Process Design and Greenhouse Gas Analysis of an Electrified Mixed Plastic Waste-to-Olefins Value Chain

Abstract

This work presents the conceptual process design and life-cycle Greenhouse Gas (GHG) analysis for converting mixed plastic waste (MPW) into polymer-grade olefins (≥99.9 wt % ethylene and propylene) via sequential pyrolysis, e-cracking, compression, and separation. The integrated plant-wide process modeling was performed within a Python-based framework as an alternative to conventional commercial simulators. Eight scenarios were assessed by combining centralised and decentralised configurations, combined heat and power (CHP)-powered and fully electrified operation, and grid versus renewable electricity supply. Under fully electrified conditions, the carbon footprint strongly depends on the electricity source. When onshore wind-harvested electricity is assumed, GHG emissions decrease to ∼0.08 kg CO2-eq per kg of high-value chemicals (HVCs), placing the process within the EU’s 2040 climate objective of a 90% reduction relative to the sector’s conventional benchmark (i.e., naphtha steam cracking, ∼1 kg CO2-eq per kg of HVC). Sensitivity analysis showed that transport-related emissions are a significant contributor in the fully electrified scenario. In particular, maintaining the targeted 90% GHG reduction relative to the conventional benchmark is only feasible for MPW transport distances of ∼ 160–180 km.