This work aims at providing a deeper insight into different possible solutions for the decarbonization of existing power plants as support for the achievement of the goals planned by the European Commission 2030 strategy for climate and energy framework. In particular, the study is focused on the conversion of carbon dioxide contained inside the exhausts of a waste-to-energy plant, into valuable products. Two different solutions are addressed: -The Power-to-gas pathway to produce synthetic natural gas (SNG) from the captured CO2 and the H2 produced by electrolysis -The CO2 capture and storage pathway (CCS) for the sequestration of CO2 and its storage in liquid form.