ECOS: Energy analysis and design assumptions for small gas turbine with external combustion of gas from biomass gasification

The use of fossil fuels for electricity generation has an adverse effect on the environment. One of the ways to significantly reduce this negative impact is to use biomass. Despite the fact that there is a number of technologies for biomass conversion, most of them feature a rather poor efficiency or low economic effectiveness caused by high costs of biomass and conversion technologies. A progress in biomass conversion technologies may be made if a technology is developed featuring a simple structure, a low power capacity and using lignin-cellulose biomass. This paper presents a thermodynamic analysis of a 200 kWe gas turbine system fitted with interstage air cooling and fed with gas from biomass gasification in which heat is given to the cycle by a high temperature heat exchanger. The thermodynamic analysis makes it possible to determine the values of the machinery parameters which are needed to obtain power efficiency comparable to the level achieved in systems with reciprocating engines. Design assumptions are specified for selected components. The analysis results indicate that it is possible to construct relatively simple gas turbine systems intended for combustion of hot fuel and featuring power efficiency comparable to the level achieved in systems with reciprocating engines.