Energy Intensity of Two-Stage Fermentative Hydrogen Production from Biomass in a Plant Equipped with Fuel Cells for Power Supply

A conceptual hydrogen production plant composed of a pretreatment unit for starchy raw material, a bioreactor for dark fermentation, a photobioreactor for photofermentation and gas upgrading & compression units is considered. In order to supply the plant with necessary heat and power, a part of the stream of raw gas is burned in a boiler and in addition some product gas is directed to fuel cells followed by a catalytic oxidant. Estimates are presented of the influence of product gas purity on the total energy demand in the plant rated 60 kg/h H2 in the raw gas.