Integrating biomass gasification with a steam-injected micro gas turbine and an Organic Rankine Cycle unit for combined heat and power production

Proper integration of different energy systems is one of the most effective strategies to achieve higher conversion efficiencies and to reduce emissions in power systems. Hence, in this study a biomass-fuelled Steam Injected micro Gas Turbine (SImGT) coupled to a bottom Organic Rankine Cycle (ORC) unit is investigated to better exploit the primary energy use while lowering the environmental impact. In the proposed integrated system configuration, a Heat Recovery Steam Generator (HRSG) produces steam for both the gasification process and the SImGT. To conduct a realistic simulation, several gas conditioning units are included in the configuration of the integrated system to purify the produced syngas to the allowable limit of mGTs. The impacts of both the mass flow rate of the injected steam and the S/B ratio on the performance of the integrated system have been assessed. Results of the analysis have shown that the produced electrical power increases as the mass flow rate of the injected steam increases, while the net electrical efficiency of the integrated system is penalized marginally. At its maximum net electricity production, the integrated system has an output of 127.6 kWel and 78.7 kWth with 23.6% electrical efficiency when the mass flow rate of the injected steam to the combustion chamber is 25 g/s, which corresponds to the maximum of the investigated range in this study.