Thermodynamic Performances and Cost Analysis of Advanced Biomass Combustion Power Plants

The use of biomass for power production reveals a growing worldwide interest, due to the strategic role it has for environmental concerns, large availability and technological advances. As a raw material, biomass contains relatively high moisture, requiring thermal drying processes in order to limit energy losses at the stack.In this paper, plant configurations with different options for drying the biomass before combustion have been discussed. Conventional indirect processes, using steam extracted from the turbine, and direct drying processes, performed through hot gases at the turbine exit, have been compared, highlighting their influence on plant layout and performance. Moreover, a thorough economic investigation has been carried out for evaluating the levelized cost of the produced electricity, as well as the profitability of each solution.The study shows that the biomass drying through recovered thermal energy from gas turbines improves the biomass power plant feasibility. It allows for enhancing performances and reducing biomass plantation extensions with respect to conventional solutions. The analysis also demonstrates that the proposed solutions allow for lowering the cost of the produced electricity and for shortening the payback periods.