Cogasification of coal and biomass in an integrated gasification combined cycle power plant: Effects on thermodynamic performance and gas composition

Taking inspiration from one of the most significant experiences of coal and biomass cogasification, such as that undertaken in the Willem-Alexander Centrale (WAC) power plant located in Buggenum, Netherlands, a modeling procedure was conceived to simulate the operation of an integrated gasification combined cycle (IGCC) power plant with different types of fuel, spanning from 100% coal to a mixture of 30% coal and 70% biomass. After a careful validation based on the experimental data currently available in the published literature, the IGCC modeling was combined with an optimization method through the use of the commercial code Thermoflex. The main goal was to find the coal/biomass mixture allowing for a twofold purpose: an effective reduction in carbon dioxide emissions, on the one side, to mitigate global warming, and an increase in the hydrogen content of syngas, on the other side, for potential economic benefits in the context of polygeneration. Different kinds of coal and biomass were taken into account, with a wide range of lower heating value (LHV). The results were found to be strongly dependent on the energy content of the selected coal/biomass blends. Overall, the optimized solutions resulted in a loss of net electric efficiency compared to the design performance with 100% coal firing.