Abstract
Biomass is a significant renewable energy source. The conversion of woody biomass into a combustible gas provides the opportunity to enhance the efficiency of biomass-based power systems, and allows solid fuels to be used in high-efficiency power generation processes. This paper discusses the energy efficient utilization of biomass by turbo machines under unpressurized conditions, working with the inverted Brayton cycle in which turbine expansion, cooling by heat exchanger and draft by compressor are made in an open cycle mode. We call this an "atmospheric pressure turbine (APT)". Thermodynamic analysis has shown that an electric efficiency up to 25%(HHV) and a total energy efficiency of more than 80% (HHV) are expected for combined heat and power applications even at small plant capacities (〜40 kW)
