Recycling of Waste Engine Oil using Acetic and Lactic Acids as Washing Agents

Abstract

Waste engine oil (WEO) is known to contain metal, carbon and oxidized contaminants which are harmful to human and the environment. This research refines WEO using acetic and lactic acids as washing agents. Parameters such as kinematic viscosity, flash point, pour point, specific gravity were analysed for oils. The result of the experiment showed that the kinematic viscosity of WEO (165.52 cSt) increased when washed with acetic (181.20 cSt) and lactic acids (179.96 cSt) at 40oC similarly at 100oC closer to fresh oil value (192.71 cSt). The decreased flash point of WEO (175 oC) increased when treated with acetic (215 oC) and lactic acids (212 oC) compared to fresh oil (230 oC). The increased pour point of WEO (-6 oC) was reduced when treated with acetic (-11.5 oC) and lactic acids (-10.9 oC) which are close to fresh oil (-13 oC). The high specific gravity of WEO (0.9186) were reduced by acetic (0.8756) and lactic acids (0.8745) closer to fresh oil (0.8815). These reduced parameters in the WEO and its increased pour point and specific gravity indicates impurities and contaminants in WEO. The improved values with acetic and lactic acids showed that they are good washing agents. FTIR analysis of WEO showed additional peaks at frequencies 1054.8, 1109.2 and 2310 cm-1 representing the primary oxidized products at high temperature which are absent in fresh oil and WEO treated with acetic and lactic acids.

Keywords — Recycling, Waste engine oil, Acetic and lactic acid, Acid/clay technique, Oil parameters,

Fourier transform infrared spectroscopy (FTIR).