CO2 valorisation from lime production via Columbus process to produce E-methane for transport sector – A comprehensive life cycle assessment

In the next decades, CO₂ capture and utilisation (CCU) technologies can contribute to climate change mitigation. The Columbus project is an example of a CCU initiative in which CO₂ is captured from lime production and converted into E-methane via CO₂ methanation. E-methane can serve as fuel for ships and lorries to replace heavy fuel oil and diesel, respectively. This paper aims to assess the environmental impacts of E-methane production via the Columbus process, powered by renewable electricity, and its utilisation in the transport sector benchmarked to conventional fuel production (references) through life cycle assessment (LCA). A basket of products approach was used to also consider the co-products obtained from the Columbus process in the assessment. Both emission and resource based indicators were selected for the LCA. The results show that E-methane production and its utilisation in ships and lorries result in a decrease of the impact on climate change (35 %), particulate matter formation (94 %) and fossil resource use (85 %) compared to the references. For this comparison, the conventional production of the co-products was also taken into account. However, the production and utilisation of this fuel consumes more minerals and metals than the references. The higher mineral and metal extraction from the environment can be explained by the construction of the solar panels required to provide electricity for electrolysis. Future research should focus on the social acceptance and techno-economic assessment of the Columbus process.