(685c) Comparative Life Cycle Assessment of Methanol Production Processes Based on Externalities Under Uncertainty

Carbon dioxide is considered as the main contributor to climate change and thus to global warming. Several technologies have been proposed to reduce atmospheric CO₂, such as CO₂ capture and storage (CCS), CO₂ capture and utilization (CCU) and enhanced oil recovery (EOR). From these proposals, converting the captured CO₂ into valuable products was seen as a promising area to explore. This research focuses on methanol production using captured carbon dioxide and hydrogen and compare it to the business as usual (BAU) process that is based on steam reforming of natural gas (SRNG) according to sustainability criteria. To achieve this objective, a systematic approach has been followed. Starting with a technoeconomic analysis of the process using simulation software Aspen-HYSYS. Then, a “cradle-­to-gate” life cycle assessment has been carried out for the methanol production processes from different CO₂ and H₂ sources that will inform on the impact caused in several damage categories. ReCipe 2008 LCA method was followed in this work that quantifies the environmental impacts per 1 kg of methanol. Later, the obtained impacts were monetised using external costs and combined with the economic performance of each alternatives. Finally, the analysis was repeated for different scenarios generated using Monte Carlo sampling in order to understand how various uncertainty sources affect the results. The holistic approach demonstrated by the life cycle assessment (LCA) combined with the externalities does not only enable decision makers to assess the proposed technologies compared to the conventional production technologies based on their economic value but also gives a better insight about the overall performance of each process based on techno economic and environmental measures.