Biomass integrated gasification combined cycle power generation with supplementary biomass firing: Energy and exergy based performance analysis

A thermodynamic analysis of a Biomass Integrated Gasification Combined Cycle (BIGCC) plant has been performed based on energy and exergy balances in a proposed configuration. Combustion of supplementary biomass fuel is considered using the oxygen available in the gas turbine (GT) exhaust. The effects of pressure and temperature ratios of the GT system and the amount of fuel burned in the supplementary firing chamber on the thermal and exergetic efficiencies of the plant have been investigated. The plant efficiencies increase with the increase in both pressure and temperature ratios; however, the latter has a stronger influence than the former. Supplementary firing of biomass increases the plant efficiencies of a BIGCC plant till an optimum level of degree of firing. The other technical issues related to supplementary firing, like ash fusion in the furnace and exhaust heat loss maintaining a minimum pinch point temperature difference are accounted and finally a set of optimum plant operating parameters have been identified. The performance of a 50 MWe plant has been analyzed with the optimum operating parameters to find out equipment rating and biomass feed rates. Exergetic efficiencies of different plant equipments are evaluated to localize the major thermodynamic irreversibilities in the plant.

► A thermodynamic analysis of a Biomass Integrated Gasification Combined Cycle (BIGCC) plant has been performed based on energy and exergy balances across various plant components in a proposed configuration in order to optimize the operating parameters.
► The effect of supplementary biomass firing in the BIGCC plant has been analyzed in detail to find out the optimum degree of firing for the best plant performance.
► The equipment ratings and fuel feed rates are evaluated and the technical feasibility of the plant configuration has been analyzed.
► Exergetic efficiencies of different plant equipments are evaluated to localize the major thermodynamic irreversibilities in the plant.