An integrated techno-economic analysis and life cycle assessment of lube oil production from post-use polypropylene and comparison with conventional base oils

Abstract

This study presents an integrated analysis of the technical, economic, and environmental performance of upcycling post-use polypropylene (PU-PP) through hydrogenolysis, using a platinum strontium titanate (Pt/SrTiO₃) catalyst. This process generates lubricating oils from upcycled plastics, also referred to as LOUPs. The refining of Group I, II, and III base oils from crude oil is also evaluated as a conventional process for comparison with LOUPs production. The minimum selling price (MSP) of LOUPs was estimated at $2.18 per gallon, representing reductions of 16%, 49%, and 61% compared to the MSPs of conventional Group I, II, and III base oils, respectively. The greenhouse gas (GHG) emissions from LOUPs production ranged between 0.6 and 0.7 kg CO₂e per kg. These emissions are up to 40% higher than those of Group I base oil but 62% and 74% lower compared to Group II and Group III base oils, respectively. Hydrogenolysis also resulted in lower GHG emissions compared to conventional end-of-life (EOL) management of PU-PP. According to these findings, the analysis presented showed the cost-effectiveness and environmental benefits of producing LOUPs from PU-PP in comparison to conventional Group II and III base oil refining.