GHG Emissions of Incineration and Anaerobic Digestion: Electricity Mix

Abstract

Waste to energy (WtE) is one of the suitable alternatives in handling municipal solid waste (MSW). This study assesses the GHG emissions (CO_2eq) of incineration and anaerobic digestion (AD) under different electricity production mix. The electricity production mix of China, Malaysia, Japan, Russia, UK, US (East), Czech Republic, Germany, France and Finland were considered. Incineration has a lower net CO_2eq emission in China and Malaysia. However, the AD is environmentally preferable than incineration in Russia, Japan, Czech Republic, Germany, US (East), UK, Finland and France. The net CO_2eq emission of incineration in China (9.41 kg CO_2eq/t MSW) is lower than a country with greener electricity mix e.g. France (401.76 kg CO_2eq/t MSW) where the main electricity source is nuclear. This is due to the higher avoided CO_2eq emission compare to generate electricity from fossil fuel. Electricity produces from the WtE process is identified as the major factors in affecting the net CO_2eq emission than the other two assessed factors (waste collection and transportation (distance), the efficiency of the WtE process). This suggests energy efficiency plays a significant role in enhancing the net CO_2eq emissions and to reduce the carbon intensity of WtE.