Design and optimization of biomass power plant

Among the renewable energy sources, biomass offers some benefits due to its low cost and presumed zero-carbon emission when compared with fossil fuels. However, the moisture content of biomass is often high that lowers its heating value, reduces the combustion temperature and causes operational problems. Because of these, when burning biomass for power generation, biomass is often dried prior to the combustion. To lower the drying cost or to maximize the power output of a biomass power plant, proper heat integration in between the steam power plant and the drying process has to be considered. In this work, heat integration studies are performed to a biomass power plant that bums empty fruit bunches (EFB) as fuel. Composite curves of all studied cases are plotted to visualize the intensity and to identify opportunities of heat integration among the drying and power generation systems. A multi-stage drying process is proposed that employs steam and waste-heat from the power plant and the drying process, respectively. Results of this study show that with proper drying and heat integration, the overall efficiency of a biomass power plant can be significantly improved. (C) 2014 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.