Rerefining of used oils — a review of commercial processes

Abstract

The total demand for lubricants in India is in the region of 855,000 tonnes a year. This constitutes 1.5% of total petroleum products consumption. Presently, there are three lubricant refineries in the country with a total installed capacity of 535,000 tonnes. The shortfall, of about 370,000 tonnes (approximately 45% of demand), is met through imports. In addition, there are generated 60,000-65,000 tonnes a year of base oil through rerefining of used oils. The three refineries are being expanded in order to raise base oil production to 810,000 tonnes per annum. Some other refiney projects are also under consideration and approval by the government. The current expansion programmes, together with the projected new refineries, are expected to make India selfsufficient in terms of base stock production lubricant.Overall, lubricant production in India is entirely dependent on imported lubricant-bearing crudes, and not on the indigenous crudes, which are non-lube bearing. With recent advances in engine design, together with improved lubricant quality through high-performance lubricants, the consumption, or demand rate, has been in decline or unchanging in most countries. In India, a gap still exists between production and demand of lubricants, necessitating import. Since they are a high-value, non-energy product, lubricant conservation measures are therefore essential.Interest in rerefining of used oil is increasing, with more and more emphasis on making the processes environmentally friendly. The conventional acid-clay rerefining process is environmentally unfriendly, and hence needs modification. An attempt is made in this paper to highlight various rerefining processes available. The relative merits and demerits of each process are discussed, and among the various processes, that based on molecular/high vacuum distillation is covered in detail. lNTRODUCTlONLubricating oils are high-value, non-energy products, obtained mainly from refining of crude oils. Recognising the finite source

Recycling of Waste Engine Oils Using a New Washing Agent

“…The process is a continuous operation as it removes metal particles and dusts from used engine oil and improves the recovered oils liquidity and flash point. Despite the above mentioned advantages, the expensive membranes may get damaged and fouled by large particles [15].…”

Compound changes in re-refined used lubricating oils using fabricated Packed-bed reactor

“…The process is carried out at 40 °C and 0.1 MPa pressure. 15 It is an uninterrupted operation procedure, it eliminates metal particles and dusts from used engine oil and also improves the recovered oils liquidity and its flash point. Its shortcomings are that the expensive membranes used in the method may get spoiled or fouled by large particulate matters.…”

“…Its shortcomings are that the expensive membranes used in the method may get spoiled or fouled by large particulate matters. 9,15 The application of the packed-bed reactor using the locally available diatomaceous material is a safe and economical small-scale purification of used lubricating oil since the contaminants have good affinity for diatomaceous materials. This approach is similar to the principle of chromatography separation, hence this study.…”

Comparative Study between Physical Properties of Virgin Oil and Re-Refining Oil

“…Therefore, good lubrication oil in an engine optimizes the yield by reducing the mechanical losses due to friction [8]. The motor oil can be re-refined by several methods such as Acid-Clay Treatment [9], Solvent Extraction [10], Membrane Filtration [11] etc., but the batch acid clay is a major process for re-refining motor oil in the Kurdistan Region as shown in Figure 1 [12].…”