Making Sense of Techno-Economic Assessment & Life Cycle Assessment Studies for CO2 Utilization (Version 2): A guide on how to commission, understand, and derive decisions from TEA and LCA studies

Carbon capture and utilization (CCU) or CO2 utilization technologies attract researchers, policy makers, and industry actors in search of sustainable solutions for industrial processes. This increasing interest can be explained by the fact that these processes comprise the capturing of CO2 – the most relevant greenhouse gas (GHG) – from the air or industrial point sources, and promote its use as a feedstock for the production of goods. CCU processes are expected to contribute to the greenhouse gas neutrality targets of several industrial sectors and the development of a circular economy. Therefore, understanding the environmental impacts and economics of CO2 utilization routes is essential for decision makers from relevant fields, such as technology developers, entrepreneurs, funding agencies, policy makers, administrators and more. A deep understanding of the specific implications of CO2 utilization technologies is needed to make decisions in line with sustainability strategies, and to discard inappropriate solutions. The ‘Techno-Economic Assessment & Life Cycle Assessment Guidelines for CO2 Utilization’1 (henceforth TEA and LCA Guidelines) published by the Global CO2 Initiative (GCI) in October 2018, represent a milestone in the harmonization of Life Cycle Assessment (LCA) and Techno-Economic Assessment (TEA) for evaluating CCU technologies. Henceforth, we refer to this document as TEA and LCA Guidelines. The TEA and LCA Guidelines provide a guide to overcoming methodological discrepancies that lead to confusion among practitioners, concerning how to conduct assessments, and which often lead to contradictory results.2 3 Documents with a similar focus have also been published by the National Energy Technology Laboratory (NETL).4 The success of the GCI publication and the demand for such guidelines is evidenced by the strong response that the authors registered in the months following its publication: more than 2,000 copies of the TEA and LCA Guidelines have been distributed in digital form or hard copy, and a growing community of practitioners, and decision makers from science, industry, and public administration are learning how to generate robust and comparable assessments when evaluating CCU technologies. In addition to the guidelines and the present report, the same research group has recently released five illustrative worked examples5 to support the application of the TEA and LCA Guidelines, and three accompanying peer-reviewed articles.6 At the same time, policy officers at national and international levels have frequently signaled the urgency of further developing these tools, to enable evaluation of innovative technologies as a basis for decision making in funding and policy design (e.g., the EU Innovation Fund). Despite the urgent need to address planetary climate change, the development and diffusion of new technologies often takes considerable time. Consequently, leveraging the current momentum amongst all involved actors that CCU has achieved to date is paramount and is an opportunity that must not be missed. Despite demands for aligned assessment methods from the industrial and policy spheres,7 there are evident challenges in dealing with the practical application of such methods in commissioning, reading, and interpreting LCA and TEA studies. There is also a risk of insufficient transfer into policy or other decision-making processes, in cases where the involved actors do not possess disciplinary expertise in the relevant methodology.