Transportation and process modelling-assisted techno-economic assessment of resource recovery from non-recycled municipal plastic waste

Abstract

Less than one-tenth of municipal plastic waste generated is mechanically recycled, resulting in the remainder ending up in incineration plants or landfills worldwide. There is limited consideration on the effects of system scales and transportation processes on the economic feasibility of municipal plastic waste treatment. In this study, a techno-economic assessment framework was developed for pyrolysis-based resource recovery from non-recycled municipal plastic waste. The framework incorporates detailed transportation and process modelling with cost-benefit analysis, which enables greater assessment flexibility and accuracy and the accounting of the effects of system scale. The techno-economic feasibility of centralized large-scale and decentralized small-scale systems that recover value-added fuels (diesel and hydrogen), with and without carbon capture and storage units, were compared. The large-scale diesel system without carbon capture and storage reflected a real-world demonstrator, while other systems considered in this study were proposed alternatives to non-recycled municipal plastic waste management. Specifically, the municipal plastic waste transportation, and pyrolysis-based diesel and hydrogen production from non-recycled municipal plastic waste were modelled and simulated using ArcGIS Pro and Aspen Plus software, respectively. The data of transportation and process modelling were feed into a cost-benefit analysis to calculate the net present values of relevant developments. It was shown that only centralized large-scale diesel production, with and without carbon capture and storage, exhibited total positive net present values (£22,240,135 and £24,449,631, respectively), indicating their economic feasibility. The decentralized small-scale hydrogen production system with carbon capture and storage yielded the lowest net present value result (−£2,391) per tonne of treated non-recycled municipal plastic waste. Particularly, the production of diesel and hydrogen from non-recycled municipal plastic systems, with carbon dioxide emissions to the environment, demonstrated better economic performance than the same systems capturing and storing carbon dioxide, attributable to its higher capital and operational expenditures. Finally, sensitivity analysis revealed that the fuel sales price and OPEX had the most significant impact on the net present values.