Methyl ethyl ketone dewaxing

MEK is also used iu solvent-based adhesives, iu printing ink formulations, as a solvent iu magnetic tape manufacture, and is the most common solvent used iu dewaxing lubricating oils. Of all these appHcations only an increasing consumption of magnetic tapes is likely to grow ia methyl ethyl ketone use. 

Solvent Treatment. Solvent processes can be divided into two main categories, solvent extraction and solvent dewaxing. The solvent used in the extraction processes include propane and cresyHc acid, 2,2 -dichlorodiethyl ether, phenol (qv), furfural, sulfur dioxide, benzene, and nitrobenzene. In the dewaxing process (28), the principal solvents are benzene, methyl ethyl ketone, methyl isobutyl ketone, propane, petroleum naphtha, ethylene dichloride, methylene chloride, sulfur dioxide, and iV-methylpyrroHdinone. 

Insofar as they are used to purify other products, several processes used in the refinery fall under the classification of dewaxing processes however, such processes must also be classified as wax production processes (2). Most commercial dewaxing processes utilize solvent dilution, chilling to crystallize the wax, and filtration (28). The MEK process (methyl ethyl ketone—toluene solvent) is widely used. Wax crystals are formed by chilling through the walls of scraped surface chillers, and wax is separated from the resultant wax—oil—solvent slurry by using fliUy enclosed rotary vacuum filters. 

Solvents used for dewaxing are naphtha, propane, sulfur dioxide, acetone—benzene, trichloroethylene, ethylenedichloride—benzene (Barisol), methyl ethyl ketone—benzene (benzol), methyl -butyl ketone, and methyl / -propyl ketone. Other solvents in commercial use for dewaxing include /V-methylpyrrolidinone, MEK—MIBK (methyl isobutyl ketone), dichloroethane—methylene dichloride, and propfyene—acetone. 

Sources. Methyl ethyl ketone (MEK) is used in some r neries as a solvent in lube oil dewaxing. Its extremely volatile characteristic makes fugitive emissions its primary source of releases to the environment. 

Lubricating Oil Manufacture This consists of solvent deasphalting, phenol treating, and solvent dewaxing. In dewaxing, waxy lube is diluted with a solvent such as propane or methyl ethyl ketone (MEK), and cooled to crystallize the wax which is then removed by filtration. 

Methyl ethyl ketone may also he produced hy the catalyzed dehydrogenation of sec-hutanol over zinc oxide or brass at about 500°C. The yield from this process is approximately 95%. MEK is used mainly as a solvent in vinyl and acrylic coatings, in nitrocellulose lacquers, and in adhesives. It is a selective solvent in dewaxing lubricating oils where it dissolves the oil and leaves out the wax. MEK is also used to synthesize various compounds such as methyl ethyl ketone peroxide, a polymerization catalyst used to form acrylic and polyester polymers and methyl pentynol by reacting with acetylene ... 

Dewaxing (Figure 4.17) processes also produce heater stack gas (carbon monoxide, sulfur oxides, nitrogen oxides, and particulate matter) as well as hydrocarbon emission such as fugitive propane and fugitive solvents. Steam stripping wastewater (oil and solvents) and solvent recovery wastewater (oil and propane) are also produced. The fugitive solvent emissions may be toxic (toluene, methyl ethyl ketone, methyl isobutyl ketone). 

Solvent dewaxing removes wax from lubricating oil stocks, promoting crystallization of the wax. Solvents include furfural, phenol, cresylic acid-propane (DuoSol), liquid sulfur dioxide (Eleleanu process), B,B-dichloroethyl ether, methyl ethyl ketone, nitrobenzene, and sulfur-benzene. The process yields de-oiled waxes, wax-free lubricating oils, aromatics, and recovered solvents. 

The first commercial installation employing special organic solvents in dewaxing was made by the Indian Refining Co. in 1927 (32). The process as originally used employed a mixture of acetone and benzene as the special solvents, based on the inventions of F. X. Govers. The process as further developed employs a mixture of methyl ethyl ketone and aromatic solvents such as benzene and toluene. It is known as the solvent dewaxing process. 

Furby (12) has developed a method for evaluating stocks in the lubricating oil range that results in a breakdown of components into asphaltenes, resins, wax, and dewaxed oil and provides a yield-viscosity index relationship for the dewaxed oil. The author has found such analyses very useful and inexpensive for evaluating a large number of potential lubricating oil stocks. Furby s method utilizes petroleum ether to precipitate asphaltenes, a fuller s earth-petroleum ether fractionation to isolate resins, methyl ethyl ketone-benzene dewaxing on the deasphalted-deresinified material to separate wax, and an adsorption fractionation to provide cuts from which the yield-viscosity index relationship for dewaxed, solvent-refined oil is obtained. 

Solvent extraction has become the most widely used method of refining lubricating oils. Selective solvents which extract the less desirable constituents include phenol, furfural, dichloroethyl ether, mixtures of cresylic acid and propane, and liquid sulfur dioxide. Liquid propane precipitates asphaltic constituents and wax and retains the more desirable oil components in solution. Dewaxing may also be accomplished by other solvents such as mixtures of benzene and methyl ethyl ketone. 

Lube oil dewaxing -use of methyl ethyl ketone m [KETONES] (Vol 14)... 

MEK dewaxing a continuous solvent dewaxing process in which the solvent is generally a mixture of methyl ethyl ketone and toluene. 

In solvent dewaxing, the oil is diluted with a solvent that has a high affinity for oil, chilled to precipitate the wax, filtered to remove the wax, stripped of solvent, and dried. The solvents (principally propane, naphtha, methyl ethyl ketone-MEK) act as diluents for the high molecular weight oil fractions to reduce the viscosity of the mixture and provide sufficient liquid volume to permit pumping and filtering. Wax produced by the solvent dewaxing process is used to make (1) paraffins for candle wax, (2) microwax for cosmetics, and (3) wax for petroleum jelly. 

Solvents in use for wax removal include propane, which also serves as an autorefrigerant for the process by solvent evaporation, methyl ethyl ketone (MEK)-toluene mixtures, and methyl isobutyl ketone (MIBK). The last two systems are in widest use at present. MEK-benzene was once a common solvent combination for dewaxing but has now been abandoned from benzene toxicity considerations. 

Methyl ethyl ketone is essentially intended for solvent uses, in direct or indirect form, chiefly in paints and resins, nitrocellulose varnishes, adhesives and inks, and also for lubricant dewaxing. Its average commercial specifications are listed in Table lOtlO. 

The waxy raffinate from the solvent-extraction process is mixed with methyl ethyl, ketone, chilled, and filtered to remove the precipitated wax, after which the ketone is distilled away from the dewaxed oil. 

These features were also observed, although perhaps not quite as clearly in the dewaxing by urea and by methyl ethyl ketone (MEK) of an Indian washed Blue oil 27 (Figure 9.14) in which the solid point (closely related to the pour point) for the fractions is plotted against midfraction percent. The conclusion from this work is the same, that urea is much more effective in reducing the pour or solidification point for low viscosity (low boiling point) fractions than is solvent dewaxing. 

Examples of proposed DCC coolants include liquid butane for the seawater desalination process (section 8.4.7) and methyl ethyl ketone for the Dilchill lubricating oil dewaxing process (Bushnell and Eagen, 1975). Chlorinated hydrocarbons, fluorocarbons and CO2 have also found application in specific cases. 

Toluene, xylenes, and benzene constitute the majority of solvent emissions since they are native components of crude oil. Methyl ethyl ketone is also emitted in large quantities because of its use in lube oil dewaxing. 

Extraction is also important outside the food industry for example, in the extraction of wood resins and rare earth metal extraction. Solvents, such as methyl ethyl ketone, are often used in wax production by the dewaxing of lubricating and other natural oils. Solvents are also used in the extraction of North American tar sands and solvent extraction is important in many other parts of the petroleum industry but this often involves the use of relatively esoteric materials which are beyond the intended scope of this book. Solvents are also used in cleaning oil-contaminated aqueous effluents. 

Acetone is used to extract fats, oils, waxes, and resins from natural products, to dewax lubricating oils, and to extract certain essential oils. The pharmaceutical industry uses acetone to extract B-vitamin complexes, alkaloids, antibiotics and enzymes. Methyl ethyl ketone is used to dewax lube oil. Methyl isobutyl ketone is used to dewax mineral oil, refine tall oil, and in extractive distillation and separation of isopropyl alcohol from ethyl and butyl alcohols. The extraction and purification of antibiotics and other pharmaceutical products utilize MIBK. Methyl isobutyl ketone is used in the extraction of rosin from pine wood and the extraction of heavy metal ion complexes from water solutions. 

The majority of dewaxing processes today use Methyl Ethyl Ketone (MEK), Methyl IsoButyl Ketone (MIBK), mixtures of MEK and MIBK, or mixtures of MEK and Toluene or propane. There are advantages and disadvantages to each solvent system. 

Methyl Ethyl Ketone or loose term for ketone dewaxing unit... 

Solvent dewaxing removes wax (normal paraffins) from deasphalted lube base stocks. The main process steps include mixing the feedstock with the solvent, chilling the mixture to crystallize wax, and recovering the solvent. Commonly used solvents include toluene and methyl ethyl ketone (MEK). Methyl isobutyl ketone (MIBK) is used in a wax deoiling process to prepare food-grade wax. 

The largest industrial SRNF plant is installed in the petrochemical industry (Bhore et al., 1999). Wax is a monoester of fatty acids that severely modifies the properties of lube oil and must therefore be removed (Hart et al., 1995). The traditional process of dewaxing involved the cooling of a hydrocarbon mixture in solvent or solvent mixtures (methyl ethyl keton, acetone) to temperatures typically ranging from —5 to — 18°C. In this chilling section, waxy components coagulated and were precipitated or filtered the solvent in the filtrate was removed by evaporation and reused in the process (Cuperus and Ebert, 2002). 

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