Enhancement of cold flow property of coconut oil by alkali esterification process and development of a bio-lubricant oil

Abstract

The low cold flow property of the coconut oil restricts its tribological applications as a lubricant. The flow property at low temperature was improved by removing the glycerol molecules from the oil thereby converting the fatty acids into esters by the process of alkali esterification. Free movement of these fatty acid esters have improved the cold flow properties of the oil from 26.8 ℃ to −4.5 ℃, but have an inverse effect of reduction on the tribological properties when compared to crude coconut oil. Additives such as tricresyl phosphate, oleic acid, and ethylene vinyl acetate were used to improve the anti-wear, anti-friction properties, and viscosity, respectively. The combined action of the additives have further improved the flow property to −6.9 ℃ and other tribological properties such as coefficient of friction and wear was reduced up to 12.8% and 2.3% respectively when compared to commercial two-stroke engine oil. Environmental hazards due to the exposure of newly formulated two-stroke engine oil were studied using bacteria ( B cereus and E coli). These results establish that the newly formulated oil is nontoxic and have comparable tribological properties to that of commercial two-stroke engine oil.