A Review on Biolubricants Based on Vegetable Oils through Transesterification and the Role of Catalysts: Current Status and Future Trends

Abstract

The use of biolubricants as an alternative to petroleum-based products has played an important role in the last decade. Due to the encouragement of global policies, which mainly support green chemistry and circular economy, there has been an increasing interest in bio-based products, including biolubricants, from scientific and industrial points of view. Their raw materials, production, and characteristics might vary, as biolubricants present different applications for a wide range of practical uses, making this field a continuously changing subject of study by researchers. The aim of this work was to study biolubricant production from vegetable oil crops from a bio-refinery perspective, paying attention to the main raw materials used, the corresponding production methods (with a special focus on double transesterification), the role of catalysts and some techno-economic studies. Thus, the main factors affecting quality parameters such as viscosity or oxidative stability have been covered, including catalyst addition, reaction temperature, or the use of raw materials, reagents, or additives were also analyzed. In conclusion, the search for suitable raw materials, the use of heterogeneous catalysts to improve the effectiveness and efficiency of the process, and the optimization of chemical conditions seem to be the most interesting research lines according to the literature.