Effects of process parameters on recovery of base oil from spent lubricants using solvent extraction method

摘要

Typically lubricants contain 90% base oil(most often petroleum fractions,called mineral oils) and less than 10% additives.Vegetable oils or synthetic liquids such as hydrogenated polyolefins,esters,silicones,fluorocarbons and many others are sometimes used as base oils.Solvent extraction is the method to eliminate the usage of high temperature or hydrogenation process in re-refining the base oil from spent lubricant oil.The main objective of this study is to recover the base oil from spent lubricants using solvent extraction method.Besides that,the effect of different solvent,the retention time and the characteristics of the extracted base oil are also determined.The raw materials that being used were spent lubricant oil and two types of solvents.These solvents are hexane mixed with potassium hydroxide in isopropyl alcohol and N-vinyl-2-pyrolidone (NNVP).During the experimental study,200 ml of lubricant oil and 800 ml of solvents were mixed and leave to settle.After that,the mixture was filtered by vacuum pump to separate the sludge.Separation was continued using rotary evaporator to get the pure base oil.Then,the characteristics of the base oil for every mixture were analyzed.Results shows that the best solvent,is solvent 1 (Hexane + KOH + IPA) because it can recover more volume of base oil compare to solvent 2 (NNVP).Besides that,the best stirring time (retention time) for both solvent is 60 minutes.Solvent 1 is better than solvent 2 because it can recover higher volume of base oil compared to solvent 2 by 37%.As a recommendation for future work,in order to recover higher volume of base oil,the amount of potassium hydroxide (KOH) used must be increased.