Palm oil as an alternative bio lubricant: A review

Abstract

Lubrication in mechanical operations involving relative motions of machine elements have been known to facilitate longer techno-economic life span of machine and its components. Lubrication reduces wear and tear of contacting surfaces in relative motion by creating a lubricous layered gap of fluid, powder or semi-solid like grease. Lubricant has also been proven to move heat away from rubbing surfaces to enhance thermal stability of their operations. Various methods, substances and technologies have been adopted to achieve the desired smooth running, minimize frictional losses and improve the thermal stability in the machine members. Mineral oils of long chain hydrocarbon as base oil have really gained ground as an extremely popular choice either in liquid or semi-solid state as lubricant. Recent research has however revealed that mineral oils are non-biodegradable, prone to pollution and hence constitute enormous risks to the environment. This observation and the need for a friendly environment have aroused the curiosity of researchers in the field of tribology and material engineering to the onerous challenge of finding alternative lubricants that will be harmless to the ecosystem and easy disposal of after use. Chief amongst the suggestions made towards the discovery of an environmentally friendly lubricant is the use of vegetable oils of distinct species. The identification of the potential available in vegetable oils has been demonstrated in certain classical operations requiring moderate temperature such as machining and few other cold working operations. This review examines the previous studies regarding the discovery of an alternative machine lubricant from the available vegetative seed oils, particularly palm oil, and suggests ways to improve previous findings and potentials.