Biogas as a source for producing hydrogen at wastewater treatment plants – EuWaK – A pilot project

•Realization of a decentralized H2 infrastructure at a WWTP and a nearby school.•Worldwide the process concept is integrated into a WWTP for the first time.•The system illustrates the processing of sewage sludge into hydrogen.•Biogas is transformed into H2 using steam reforming and pressure swing adsorption.•Production of hydrogen gas of 99.99% vol. and 99.999% vol. H2.

Hydrogen can play an important role in a future renewable energy economy. One promising method for hydrogen production with the potential for integration into a local supply chain in the vicinity of wastewater treatment plants was investigated during the EuWaK project at Emschergenossenschaft's Bottrop wastewater treatment plant (WWTP). The raw material for hydrogen production is digester gas, a renewable energy source. The digester gas is processed into bio natural gas and hydrogen. The hydrogen is used in a combined heat and power plant with a hydrogen engine to produce electricity and heat to supply a nearby school. An attractive alternative to a hydrogen engine is a fuel cell. Fuel cells require hydrogen conforming to stricter quality standards than H2 engines; therefore trialling quality management methods with a model fuel cell is an important safeguard in order to protect downstream fuel cells if digester gas derived hydrogen is to be used.