For the process engineering aspects, a plant concept for the production of biohydrogen from wood waste by means of biotechnological processes is analyzed and evaluated as an alternative to thermochemical processes. As a first step, a pretreatment process will be developed to remove chemical components such as adhesives or varnishes from waste wood, followed by fractionation and cleavage of the cellulose obtained into sugars. For the biotechnological conversion of the wood sugars into hydrogen, Fraunhofer IGB investigates and combines two fermentation processes using hydrogen-producing microalgae and bacteria, respectively.
To demonstrate the technical feasibility and obtain initial operating data, the process stages will be set up as semi-mobile modules on the basis of the design data determined on a laboratory scale at Fraunhofer IGB and integrated into an automated plant at the Black Forest Campus.
Impact and application potentials
By reducing CO2 emissions, the project helps to achieve the climate protection targets. On the one hand, the regeneratively produced energy source biohydrogen replaces previous fossil energy sources, for example in the mobility and industry sectors. On the other hand, the biotechnological approach links the energy recovery of the wood waste with a material use, in which the CO2 released from the wood during the biotechnological conversion is bound in the form of carbon-based co-products. Thus, the combined material utilization of waste wood and wood production waste also contributes to the establishment of a circular economy based on renewable raw materials with biobased products for the food and feed industry as well as the chemical industry.