What are the reasons for corrosion and leakage in the alkali solution filter, alkali solution cooler, and oxygen separator of hydrogen production equipment via water electrolysis?
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What are the reasons for corrosion and leakage in the alkali solution filter, alkali solution cooler, and oxygen separator of hydrogen production equipment via water electrolysis? Hydrogen production by water electrolysis at 90 degrees Celsius with 30% KOH: The corrosivity is quite high, but it isn’t strong enough to cause rapid corrosion of 316L pipes and containers. In hydrogen production equipment using water electrolysis, corrosion occurs most frequently in the oxygen-side pipelines and at the welds of containers. The reasons for this are the high corrosivity of 30% KOH and the temperature of 90 degrees Celsius ； But this is not the main reason; the primary cause is electrochemical corrosion. The electrode potential of stainless steel is always lower than that of oxygen, so stainless steel acts as the negative electrode and is corroded. Meanwhile, 30% potassium hydroxide has high electrical conductivity, which creates a galvanic cell circuit. For the locations where corrosion has occurred, determine the causes and develop solutions: 1. Check whether the pipe material is 316l; if not, replace it. 2. Examine whether the welding wire used at the joints between pipes and between pipes and the separator flanges is of the same type; if not, changes in the stress levels of the pipes occur during welding. 3. As for why the corrosion is so severe, KOH is a strong alkali, and it is generally the oxygen-side that suffers from corrosion the most. This is because the O ions present in the alkaline solution on that side have strong oxidizing properties, and the process by which these ions combine to form oxygen leads to electrochemical corrosion. Therefore, corrosion on the oxygen side tends to be severe. Alkaline solution-based equipment should not operate in a state of alternating temperatures (being turned on and off periodically); even when the equipment is stopped, the alkaline solution circulation pump should continue to run to prevent the equipment from staying in a cold state. 4. Install a negative potential electrode on the oxygen-side containers that are prone to corrosion (with a negative potential with respect to ground). The voltage of the voltage stabilizing supply should be lower than the water decomposition voltage of 1.23 V, and the current should be less than 6 A depending on the load; at the same time, a sufficient current density of 1.5 mA/cm2 must be maintained in order to counteract the galvanic cell potential formed between oxygen and stainless steel, thereby preventing electrochemical corrosion. Our company, Tianjin Xinqi New Energy Technology Co., Ltd., specializes in providing services related to hydrogen production through water electrolysis, including the installation and renovation of hydrogen production equipment, the supply of analytical instruments, as well as spare parts services.
At the same time, all outlet flanges of the electrolyzer should be short-circuited with grounding copper wires and connected to the ground, in order to reduce the charged particles present in the alkaline solution and thereby minimize electrochemical corrosion.
1. Beijing Zhongdian Fengye Technology Development Co., Ltd. (www.bjzdfy.com.cn) was established in 2007 and has been focusing on the field of water electrolysis for hydrogen production and hydrogen storage ever since; it is a **high-tech enterprise. After a decade of development, it has become a hydrogen energy technology company with core technologies and extensive domestic and international resource networks, boasting assets worth over 100 million. The company’s headquarters is located in the Beijing Headquarters Base. It has a R&D center of 2,000 square meters in Yanjiao, and a production facility of 10,000 square meters in Weifang, Shandong. It currently has over 50 professional and technical staff, as well as a wholly-owned subsidiary, Shandong HaiHydro Energy Technology Co., Ltd., and a branch in Hebei named Zhongdian Fengye. 2. Beijing Zhongdian Fengye Technology Development Co., Ltd. holds over 20 core intellectual property rights in the field of water electrolysis; it possesses advanced alkaline water electrolysis hydrogen production technology, with the largest single electrolyzer having a capacity of 1,200 cubic meters per hour (6MW) ； There are also mature PEM pure water hydrogen production systems, with the largest single electrolyzer having a capacity of 200 cubic meters per hour (1 MW) ； It is also committed to the research and development of AEM ion-exchange membrane hydrogen production technology. Its product patents cover the entire range of components in the water electrolysis hydrogen production process, including the electrolyzers as well as the auxiliary systems (BOP). The company possesses mature technical expertise in various application areas, including the reuse of hydrogen produced from renewable energy for storage, fixed/pivot-mounted hydrogen refueling stations, the production of hydrogen from by-product gases and waste streams, hydrogen refueling for backup/emergency fuel cell vehicles, peak shaving and frequency regulation in thermal power plants, as well as microgrids powered by deep green hydrogen. It offers comprehensive solutions across the entire hydrogen value chain, ranging from hydrogen production and storage to the use of renewable energy to produce hydrogen for storage, as well as hydrogen refueling stations for fuel cell vehicles. To date, the company has successfully participated in the design, production, installation, commissioning, and technical services for over 200 hydrogen production and refueling stations. It was the main equipment supplier for China’s first 500-kilogram on-site hydrogen production and refueling integrated station (Datong) as well as the first megawatt-class PEM hydrogen production, energy storage, and combined heat and power project (Anhui). 3. Beijing Zhongdian Fengye Technology Development Co., Ltd. has established extensive cooperation with domestic and international academic institutions as well as well-known industry peers. It maintains close cooperative relationships with the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Beijing University of Chemical Technology, Tongji University, Wuhan University of Technology, Drytech Energy Systems in the United States, Areva Hydrogen in France, and Ginor in the United States, all working together to research and promote various water electrolysis hydrogen production technologies such as AKL, PEM, and AEM. 4. The company is the vice-chairman unit of the China Hydrogen Energy Industry Technology Innovation and Application Alliance, one of the founding members of the Zhongguancun Hydrogen Energy Alliance, and the entity responsible for drafting standards for solid metal hydrogen storage by the China Electricity Council. Those in need, please add WeChat 13356764627; kindly indicate the purpose of your request!
Hello, I heard that using carbon steel pipelines would be much better, but I’m too hesitant to make the change. What do you recommend?
Technical Process Engineer: Job Responsibilities: 1. Understand the working principles and mechanical structure of hydrogen production equipment, and be proficient in process drawing techniques； 2. Resolve various difficult faults that arise during the equipment manufacturing process, and be able to work closely with the production department ； 3. Develop production operation guidelines for relevant hydrogen production equipment and assist the production department in implementing them ； 4. Prepare project technical plans and draw relevant drawings based on the requirements of different projects as provided by the sales department ； 5. Carry out technical upgrades and improvements to the equipment in accordance with the requirements of the production process. Work location: Nantong, Jiangsu. Those interested please contact Ms. Zhang at 18068620716; WeChat: zy*ao*ao6009
If carbon steel pipe fittings are used, oxidation occurs on their surface, resulting in the formation of iron oxides, usually Fe3O4. This can provide some corrosion protection, but nickel plating is still the better option. However, once alkali solutions penetrate the oxide layer, corrosion occurs more easily than in stainless steel pipes. Carbon steel pipe fittings can transport 30% alkaline solutions at temperatures below 90 degrees Celsius. Tianjin Xinqi New Energy Technology Co., Ltd