Development of P-Graph Models for the Synthesis of Plastic Waste-To-Fuel Supply Chain

Abstract

The conversion of plastic waste into fuel presents a sustainable solution to plastic pollution and fuel shortages. Several plastic waste-to-fuel technologies exist, and the quality and yield of the resulting fuels depend on factors like feedstock composition and treatment processes. Large-scale commercialization is hindered by environmental concerns, particularly carbon emissions. To address this, a systematic optimization approach is necessary to ensure environmental and operational viability. This study applies Process Graph (P-Graph) models to optimize the plastic waste-to-fuel supply chain, identifying network configurations that meet fuel demand while minimizing carbon emissions. An illustrative case study was analysed to delineate the capabilities of the P-graph framework in the fuel distribution system. The case study considers the carbon emissions of networks where the optimal solution yielded a carbon footprint of 0.1229 t CO₂/GJ. Carbon footprint values of the 32 feasible structures were found to range up to 0.1266 t CO₂/GJ. These findings demonstrate the P-Graph framework’s potential in supporting low-emission, flexible system designs.