043] The multi-energy complementary power supply module includes a power distribution cabinet 3-7. The power distribution cabinet 3-7 is respectively connected to a wind power station 3-1, a photovoltaic power station 3-2, a power grid 3-3 and an energy storage battery 3-4. The photovoltaic power station 3-2 is connected to the power distribution cabinet 3-7 through a busbar trunking 3-5 and a photovoltaic inverter 3-6. The power grid 3-3 is connected to the power distribution cabinet 3-7 through a transformer 3-8. The energy storage battery 3-4 is respectively connected to the wind power station 3-1 and the photovoltaic power station 3-2.

[0044] The brine pump 1-5, the ion-exchange membrane electrolyzer 1-6, the liquid caustic soda pump 1-8, the evaporation, crystallization and drying system 1-9, the circulation water pump 2-8, the flash tank 2-10, the hot water circulation pump 2-12, the steam compressor 2-13 and the brine dissolving and dosing pump 2-15 are respectively electrically connected to the power distribution cabinet 3-7.

[0045] The wind power station 3-1 is a device that converts wind energy into electrical energy, and the photovoltaic power station 3-2 is a device that converts solar energy into electrical energy; the busbar trunking 3-5 converges the electrical energy generated by multiple photovoltaic modules together, and the PV inverter 3-6 converts the DC power generated by the photovoltaic modules into AC power and adjusts the voltage to meet the voltage requirements of the distribution cabinet 3-7 and the energy storage battery 3-4; the energy storage battery 3-4 is a system that can independently realize the functions of electrical energy storage, conversion and release. The wind power station 3-1 and the photovoltaic power station 3-2 can charge the energy storage battery 3-4, and the energy storage battery 3-4 can also independently supply power to each electrical facility in the system through the distribution cabinet; the energy storage battery 3-4 can be selected from lithium-ion batteries, lead-acid or lead-carbon batteries.

[0046] It is preferred to use the electrical energy obtained from the wind power station 3-1 and the photovoltaic power station 3-2 to supply power to the electrical facilities in the whole device through the distribution cabinet 3-7. The electrical facilities include the brine pump 1-5, the ion-exchange membrane electrolyzer 1-6, the caustic soda pump 1-8, the evaporation crystallization drying system 1-9, the circulating water pump 2-8, the flash tank 2-10, the hot water circulating pump 2-12, the steam compressor 2-13 and the salt dissolving and dosing pump 2-15. When the electrical load is low and the power generation of the wind power station 3-1 and the photovoltaic power station 3-2 is surplus, while supplying power to the electrical facilities, it also charges the energy storage battery 3-4.

[0047] When the power supply of the wind power station 3-1 and the photovoltaic power station 3-2 is insufficient, the energy storage battery 3-4 starts to discharge and supplies supplementary power to the electrical facilities in the whole device through the distribution cabinet 3-7.

[0048] When the power supplies of the wind power station 3-1, the photovoltaic power station 3-2 and the energy storage battery 3-4 are all insufficient, electrical energy is obtained from the power grid 3-3 and supplied to the electrical facilities in the whole device through the transformer 3-8 and the distribution cabinet 3-7, thus forming a multi-energy complementary power supply mode.

[0049] The advantage of this power supply mode is that through the form of multi-energy complementarity, on the premise of ensuring uninterrupted power supply, the electrical facilities of the whole device preferentially use the "green electricity" generated by the wind power station and the photovoltaic power station. Since the "green electricity" is generated by two renewable energy sources, namely wind energy and solar energy, its power generation process hardly produces carbon emissions and has a low impact on the environment. At the same time, an energy storage battery is set as a regulating means, which can not only ensure the power supply stability, but also minimize the externally purchased electricity. The two products, caustic soda and hydrochloric acid, obtained thereby also belong to green chemical products.

Claims

1. Green acid and alkali chemical production system, characterized by: The invention comprises a brine refining system (1-3), an ion membrane electrolyzer (1-6), a liquid alkali storage tank (1-7), an evaporation crystallization drying system (1-9) and a finished product warehouse (1-10) which are connected in sequence. The gas outlet of the ion membrane electrolyzer (1-6) is connected to a hydrogen chloride synthesis furnace (2-3), the gas outlet of the hydrogen chloride synthesis furnace (2-3) is connected to a hydrochloric acid absorption tower (2-5), a jacketed heat exchanger is arranged inside the hydrogen chloride synthesis furnace (2-3), the liquid inlet of the jacketed heat exchanger is connected to a hot water tank (2-11), the liquid outlet is connected to a flash tank (2-10), the gas outlet of the flash tank (2-10) is connected to the evaporation crystallization drying system (1-9) via a steam compressor (2-13), the liquid outlet of the evaporation crystallization drying system (1-9) is connected to a condensed water tank (2-14), and the condensed water tank (2-14) is connected to the brine refining system (1-3).

2. The green acid-base chemical production system according to claim 1, characterized in that: A salting barrel (1-2) is connected between the water outlet of the condensed water tank (2-14) and the brine refining system (1-3), and a feed port of the salting barrel (1-2) is connected to a raw salt warehouse (1-1) via a belt conveyor mechanism.

3. The green acid-base chemical production system according to claim 2, characterized in that: A refined brine storage tank (1-4) is connected between the brine refining system (1-3) and the ion membrane electrolyzer (1-6), and a brine pump (1-5) is installed at the liquid outlet of the refined brine storage tank (1-4).

4. The green acid-base chemical production system according to claim 3, characterized in that: The water outlet of the condensed water tank (2-14) is equipped with a salt water distribution pump (2-15); the water inlet of the condensed water tank (2-14) is connected to a process water storage tank (2-16) via a pipeline B; and a water valve (2-17) is installed in the middle of the pipeline B.

5. The green acid-base chemical production system according to claim 4, characterized in that: A chlorine buffer tank (2-1) and a hydrogen buffer tank (2-2) are respectively connected between the ion membrane electrolyzer (1-6) and the hydrogen chloride synthesis furnace (2-3) via pipelines.

6. The green acid-base chemical production system according to claim 5, characterized in that: A cooler (2-4) is connected between the hydrogen chloride synthesis furnace (2-3) and the hydrochloric acid absorption tower (2-5) via a pipeline; a spray layer (2-9) is installed at the top of the hydrochloric acid absorption tower (2-5); a water inlet of the spray layer (2-9) is connected to a circulating water tank (2-7) via a pipeline C; a circulating water pump (2-8) is installed in the middle of the pipeline C; the hydrochloric acid absorption tower (2-5) is provided with a liquid outlet A and a liquid outlet B; the liquid outlet A is connected to the circulating water tank (2-7) via a pipeline; the liquid outlet B is connected to the hydrochloric acid storage tank (2-6) via a pipeline; and valves are installed on the liquid outlet A and the liquid outlet B.

7. The green acid-base chemical production system according to claim 6, characterized in that: The hot water tank (2-11) is connected to the hydrogen chloride synthesis furnace (2-3) via a pipeline D, and a hot water circulation pump (2-12) is installed in the middle of the pipeline D.

8. The green acid-base chemical production system according to claim 7, characterized in that: The liquid caustic soda storage tank (1-7) is connected to the evaporation crystallization drying system (1-9) via a pipeline A, and a liquid caustic soda pump (1-8) is installed in the middle of the pipeline A.

9. The green acid-base chemical production system according to claim 8, characterized in that: The multi-energy complementary power supply module includes a distribution cabinet (3-7), the distribution cabinet (3-7) is respectively connected to a wind power station (3-1), a photovoltaic power station (3-2), a power grid (3-3) and an energy storage battery (3-4), the photovoltaic power station (3-2) is connected to the distribution cabinet (3-7) via a junction box (3-5) and a photovoltaic inverter (3-6), the power grid (3-3) is connected to the distribution cabinet (3-7) via a transformer (3-8), and the energy storage battery (3-4) is respectively connected to the wind power station (3-1) and the photovoltaic power station (3-2).

10. The green acid-base chemical production system according to claim 9, characterized in that: The brine pump (1-5), ion membrane electrolyzer (1-6), liquid alkali pump (1-8), evaporation crystallization drying system (1-9), circulating water pump (2-8), flash tank (2-10), hot water circulating pump (2-12), steam compressor (2-13) and chemical salt water distribution pump (2-15) are respectively electrically connected to the power distribution cabinet (3-7).

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