A chlor-alkali hydrogen production system

Abstract

The present application proposes a chlor-alkali hydrogen production system, comprising an electrolyzer, a hydrogen scrubber and a chlorine scrubber, wherein a NaCl solution is introduced into the electrolyzer, a hydrogen production port of the electrolyzer introduces hydrogen to the hydrogen scrubber through a pipeline, and a chlorine production port of the electrolyzer introduces chlorine to the chlorine scrubber through a pipeline, and further comprises a power grid system and a renewable energy power generation system, wherein the power grid system and the renewable energy power generation system are connected in parallel to a power input end of the electrolyzer, and the carbon footprint of the chlor-alkali industry can be greatly reduced by using renewable energy power generation to replace the electric energy in the traditional chlor-alkali industry. During the operation of the electrolyzer, the outlet water of the hydrogen scrubber is heated up by heat exchange with hydrogen, and then mixed with a small amount of alkali solution and enters the electrolyzer, so that the waste heat generated in the chlor-alkali process can be fully utilized, and the heat consumed by the electrolyzer water replenishment and temperature increase can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of electrolytic hydrogen production, and in particular to a chlor-alkali hydrogen production system. Background Art

[0002] The chlor-alkali industry is one of the most basic chemical industries, and it has important applications in food processing, building materials, electricity, military industry and national defense. Chlor-alkali, or the chlor-alkali industry, also refers to the method of using saturated salt water to produce chlorine, hydrogen and caustic soda. The industry uses the method of electrolyzing saturated NaCl solution to produce NaOH, Cl2 and H2, and uses them as raw materials to produce a series of chemical products, which is called the chlor-alkali industry. The existing chlor-alkali industry has high energy consumption in the actual development process and faces huge challenges in energy. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the purpose of this application is to propose a chlor-alkali hydrogen production system. By using renewable energy to generate electricity instead of electricity in the traditional chlor-alkali industry, the carbon footprint of the chlor-alkali industry can be greatly reduced, which is in line with the overall goal of my country's current energy structure transformation. During the operation of the electrolyzer, the outlet water of the hydrogen scrubber is heated up by heat exchange with hydrogen, and then mixed with a small amount of alkaline solution and enters the electrolyzer. The waste heat generated in the chlor-alkali process can be fully utilized, and the heat consumed by the electrolyzer water replenishment and temperature increase can be effectively reduced. In the salting process of the chlor-alkali industry, in order to accelerate the dissolution rate of crude salt, the salting water needs to be heated, and the chlorine scrubbing liquid is used as the salting water. The waste heat is used to replace the steam required for heating the salting water, thereby reducing the energy consumption of the system and promoting the green and sustainable development of the chlor-alkali industry.

[0005] To achieve the above-mentioned purpose, the chlor-alkali hydrogen production system proposed in the present application includes an electrolytic cell, a hydrogen scrubber and a chlorine scrubber, wherein a NaCl solution is introduced into the electrolytic cell, a hydrogen production port of the electrolytic cell introduces hydrogen to the hydrogen scrubber through a pipeline, and a chlorine production port of the electrolytic cell introduces chlorine to the chlorine scrubber through a pipeline, and further includes a power grid system and a renewable energy power generation system, wherein the power grid system and the renewable energy power generation system are connected in parallel to the power input end of the electrolytic cell, and further includes a salt-forming mechanism, wherein the liquid outlet of the chlorine scrubber is connected to the salt-forming mechanism through a pipeline, the chlorine scrubber introduces chlorine scrubbing liquid to the salt-forming mechanism for dissolving salt, and the salt-forming mechanism is used to supply brine to the electrolytic cell.

[0006] Furthermore, the hydrogen scrubbing tower is also connected to the liquid inlet of the electrolyzer through a pipeline, and the hydrogen scrubbing tower introduces hydrogen scrubbing liquid into the electrolyzer.

[0007] Furthermore, it also includes an alkali liquid heat exchanger, the external water pipe of the alkali liquid heat exchanger is used to introduce cooling water, the liquid outlet of the electrolytic cell is connected to the alkali liquid heat exchanger through a pipeline, the electrolytic cell is used to introduce alkali liquid into the alkali liquid heat exchanger, and the alkali liquid and the cooling water exchange heat.

[0008] Furthermore, the salt-forming mechanism includes a salt-forming barrel and a brine refining device which are interconnected. The liquid outlet of the chlorine scrubbing tower is connected to the salt-forming barrel through a pipeline, and the liquid outlet of the brine refining device is connected to the electrolytic cell through a pipeline. The salt-forming barrel passes crude brine into the brine refining device, and the brine refining is used to refine the crude brine so as to pass filtered brine into the electrolytic cell.

[0009] Furthermore, the brine refining equipment includes a siphon filter for primary brine refining and a carbon tube filter for secondary brine refining.

[0010] Furthermore, the alkali liquid heat exchanger is connected to the liquid inlet of the salt-removing barrel through a pipeline so as to introduce cooling water into the salt-removing barrel.

[0011] Furthermore, the waste liquid outlet of the electrolytic cell is connected to the salt-removing barrel through a pipeline so as to allow the salt water to flow into the salt-removing barrel.

[0012] Furthermore, the renewable energy power generation system includes at least one of a wind power generation system, a solar power generation system and a hydropower generation system.

[0013] Furthermore, the alkali liquid outlet of the alkali liquid heat exchanger and the alkali liquid outlet of the electrolytic cell are connected to a liquid storage tank through a pipeline.

[0014] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0016] Figure 1 It is a structural schematic diagram of a chlor-alkali hydrogen production system proposed in one embodiment of the present application. DETAILED DESCRIPTION

[0017] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0018] Figure 1 It is a structural schematic diagram of a chlor-alkali hydrogen production system proposed in one embodiment of the present application.

[0019] See also Figure 1 A chlor-alkali hydrogen production system comprises an electrolyzer 1, a hydrogen scrubber 2 and a chlorine scrubber 3, wherein a NaCl solution is introduced into the electrolyzer 1, a hydrogen production port of the electrolyzer 1 introduces hydrogen to the hydrogen scrubber 2 through a pipeline, and a chlorine production port of the electrolyzer 1 introduces chlorine to the chlorine scrubber 3 through a pipeline, and further comprises a power grid system 4 and a renewable energy power generation system 5, wherein the power grid system 4 and the renewable energy power generation system 5 are connected in parallel to the power input end of the electrolyzer 1, and further comprises a salt-forming mechanism, wherein the liquid outlet of the chlorine scrubber 3 is connected to the salt-forming mechanism through a pipeline, the chlorine scrubber 3 introduces chlorine scrubbing liquid to the salt-forming mechanism for dissolving salt, and the salt-forming mechanism is used to supply brine to the electrolyzer.

[0020] In this embodiment, the anode side of the electrolytic cell 1 produces chlorine, and the cathode side of the electrolytic cell 1 produces hydrogen. The power input end of the electrolytic cell 1 is connected to the power output end of the renewable energy power plant to absorb renewable energy power generation. When the renewable energy power generation is not enough to provide the power required by the electrolytic cell, it is supplemented by grid power. This not only ensures the safe production of the electrolytic cell, but also reduces the carbon output during the power consumption process.

[0021] The chlorine produced by the electrolytic cell 1 is washed by the chlorine washing tower 3 and heat-exchanged with the chlorine washing liquid. The heated chlorine washing liquid is passed into the salt-dissolving mechanism for dissolving salt, thereby improving the utilization effect of thermal energy and reducing system energy consumption. In the entire process, the chlorine washing water is reused, which greatly reduces wastewater discharge and reduces water consumption.

[0022] A chlor-alkali hydrogen production system further includes a desalted water pump 6, which is connected to the hydrogen scrubber 2 through a pipeline, and is used to pump desalted water into the hydrogen scrubber 2. It can be understood that the desalted water pump is externally connected to the desalted water pipeline to pass desalted water into the hydrogen scrubber to wash and de-alkali the hydrogen in the hydrogen scrubber, ensure sufficient supply of desalted water in the hydrogen scrubber, and fully wash the hydrogen passed into the hydrogen scrubber.

[0023] The hydrogen scrubber 2 is also connected to the liquid inlet of the electrolyzer 1 through a pipeline, and the hydrogen scrubber 2 introduces hydrogen scrubbing liquid into the electrolyzer 1. Hydrogen is introduced into the hydrogen scrubber 2 for heat exchange with the hydrogen scrubbing liquid, and the hydrogen scrubbing liquid after heat exchange and temperature increase is mixed with a small amount of alkali solution and then enters the electrolyzer 1, which can make full use of the waste heat generated in the chlor-alkali process and effectively reduce the heat consumed by the electrolyzer water replenishment and temperature increase. The generated hydrogen is sold as a product after a series of purification.

[0024] A chlor-alkali hydrogen production system also includes an alkali liquid heat exchanger 7, the external water pipe of the alkali liquid heat exchanger 7 is used to pass cooling water, the liquid outlet of the electrolytic cell 1 is connected to the alkali liquid heat exchanger 7 through a pipeline, and the electrolytic cell 1 is used to pass alkali liquid into the alkali liquid heat exchanger 7, and the alkali liquid and the cooling water exchange heat. During the electrolysis process, since the temperature of the alkali liquid in the electrolytic cell 1 continues to rise, it is necessary to pass it into the alkali liquid heat exchanger to exchange heat and cool it with the cooling water passed into the alkali liquid heat exchanger, and then return it to the electrolytic cell to achieve the recycling of the alkali liquid. Among them, the cooling water after heat exchange and temperature increase is passed into the salting barrel for salting, which can improve the dissolution efficiency of crude salt, and there is no need to heat the water for salting additionally, so as to achieve the recycling of heat energy in the system and reduce the overall energy consumption of the system.

[0025] The salting mechanism includes a salting barrel 8 and a brine refining device that are interconnected. The liquid outlet of the chlorine scrubber 3 is connected to the salting barrel 8 through a pipeline, and the liquid outlet of the brine refining device is connected to the electrolytic cell 1 through a pipeline. The salting barrel 8 passes crude brine to the brine refining device, and the brine refining is used to purify the crude brine to pass filtered brine to the electrolytic cell. Raw salt is transported from the salt warehouse to the salting barrel, and the height of the salt layer in the salting barrel is maintained above 2.5m. The alkali liquid heat exchanger is connected to the liquid inlet of the salting barrel through a pipeline to pass cooling water to the salting barrel. The waste liquid outlet of the electrolytic cell is connected to the salting barrel through a pipeline to pass dilute brine to the salting barrel. The water for salting comes from the dilute brine in the electrolytic cell, the heating and cooling water in the alkali liquid heat exchanger, and the chlorine scrubbing liquid. The water for salting and raw salt are in countercurrent contact, and impurities such as grass clippings in the raw salt are removed by the iron grid above the salting barrel. The sediment deposited at the bottom of the barrel is regularly removed from the mud outlet. To speed up the salt dissolution rate, the water used for salting should be heated to 50-60°C. In this embodiment, the temperature of the salt water introduced into the salting barrel is guaranteed to be 50-60°C by controlling the amount of hydrogen introduced, the flow rate of cooling water, and the flow rate of light brine, so as to achieve a better raw salt dissolution efficiency. In addition to the dissolution of raw salt in the salting barrel, the magnesium ions and other heavy metal ions in the raw salt also react with the NaOH in the salt water to generate insoluble hydroxides. In order to ensure the concentration of the salt water, the residence time of the salt water in the barrel should be no less than 30 minutes.

[0026] Specifically, the salt tank is a vertical rubber-lined steel cylindrical device, with a mushroom-shaped baffle cap at the bottom of the salt tank to ensure that the salt water enters the tank and is evenly distributed. There are salt water overflow troughs and iron grids on the top.

[0027] The brine refining equipment includes a siphon filter 9 for primary brine refining and a carbon tube filter 10 for secondary brine refining. The siphon filter 9 is composed of a filter body, a water inlet distribution box, a water seal tank and a siphon system. The siphon system is the main component for automatic filtration. The filter is divided into a filter material layer and a washing water storage tank by a middle partition. The siphon filter has the advantages of unmanned operation, power saving and low investment.

[0028] The carbon tube filter 10 is composed of many sintered carbon tubes. The carbon tube has good corrosion resistance and is sintered from pure carbon. The carbon content is 99.93%, and there are uniform micropores distributed on the tube wall. The pore size is 100um and the pore size ratio is 42%.

[0029] The renewable energy power generation system includes at least one of a wind power generation system, a solar power generation system and a hydropower generation system. In this embodiment, the renewable energy power generation system can be a single selection of the above power generation system, or a combination of the above power generation systems, mainly using renewable energy to reduce carbon emissions, which is not limited in this application. Preferably, in this embodiment, a wind power generation system is selected, and the electric energy produced by the wind power plant is used to electrolyze a saturated NaCl solution, which can fully absorb the wind energy.

[0030] The alkali liquid outlet of the alkali liquid heat exchanger 7 and the alkali liquid outlet of the electrolytic cell 1 are connected to the liquid storage tank through a pipeline. The alkali liquid stored in the liquid storage tank is used and sold as a finished alkali after a subsequent concentration and purification process.

[0031] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" is two or more.

[0032] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0033] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0034] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A chlor-alkali hydrogen production system, characterized in that: The invention comprises an electrolytic cell, a hydrogen scrubber and a chlorine scrubber, wherein a NaCl solution is introduced into the electrolytic cell, a hydrogen production port of the electrolytic cell introduces hydrogen into the hydrogen scrubber through a pipeline, and a chlorine production port of the electrolytic cell introduces chlorine into the chlorine scrubber through a pipeline, and further comprises a power grid system and a renewable energy power generation system, wherein the power grid system and the renewable energy power generation system are connected in parallel to the power input end of the electrolytic cell, and further comprises a salt-forming mechanism, wherein the salt-forming mechanism comprises a salt-forming barrel and a brine refining device which are interconnected, wherein the liquid outlet of the chlorine scrubber is connected to the salt-forming mechanism through a pipeline, the chlorine scrubber introduces chlorine scrubbing liquid into the salt-forming mechanism to dissolve salt, and the salt-forming mechanism is used to supply brine to the electrolytic cell; The hydrogen scrubbing tower is also connected to the liquid inlet of the electrolytic cell through a pipeline, and the hydrogen scrubbing tower introduces hydrogen scrubbing liquid into the electrolytic cell, and the hydrogen scrubbing liquid after heat exchange and temperature increase is mixed with a small amount of alkali solution and then enters the electrolytic cell; It also includes an alkali liquid heat exchanger, the external water pipe of the alkali liquid heat exchanger is used to pass cooling water, the liquid outlet of the electrolytic cell is connected to the alkali liquid heat exchanger through a pipeline, the electrolytic cell is used to pass alkali liquid into the alkali liquid heat exchanger, and the alkali liquid and the cooling water perform heat exchange; The alkali liquid heat exchanger is connected to the liquid inlet of the salt-removing barrel through a pipeline so as to introduce cooling water into the salt-removing barrel.

2. The chlor-alkali hydrogen production system according to claim 1, characterized in that: It also includes a desalted water pump, which is connected to the hydrogen scrubbing tower through a pipeline and is used to pump desalted water into the hydrogen scrubbing tower.

3. The chlor-alkali hydrogen production system according to claim 1, characterized in that: The liquid outlet of the chlorine scrubbing tower is connected to the salt tank through a pipeline, and the liquid outlet of the brine refining equipment is connected to the electrolytic cell through a pipeline. The salt tank passes crude brine to the brine refining equipment, and the brine refining is used to purify the crude brine so as to pass filtered brine into the electrolytic cell.

4. The chlor-alkali hydrogen production system according to claim 3, characterized in that: The brine refining equipment comprises a siphon filter for primary brine refining and a carbon tube filter for secondary brine refining.

5. The chlor-alkali hydrogen production system according to claim 3, characterized in that: The waste liquid outlet of the electrolytic cell is connected to the salt-removing barrel through a pipeline so as to allow the salt water to flow into the salt-removing barrel.

6. The chlor-alkali hydrogen production system according to claim 1, characterized in that: The renewable energy power generation system includes at least one of a wind power generation system, a solar power generation system and a hydropower generation system.

7. The chlor-alkali hydrogen production system according to claim 1, characterized in that: The alkali liquid outlet of the alkali liquid heat exchanger and the alkali liquid outlet of the electrolytic cell are connected to the liquid storage tank through a pipeline.

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