Hydroconversion and solvent refining are now well established processes to produce high quality lubricant oils. The choice of a particular process depends mainly on the quality of the end product. Other important factors have also to be considered:1. Hydrogen availability and cost2. Market demand for by-product of solvent refining and solvent dewaxing (aromatic extracts and waxes)3. Capital investment and operating costs.At the Naftec refinery in Arzew, the first lubricant plant that started in the early seventies was based on the most recent process at that time, to make high quality base oils i.e. furfural extraction plus solvent dewaxing. Ten years later a newer and bigger lubricating oil plant (twice and a half the size of the old one: 120 000 MT/A) started producing the same base oils under the same process. The choice of the same process for the new lubricant oil plant was deliberate since first of all the quality of the base oils already produced was good enough to formulate all qualities of finished oils, there was a great demand for waxes on the national market, and last but not least trained operators on fairly identical units were available to start-up this new plant rapidly.If new lubricating oil facilities were to be built on the same site today, the choice would probably be different.Hydrorefining would be competitive against furfural extraction since with this newer process higher yields and higher viscosity index oils can be obtained. Distillates in excess and hydrogen being readily available on site. Furthermore hydrodewaxing looks very attractive nowadays since high yield and low pour point base oils can be obtained at a lower capital investment and reduced operating costs compared to solvent dewaxing.
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