Corrosion of aluminium in water-in-diesel-emulsion fuel

Abstract

This study aimed to determine the corrosion characteristics of water-in-diesel emulsion fuel towards aluminium. Investigation was performed by immersing aluminium coupons in emulsified diesel for 240 hours, 480 hours, 720 hours, 960 hours and 1200 hours at 25 °C. For comparison, additional aluminium coupons were immersed in diesel for 1200 hours at 25 °C. Span 80 and Tween 80 surfactants were used to prepare the emulsified diesel which consisted of 5 vol% of water and 95 vol% of diesel. Mass loss of the coupons were measured to calculate the corrosion rate. Water content, total acid number, density and viscosity of the fuel samples were measured before and after immersion. The corrosion rate of aluminium coupons exposed to emulsified diesel reduced by 97.6% between 240 hours and 1200 hours of immersion duration. The aluminium coupons immersed in emulsified diesel had 2.2 times higher corrosion rate than in diesel. The higher total acid number of emulsified diesel by 4.7 times than diesel is suggested to have influenced this. To benefit the potential reduction in harmful exhaust emission through the adoption of emulsified diesel, studies towards producing less acidic stable emulsified diesel are essential.