Environmental assessment of gasification technology for biomass conversion to energy in comparison with other alternatives: the case of wheat straw

This paper assesses the environmental performance of biomass gasification for electricity production based on wheat straw and compares it with that of alternatives such as straw-fired electricity production and fossil fuel-fired electricity production. In the baseline simulation, we assume that the combustion of biomass and fossil fuel references for electricity production takes place in a combined heat and power plant, but as a sensitivity analysis, we also consider combustion in a condensing mode power plant where only electricity is produced. Our results show that the production of 1 kWh of electricity from straw through gasification would lead to a global warming potential of 0.08 kg CO2e, non-renewable energy use of 0.2 MJ primary, acidification of 1.3 g SO2e, respiratory inorganics of 0.08 g PM2.5e and eutrophication potential of −1.9 g NO3e. The production of electricity from straw based on gasification technology appears to be more environmentally friendly than straw direct combustion in all impact categories considered. The comparison with coal results in the same conclusion as that reached in the comparison with straw direct combustion. The comparison with natural gas shows that using straw gas as an alternative energy source reduces global warming, non-renewable energy use and eutrophication but increases acidification and respiratory inorganics. The relative performance of straw gasification versus direct combustion and fossil fuel references does not change with varying assumptions about whether or not heat recovery is considered.