Biogas is an eco-friendly energy source that is becoming increasingly important in today‘s energy supply. It can be used to generate power or heat or as a fuel, and provides a high energy yield per square meter of land. But an extensive upgrading and purification process is required before biogas is fed into the natural gas grid. New and highly selective polymer membranes from Evonik convert raw biogas simply and efficiently into highly pure biomethane. This increases yield and conserves valuable resources.