Thermoeconomic comparison between the performance of small-scale internal combustion engines and gas turbines integrated with a biomass gasifier

Abstract

Recently, many countries have paid substantial attention to power generation from biomass gasification, particularly through small-scale plants. A number of power plant models have been suggested and analyzed; however, certainly, desirable configurations have not been identified yet. Moreover, their performances are ordinarily difficult to compare, especially owing to the fact that working hypotheses are often inconsistent. The objective of this research is to provide an overview on small-scale technologies regarding woody biomass syngas utilization for power production, with the purpose of introducing the most promising solutions from both thermodynamic and economic viewpoints. Existing technologies or those possibly anticipated to be available on the market in the near future have been taken into consideration. Three plant scales have been investigated including 100 kWel, 1 MWel and 5 MWel. As small-scale power plants, internal combustion engines and internal (micro) gas turbines have been taken into account, while gasification has been focused for biomass. Simulations demonstrate that internal combustion engine integrated with an ambient pressure gasifier and regenerative gas turbine integrated with a pressurized gasifier are the most favorable technologies at all the three sizes from a thermodynamic point of view. However, among these two solutions, the former configuration is the most promising one at all the scales from an economic point of view as well.