From fossil to green chemicals: sustainable pathways and new carbon feedstocks for the global chemical industry

Abstract

Following current trends, the global chemical industry is set to become the largest consumer of fossil fuels. Among energy intensive industries, the chemical industry is one of the most challenging to defossilise due to the abundance of cheap fossil fuel-feedstocks and it is currently responsible for roughly 3% of global anthropogenic CO₂ emissions. Unlike other energy-intensive industries, the chemical industry cannot be made fully sustainable directly with renewable electricity and green electricity-based hydrogen (e-hydrogen). Therefore, new green carbon feedstocks must be developed to defossilise the production of large volume organic chemicals. The most promising green carbon feedstocks are electricity-based methanol (e-methanol) and biomass-based methanol (bio-methanol), which can be used directly or as a feedstock for olefin and aromatic production. Increased recycling of plastics will reduce the amount of primary feedstock that will be required for chemical production. To investigate the energy and feedstock requirements for a global defossilisation of chemical production, scenarios are developed that reach net-zero emissions by 2040, 2050, and 2060 compared to business-as-usual conditions to 2100. High and low biomass feedstock variations are included to investigate the potential of biomass feedstocks in the future chemical industry, which are limited due to strict sustainability criteria. The results suggest that the chemical industry could become the largest e-hydrogen consumer, with a demand ranging from 16 100 to 23 100 TWh_H2,LHV in 2050. High shares of electricity-based chemicals (e-chemicals) were found to provide the lowest annualised costs, suggesting that an e-chemical transition pathway may be the most economically competitive pathway to defossilise the global chemical industry.