Methyl ethyl ketone Production

Table 5. United States, East Asia, and Western Europe Methyl Ethyl Ketone Production ...

Manufacturing processes for sustainability can be optimized in the context of life cycle analysis (Shoimard and Hiew 2000). It involves definition of the process boundaries and quantifiable sustainability impacts in the form of established metrics, incorporated into process design and optimization. It has been applied to determining waste treatment options, abatement of pollution, and designing the optimal recipe of solvents. Impact indices, such as ozone depletion potential to human toxicity and eco-toxicity, developed by the EPA, can be used. This method has been applied in a methyl ethyl ketone production plant to determine the effect of recycling on the enviromnent (Shonnard and Hiew 2000). 

This oxidation process for olefins has been exploited commercially principally for the production of acetaldehyde, but the reaction can also be apphed to the production of acetone from propylene and methyl ethyl ketone [78-93-3] from butenes (87,88). Careflil control of the potential of the catalyst with the oxygen stream in the regenerator minimises the formation of chloroketones (94). Vinyl acetate can also be produced commercially by a variation of this reaction (96,97). 

Certain bacterial strains convert propylene glycol to pymvic acid in the presence of thiamine (15) other strains do the conversion without thiamine (16). Propylene oxide is the principal product of the reaction of propylene glycol over a cesium impregnated siHca gel at 360°C in the presence of methyl ethyl ketone and xylene (17). 

The methyl ethyl ketazine forms an immiscible upper organic layer easily removed by decantation. The lower, aqueous phase, containing acetamide and sodium phosphate, is concentrated to remove water formed in the reaction and is then recycled to the reactor after a purge of water-soluble impurities. Organic by-products are separated from the ketazine layer by distillation. The purified ketazine is then hydrolyzed under pressure (0.2—1.5 MPa (2—15 atm)) to give aqueous hydrazine and methyl ethyl ketone overhead, which is recycled (122). The aqueous hydrazine is concentrated in a final distillation column. 

Although it appears that methyl ethyl ketone [78-93-3] caimot be the principal product in butane LPO, it has been reported that the ratio of methyl ethyl ketone to acetic acid [64-19-7] can be as high as 3 1 in a plug-flow-type reactor (214). However, this requires a very unusual reactor (length dia = 16, 640 1). The reaction is very unstable and wall reactions may influence mechanisms. 

Production of maleic anhydride by oxidation of / -butane represents one of butane s largest markets. Butane and LPG are also used as feedstocks for ethylene production by thermal cracking. A relatively new use for butane of growing importance is isomerization to isobutane, followed by dehydrogenation to isobutylene for use in MTBE synthesis. Smaller chemical uses include production of acetic acid and by-products. Methyl ethyl ketone (MEK) is the principal by-product, though small amounts of formic, propionic, and butyric acid are also produced. / -Butane is also used as a solvent in Hquid—Hquid extraction of heavy oils in a deasphalting process. 

Direct oxidation yields biacetyl (2,3-butanedione), a flavorant, or methyl ethyl ketone peroxide, an initiator used in polyester production. Ma.nufa.cture. MEK is predominandy produced by the dehydrogenation of 2-butanol. The reaction mechanism (11—13) and reaction equihbtium (14) have been reported, and the process is in many ways analogous to the production of acetone (qv) from isopropyl alcohol. 

Other uses include use as a reaction and extraction solvent in pharmaceutical production as an intermediate for the preparation of catalysts, antioxidants (qv), and perfumes and as a feedstock in the production of methyl isopropenyl ketone, 2,3-butanedione, and methyl ethyl ketone peroxide. Concern has also arisen at the large volume of exported MEK which has been covertly diverted and used to process cocaine in Latin American countries... 

Methyl Isopropyl Ketone. Methyl isopropyl ketone [563-80-4] (3-methyl-2-butanone) is a colorless Hquid with a characteristic odor of lower ketones. It can be produced by hydrating isoprene over an acidic catalyst at 200—300°C (150,151) or by acid-catalyzed condensation of methyl ethyl ketone and formaldehyde to 2-methyl-l-buten-3-one, foUowed by hydrogenation to the product (152). Other patented preparations are known (155,156). Methyl isopropyl ketone is used as an intermediate in the production of pharmaceuticals and fragrances (see Perfumes), and as a solvent (157). It is domestically available from Eastman (Longview, Texas) (47). 

Methyl vinyl ketone can be produced by the reactions of acetone and formaldehyde to form 4-hydroxy-2-butanone, followed by dehydration to the product (267,268). Methyl vinyl ketone can also be produced by the Mannich reaction of acetone, formaldehyde, and diethylamine (269). Preparation via the oxidation of saturated alcohols or ketones such as 2-butanol and methyl ethyl ketone is also known (270), and older patents report the synthesis of methyl vinyl ketone by the hydration of vinylacetylene (271,272). 

Biacetyl is produced by the dehydrogenation of 2,3-butanediol with a copper catalyst (290,291). Prior to the availabiUty of 2,3-butanediol, biacetyl was prepared by the nitrosation of methyl ethyl ketone and the hydrolysis of the resultant oxime. Other commercial routes include passing vinylacetylene into a solution of mercuric sulfate in sulfuric acid and decomposing the insoluble product with dilute hydrochloric acid (292), by the reaction of acetal with formaldehyde (293), by the acid-cataly2ed condensation of 1-hydroxyacetone with formaldehyde (294), and by fermentation of lactic acid bacterium (295—297). Acetoin [513-86-0] (3-hydroxy-2-butanone) is also coproduced in lactic acid fermentation. 

Low temperature filtration (qv) is a common final refining step to remove paraffin wax in order to lower the pour point of the oil (14). As an alternative to traditional filtration aided by a propane or methyl ethyl ketone solvent, catalytic hydrodewaxing cracks the wax molecules which are then removed as lower boiling products. Finished lubricating oils are then made by blending these refined stocks to the desired viscosity, followed by introducing additives needed to provide the required performance. Table 3 Usts properties of typical commercial petroleum oils. Methods for measuring these properties are available from the ASTM (10). 

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. 

Eigure 2 iHustrates the situation for the system methyl ethyl ketone (MEIQ, methyl isopropyl ketone (MIPK), and water, and the problem of recovering a pure MIPK product from such mixtures. The bow-tie approximation of reachable compositions for several feeds is shown in Eigure 2a the exact reachable compositions are shown in Eigure 2b. 

Oil Content. The production of petroleum waxes involves the removal of oil therefore, the oil content (actually the percentage of oil and low molecular weight fractions) is one indication of the quaUty of the wax. Oil content is deterrnined (ASTM D721) as that percentage of the wax soluble in methyl ethyl ketone at —31.7 C. 

Two solvent processes for preparation of Ca(OCl)2 have been described. In one, a CCl solution of /-C H OCl is allowed to react with a thin lime slurry and the aqueous phase, a solution of Ca(OCl)2, is evaporated to a product with a purity of >95% (217). In the other, a solution of HOCl in methyl ethyl ketone reacts with either CaO or Ca(OH)2 (133). FoUowing filtration, the residual solvent in the product is removed under vacuum. 

Ghlorohydrination with Nonaqueous Hypochlorous Acid. Because the presence of chloride ions has been shown to promote the formation of the dichloro by-product, it is desirable to perform the chlorohydrination in the absence of chloride ion. For this reason, methods have been reported to produce hypochlorous acid solutions free of chloride ions. A patented method (48) involves the extraction of hypochlorous acid with solvents such as methyl ethyl ketone [78-93-3J, acetonitrile, and ethyl acetate [141-78-6J. In one example hypochlorous acid was extracted from an aqueous brine with methyl ethyl ketone in a 98.9% yield based on the chlorine used. However, when propylene reacted with a 1 Af solution of hypochlorous acid in either methyl ethyl ketone or ethyl acetate, chlorohydrin yields of only 60—70% were obtained (10). 

Cobalt salts are used as activators for catalysts, fuel cells (qv), and batteries. Thermal decomposition of cobalt oxalate is used in the production of cobalt powder. Cobalt compounds have been used as selective absorbers for oxygen, in electrostatographic toners, as fluoridating agents, and in molecular sieves. Cobalt ethyUiexanoate and cobalt naphthenate are used as accelerators with methyl ethyl ketone peroxide for the room temperature cure of polyester resins. 

As with poly(vinyl alcohol), poly(vinyl cinnamate) is prepared by chemical modification of another polymer rather than from monomer . One process is to treat poly(vinyl alcohol) with cinnamoyl chloride and pyridine but this is rather slow. Use of the Schotten Baumann reaction will, however, allow esterification to proceed at a reasonable rate. In one example poly(vinyl alcohol) of degree of polymerisation 1400 and degree of saponification of 95% was dissolved in water. To this was added a concentrated potassium hydroxide solution and then cinnamoyl chloride in methyl ethyl ketone. The product was, in effect a vinyl alcohol-vinyl cinnamate copolymer Figure 14.8)... 

Ethyl Propianyl-Pyruvate 36 grams of methyl ethyl ketone and 73 grams of ethyl oxalate are condensed in the presence of sodium ethylate, the reaction mixture being refluxed in an alcoholic medium. 28 grams of the desired product having a boiling point of 100° to 105°C/6 mm are obtained. 

The N-carboxybenzoyl compound (2.7 g) was refluxed for 30 minutes with acetic anhydride (10 ml), the mixture taken to dryness (vacuum) and the residue heated with water. The cooled gummy product became granular on rubbing and crystallized from methyl ethyl ketone-petrol or aqueous ethanol in almost colorless needles, MP 184° to 186°C, of p-nitro-N-phthaloyl-D L-phenylalanine. 

TDicvclohexvl-2-(2 -pvridvl)ethylene hydrochloride (15 grams) in 150 ml of ethanol was hydrogenated in the presence of platinum oxide at about 60 pounds per square inch of hydrogen pressure. The product, 1,1-dicvclohexvl-2-(2 -piperidyl)ethane hydrochloride, crystal-Ii2ed from a mixture of methanol and methyl ethyl ketone as a white solid melting at 243 to 245.5 C. 

This oil (55 g) is dissolved in methyl ethyl ketone (20 cc) and chromatographed over silica (232 g) contained in a column 4S cm in diameter. The column is eluted with methyl ethyl ketone the first 600 cc of eluate are discarded and 500 cc of eluate are then collected and concentrated under reduced pressure (25 mm Hg) a partially crystalline product (2.4 g) is thus obtained. 1-(2-Hydroxypropyl)-2-methyl-5-nitroimida2ole (0.96 g), melting point 72°C, is obtained on recrystallization from water (4 cc). 

The mixture of n-hutenes (1- and 2-hutenes) could he oxidized to different products depending on the reaction conditions and the catalyst. The three commercially important oxidation products are acetic acid, maleic anhydride, and methyl ethyl ketone. 

Methyl ethyl ketone MEK (2-butanone) is a colorless liquid similar to acetone, but its boiling point is higher (79.5°C). The production of MEK from n-butenes is a liquid-phase oxidation process similar to that used to... 

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