Life cycle assessment of carbon capture and storage value chains: A systematic, critical literature review

Quantification of greenhouse gas emissions is required for carbon capture and storage (CCS) projects to determine carbon offsets. Application of life cycle assessment (LCA) is the commonly applied framework for assessing life cycle impacts yet consensus and formal guidance on a rigorous approach is lacking for CCS. This study inter alia seeks to determine the level of consistency and uncertainty in reported LCAs. It follows a systematic literature-review protocol involving peer-reviewed articles on Scopus and Web-of-Science published between 2013 and 2024. A total of 33 articles were analysed according to a pre-defined set of criteria for data collection, analysis and reporting. We observed larger discrepancies in the general study characteristics, input values for energy demands and reported results. Low comparability across studies is caused by differences in methodological choices, functional unit and system boundaries. Less than half of the articles apply a full value chain perspective, and below one quarter includes projection of electricity carbon intensities. This review concludes that ambiguity arises in LCAs of CCS value chains due to repetitive omission of transport, storage and monitoring activities. We call for greater distinguishment between energy demands needed for capturing such as electricity use, heat generation, compression and liquefaction. Seeking standardization of carbon offsetting methodologies, we suggest including energy and material demands for transport, intermediate tank storage and injection processes along with drilling and post-injection monitoring as minimum system boundaries. Moreover, we propose the use of mechanistic modelling for validation of energy demands in life cycle inventories for prospective CCS projects.