Using CO2 as a feedstock for the chemical industry could help both to offset emissions and to conserve fossil fuels. Many reactions using carbon dioxide to synthesize a range of products on a laboratory scale have been reported. However, the environmental and economic aspects on an industrial scale have to be evaluated to find the reactions with the highest potential for future use.
Alexander Otto, Forschungszentrum Jülich, Germany, and colleagues have assessed the industrial viability of 123 different reactions producing both bulk and fine chemicals which use CO2 as a feedstock. The team looked at both the profitability and the environmental impact and compared them to conventional processes. Their criteria included, among others, the relative mass of CO2 present in the final product, the added value of the products compared to CO2 and other reactants, the possibilty to avoid fossil fuels entirely, and the scientific relevance of the products for fine chemicals.
Based on their analysis, the researchers recommend a range of specific reactions for further development. Some of the bulk chemicals they consider viable synthesis targets for CO2 use are formaldehyde, methanol, urea, and dimethyl ether. For the fine chemicals, they see high potential for 2-imidazolidinone, ethylurethane, 2-oxazolidone, and isopropyl isocyanate, among others.
- Closing the loop: captured CO2 as a feedstock in the chemical industry,
Alexander Otto, Thomas Grube, Sebastian Schiebahn, Detlef Stolten,
Energy Environ. Sci. 2015.