pH Control and Conductivity Monitoring in Water Electrolysis

Applying controlled amounts of electricity to water to separate the oxygen and hydrogen atoms is a process known as water electrolysis. Electrolysis is conducted within an electrolytic cell. These cells typically consist of two electrodes: an anode and a cathode, which are immersed in an electrolyte solution. The cathode collects hydrogen gas, while the anode collects oxygen gas. Various industrial applications, such as fuel cells, chemical synthesis, and energy storage, can then utilize, store, or further purify these gases.

pH and conductivity measurements support water electrolysis efficiency at various stages of the process. The pH of the electrolyte influences the efficiency of the electrolysis process. For water electrolysis, a lower pH value is more effective for separating oxygen and hydrogen gas.
Before the water reaches the gas separators, researchers must also monitor the conductivity values of the high purity water itself. This is to ensure no impurities that would negatively impact the process are present.

Challenges of Water Electrolysis

In the Hydrogen production process, the primary goal of electrolysis is to harvest the separated hydrogen gas as a fuel source. To enhance safety, efficient ventilation, detectors, and explosion-proof equipment are necessary precautions due to the highly flammable nature of hydrogen gas. To prevent corrosion and enhance operator safety, it is essential to properly monitor the strong acids/bases used in the water electrolysis process.

Maintaining optimal conductivity levels while minimizing electrical resistance and energy losses can also be challenging, especially in large-scale electrolysis systems. Factors such as electrolyte concentration, temperature, and electrode spacing affect conductivity and require careful control to optimize performance. Additionally, water electrolysis systems are sensitive to contaminants present in the electrolyte solution, which can adversely affect pH and conductivity. Impurities such as metal ions, organic compounds, and particulate matter can catalyze side reactions, promote electrode fouling, and degrade electrolyte properties.

pH control can also be challenging due to the sensitivity of alkaline electrolytes to impurities. Measurements must be accurate to account for all of these factors and ensure the electrolysis process can proceed efficiently.

Solutions for Water Electrolysis

One of the most effective ways to ensure electrolysis proceeds efficiently is to ensure the accuracy of pH and conductivity measurements. Due to the potential of hazardous risk when dealing with hydrogen and oxygen gas, it is recommended that analyzers and equipment carry hazardous location classifications. The PEEK design of the SE 655X toroidal conductivity sensor maintains mechanical and chemical resistant properties even under high temperatures. The sensor is intrinsically safe, making it ideal for installations in hazardous processes. With a measuring range of 0.001 … 2,000 mS/cm, this sensor is more than suitable for the demands of water electrolysis.

The SE 555X pH sensor can withstand extreme pH ranges and aggressive media. An integrated NTC 30K temperature element ensures accurate compensation for the process media temperature in all pH measurements. The pressurized reference system, along with the Silamid reference electrode, helps extend the time between calibrations and reduce sensor replacement frequency. The sensor also carries Class 1, Division 1 approvals.

Finally, the Portavo 904X is a versatile instrument that provides portable field measurements, sensor diagnostics, data logging, and offline sensor calibration. As the only portable meter with hazardous approvals on the market, the Portavo 904x is a key tool for use inside of plant operations, as well as in the shop or lab.

Customer ROI

  • Enhance Safety: Implementing intrinsically safe and durable equipment enhances operator safety. The increased efficiency of process measurement minimizes the potential of process fouling and exposure.
  • Boost Operational Efficiency: Reliable pH and conductivity measurement systems with safe and durable sensor holders minimize downtime associated with sensor maintenance, calibration, or replacement. This enhances overall process efficiency by reducing unplanned shutdowns and maximizing production uptime.
  • Promote Corrosion Prevention: Improper levels of pH can increase the threat of corrosion to equipment on process streams. Monitoring pH and conductivity accurately allows operators to detect conditions that could accelerate corrosion within the electrolyzer or associated piping. Adept sensors can help maintain optimal pH and conductivity levels through accuracy and reliability. This minimizes corrosion rates, extending equipment lifespan, and reduces maintenance costs.

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pH Control and Conductivity Monitoring in Water Electrolysis