In continuous operation of a hydrogen generator, electrolyte concentration decay is a key issue affecting hydrogen production efficiency and purity. The core reasons are water evaporation, solute precipitation, and impurity intrusion, causing the electrolyte concentration to deviate from the optimal reaction concentration. To solve this problem, a systematic protection plan needs to be formed through coordinated optimization of electrolyte management, equipment maintenance, and operating procedures.
The selection and proportioning of the electrolyte are fundamental. Hydrogen generators typically use potassium hydroxide (KOH) solution as the electrolyte, and its concentration directly affects electrolysis efficiency. The initial proportioning must strictly follow the equipment manual requirements, generally around 10% by mass. Deionized water or double-distilled water should be used during preparation to avoid the deposition of impurities such as calcium and magnesium ions that may clog the electrolysis channels. For example, 150 grams of high-purity potassium hydroxide needs to be thoroughly dissolved in 1500 ml of deionized water to ensure complete solute dispersion. During preparation, attention should be paid to ambient humidity to prevent rapid water evaporation and concentration deviation.
Level monitoring and dynamic replenishment are core aspects of daily maintenance. The electrolyte level gauge is usually located on the front panel of the equipment and has clear graduation markings. During continuous operation, the electrolyte will gradually decrease due to evaporation and electrolysis. When the liquid level approaches the lower limit, deionized water or distilled water should be added promptly. The principle of "small amounts, multiple times" should be followed when adding water to avoid overflow and corrosion of the equipment. For example, a certain model of hydrogen generator recommends checking the liquid level every 200 hours of operation. If the liquid level drops to 10% below the mark, 50-100 ml of distilled water should be added immediately. During long-term operation, if the electrolyte becomes cloudy or precipitation occurs, it indicates a severe imbalance in solute concentration, and the electrolyte needs to be completely replaced.
Regular electrolyte replacement is a key measure to prevent concentration decay. Over long-term use, the electrolyte's performance will decline due to water evaporation, solute decomposition, and impurity accumulation. It is generally recommended to replace the electrolyte every 6-8 months, but the specific interval can be adjusted according to the equipment's operating intensity. When replacing the electrolyte, first turn off the power, drain the old electrolyte, rinse the electrolytic cell 3-5 times with distilled water, and then inject the newly prepared electrolyte. For example, after six months of continuous operation, the electrolyte pH of a hydrogen generator in a laboratory dropped from 14 to 12.5, and hydrogen production decreased by 15%. Replacing the electrolyte restored performance to its initial level.
Maintaining equipment airtightness can reduce the intrusion of external impurities. Another cause of electrolyte concentration decay is the entry of impurities such as carbon dioxide and dust from the air into the electrolyzer through equipment gaps, reacting with potassium hydroxide to form potassium carbonate precipitate. Therefore, it is necessary to regularly check the equipment seals, pipe connections, and filter condition. For example, check the ends of the drying tube monthly, testing for bubbles with soapy water. If leaks are found, replace the seals or reassemble. Replace the silica gel in the filter immediately if it changes color to prevent moisture backflow into the electrolyzer.
Operating procedures are just as important as environmental control. The hydrogen generator should be installed in a well-ventilated, temperature-stable environment, avoiding direct sunlight which can cause localized overheating and accelerate moisture evaporation. During continuous operation, ensure the equipment load is within the rated range to prevent overload operation and excessively high electrolyzer temperatures. For example, a company's hydrogen generator experienced a 30% acceleration in electrolyte concentration decay due to prolonged overload operation, causing the electrolyzer temperature to rise to 70°C. This problem was resolved by adjusting operating parameters.
Cleaning and activation of the electrolyzer are essential maintenance methods. When electrolyte concentration decay leads to a continuous decrease in hydrogen production, cleaning and activation of the electrolyzer can be attempted. After power failure, empty the electrolyzer, soak it in a 10% citric acid solution for 30 minutes to remove scale and metal ion deposits from the electrode surfaces, and then rinse with deionized water until neutral. This method can restore the electrolyzer's activity and extend the electrolyte's lifespan.
Through strict electrolyte management, regular maintenance, optimized sealing, and standardized operation, hydrogen generators can effectively prevent concentration decay during continuous operation. This not only improves the equipment's hydrogen production efficiency and purity but also extends the lifespan of the electrolyzer and the overall equipment, providing crucial assurance for the stability of hydrogen energy applications.
