Given the critical role that measurement plays in process safety, Endress+Hauser joined the Center for Hydrogen Safety (CHS) to offer its expertise, advance hydrogen safety advocacy and ensure that safety information, guidance and expertise are available to all stakeholders. “Technologies and guidelines are currently under development regarding the measurement equipment that can be used, the characteristics they should have and where they should be installed so that the measured values represent the reality of the green hydrogen production process,” commented Tomás Godoy, Solutions Application Expert and measurement challenge specialist at Endress+Hauser. CHS was established in 2019 as a technical community with the American Institute of Chemical Engineers (AIChE). In addition to safety information and guidance, CHS members benefit from access to training, global forums and more. “We are pleased to welcome Endress+Hauser as a member. Their products can influence a wide range of hydrogen applications. We look forward to their contributions to our community that is committed to supporting the safe and timely transition to hydrogen and transportation technologies,” said Nick Barilo, CHS Executive Director. Measurement Challenges In the green hydrogen production process there are 6 applications that from a measurement standpoint are critical: electrolyzer, water quality, potassium hydroxide concentration, gas purity, ammonia catalytic reaction, blending with natural gas, and liquid transportation. “The electrolyzer is equipment that allows splitting the water molecule into oxygen and hydrogen by using electrical energy. A major risk is the contamination of hydrogen by oxygen or water. Proper control of the temperature and pressure of the electrolyzer plays a key role here,” he says. In the case of water, the measurement is also complex because this equipment requires filtered, treated and purified water, and if the electrolyzer is PEM, the conductivity of the water must be very low. “This is a challenge because this water, to maintain this condition, must be isolated from contaminants. Likewise, flow measurements to control the flow of water to the electrolyzer must be made with ultrasonic or mass flowmeters”. According to the specialist, in the case of alkaline electrolyzers, the complexity lies in the supply of potassium hydroxide. “In general, the concentration of potassium hydroxide in alkaline electrolyzers is between 25 to 30% in water, so pH and conductivity measurements must be taken to ensure that this ratio is constant. In addition, flow and differential pressure transmitters are used to control the filtering process”. Another fundamental aspect to consider is the purity of the gas. “For this, systems that detect traces of oxygen or moisture can be used,” he concludes. According to current projections, one of the relevant uses for green hydrogen will be the production of ammonia, where level measurement in storage tanks is relevant, or in the case of blending hydrogen with natural gas, where the composition and calorific value of the mixture is essential to deliver a product to households similar to the gas currently used. In some particular cases, the use of hydrogen in liquid form becomes important. In these cases, the temperatures at which it works are so low that few instruments are currently capable of measuring it correctly. Thus, the level measurement in storage tanks can be performed by radar and the flow rate by orifice plates. Along these same lines and to reinforce its commitment to the energy transition to a decarbonized world, Endress+Hauser is organizing an Electrolyzer Technical Forum to be held on October 17 in Houston. The event will focus on operationalizing safety in green hydrogen production and will include leaders from the electrolysis industry.