Biofuel is a renewable and environmentally friendly alternative fuel that can be used in diesel engines with little or no modification. Low cost feed stocks such as waste oils, used cooking oils and animal fats are important sources of biofuel production. Use of waste cooking oil as a biofuel offers the possibility of transforming a pollutant waste into a sustainable and renewable energy source. During production, transportation and usage, biofuels come in contact with materials at various stages. Therefore it is important to understand the influence of biofuels on materials. The corrosive nature of biofuels can be more aggravated if free water and free fatty acid are present in it. Hence the present study aimed to investigate the corrosion behavior of aluminium, mild steel and copper in used palm oil in comparison with that in aqueous medium by various methods. Surface morphology was examined by optical microscope. The negligible corrosion rate in 100% oil for all three metals indicates that the oil may be used as alternate fuel alone or in blends with petrodiesel. The measured contact angle is obtuse for the three metals suggesting that oil preferably wets the metals and thereby preventing corrosion.
