LAUSR

Abstract The Heatpipe Reformer technology allows the generation of hydrogen-rich, pressurized synthesis gas from solid feedstock like lignite or biomass. The resulting high hydrogen partial pressure and thus driving force makes it suitable for membrane separation. This work promotes the application of hydrogen permeable membranes as hydrogen separators directly in the reformer. This should allow a high hydrogen yield due the shift of the gasification reactions to the product side when hydrogen is removed continuously. The material of choice for this task is nickel as it combines good hydrogen permeability with good mechanical properties at the operation temperature of biomass gasification of 800 °C. The experimental section presents measurements with a bundle of nickel membranes used for the demonstration of the shift of different gas mixtures to the product side by hydrogen removal. Hydrogen removal enhanced CO and CH 4 conversion at an operation temperature of 800 °C. A high purity of at least 99.9% was achieved by the highly selective solution-diffusion process of the separation. The experimental data was also used for an energy balance of the membrane process to allow a proper membrane layout in terms of membrane area per hydrogen production. As a last step, the membrane bundle was applied directly in the Heatpipe Reformer, an allothermal pressurized gasifier. It produced 200 ml min − 1 of hydrogen and showed no signs of degradation or fouling. This proof of concept showed the suitability of nickel membranes for hydrogen separation under gasification conditions.