Lubricating oils keep machinery cleaner and allow the machinery to work under severe operating conditions. However once used, they need special attention as if they are disposed of without treatment, they cause serious pollution problems. The motivation of our Process Report was to develop a method which is energy economical i.e. uses less energy owing to increasing energy issues of Pakistan. In this project we studied different existing processes and then formulated a process which is more energy efficient. We found re-refining of waste lubricating oil by Acid treatment method as one of the potential techniques. Used lubricating oil sample is collected from a service station and tests are performed on it in post graduate lab, sample is heated in  a beaker by heating coils in control temperature  60⁰C because lube oil is start to decompose at about 65⁰C. Sulfuric acid is used as a hydroscopic compound sample and acid ratio is about 10:1 in ml. When water is removed from our sample activated charcoal is added in it to remove dirt particles from the sample at the end when sample viscosity and density is achieved as per requirement it is filtered with the help of clay to regenerated its yellowish color Different acids were tested with oil samples and sulphuric acid  gave out the best results. The Base oil that was regenerated was tested for various properties like Flash point, Pour point, Specific gravity, Viscosity etc