Membrane separation in solvent lube dewaxing

Abstract Exxon Mobil Corporation and W.R. Grace have developed an enhanced process for recovering solvents used in the refining of lubricants. The membrane‐based process provides higher yields of lube oil, while simultaneously consuming less energy, decreasing cooling water use, and potentially reducing the level of volatile organic emissions from the dewaxing operation. The yield increase equates to a process savings, for a typical commercial plant, of about 2 million barrels of crude oil per year. By recovering and recycling the dewaxing solvent while bypassing the energy intensive parts of the plant, a single facility could reduce fuel oil consumption by 36,000 barrels/year, and greenhouse gas emissions by about 20,000 tons/year for each plant. The same plant would reduce cooling water use by nearly 4 million gallons/day, and, the release of dewaxing solvents, which are volatile organic materials, could be decreased by 50–200 tons/year per plant depending on the mechanical condition of its equipment. This technology was first implemented commercially at Exxon Mobil's Beaumont, Texas, Refinery. It can be easily retrofitted into existing plants or incorporated into new plant designs, and is currently available for license as the trademarked process MAX‐DEWAX®.