A techno-economic assessment of biomass fuelled trigeneration system integrated with organic Rankine cycle

This work focuses on the modelling, simulation and techno-economic analysis of small scale biomass trigeneration applications. The Organic Rankine Cycle (ORC) integrated with conventional combustion provides electricity for building use. The waste heat recovered from the ORC system and exhaust gases is used to supply hot water to space heating and excess heat is also used to drive an absorption cooling system. In order to use energy resources most efficiently, the proposed process is modelled and simulated using the ECLIPSE process simulation package. Based on the results achieved, the key technical and environmental issues have been examined. The study also investigates the impact of different biomass feedstock on the performance of trigeneration plant, biomass ash content ranges from 0.57 to 14.26% ash and a range of moisture content 10.6-33.51%. The calorific value across the biomass sources ranges between 16.56 and 17.97 MJ/kg daf. Finally, an economic evaluation of the system is performed along with sensitivity analyses such as capital investments, plant load factors and fuel costs. The results show that the maximum efficiencies and the best breakeven electricity selling price for the cases considered in this study are as follows: 11.1% and 221 £/MWh for power only, 85.0% and 87 £/MWh for combined heat and power and 71.7% and 103 £/kWh for trigeneration respectively.