Lube refining

Lube refining consists of several treating steps. Lube oil fractions as obtained from the VPS are seldom suitable as base stocks for blending branded lubricants or... 

At the time of this writing, urea dewaxing has ceased to be a significant process in lube refining, overtaken by superior technologies. There is still interest in the chemistry, however, and it is conceivable that it may reemerge for other specific purposes. Papers on urea inclusion compounds regularly appear in the... 

Examines traditional methods and the newer hydroprocessing steps employed by major lube refiners... 

Simple conventional refining is based essentially on atmospheric distillation. The residue from the distillation constitutes heavy fuel, the quantity and qualities of which are mainly determined by the crude feedstock available without many ways to improve it. Manufacture of products like asphalt and lubricant bases requires supplementary operations, in particular separation operations and is possible only with a relatively narrow selection of crudes (crudes for lube oils, crudes for asphalts). The distillates are not normally directly usable processing must be done to improve them, either mild treatment such as hydrodesulfurization of middle distillates at low pressure, or deep treatment usually with partial conversion such as catalytic reforming. The conventional refinery thereby has rather limited flexibility and makes products the quality of which is closely linked to the nature of the crude oil used. 

A new countercurrent continuous centrifugal extractor developed in the former USSR (214) has the feature that mechanical seals are replaced by Hquid seals with the result that operation and maintenance are simplified the mechanical seals are an operating weak point in most centrifugal extractors. The operating units range between 400 and 1200 mm in diameter, and a capacity of 70 m /h has been reported in service. The extractors have been appHed in coke-oven refining (see Coal conversion processes), erythromycin production, lube oil refining, etc. 

Lubricants. Petroleum lubricants continue to be the mainstay for automotive, industrial, and process lubricants. Synthetic oils are used extensively in industry and for jet engines they, of course, are made from hydrocarbons. Since the viscosity index (a measure of the viscosity behavior of a lubricant with change in temperature) of lube oil fractions from different cmdes may vary from +140 to as low as —300, additional refining steps are needed. To improve the viscosity index (VI), lube oil fractions are subjected to solvent extraction, solvent dewaxing, solvent deasphalting, and hydrogenation. Furthermore, automotive lube oils typically contain about 12—14% additives. These additives maybe oxidation inhibitors to prevent formation of gum and varnish, corrosion inhibitors, or detergent dispersants, and viscosity index improvers. The United States consumption of lubricants is shown in Table 7. 

Petroleum sulfonates have traditionally been produced by both batch and continuous treatment of petroleum oils with oleum. These processes have been covered in several reviews (138,139). Natural petroleum sulfonates are coproducts in the manufacture of a variety of refined oils, most notably white (mineral) oils, lube oils, and process oils (plasticizer oils for mbber compounding). The feedstocks are selected primarily on the basis of the desired characteristics of the refined oils which generally contain 15—30% aromatics. 

Gasoline accumulator Solvents Storage vessels Lube oil refining Polyethylene gas vents Styrene Copper naphthenates Insecticides Phthalic anhydride Resin reactors Ammonia Chlorine solutions Dry cleaning Degreasers Tar dipping Kraft paper... 

In practice, treatment (1) usually involves a contractor collecting a segregated batch of oil, reconditioning and returning it for re-use. A contractor can carry out the simple filtration process, but it is more usually done on-site. Re-refining is the removal of contaminants and oxidation products and previously incorporated additives to recover the lube base stock for new lubricant or other applications. 

Bridge, A.G. (1997) Chevron isocracking-hydrocracking for superior fuels and lubes production, in Handbook of Petroleum Refining Processes, 2nd edn (ed. R.A. Myers), McGraw-Hill,... 

The major solvent refining processes include solvent deasphalting, solvent dewaxing, lube oil solvent refining, aromatic extraction, and butadiene extraction. These processes are briefly described below. 

Lube oil solvent refining includes a collection of subprocesses improving the quality of lubricating oil stock. The raffinate or refined lube oils obtain improved viscosity, color, oxidation resistance, and temperature characteristics. A particular solvent is selected to obtain the desired quality raffinate. The solvents include furfural, phenol, sulfm dioxide, and propane. 

Solvent-refined and dewaxed lube oil stocks can be further refined by clay or acid treatment to remove color-forming and other undesirable materials. Continuous contact filtration, in which an oil-clay slurry is heated and the oil removed by vacuum filtration, is the most widely used... 

ZSM-5 is a Mobil-proprietary, shape-selective zeolite which is used commercially in synthetic fuels (methanol-to-gasoline), petrochemicals (xylene isomerization, toluene disproportionation, benzene alkylation) and in petroleum refining (lube and... 

The petroleum refining companies have an intermediate position, since 44% of the products are sold directly to individuals, as gasoline and lube oil at gasoline stations. The other main customers are the four transportation industries taking 12% of products as jet fuel for airplanes, bunker oil for ships, and kerosene for buses and trucks. The Utility-sector buys heavy fuel oil to generate heat and electricity. The heavy sale to the Construction industry is both for fuel and for asphalt for paving roads and for roofs. 

Lube Stock—Refiner term for fraction of crude petroleum suitable in terms of boiling range and viscosity to yield lubricating oils when further processed and treated. 

EPA) to aid in registering chemicals under the federal Toxic Substances Control Act (TSCA) of 1976. CAS numbers are assigned to generic refinery process streams, such as kerosene and lube base stocks, that contain no additives. Petroleum products containing additives are termed "mixtures" by the TSCA and, as such, do not have CAS numbers. All chemical substances used in such mixtures are assigned CAS numbers and must be listed with the EPA by the refiner or the additive supplier. 

Lube cut a fraction of crude oil of suitable boiling range and viscosity to yield lubricating oil when completely refined also referred to as lube oil distillates or lube stock. 

ExxonMobil is now licensing this technology to other refineries. Development of similar applications in other operations is likely. Initially, applications will probably involve relatively easy separations such as the separation of methyl ethyl ketone/toluene from lube oil described above or soybean oil from hexane in food oil production. Long-term, however, the technology may become sufficiently advanced to be used in more important refining operations, such as fractionation... 

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