Analysis of combined cycle plants integrating biomass and natural gas

Abstract

Biomass plays a vital role in broadening the energy portfolio and reducing reliance on traditional fossil fuels. Combining biomass with natural gas-powered combined cycle plants offers an opportunity to improve biomass conversion efficiency. This study aims to conduct a comprehensive technical and economic analysis, comparing two configurations of combined-cycle plants fueled by natural gas and lignocellulosic biomass. The first configuration implements traditional post-combustion methods to augment steam cycle output, while the second directs exhaust gases to a heat exchanger, pre-heating the compressor’s outgoing air. A significant focus was placed on assessing biomass conversion efficiency, specifically the marginal efficiency in electricity generation attributed to biomass input. This parameter was compared with the performance of standard conventional biomass-only plants. The research delved into the impact of varying biomass feed ratio on key performance indicators, including the cost of electricity generation, the overall and marginal biomass efficiency, and the share of electricity production due to biomass. The determination of the optimal plant configuration and the ideal biomass fraction was achieved through multivariable optimization techniques.