CO2 utilization is gaining attention as a greenhouse gas abatement strategy complementary to CO2 storage. This study explores the techno-environmental performance of CO2 utilization trough dry reforming of methane into syngas for the production of dimethyl ether (DME). The CO2 source is a hydrogen production unit at a refinery, where solvent based CO2 capture is applied. Aspen+ modelling and hybrid life cycle assessment (LCA) is used to assess the techno-environmental performance of this utilization option compared to a reference case without CO2 capture and a case with CO2 capture and storage. Results of the technical assessment show that although 94% of the captured CO2 can be utilised for DME production, only 9% of CO2 is avoided in the entire process as a result of direct CO2 formation during DME synthesis and the combustion of syngas to provide the heat demanded by the dry reforming process. Besides, a substantial amount of electricity is required for syngas compression. Consequently, the LCA results indicate that climate change potential (CCP) is reduced by 8% while it is 37% higher than CCP when CO2 is stored and DME is produced conventionally. Sensitivity analyses are performed on various process conditions. Overall, this study indicates that this utilization route lowers the CCP although the reduction is limited compared to CCS. While the techno-environmental analysis is a useful tool to gain better insights in the performance of CO2 utilization options, the complex environmental trade-offs make it difficult to draw robust conclusions on the performance.@en

This work presents the results of a comparative life cycle assessment study for three CCS technologies applied to a coal-fired power plant: post-combustion capture with MEA, post combustion capture with AMP/PZ and cryogenic oxy-fuel. This study has been performed in the context of the EDDiCCUT project, which aims to develop an environmental due diligence framework for assessing novel CCUS technologies. The research shows that there are no significant differences in climate change potential (CCP) for the technologies under study. In the three cases the reduction is about 70% (70% for the plant with MEA, 71% for the plant with AMP-PZ, and 73% for the plant with oxy-fuel technology). With regard to other impacts (e.g., acidification, toxicity, resource depletion) the results show an increase in the impacts as consequence of CCS, mostly driven by the increase amount of feedstock per kWh. Contrary to CCS, there are clear differences among the technologies with results ranging between 20 and 30%. Toxicity impacts related to the operation of the solvent-based carbon capture unit were also considered; however, it was observed that their contribution was only around 2% of the total impact for human toxicity potential. Rather, the largest contributor to human toxicity impacts in the life cycle of coal power plants with and without CCS is coal mining waste disposal.@en