From fossil to biobased: a life cycle assessment of commercial-scale polyol ester lubricant base oils

Abstract

Lubricants are essential to industrial and transportation systems but remain largely petroleum-based, raising environmental concerns. Biobased alternatives offer a promising pathway to reduce fossil fuel dependence, yet their benefits remain underexplored, particularly in forward-looking assessments. Here, we present a cradle-to-gate and prospective life cycle assessment (pLCA) of a novel biobased secondary polyol ester (SPE) lubricant base oil developed by an industrial manufacturer, using high-resolution primary data from a commercial-scale production facility. The assessment incorporates Shared Socioeconomic Pathway scenarios (SSP1 and SSP2) modeled with the IMAGE integrated assessment model. The results show that SPE base oils reduce greenhouse gas emissions by up to 41% relative to fossil-derived polyol ester (DITA), and up to 84% when biogenic carbon uptake is considered. Performance is comparable to or better than both DITA and the European biobased ester LIGALUB 19 TMP across impact categories, including acidification and eutrophication. However, the analysis also reveals burden shifting: while GWP and cumulative energy demand decrease, freshwater ecotoxicity and ozone formation potential remain elevated due to upstream agricultural and chemical inputs. Fatty acids and polyols were identified as the dominant environmental hotspots, contributing over 80% to several categories. Geospatial and prospective modeling further show that regional electricity grid composition and global decarbonization pathways can moderately affect outcomes, with SSP1 scenarios offering future reductions. This case study advances the life cycle understanding of industrial biobased intermediates, emphasizing both the promise and complexity of low-carbon lubricants. Future progress will require integrated feedstock optimization, cleaner energy sourcing, and stronger alignment with circular economy principles.