Environmental impacts of CO2-based chemical production: A systematic literature review and meta-analysis

Abstract Carbon capture and utilization (CCU) is perceived as a technology to mitigate climate change and conserve non-renewable resources, especially in the chemical industry. Numerous life cycle assessments (LCA) of individual CCU systems have been carried out. The goal of this review is to understand the environmental effects of CO2-based chemical production comprehensively. In order to achieve this goal, a systematic literature review and a meta-analysis were conducted. 52 peer-reviewed articles were found that deal with LCA and CO2-based chemical production. Amongst the case studies found, the methodological choices and technological parameters differ. The meta-analysis reveals that there is no CO2-based chemical production technology that performs better in all analyzed impact categories (IC) compared to conventional production. Nevertheless, looking at the results from the meta-analysis, it has been found that the CO2-based production of formic acid (FA) via H2 is a promising CCU pathway. FA produced via hydrogenation performs better in 11 out of 15 ICs using the German grid mix as the electricity supplier and better in 14 out of 15 ICs using wind power as the electricity supplier compared to the conventional production. The global warming impact of FA production can be reduced by 95.01% when produced via CO2 hydrogenation. The meta-analysis also unveils CCU technologies that are not favorable from an environmental perspective because CO2-based kerosene and dimethyl carbonate (DMC) production lead to higher impacts in all ICs compared to conventional production. This study can inform decision-makers about the differences in published LCA studies on CCU and the harmonized environmental impacts of CO2based chemical production.