Olefins production through sustainable pathways: techno-economic and environmental assessment

This study presents a comparative analysis of various configurations for sustainable olefins production via chemical recycling of plastic/biomass wastes, integrating CO2 capture, storage and management technologies. The co-gasification, methanol synthesis and methanol-to-olefins process models were developed on the Aspen Plus software. Optimization of processing conditions is achieved through the OSMOSE Lua platform, for minimizing the total cost of operation while accounting for seasonal variability in the electricity prices. CO2 valorization processes have been shown to increase carbon efficiency from 55% up to 97% compared to steam naphtha cracking, making chemical recycling of plastics an appealing alternative. In addition, direct CO2 emissions can be fully eliminated, resulting in up to 70% lower net CO2 emissions even when fossil-based plastic waste is used as feedstock. Seasonal CO2 storage can extend the economic benefits by acting as a buffer against high electricity costs and serving as a feedstock for CO2 valorization processes when excess renewable electricity is available. The benefits of the proposed configurations are expected to become increasingly significant with the decarbonization of the electricity generation, relying more on renewable resources.