Choosing the Right Metals for Components in Hydrogen-based Systems

In a recent podcast, a company engineer specializing in material science discussed the importance of this field in hydrogen production. The engineer, Buddy Damm, who is the Senior Scientist of Metallurgy at Swagelok, focused on the roles of fluid control components in processes like steam-methane reforming and electrolysis, emphasizing the significance of stainless steel, particularly 316 stainless steel, in these systems.

Alkaline water electrolysis, one of the processes mentioned, involves the use of electro-chemical cells (or stacks) immersed in an alkaline solution to split water into its component parts using an electric current. In this process, gases are collected at each cell, and fluid components are critical for sampling these gases, allowing for improved cost-effective operation by determining when to purge the system with nitrogen or steam.

The process fluid from the water gas shift reaction, which converts carbon monoxide and water to more hydrogen at lower temperatures, is sent to a bank of pressure swing absorbers for separation of hydrogen from other gases. Steam methane reforming, another process discussed, involves breaking carbon and hydrogen bonds at high temperatures, producing carbon dioxide. The fluid control systems in these processes, including sampling, are not subject to high temperatures.

However, both processes come with their own set of challenges. In alkaline water electrolysis, temperatures and pressures are modest, but the solution generates cost and corrosion concerns. For PEM electrolysis, some corrosion concerns disappear, but high pressures drive stresses, and embrittlement needs to be taken into account. Material science plays a role in addressing these challenges, helping to combat issues such as metal dusting, oxidation, and cracking that can occur at high temperatures in hydrogen production processes.

Swagelok's mission is to be fluid system experts and to support construction and flow paths to optimize efficiencies and maintain sealing. Their 3/16-inch tubing, made of 316 stainless steel, works well in the fluid control systems of steam methane reforming. Appropriate high-quality 316 stainless steel components are also effective in handling higher pressures in hydrogen production processes.

Damm describes material science as a blend of chemical engineering, solid state physics, and mechanics. He believes that understanding these principles is crucial for designing and manufacturing components that can withstand the demands of hydrogen production processes. By focusing on material science, companies like Swagelok are helping to make hydrogen production more efficient, cost-effective, and safer.