Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Proceedings
Publication Acceptance Date: 6/20/2005
Publication Date: 9/17/2005
Citation: Erhan, S.Z., Sharma, B.K., Adhvaryu, A. 2005. Biobased lubricants: improvement in oxidation and low temperature stability. Association for the Advancement of Industrial Crops Conference. p. 204. Interpretive Summary:
Technical Abstract: The search for environmentally friendly materials that have potential to substitute for mineral oil in various industrial applications is currently being considered a top priority research in the fuel and energy sector. This emphasis is largely due to the rapid depletion of world fossil fuel reserves and increasing concern for environmental pollution from excessive mineral oil use and their disposal, especially in loss lubrication, military applications, and in outdoor activities such as forestry, mining, railroads, dredging, fishing and agriculture hydraulic systems. Vegetable oils have a capability to contribute towards the goal of energy independence and security due to their natural renewability. Vegetable oils are promising candidates as base fluid for eco-friendly lubricants because of their excellent lubricity, biodegradability, better viscosity-temperature characteristics and low evaporation loss. Their use, however, is restricted due to low thermo-oxidative stability and poor cold flow behavior. This paper presents a systematic approach to improve the oxidation and cold flow behavior of vegetable oil derivatives and the study of antioxidant/antiwear additive synergism in vegetable oils using pressure differential scanning calorimetry (PDSC) and Rotary Bomb Oxidation Test (RBOT). Synergism was investigated on a set of four antioxidants and three antiwear additives. Among the various possible avenues available, the combination of chemical additives and high-oleic vegetable oils offer the best option for achieving the ultimate goal. Vegetable oil-based lubricants formulated using the above approach exhibit superior oxidative stability, improved low temperature properties such as pour points and better wear properties compared to some of the commercially available industrial oils such as bio-based hydraulic fluids, biodegradable oils for heavy equipment and bio-based drip fluid for agriculture equipment. The above vegetable oil-based formulations compare at par with petroleum-based lubricants for use in high-temperature and high-pressure applications and often outperform the competition in some of its properties.