Panorama of CO2 chemical conversion pathways

Different technological solutions exist to tackle carbon dioxide (CO2) emissions. Some inevitable short-term emissions can be captured to avoid direct emissions into the atmosphere. This CO2 must then be managed and geological storage seems to currently be the only way of dealing with the large volumes involved. However, this solution faces major economic profitability and societal acceptance challenges. In this context, alternative pathways that use CO2 instead of storing it are generating growing interest.

The study, for the French Environment and Energy Management Agency (ADEME, Agence de l’Environnement et de la Maîtrise de l’Energy), aimed to take stock of the different technologies used for the chemical conversion of CO2 to improve understanding of their development potential by 2030, of the conditions in which they could be competitive and of the main actions to be implemented in France to foster their emergence. To do this, the study was broken down into two main areas of focus:

• The review and characterisation of the main CO2 chemical conversion routes for the synthesis of basic chemical products, energy products and inert materials. This review includes a presentation of the main principles underpinning the studied routes, a preliminary assessment of their performances, advantages and drawbacks, a list of the main R&D projects underway, a focus on emblematic projects as well as a brief analysis of the markets for the main products produced.
• Based on these elements, 3 routes were selected from among the most promising by 2030 for an in-depth modelling and assessment of their energy, environmental and economic performances.

The study shows that the processes modelled do have favorable CO2 balances (from 1 to 4 tCO2 per tonne of product) and effectively constitute solutions to reduce CO2 emissions, despite limited volumes of CO2 in question. Moreover, the profitability of certain solutions will remain difficult to reach, even with an energy mix very rich in renewable energies allowing facilities to benefit from a high number of hours of supply at a very low cost.