Upgrading with chemical transformation
CO2 reuse chemically

There are various chemical pathways for CO₂ valorization. They involve either inserting a CO₂ molecule into a carbon chain (carboxylation) or mineral chain (mineralization), or on the contrary reducing this CO₂ by adding hydrogen, for example. The reduction pathways take various forms, depending on the reactant used and technical specificities: the use of very high temperatures (thermochemistry), electricity (electrolysis), methane (reforming), or hydrogen (hydrogenation)... (see figure 1).