Most conventional processes for used lubricant regeneration involve physical separation and chemical treatments to remove the contaminants and impurities from used lubricants to make it suitable for re-use. Some of these technologies generate liquid effluents, solid wastes, and air emissions during the regenerating process. The types of wastes, effluents, and wastes vary with the technology and processes used, and the environmental control methods [CEPA, 1994].
Liquid effluents are required additional treatments before they can be reused for cooling or discharged to a sewer system [CEPA, 1994]. Solid wastes generated from the regenerating process include various types of sludge (e.g., acid sludge, soot sludge, used clays, and other impurities) depending on the …show more content…
Using the centrifugal force is one of the solutions to settle water and suspending impurities from used lubricants [Audibert 2006]. However, centrifugation still cannot remove all impurities in used lubricants. Thus, centrifugation is commonly used as a pretreatment to eliminate large and heavy such as metal fragments from tear and wear of moving parts and sands. Centrifugation is also used to separate acid sludge in acid treatment process [Hamad, et al., 2002].
Used Lubricant Regeneration Systems
Used lubricant is a complex mixture of various materials, such as liquid phase of hydrocarbons and solid phase of impurities. Thus, there is no single process or technology that can achieve all requirements needed for the regeneration of used lubricants. The conventional systems usually combine two or more processes as discussed in the previous section in order to regenerate used lubricants into an acceptable quality. Table-1 summaries the most popular systems used today for the regeneration of used lubricants.
Process Name