Today, the production of chemicals and derived materials heavily relies on the use of fossil carbon. Industrial processes need hydrocarbons to provide process energy (electricity and heat) and to provide embedded carbon (i.e. the carbon bound in molecular structures) of diverse substances.
Beyond fossil hydrocarbons, CO2 capture can also provide a useful source of embedded carbon. Fragrance giant Coty, for instance, recently started manufacturing fragrances using ethanol made from recycled carbon. The company aims to integrate sustainable ethanol into the majority of its fragrance portfolio by 2023 through its partnership with LanzaTech. A pioneer in carbon capture LanzaTech has also joined forces with France’s beauty L’Oréal group and energy giant Total to develop a plastic bottle made with polyethylene derived from captured and recycled carbon emissions. After a successful test, L’Oréal, Total and Lanzatech expect the industrialization phase to be completed by 2024.
In an exploratory scenario, the study “CO2 reduction potential of the chemical industry through CCU”  investigates the greenhouse gas (GHG) reductions that can be achieved in the global chemical and derived material industries if the entire demand for embedded carbon is met solely and exclusively via CO2 instead of from fossil sources.
Major simplifications are used in the study. For instance, methanol (CH3OH) is considered to cover the needs for hydrocarbons for chemicals and derived materials among the various chemical intermediates as a representative pathway for renewable carbon.
The examined production route includes CO2 capture as a mix of direct air capture (DAC) and capture from different point sources, hydrogen supply and the hydrogenation reaction for methanol synthesis.
Very significant reduction in GHG emissions
The GHG emissions related to CCU-based methanol synthesis depend on the emissions of the renewable energy production. According to the study, emissions of CCU-based methanol could be 67 to 77% lower compared to emissions from releasing embedded carbon of fossil fuels, when using current energy supply based on photovoltaics. With improvements in renewable energy production, the reduction could increase to levels between 96 and 100%.
Meeting the annual global demand for carbon embedded in chemicals and derived materials (450 million tonnes of carbon today and maybe 1,000 million tonnes by 2050) with CCU-based methanol would cause an immense demand of renewable energy.
Enormous efforts would have to be made to deploy sufficient renewable energy, but the results are worth it. Indeed, with fully decarbonised energy supply, an amount of 3.7 Gt CO2 per year can be saved.
“These GHG emission savings are significant - even in comparison to today’s global emissions of 55.6 Gt CO2 eq/year. The result shows that CCU is a promising technology to reduce GHG emissions related to embedded carbon supply - if sufficient renewable energy is available,” said the authors of the study.
As a conclusion, while CCU-based carbon could be an important pillar of a future build on renewable carbon, complementing carbon from recycling and from biomass, the production of renewable energies must be rapidly expanded to enable the full deployment of the technology.