Life Cycle Analysis of CO₂ Valorisation

Carbon capture and utilisation (CCU) is generally assumed to be a sustainable production alternative with lower environmental impacts than conventional products produced from fossil sources. The main advantage of CCU is twofold: (i) it generally reduces global warming by removing or reducing CO₂ emissions to the atmosphere and (ii) uses a non-fossil feedstock as raw material to manufacture such products, thereby reducing resource depletion. Nevertheless, such superior environmental impact performance must be confirmed on a case-by-case basis by rigorous environmental assessment studies.

This chapter describes the main steps of life cycle assessment (LCA), a widely used methodology to assess environmental impacts. Then, it presents the environmental impacts of the following CCU products: methane, methanol, carbon monoxide (CO), dimethyl ether (DME), dimethyl carbonate (DMC), and polyols. The following environmental-impact categories are considered: global warming impact, acidification, ecotoxicity, freshwater eutrophication, and abiotic resource use. These results are also compared with the conventional industrial production methods for these products, allowing elucidating whether CCU technologies are more environmentally sustainable than their conventional counterparts.