A membrane contactor for efficient CO2 removal in biohydrogen production

Relatively low and frequently changing flow rates and compositions in biohydrogen production require a highly efficient and low energy consuming gas cleaning technology to let this process become a competitive alternative in hydrogen production. Membrane contactors with non-porous polymeric membranes were selected to be suitable since they do not only absorb the by-product carbon dioxide effectively but they also supply sterile conditions, they withstand high feed pressures and they prevent a contamination of the gas products by the liquid phase. The latter even allows the use of harmful substances such as mono ethanol amine (MEA) as liquid carriers. By testing different membrane materials and liquid carriers the contactors have been optimized and the applicability of this technology in biohydrogen production processes has been proven.