Power generation based on biomass by combined fermentation and gasification – A new concept derived from experiments and modelling

•Large scale fermenter and small scale gasifier with CO2 separation are coupled.•Hybrid power plant, consisting of an SOFC and a gas turbine is integrated.•Process Chain is holistically studied, considering heat and mass flow integration.•Combustion properties of process gases are evaluated due to gas turbine operation.•Process results in electric efficiency of 42%, including conversion of raw biomass. A new concept is proposed for combined fermentation (two-stage high-load fermenter) and gasification (two-stage fluidised bed gasifier with CO2 separation) of sewage sludge and wood, and the subsequent utilisation of the biogenic gases in a hybrid power plant, consisting of a solid oxide fuel cell and a gas turbine. The development and optimisation of the important processes of the new concept (fermentation, gasification, utilisation) are reported in detail. For the gas production, process parameters were experimentally and numerically investigated to achieve high conversion rates of biomass. For the product gas utilisation, important combustion properties (laminar flame speed, ignition delay time) were analysed numerically to evaluate machinery operation (reliability, emissions). Furthermore, the coupling of the processes was numerically analysed and optimised by means of integration of heat and mass flows. The high, simulated electrical efficiency of 42% including the conversion of raw biomass is promising for future power generation by biomass.