A Comparison of Life Cycle Assessment Guidelines for Carbon Capture and Utilization (CCU) Technologies

With the acceleration of global Net-zero goals, Carbon Capture and Utilization (CCU) technologies are increasingly recognized for their potential to mitigate greenhouse gas (GHG) emissions through the conversion of captured CO2 into value-added products. Life Cycle Assessment (LCA) is widely regarded as a critical tool for evaluating the net environmental impacts of CCU technologies. However, inconsistencies in methodology across existing guidelines limit their comparability and policy relevance. This study presents a systematic comparison of five major CCU-specific LCA guidelines developed by the United States (NETL, 45Q Addendum), the European Union (LCA4CCU), the Global CO2 Initiative (GCI), and Korea (KRICT). The analysis focuses on key methodological components, including goal and scope definition, system boundaries, functional units, data quality requirements, and impact assessment metrics. The results reveal substantial variation in how these guidelines address key issues such as multifunctionality, displacement effects, and data uncertainty, particularly in relation to low Technology Readiness Level (TRL) technologies. The study highlights the imperative for harmonized, CCU-specific LCA frameworks to ensure environmental integrity, increase transparency, and effectively inform policy mechanisms such as subsidy structures and certification schemes. Recommendations are provided to update and align Korea’s existing LCA guideline with international best practices, thereby supporting robust decision-making in the deployment and regulation of emerging CCU technologies.