Sensitivity analysis of small scale biomass gasification-based CHP system: a way forward for sustainable urban waste to energy technology

Abstract

A biomass gasification-based combined heat power (CHP) system emerges as a potential sustainable urban waste-to-energy (WtE) technology that can offer solutions to the excessive anthropogenic CO2 emissions and the escalation of energy demand as well as to the incremental of domestic and agriculture wastes. In this work, a steady state flowsheet model of 25 kW APL power pallet is developed by Aspen Plus software. The developed power pallet model integrates physical and chemical processes which involves pyrolysis, combustion, and gasification processes. The developed gasification model is validated with experimental data using biomass woodchip as a feedstock. This study focuses on the gasification of biomass to produce syngas (mainly H2 and CO) which subsequently converts to electric power. As an initial study towards large scale WtE plant, a detailed parameter sensitivity analysis is performed by analysing variables effects on syngas production subjected to the manipulation of gasification temperature, pressure and air-to-biomass ratio. The results show that the elevation of air-tobiomass ratio and gasification temperature contribute to the high conversion of CO subsequently enhance the potential of electrical power load. Moreover, power pallet exhibits optimal operation at 3.9 of air-to-biomass ratio with gasification temperature approximately at 1200 K. The initial results obtained in this study are valuable in determining the feasibility of biomass gasification-based CHP system as a sustainable and robust WtE technology.