Acetic acid commercial production

Although this process has not been commercialized, Daicel operated a 12,000-t/yr propylene oxide plant based on a peracetic acid [79-21-0] process during the 1970s. The Daicel process involved metal ion-catalyzed air oxidation of acetaldehyde in ethyl acetate solvent resulting in a 30% peracetic acid solution in ethyl acetate. Epoxidation of propylene followed by purification gives propylene oxide and acetic acid as products (197). As of this writing (ca 1995), this process is not in operation. 

Some monomers are also polymerized by a cationic mechanism in a series of steps not too unlike those of anionic chain-growth. Initiators are often Lewis acids such as AICI3. The polymerization is not quite as straightforward as anionic, because for one thing cationic intermediates are subject to more side reactions. Common monomers that undergo cationic polymerization include styrene, isobutylene, and vinyl acetate. Some commercial products... 

Ethyl acetate. Various grades of ethyl acetate are marketed. The anhydrous comjjound, b.p. 76-77°, is of 99 per cent, purity, is inexpensive, and is suitable for most purposes. The 95-98 per cent, grade usually contains some water, ethyl alcohol and acetic acid, and may be ptuified in the following manner. A mixture of 1 litre of the commercial ethyl acetate, 100 ml. of acetic anhydride and 10 drops of concentrated sulphuric acid is refluxed for 4 hours and then fractionated. The distU-late is shaken with 20-30 g. of anhydrous potassium carbonate, filtered and redistilled. The final product has a purity of about 99-7% and boils at 77°/760 mm. 

Acetonylacetone is available commercially as a by-product of the manufacture of acetic acid from acetylene. It may be prepared by condensation of chloroacetone with ethyl sodioacetoacetate the resulting ethyl acetonylacetoacetate when heated with water under pressure at 160° undergoes ketonic scission to give acetonylacetone. 

Acetaldehyde, first used extensively during World War I as a starting material for making acetone [67-64-1] from acetic acid [64-19-7] is currendy an important intermediate in the production of acetic acid, acetic anhydride [108-24-7] ethyl acetate [141-78-6] peracetic acid [79-21 -0] pentaerythritol [115-77-5] chloral [302-17-0], glyoxal [107-22-2], aLkylamines, and pyridines. Commercial processes for acetaldehyde production include the oxidation or dehydrogenation of ethanol, the addition of water to acetylene, the partial oxidation of hydrocarbons, and the direct oxidation of ethylene [74-85-1]. In 1989, it was estimated that 28 companies having more than 98% of the wodd s 2.5 megaton per year plant capacity used the Wacker-Hoechst processes for the direct oxidation of ethylene. 

Oxidation. Acetaldehyde is readily oxidised with oxygen or air to acetic acid, acetic anhydride, and peracetic acid (see Acetic acid and derivatives). The principal product depends on the reaction conditions. Acetic acid [64-19-7] may be produced commercially by the Hquid-phase oxidation of acetaldehyde at 65°C using cobalt or manganese acetate dissolved in acetic acid as a catalyst (34). Liquid-phase oxidation in the presence of mixed acetates of copper and cobalt yields acetic anhydride [108-24-7] (35). Peroxyacetic acid or a perester is beheved to be the precursor in both syntheses. There are two commercial processes for the production of peracetic acid [79-21 -0]. Low temperature oxidation of acetaldehyde in the presence of metal salts, ultraviolet irradiation, or osone yields acetaldehyde monoperacetate, which can be decomposed to peracetic acid and acetaldehyde (36). Peracetic acid can also be formed directiy by Hquid-phase oxidation at 5—50°C with a cobalt salt catalyst (37) (see Peroxides and peroxy compounds). Nitric acid oxidation of acetaldehyde yields glyoxal [107-22-2] (38,39). Oxidations of /)-xylene to terephthaHc acid [100-21-0] and of ethanol to acetic acid are activated by acetaldehyde (40,41). 

Since 1960, the Hquid-phase oxidation of ethylene has been the process of choice for the manufacture of acetaldehyde. There is, however, stiU some commercial production by the partial oxidation of ethyl alcohol and hydration of acetylene. The economics of the various processes are strongly dependent on the prices of the feedstocks. Acetaldehyde is also formed as a coproduct in the high temperature oxidation of butane. A more recently developed rhodium catalyzed process produces acetaldehyde from synthesis gas as a coproduct with ethyl alcohol and acetic acid (83—94). 

Commercial production of acetic acid has been revolutionized in the decade 1978—1988. Butane—naphtha Hquid-phase catalytic oxidation has declined precipitously as methanol [67-56-1] or methyl acetate [79-20-9] carbonylation has become the technology of choice in the world market. By-product acetic acid recovery in other hydrocarbon oxidations, eg, in xylene oxidation to terephthaUc acid and propylene conversion to acryflc acid, has also grown. Production from synthesis gas is increasing and the development of alternative raw materials is under serious consideration following widespread dislocations in the cost of raw material (see Chemurgy). 

Currently, almost all acetic acid produced commercially comes from acetaldehyde oxidation, methanol or methyl acetate carbonylation, or light hydrocarbon Hquid-phase oxidation. Comparatively small amounts are generated by butane Hquid-phase oxidation, direct ethanol oxidation, and synthesis gas. Large amounts of acetic acid are recycled industrially in the production of cellulose acetate, poly(vinyl alcohol), and aspirin and in a broad array of other... 

Acetic anhydtide [108-24-7] (CH2C0)20, is a mobile, colorless liquid that has an acrid odor and is a more pierciag lacrimator than acetic acid [64-19-7]. It is the largest commercially produced carboxyUc acid anhydride U.S. production capacity is over 900,000 t yearly. Its chief iadustrial appHcation is for acetylation reactions it is also used ia many other appHcations ia organic synthesis, and it has some utility as a solvent ia chemical analysis. 

Liquid- and vapor-phase processes have been described the latter appear to be advantageous. Supported cadmium, zinc, or mercury salts are used as catalysts. In 1963 it was estimated that 85% of U.S. vinyl acetate capacity was based on acetylene, but it has been completely replaced since about 1982 by newer technology using oxidative addition of acetic acid to ethylene (2) (see Vinyl polymers). In western Europe production of vinyl acetate from acetylene stiU remains a significant commercial route. 

Metallic Dyes. MetaUic dyes are among the older hair color materials known. Commercial products are based on a 1% solution of lead acetate in an aqueous, slightly acidic, alcohoHc medium. Precipitated sulfur appears to be essential. The convenience aspect is stressed by the leave-in appHcation method. Actually, the color development is so slow, taking about a week to ten days, that there is no alternative to this technique. Daily appHcation is needed at first. 

Butane. Butane LPO has been a significant source for the commercial production of acetic acid and acetic anhydride for many years. At various times, plants have operated in the former USSR, Germany, Holland, the United States, and Canada. Only the Hoechst-Celanese Chemical Group, Inc. plants in Pampa, Texas, and Edmonton, Alberta, Canada, continue to operate. The Pampa plant, with a reported aimual production of 250,000 t/yr, represents about 15% of the 1994 installed U.S. capacity (212). Methanol carbonylation is now the dominant process for acetic acid production, but butane LPO in estabhshed plants remains competitive. 

Vinyl acetate (ethenyl acetate) is produced in the vapor-phase reaction at 180—200°C of acetylene and acetic acid over a cadmium, 2inc, or mercury acetate catalyst. However, the palladium-cataly2ed reaction of ethylene and acetic acid has displaced most of the commercial acetylene-based units (see Acetylene-DERIVED chemicals Vinyl polymers). Current production is dependent on the use of low cost by-product acetylene from ethylene plants or from low cost hydrocarbon feeds. 

Liquid-Phase Oxidation. Liquid-phase catalytic oxidation of / -butane is a minor production route for acetic acid manufacture. Formic acid (qv) also is produced commercially by Hquid-phase oxidation of / -butane (18) (see HYDROCARBON OXIDATION). 

Other methods of production iaclude hydrolysis of glycolonittile [107-16 ] with an acid (eg, H PO or H2SO2) having a piC of about 1.5—2.5 at temperatures between 100—150°C glycolonittile produced by reaction of formaldehyde with hydrogen cyanide recovery from sugar juices and hydrolysis of monohalogenated acetic acid. None of these has been commercially and economically attractive. 

Acetic anhydride and acetic acid increase the solubiUty of the two phases in each other, and they are employed for the commercial N-nitration of hexamethylenetetramine [100-97-0] (11) to form cyclotrimethylenetrinitramine [121-82-4] (RDX), (CH2)3(NN02)3. Renewed consideration has been given to replacing H2SO4 with an improved soHd catalyst to reduce the environmental problems of disposal or reconcentration of the waste acid and to increase production of desired nitrated isomers. For example, a catalyst with suitable pore size might increase the production of 4-MNT and reduce that of 3-MNT when toluene is nitrated. 

Chevron Chemical Co. began commercial production of isophthahc acid in 1956. The sulfur-based oxidation of / -xylene in aqueous ammonia at about 320°C and 7,000—14,000 kPa produced the amide. This amide was then hydrolyzed with sulfuric acid to produce isophthahc acid at about 98% purity. Arco Chemical Co. began production in 1970 using air oxidation in acetic acid catalyzed by a cobalt salt and promoted by acetaldehyde at 100—150°C and 1400—2800 kPa (14—28 atm). The cmde isophthahc acid was dissolved and recrystallized to yield a product exceeding 99% purity. The Arco technology was not competitive and the plant was shut down in 1974. 

Amine salts, especially acetate salts prepared by neutralization of a fatty amine with acetic acid, are useflil as flotation agents (collectors), corrosion inhibitors, and lubricants (3,8). Amine acetates are commercially available from a number of suppHers Akzo Chemicals Inc. (Armac) (73) Henkel Corporation (formerly General Mills) (Alamac) (74) Jetco Chemicals Inc. (The Procter Gamble Company) (fet Amine) (75) Sherex (Adogen) (76) and Tom ah Products (Exxon Chemical Company) (Tomah) (77). 

Esterification. Extensive commercial use is made of primary amyl acetate, a mixture of 1-pentyl acetate [28-63-7] and 2-metliylbutyl acetate [53496-15-4]. Esterifications with acetic acid are generally conducted in the Hquid phase in the presence of a strong acid catalyst such as sulfuric acid (34). Increased reaction rates are reported when esterifications are carried out in the presence of heteropoly acids supported on macroreticular cation-exchange resins (35) and 2eohte (36) catalysts in a heterogeneous process. Judging from the many patents issued in recent years, there appears to be considerable effort underway to find an appropriate soHd catalyst for a reactive distillation esterification process to avoid the product removal difficulties of the conventional process. 

The analogous reaction between anhydrides and alkoxysilanes also produces acyloxysilanes. The direct reaction of acids with chlorosilanes does not cleanly lead to full substitution. Commercial production of methyltriacetoxysilane direcdy from methyltrichlorosilane and acetic acid has been made possible by the addition of small amounts of acetic anhydride or EDTA, or acceptance of dimethyltetraacetoxydisiloxane in the final room temperature vulcanising (RTV) appHcation (41—43). A reaction that leads to the formation of acyloxysilanes is the interaction of acid chlorides with silylamides. 

Uses ndReactions. The Prins reaction of 3-carene with formaldehyde in acetic acid gives mainly 2-carene-4-methanol acetate, which when saponified produces the 2-carene-4-methanol, both of which are commercial products of modest usage (60). 3-Carene (28) also reacts with acetic anhydride with a catalyst (ZnCl2) to give 4-acetyl-2-carene (29) (61), which is also a commercial product. Although 3-carene does not polymerize to produce terpene resins, copolymerization with phenol has been successfully commercialized by DRT in France (62). 

Reaction of acetic acid and a catalytic amount of sulfuric acid at reflux temperatures for 6—8 hours with dihydromyrcene can cause rearrangement of the dihydromyrcenyl acetate to give a mixture of the cycHc acetates analogous to the cycHc formate esters (108). The stereochemistry has also been explained for this rearrangement, depending on whether (+)- or (—)-dihydromyrcene is used (109). The cycHc acetates are also commercially avaUable products known as Rosamusk and CyclocitroneUene Acetate. 

Acid-catalyzed esterification of nerol and geraniol with acid anhydrides produces the corresponding esters. The acetates and isobutyrates are also avaUable commercial products. U.S. production of neryl acetate [141-12-8] in 1993 was 18 t at a price of 11.56/kg and that of geranyl acetate [105-37-3] was 132 t at a price of 9.86/kg (67). 

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