To nip it or let it bloom: Life cycle assessment of lab-scale catalysts used in low-TRL CCUS technologies

Abstract

Excessive reliance on fossil fuels results in the increasing accumulation of carbon dioxide (CO₂) in the atmosphere, contributing to substantial global warming. To mitigate the release of this greenhouse gas, CCUS technology integrates carbon capture, utilization, and storage, providing a comprehensive solution to address the impact of industrial activities on climate change. While numerous experimental-scale CCUS processes are being studied, there is a need to compare their environmental impacts. This paper focuses on the life cycle assessment (LCA) of lab-scale catalysts used in low technology readiness level (TRL) CCUS methodologies, employed to obtain a single target product. It includes a case study of two Cu-based catalysts for the conversion of CO₂ into ethanol. Selection of ethanol as the CCU product is due to its prospects as a renewable fuel. Both grid electricity and photovoltaic-based electricity for catalyst synthesis have been used, resulting in a comparative study of four separate product systems. The two catalysts used in this assessment are Cu/C-0.4, and Cu@Na-Beta. Cu/C-0.4 catalyst has Cu nominal loading of 0.4wt%, over carbon support. Cu@Na-Beta consists of embedded 2–5 nm Cu nanoparticles in crystalline particles of Na- Beta zeolite. 17 impact categories were selected for the life cycle impact assessment (LCIA). In all categories, Cu/C-0.4 has more environmental impact than Cu@Na-Beta, indicating that it is environmentally less harmful to synthesize Cu@Na-Beta for CCU applications than Cu/C-0.4 under the studied conditions. Thus this study outlines the method of using LCA for preliminary screening of potential technologies that can be considered for commercial implementation.