Making use of CO2: a strategy for extracting economic value from CO2 while contributing to regional development

Suren Erkman, December 2023

The traditional climate strategy of mitigation, which naturally remains the priority, seeks to reduce greenhouse gas emissions at source.


However, it is clear that this strategy alone is not producing the desired results.


That’s why another approach has been developing rapidly in recent years: capturing CO2 from concentrated sources (cement works, steelworks, fertiliser plants, incinerators, etc.) or diluted sources, by capturing it directly in the air (Direct Atmospheric Capture, DAC). It can then be stored or recovered. It is this second option, which is of particular interest to local and regional authorities, that is presented here, along with the three methods of recovery: the direct use of CO2, its chemical transformation and its biological transformation. All three are part of the vast movement towards industrial and territorial ecology, which aims to take advantage of the complementarities between activities in the same area, just as nature itself does in ecosystems, with the waste from one being the raw material for the other.

Once the CO2 has been captured (and sometimes purified), there are two main options:

The possibilities for using CO2 are many and varied, and fall into three main categories:

In particular, large quantities of CO2 can be recovered using two approaches:

This process (known generically as Power to gas) naturally has an energy cost: but it is preferable to accept an energy penalty rather than having to offload all the surplus renewable electricity.

Energy issues :

Capturing and, above all, converting CO2 requires energy, particularly heat. However, certain chemical reactions such as the conversion of CO2 into methane (methanation) or the carbonation of mineral raw materials release heat (exothermic reactions).

For the transformation stages that require heat (endothermic reactions), the general principle is that of « territorial opportunism »: in a given area, there are always numerous sources of waste heat (incinerators, cement works, various industrial installations, etc.) available, often in large quantities. This considerably reduces the net energy input for capture and transformation operations.

Research into new catalysts that reduce the energy required for CO2 conversion reactions is also making rapid progress.

Territorial issues :

In a given area, there are three factors in favour of an approach such as CCU:

The combination of these three factors epitomises the industrial ecology approach: optimising flows and stocks of resources through synergies (or symbiosis) between existing (or even new) activities, taking advantage of resources that are currently little or poorly used.

In this context,the CO2 utilisation strategy makes it possible to set in motion development dynamics on a regional scale, combining socio-economic development (local production of value) and contribution to climate policies.