Solvent Refining of Waste Locomotive Oil

The potential of ten solvent in the refining of waste locomotive oil have been examined and evaluated The solvents studied were butanone, methyl-isobutyl ketone (MIBK), methyl normal - propyl ketone (MNPK), methyl ethyl ketone (MEK), butyl alcohol, sec-butyl alcohol, pentanol, hexanol, hexane and n-heptane. The solvents were evaluated on the basis of the percent sludge removal, sludge settling rate, oil recovery (yield) and their physico - chemical properties. The optimum settling time and solvent to waste oil ratio were determined to be 24 hours and 5:1 respectively. On the basis of sludge removal potential butyl alcohol ranks first followed by sec-butyl alcohol, butanone, pentanol, hexanol, MEK, MNPK, MIBK, hexane and n-heptane in that order. All the solvents gave very high yields of the refined oils. The physico-chemical properties of the re-refined oils are within acceptable limits. Generally, the properties remained approximately constant regardless of the solvent used for extraction.