Biolubricants through renewable hydrocarbons: A perspective for new opportunities

An overview is provided of commercially-available biolubricants, along with the manufacturing technologies used to make them, and emerging production technologies that show promise. Ester-based biolubricants enjoy the most widespread commercial use, even though complex chemical modifications are required to improve their physicochemical properties. Renewable-hydrocarbon biolubricants can be more attractive because they possess desirable qualities such as superior cold-flow properties and oxidative and hydrolytic stability. In addition, hydrocarbon-based biolubricants are more similar to conventional lubricants and can be easily substituted using existing infrastructure and lubricant formulations. Current research on renewable hydrocarbons is heavily focused on hydrodeoxygenation of vegetable oils involving operating conditions in excess of 50 bar and 450 degrees C. Alternative routes such as those involving electrochemical decarboxylation through Kolbe electrolysis benefit from milder conditions and consume less hydrogen overall. A further benefit of Kolbe electrolysis is the potential for integration into renewable energy systems. Further research into this technology could open the doors to low-cost, high-quality renewable hydrocarbons for use as biolubricants.