System and process for producing hydrogen by recycling waste aluminum alloy

Abstract

The invention discloses a system and process for producing hydrogen by recycling waste aluminum alloy, and relates to the technical field of aluminum alloy recycling, the system comprises a crusher, a reaction tank, a solid-liquid separator, a steam-water separator, a membrane type hydrogen separator and an electrolyzer, the bottom of the reaction tank is connected with the solid-liquid separator, and the top of the reaction tank is connected with the steam-water separator; the solid-liquid separator is connected with the reverse osmosis separator, the reverse osmosis separator is connected with the adjusting tank, and the adjusting tank is connected to the reaction tank; the steam-water separator is connected with a membrane type hydrogen separator, and the membrane type hydrogen separator is connected to a hydrogen storage cabinet; the bottom of the solid-liquid separator is connected with the sludge temporary storage pool, the sludge temporary storage pool is connected with the baking chamber, the baking chamber is further connected with the electrolysis device, and the electrolysis device is connected with the crusher. The technological process is reasonable in design, flexible and ingenious, recycling of the waste aluminum alloy recycled material is guaranteed, recycling of the catalyst and carbon dioxide is achieved, and industrial production is easy to achieve.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy recycling, and in particular to a system and process for recycling waste aluminum alloy to produce hydrogen. Background Art

[0002] In modern society, aluminum is a very important nonferrous metal. Due to its good properties, the consumption and demand of aluminum-containing products have increased significantly in recent decades. However, aluminum resources are limited. Therefore, in addition to increasing the mining of raw aluminum, countries have mainly increased the breadth and depth of the use of scrap aluminum. In recent years, the desirability of treating waste generated in the process of aluminum recycling and how to do so have caused a lot of debate in the scientific and industrial communities. Since there is no mature recycling and reuse process at present, many scrap aluminum materials are treated as industrial waste and landfilled. According to statistics, the UK consumes 80 million euros to treat aluminum waste every year, and in Japan, 350,000 tons of slag are produced every year, and it costs 200-300 US dollars to landfill each ton of slag. This is not only a waste of resources, but also harmful to the environment. Studies have shown that the energy required for recycled aluminum and secondary aluminum is only 5% to 20% of the energy required for producing aluminum and recycled aluminum. Therefore, the economy and benefits of aluminum recycling are obvious.

[0003] At present, many scholars focus on the recycling of large aluminum wastes, and have proposed many methods such as fluidized bed method, pulse atomization recovery method, electrolytic refining method, etc., and have achieved remarkable results. Uan et al. proposed a new method to produce hydrogen in NaCl aqueous solution, and the H2 generation rate can reach 432.4ml min -1 . In the process of aluminum production, processing and grinding, a large amount of waste aluminum alloy dust will be generated. The particle size of these dusts is basically between a few microns and tens of microns. When exposed to air or entering water, they will quickly oxidize and hydrolyze to form aluminum hydroxide, which will reduce the performance of aluminum and severely limit the reuse of aluminum alloys. Therefore, this type of aluminum waste is basically treated as industrial waste. At present, no scholars have conducted research on the recycling of such aluminum waste. From an environmental perspective, aluminum hydroxide will destroy the acid-base balance of the soil and inhibit the growth of crops. The Basel Convention on the Control of Transboundary Movements of Hazardous Substances and Their Disposal, which was formulated under the auspices of the United Nations Environment Program (UNEP), also requires strict management measures for hazardous wastes, and the secondary recycling of raw materials is a priority for waste treatment. Therefore, if the activity of waste aluminum alloy dust can be inertized, the generation of oxides and hydroxides can be avoided, and the purity of metal dust can be guaranteed, it will provide the possibility for subsequent recycling and reuse. Summary of the invention

[0004] In order to solve the above technical problems, the present invention discloses a system and process for producing hydrogen by recycling waste aluminum alloy. The process is reasonably and ingeniously designed, which can ensure the recycling of waste aluminum alloy recovered materials while realizing the recycling of catalysts, and has broad prospects for industrial application.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] A system for recycling and reusing waste aluminum alloy to produce hydrogen comprises a crusher, a reaction tank, a solid-liquid separator, a steam-water separator, a membrane hydrogen separator and an electrolysis device, wherein the crusher is connected to the reaction tank, the bottom of the reaction tank is connected to the solid-liquid separator, and the top of the reaction tank is connected to the steam-water separator; the solid-liquid separator is connected to a reverse osmosis separator, the reverse osmosis separator is connected to a regulating tank, and the regulating tank is connected to the reaction tank; the steam-water separator is connected to a membrane hydrogen separator, and the membrane hydrogen separator is connected to a hydrogen gas storage cabinet; the bottom of the solid-liquid separator is connected to a sludge temporary storage tank, the sludge temporary storage tank is connected to a baking chamber, the baking chamber is also connected to the electrolysis device, and the electrolysis device is connected to the crusher.

[0007] Furthermore, the waste aluminum alloy raw material is crushed by a crusher to become aluminum alloy powder with a particle size of 100 μm.

[0008] Furthermore, cerium trichloride and sodium chloride are added into the reaction tank as reaction catalysts.

[0009] Furthermore, the baking chamber is subjected to vacuum dehydration, and the temperature is controlled at 1200° C. for 3 hours.

[0010] Furthermore, a stirrer is installed in the reaction tank, and the rotation speed of the stirrer is set to 100 revolutions per minute.

[0011] Furthermore, the solid-liquid separator is also connected to a water tank.

[0012] The present invention also discloses a process for recycling waste aluminum alloy to produce hydrogen, which adopts the above system and includes a crushing process, a reaction process, a hydrogen storage process, a catalyst extraction process, a sludge temporary storage process, a baking process and an electrolysis process; specifically,

[0013] Crushing process: The waste aluminum alloy raw materials are crushed in the crusher. Carbon dioxide gas is filled into the crusher as a protective gas during crushing. The crushed aluminum alloy powder enters the reaction tank;

[0014] Reaction process: first add a certain amount of cerium trichloride and sodium chloride to the reaction tank, then add an appropriate amount of water, turn on the stirrer, and heat the reaction tank to 60°C to keep the temperature stable;

[0015] Hydrogen storage process: The hydrogen generated during the reaction forms a mixed gas with the air in the reaction tank, which enters the steam-water separator from the top of the reaction tank to separate the water vapor therein. The dehydrated mixed gas passes through a membrane hydrogen separator to separate the hydrogen and is sent to a hydrogen storage cabinet for storage;

[0016] Catalyst extraction process: the mixture after the reaction in the reaction tank enters the solid-liquid separator, and the mixture is continuously filtered and washed with water from the water tank, and filtered multiple times to form filtrate and reaction sludge in the solid-liquid separator; the filtrate reverse osmosis separator separates the sodium chloride and cerium trichloride therein, and after the proportion is adjusted, the sodium chloride, cerium trichloride and water are added to the adjustment tank; before the next reaction, the catalyst solution with the adjusted proportion is sent to the reaction tank to realize the recycling of the catalyst;

[0017] Reaction sludge temporary storage process: the reaction sludge formed after the solid-liquid separator is filtered is stored in the sludge temporary storage tank;

[0018] Calcination process: The reaction sludge is sent into the calcination chamber, heated to 1200°C, and calcined for 2 hours to dehydrate the hydroxides in the reaction sludge to form oxides;

[0019] Electrolysis process: The calcined sludge is sent to the electrolysis device, and hydrochloric acid solution and activated carbon powder are added to the electrolytic cell. After electrolysis, metal aluminum alloy and carbon dioxide gas are obtained. The carbon dioxide is sent to the crushing process to achieve the recycling of carbon dioxide, and the obtained metal aluminum alloy is sent to the crusher as raw material to achieve the recycling of aluminum alloy materials.

[0020] Furthermore, the mass ratio of the aluminum alloy powder, cerium trichloride, sodium chloride and water in the reaction tank is 1:1:1:10.

[0021] Furthermore, in the catalyst extraction process, the mass ratio of reaction sludge to water is 1:2.

[0022] Furthermore, the mass ratio of sodium chloride, cerium trichloride and water in the regulating tank is 1:1:10.

[0023] The beneficial effects of the present invention are that, compared with the prior art, it has the following advantages:

[0024] (1) In the reaction tank, the mixed gas and the mixture generated after the aluminum alloy powder reacts with the catalyst can be separated and extracted respectively; the mixed gas is dehydrated in the steam-water separator to separate the water vapor, and then enters the membrane hydrogen separator to separate the hydrogen and store it in the hydrogen storage cabinet; and the mixture generated by the reaction enters the solid-liquid separator downward for solid-liquid separation, and the catalysts sodium chloride and cerium trichloride are obtained through osmotic separation, which are sent to the regulating tank to adjust the catalyst ratio, and then enter the reaction tank for circulation, thereby realizing the recycling of the catalyst.

[0025] (2) After being calcined, the reaction sludge enters the electrolytic cell, where hydrochloric acid solution and activated carbon powder are added for electrolytic treatment to obtain metal aluminum alloy and carbon dioxide gas. The carbon dioxide is sent to the crushing process to achieve the recycling of carbon dioxide. The obtained metal aluminum alloy is sent to the crusher as raw material to achieve the recycling of aluminum alloy materials.

[0026] In summary, the process flow is reasonably designed, flexible and ingenious. In addition to ensuring the recycling of waste aluminum alloy recycled materials, it can also realize the recycling of catalysts and carbon dioxide. Each process is extremely easy to realize industrial production and has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the present invention.

[0028] In the figure, 1-electrolysis device; 2-baking chamber; 3-sludge temporary storage tank; 4-water tank; 5-solid-liquid separator; 6-reverse osmosis separator; 7-adjusting tank; 8-crusher; 9-reaction tank; 10-agitator; 11-steam-water separator; 12-membrane hydrogen separator; 13-hydrogen gas storage cabinet. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The invention discloses a system for producing hydrogen by recycling waste aluminum alloy, comprising a crusher 8, a reaction tank 9, a solid-liquid separator 5, a steam-water separator 11, a membrane hydrogen separator 12 and an electrolysis device 1, wherein the crusher 8 is connected to the reaction tank 9, the bottom of the reaction tank 9 is connected to the solid-liquid separator 5, and the top of the reaction tank 9 is connected to the steam-water separator 11; the solid-liquid separator 5 is connected to a reverse osmosis separator 6, the reverse osmosis separator 6 is connected to a regulating tank 7, and the regulating tank 7 is connected to the reaction tank 9; the steam-water separator 11 is connected to a membrane hydrogen separator 12, and the membrane hydrogen separator 12 is connected to a hydrogen gas storage cabinet 13; the bottom of the solid-liquid separator 5 is connected to a sludge temporary storage tank 3, the sludge temporary storage tank 3 is connected to a baking chamber 2, the baking chamber 2 is also connected to the electrolysis device 1, and the electrolysis device 1 is connected to the crusher 8.

[0031] The specific process of this system is:

[0032] The waste aluminum alloy is put into the crusher 8 for crushing; the crushed waste aluminum alloy is placed in the reaction tank 9, and a catalyst (cerium trichloride and sodium chloride) is added for reaction, and gas (hydrogen) and precipitate (cerium hydroxide, aluminum hydroxide, magnesium hydroxide) and aqueous solution (sodium chloride aqueous solution, cerium trichloride aqueous solution) are generated after the reaction; the mixed gas in the reaction tank 9 is extracted, and the water vapor is removed by the steam-water separator 11, and then the hydrogen is separated by the membrane hydrogen separator 12, and the separated hydrogen is stored in the hydrogen gas storage cabinet 13; the liquid and sludge in the reaction tank 9 are filtered and then solid-liquid separated, and the liquid generated by the solid-liquid separation is (chlorine The separated mixed aqueous solution is then adjusted to a certain concentration by adding water and a catalyst (cerium trichloride and sodium chloride) into a regulating tank 7, and then added into a reaction tank 9; the reaction sludge after solid-liquid separation is placed in a sludge temporary storage tank 3; the reaction sludge is subjected to a vacuum dehydration reaction in a baking chamber 2 to generate a dry mixture (aluminum oxide, magnesium oxide, cerium oxide), and then the dry mixture is added with carbon powder and electrolyzed through an electrolysis device 1 to generate aluminum alloy and carbon dioxide, which can be fed into a crusher 8 for crushing and then recycled; the carbon dioxide can be recycled as an inert protector inside the crusher 8.

[0033] A process for recycling waste aluminum alloy to produce hydrogen, comprising a crushing process, a reaction process, a hydrogen storage process, a catalyst extraction process, a sludge temporary storage process, a baking process and an electrolysis process; specifically,

[0034] Crushing process: The waste aluminum alloy raw materials are crushed in the crusher 8. During the crushing process, carbon dioxide gas is filled into the crusher 8 as a protective gas. The crushed aluminum alloy powder is about 100 μm and enters the reaction tank 9.

[0035] Reaction: first add a certain amount of cerium trichloride and sodium chloride into the reaction tank 9, and then add an appropriate amount of water, the mass ratio of aluminum alloy powder: cerium trichloride: sodium chloride: water = 1:1:1:10, turn on the stirrer 10, set the speed of the stirrer 10 to 100 rpm, and heat the reaction tank 9 to 60°C to keep the temperature stable.

[0036] Hydrogen storage: The hydrogen generated during the reaction forms a mixed gas with the air in the reaction tank 9, which enters the steam-water separator 11 from the top of the reaction tank 9 to separate the water vapor therein. The dehydrated mixed gas passes through the membrane hydrogen separator 12 to separate the hydrogen and is sent to the hydrogen storage cabinet 13 for storage.

[0037] Catalyst extraction: The mixture after the reaction in the reaction tank 9 enters the solid-liquid separator 5, and the mixture is continuously filtered and washed with water from the water tank 4, the sludge mass: water mass = 1:2, and the filtration is performed 5 times to form the filtrate and reaction sludge in the solid-liquid separator 5.

[0038] The filtrate is separated into sodium chloride and cerium trichloride by reverse osmosis separator 6. After the proportion is adjusted, sodium chloride, cerium trichloride and water are added to adjustment tank 7; the mass ratio of sodium chloride: cerium trichloride: water is adjusted to 1:1:10. After the proportion is adjusted, the catalyst solution with the adjusted proportion is sent to reaction tank 9 before the next reaction to realize the recycling of the catalyst.

[0039] Temporary storage of reaction sludge: The reaction sludge formed after the solid-liquid separator 5 is filtered enters the sludge temporary storage tank 3 for storage.

[0040] Calcination: The reaction sludge is sent to the calcination chamber 2, heated to 1200°C, and calcined for 2 hours to dehydrate the hydroxides in the reaction sludge to form oxides.

[0041] Electrolysis: The calcined sludge is fed into the electrolysis device 1, and hydrochloric acid solution and activated carbon powder are added into the electrolytic cell. After electrolysis, metal aluminum alloy and carbon dioxide gas are obtained. The carbon dioxide is fed into the crushing process to achieve the recycling of carbon dioxide, and the obtained metal aluminum alloy is fed into the crusher 8 as a raw material to achieve the recycling of aluminum alloy materials.

[0042] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A system for recycling waste aluminum alloy to produce hydrogen, characterized in that: It includes a crusher, a reaction tank, a solid-liquid separator, a steam-water separator, a membrane hydrogen separator and an electrolysis device. The crusher is connected to the reaction tank, the bottom of the reaction tank is connected to the solid-liquid separator, and the top of the reaction tank is connected to the steam-water separator; the solid-liquid separator is connected to the reverse osmosis separator, the reverse osmosis separator is connected to the regulating tank, and the regulating tank is connected to the reaction tank; the steam-water separator is connected to the membrane hydrogen separator, and the membrane hydrogen separator is connected to the hydrogen gas storage cabinet; the bottom of the solid-liquid separator is connected to the sludge temporary storage tank, the sludge temporary storage tank is connected to the baking chamber, the baking chamber is also connected to the electrolysis device, and the electrolysis device is connected to the crusher.

2. The system for recycling waste aluminum alloy to produce hydrogen as claimed in claim 1, characterized in that: The waste aluminum alloy raw materials are crushed by a crusher to become aluminum alloy powder with a particle size of 100μm.

3. The system for recycling waste aluminum alloy to produce hydrogen as claimed in claim 2, characterized in that: Cerium trichloride and sodium chloride are added into the reaction tank as reaction catalysts.

4. The system for recycling waste aluminum alloy to produce hydrogen as claimed in claim 3, characterized in that: The baking chamber is vacuum dehydrated, the temperature is controlled at 1200° C., and the time is 3 hours.

5. The system for recycling waste aluminum alloy to produce hydrogen as claimed in claim 4, characterized in that: The reaction tank is equipped with a stirrer, and the rotation speed of the stirrer is set to 100 rpm.

6. The system for recycling waste aluminum alloy to produce hydrogen as claimed in claim 5, characterized in that: The solid-liquid separator is also connected to a water tank.

7. A process for recycling waste aluminum alloy to produce hydrogen, using the system of claim 6, characterized in that: It includes crushing process, reaction process, hydrogen storage process, catalyst extraction process, sludge temporary storage process, baking process and electrolysis process; specifically, Crushing process: The waste aluminum alloy raw materials are crushed in the crusher. Carbon dioxide gas is filled into the crusher as a protective gas during crushing. The crushed aluminum alloy powder enters the reaction tank; Reaction process: first add a certain amount of cerium trichloride and sodium chloride into the reaction tank, then add an appropriate amount of water, turn on the stirrer, and heat the reaction tank to 60°C to keep the temperature stable; Hydrogen storage process: The hydrogen generated during the reaction forms a mixed gas with the air in the reaction tank, which enters the steam-water separator from the top of the reaction tank to separate the water vapor therein. The dehydrated mixed gas passes through a membrane hydrogen separator to separate the hydrogen and is sent to a hydrogen storage cabinet for storage; Catalyst extraction process: the mixture after the reaction in the reaction tank enters the solid-liquid separator, and the mixture is continuously filtered and washed with water from the water tank, and filtered multiple times to form a filtrate and a reaction sludge in the solid-liquid separator; the filtrate and the washing liquid are separated into sodium chloride and cerium trichloride by a reverse osmosis separator, and after the proportion is adjusted, sodium chloride, cerium trichloride and water are added to the regulating tank; the catalyst solution with the adjusted proportion is sent to the reaction tank before the next reaction to realize the recycling of the catalyst; Reaction sludge temporary storage process: the reaction sludge formed after the solid-liquid separator is filtered is stored in the sludge temporary storage tank; Calcination process: The reaction sludge is sent into the calcination chamber, heated to 1200°C, and calcined for 2 hours to dehydrate the hydroxides in the reaction sludge to form oxides; Electrolysis process: The calcined sludge is sent to the electrolysis device, and hydrochloric acid solution and activated carbon powder are added to the electrolytic cell. After electrolysis, metal aluminum alloy and carbon dioxide gas are obtained. The carbon dioxide is sent to the crushing process to achieve the recycling of carbon dioxide, and the obtained metal aluminum alloy is sent to the crusher as raw material to achieve the recycling of aluminum alloy materials.

8. The process for recycling waste aluminum alloy to produce hydrogen as claimed in claim 7, characterized in that: The mass ratio of the aluminum alloy powder, cerium trichloride, sodium chloride and water in the reaction tank is 1:1:1:

10.

9. The process for recycling waste aluminum alloy to produce hydrogen as claimed in claim 8, characterized in that: In the catalyst extraction process, the mass ratio of reaction sludge to water is 1:

2.

10. The process for recycling waste aluminum alloy to produce hydrogen as claimed in claim 9, characterized in that: The mass ratio of sodium chloride, cerium trichloride and water in the regulating tank is 1:1:10.

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