ADEME’s expert opinion on CCU (carbon capture and use)
Currently, 230 Mt/year of CO2 are consumed worldwide for industrial purposes.
CO2 capture and utilisation (CCU) consists of capturing CO2 to use it as a direct raw material or for the synthesis of fuels, chemicals or materials.
It has the same capture component (separation of CO2 from flue gases) as CO2 capture and geological storage (CCS), but the fate of the CO2 is different because instead of being stored underground, it is re-used. As CO2 recovery encompasses a wide variety of products and processes, the realities of decarbonisation vary greatly depending on the type of technology and substitution chosen.
CO2 capture and utilisation (CCU) encompasses a variety of technologies that use CO2 captured from industrial sources (combustion flue gases in particular) or biomass sources (biogenic CO2) or even from the air as a raw material for a wide range of applications and products.
UCC can be considered as a lever for decarbonisation. However, the overall contribution of CO2 recovery in terms of CO2 emissions reduction remains difficult to quantify. Indeed, analyses of actual CO2 emission reductions depend on many parameters and potential volumes vary greatly from one recovery pathway to another.
Thus, this opinion aims to provide analytical keys to identify the relevant conditions for CO2 recovery by analysing the different recovery routes (direct use, chemical recovery, biological recovery) according to the maturity of the technologies, their market, their costs and the regulations.
This document shows that CO2 recovery can contribute to the objectives of carbon neutrality, provided that the use of biogenic CO2 is favoured while making massive use of renewable energy, and by favouring the manufacture of products with a long time storage of CO2 (at least several decades). In this respect, the mineralisation of CO2 (for the construction industry, for example) is a relevant avenue.
ADEME recommends :
- To strengthen the normative framework on the evaluation of the climate impact of UCC in a life cycle analysis (LCA) logic, in particular to clarify the allocation of emission reductions between the CO2 emitter and the user of this captured and recovered CO2.
- To develop a strategic and shared vision for the development of UCC and the support systems that could be put in place to encourage the development of the most environmentally relevant pathways.