Life cycle assessment of four waste-to-energy plant configurations equipped with post-combustion carbon capture and storage

• Waste-to-Energy with CCS is net carbon negative via storage of biogenic carbon. • Limited burden shifting to other environmental impact categories. • The carbon benefits of ultra-high capture rates significantly outweigh the impacts. • Combined Heat and Power configuration achieves -482 kg CO 2 eq per tonne of waste. • Energy export and material recovery reduces emissions further through displacement. When equipped with Carbon Capture and Storage (CCS), Waste to Energy plants can directly reduce fossil carbon dioxide emissions from post-recycling residual waste while also re-capturing atmospheric carbon dioxide via the permanent geological storage of biogenic carbon uptake. Increasingly, municipal solid waste (MSW) is treated by incineration in dedicated plants where the heat from combustion is recovered via electricity generation and district heating. Post-combustion CO 2 capture with amine-based technology can achieve ultra-high CO 2 capture rates such that CO 2 generated in the combustion of the waste feedstock results in no direct CO 2 emissions to the atmosphere. The large biogenic content of residual waste feedstock presents a particular opportunity for bioenergy with CCS (BECCS). A life cycle assessment LCA of the environmental impacts of a state-of-the-art WtE facility with CCS at ultra-high capture rates shows that adding CCS can provide a significant improvement in climate change impact, and achieve a net climate benefit. Without significant burden shifting to other environmental impact categories, the climate change impact of a WtE plant treating 500 tpd of MSW is reduced from 388 kg CO 2 eq/t MSW to -483 kg CO 2 eq/t MSW , with the biogenic CO 2 captured and permanently stored accounted as negative CO 2 emissions. When the avoided greenhouse gas emissions from electricity, district heating and material recovery are also included, the climate impact is -777 kg CO 2 eq/t MSW for a power-only WtE plant exporting 9.6 MW e , and -907 kg CO 2 eq/t MSW for a combined heat and power WtE plant exporting 6.2 MW e and 18.5 MW th .