Comparative Life Cycle Assessment of Biolubricants and Mineral Based Lubricants

Biolubricants are employed to various degrees with the hope of minimizing the life cycle environmental impacts compared to mineral based lubricants. Approximately 50 percent of all traditional lubricants are released into the environment during use, spills, and disposal causing impacts that could be reduced with the use of biolubricants. Traditional lubricants, mostly mineral based, are not completely biodegradable and have high toxic content compared to biobased options produced from plant oils, such as: sunflower, soybean, rapeseed, algae, palm, and coconut. Therefore, new and used lubricants can cause significant damage to the environment, especially to water sources. Research on biobased lubricants has generated varying conclusions regarding the environmental effects of these products. A comparative life cycle assessment of rapeseed, soybean, and mineral based lubricants was performed in this study to determine the environmental impacts caused by these products. The assessment included an evaluation of the impacts to air and water created during extraction and production of these materials. A detailed analysis of the eutrophication potential impact category was completed to address missing inventory data. Additives, lubricant use, and lubricant disposal were not included in the assessment. The assessment resulted in rapeseed lubricants with the largest contribution in several impact categories including: acidification potential, photochemical smog, and eutrophication potential. Mineral lubricants dominated the global warming potential and ozone depletion potential categories.The effects of an increase in the use of biobased lubricants in the U.S. are discussed in addition to the environmental effects caused by the use of different lubricants. A comparison of the acidification potential and ozone depletion potential emissions from each of the lubricants for different use scenarios was also calculated. In addition, the direct land use impacts from producing 2 billion gallons of lubricants from biobased sources instead of mineral based sources were determined. Finally, a decision matrix framework is developed to include life cycle assessment results and other lubricant properties