Alternative feedstocks were derived from non-fossil sources of carbon, where carbon atoms came from the atmosphere (bio-based and direct air capturecarbon capture and utilization (DAC-CCU)) or from recyclates (chemical recycling, such as pyrolysis and gasification, as well as point-source CCU). The energy used in the production processes for the seven chemicals within the scope of this study was assumed to be net zero by 2050, coming from renewable sources such as solar and wind, and non-fossil sources such as nuclear energy. CCS was deployed to capture scope 1 CO2 emissions from production processes, such as steam methane reformers used to produce hydrogen and off-gas used as fuel in naphtha crackers. CCS was also used to capture CO2 emissions from incinerators in waste treatment in the downstream of the value chain, with all incinerators assumed to be fitted with CCS by 2050.