Re-refining of used oil using multi-component solvents
Edeoji MI, Enebe CC, Amadi CC
Engine oil is used to lubricate moving parts, reduce friction and to protect engine from knocks. They also help to suspend solids, particulate matter, metal particles, notably iron and steel as well as other compounds like burnt carbon, ash and water. Re-refining of engine oil involves the separation of water and suspended particles, other compounds and sludge from used oil. It also involves an improvement on the colour and removal of any associated contaminants that infiltrated into the engine oil during use. This study concerns itself with the application of multi-component solvents in the treatment of used engine oil with a view to restoring it to re-useable state and original state or its equivalent. The used engine oil was blended with different solvents as samples A, B and C. The solvent to oil ratios were varied and identified as sample D and E. Given samples were treated with alumina and silica gel identified as sample F. The various samples were analyzed. The ash content, fire point, pour point, viscosity, specific gravity, density colour and colour reduction were determined. The ash content decreased from 0.56 to as low as 0.37 and closer to the ash content of the original oil (Mobil special) of 0.27. The fire point improved to 330 from 280 and moved closer to the fire point of Mobil special, which is 322. The pour point improved to -30 as against -29 of Mobil special from the original value of -24. The specific gravity moved from 0.888 to 0.8807 which is quite close to Mobil special’s 0.8805. Density decreased from 0.8841 to 0.8751 which is quite close to Mobil special’s 0.8759. The colour of the samples indicated optical change from black to yellow. The ranges approximates to the standard properties of engine oils although with slight deviation from the reference Mobil special except for viscosity which has been altered by the blended solvents.