Climate and biodiversity impacts of low-density polyethylene production from CO₂ and electricity in comparison to bio-based polyethylene

Plastics are essential materials for modern societies, but their production contributes to significant environmental issues. Power-to-X processes could produce plastics from captured CO₂ and hydrogen with renewable electricity, but these technologies may also face challenges from environmental perspective. This paper focuses on environmental sustainability assessment of CO₂-based low-density polyethylene (LDPE) compared to bio-based LDPE. Life cycle assessment has been applied to study climate impacts and land use related biodiversity impacts of different plastic production scenarios. According to the climate impact results, the carbon footprint of the produced plastic can be negative if the energy used is from wind, solar, or bioenergy and the carbon captured within the plastic is considered. In terms of biodiversity, land-use related biodiversity impacts seem to be lower from CO₂-based polyethylene compared to sugarcane-based polyethylene. Forest biomass use for heat production in CO₂-based polyethylene poses a risk to significantly increase biodiversity impacts. Taken together, these results suggest that CO₂-based LDPE produced with renewable electricity could reduce biodiversity impacts over 96 % while carbon footprint seems to be 6.5 % higher when compared to sugarcane-based polyethylene.