Fumatech Fumatech (officially Fumatech BWT GmbH, subsidiary of BWT Group) is a German company specializing in the development of membrane technology, supplying ion exchange membranes to water treatment and energy-related applications, such as fuel cells, electrolyzers, and redox flow batteries (RFBs). This profile will focus on Fumatech's products for electrolyzer and fuel cell applications. Fumatech