Propylene acetone from

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). 

Acrolein is produced according to the specifications in Table 3. Acetaldehyde and acetone are the principal carbonyl impurities in freshly distilled acrolein. Acrolein dimer accumulates at 0.50% in 30 days at 25°C. Analysis by two gas chromatographic methods with thermal conductivity detectors can determine all significant impurities in acrolein. The analysis with Porapak Q, 175—300 p.m (50—80 mesh), programmed from 60 to 250°C at 10°C/min, does not separate acetone, propionaldehyde, and propylene oxide from acrolein. These separations are made with 20% Tergitol E-35 on 250—350 p.m (45—60 mesh) Chromosorb W, kept at 40°C until acrolein elutes and then programmed rapidly to 190°C to elute the remaining components. 

Production of a-methylstyrene (AMS) from cumene by dehydrogenation was practiced commercially by Dow until 1977. It is now produced as a by-product in the production of phenol and acetone from cumene. Cumene is manufactured by alkylation of benzene with propylene. In the phenol—acetone process, cumene is oxidized in the Hquid phase thermally to cumene hydroperoxide. The hydroperoxide is spHt into phenol and acetone by a cleavage reaction catalyzed by sulfur dioxide. Up to 2% of the cumene is converted to a-methylstyrene. Phenol and acetone are large-volume chemicals and the supply of the by-product a-methylstyrene is weU in excess of its demand. Producers are forced to hydrogenate it back to cumene for recycle to the phenol—acetone plant. Estimated plant capacities of the U.S. producers of a-methylstyrene are Hsted in Table 13 (80). 

Other Derivatives and Reactions. The vapor-phase condensation of ethanol to give acetone has been well documented in the Hterature (376—385) however, acetone is usually obtained as a by-product from the cumene (qv) process, by the direct oxidation of propylene, or from 2-propanol. 

A direct route for acetone from propylene was developed using a homogeneous catalyst similar to Wacker system (PdCl2/CuCl2). The reaction conditions are similar to those used for ethylene oxidation to acetaldehyde. ... 

Liquid phase oxidation of hydrocarbons by molecular oxygen forms the basis for a wide variety of petrochemical processes,3 "16 including the manufacture of phenol and acetone from cumene, adipic acid from cyclohexane, terephthalic acid from p-xylene, acetaldehyde and vinyl acetate from ethylene, propylene oxide from propylene, and many others. The majority of these processes employ catalysis by transition metal complexes to attain maximum selectivity and efficiency. 

The economics of any manufacturing process improves if the co-product or side product has a market. 90% of the world production of phenol is through the cumene hydroperoxide route because of the economic advantage of the coproduct acetone. Oxirane technology for the production of propylene oxide from ethyl benzene leads to a co-product styrene and from isobutane leads to a co-product /-butyl alcohol. 

Autoxidation is one of the key steps in the industrial synthesis of phenol and acetone from benzene and propylene. In the second step of this synthesis, cumene (isopropylbenzene) is autoxidized to give cumyl hydroperoxide. 

Oxidation of hydrocarbons in zeolites with blue light gives improved selectivity.442 Isobutane can be converted to tert-butylhydroperoxide with 98% selectivity. Benzalde-hyde is produced from toluene, acrolein from propylene, and acetone from propane. 

The first totally synthetic route to a solvent in the United States was the synthesis of isopropyl alcohol from propylene by Melco Chemical Corporation in 1917. In 1928 Union Carbide made acetone from isopropyl alcohol the synthesis of acetone in the cumene-to-phenol process came much later and now is the source of about 85% of acetone production. In 1927 Du Pont began the synthesis of methanol. Synthetic ethyl alcohol was made from ethylene by Union Carbide in 1929. Specialized books on ethyl alcohol (14. 15) and isopropyl alcohol (16) give many details on the manufacture, properties, and uses of these major products. 

Vapour-phase oxidation of IBA was carried out in a continuous-flow laboratoiy reactor, at atmospheric pressure. The standard feed composition was IBA 2%, O2 20%, H2O 4%. liie toted flow rate was 60 mL/min and the amount of catalyst used was 1 g (approximately 1 mL). The reaction products, kept at 200C to prevent condensation, were analysed by gas chromatography a GP 10% SP-1200/1% H3PO4 on Chromosorb WAW was used to separate IBA, propylene, acetone and MAA, with oven temperature programmed om 40 to lOOC (FID) a Carbosieve S column was utilized for analysis of CO and CO2, with oven temperature programmed from 40C to 200C (TCD). All the catalysts were kept under reaction environment for approximately 50-70 hours along this period, after an initial unstable behavior, no deactivation phenomena were observed. 

A more complex example is the manufacture of cumene (isopropyl benzene) by the alkylation of benzene with propylene, taken from the 1997 National Student Design Competition of the AIChE. Cumene is widely used to make acetone and phenol. The fresh feeds are as follows, where the benzene feed is nearly pure, but a refinery cut of a propylene-propane mixture is used rather than a more expensive feed of nearly pure propylene. 

The yield of propylene oxide is about 94% and approximately 2.2 mol of the co-product tert-butanol is produced per mol of propylene oxide. From this ratio it becomes immediately understandable that it is essential for an economic indirect propylene oxidation process to find a good market for the coupling product, here tert-butanol. For the isobutane hydroperoxidation reaction propylene is converted with pure oxygen at 120-140 °C, applying pressures of 25-35 bar. The non-catalyzed reaction takes places in the liquid-phase and acetone is formed as a minor by-product. The subsequent epoxidation is carried out in the liquid phase at 110-135 °C under 40-50 bar pressure in five consecutive reactors. The reaction is catalyzed by a homogeneous molybdenum naphthenate catalyst. The co-product tert-butanol can be dehydrated and is afterwards converted into methyl tert-butyl ether (MTBE), an important fuel additive for lead-free gasoline. 

Isopropanol is used in the production of other chemicals such as derivative ketones, isopropylamines, and isopropyl esters. The use of isopropanol in the production of monoisopropylamine for herbicides (primarily glyphosate) continues to be the fastest growing segment (Anonymous 2001b). A minor use for isopropanol is to serve as a feedstock for the production of acetone to meet the demand in excess of the coproduct acetone from phenol production. However, isopropanol is also produced from crude acetone, which is generated as a by-product of propylene oxide manufacture (Anonymous 2001b). 

In general, ketones are formed, e.g., acetone from propylene. Other functional groups such as aldehydes are tolerated (Scheme 5-185). Alkenes with hydroxy functionalities within reach undergo hemiacetal or acetal formation. 

Production of acetone by dehydrogenation of isopropyl alcohol began in the early 1920s and remained the dominant production method through the 1960s. In the mid-1960s virtually all United States acetone was produced from propylene. A process for direct oxidation of propylene to acetone was developed by Wacker Chemie (12), but is not beheved to have been used in the United States. However, by the mid-1970s 60% of United States acetone capacity was based on cumene hydroperoxide [80-15-9], which accounted for about 65% of the acetone produced. 

Although the selectivity of isopropyl alcohol to acetone via vapor-phase dehydrogenation is high, there are a number of by-products that must be removed from the acetone. The hot reactor effluent contains acetone, unconverted isopropyl alcohol, and hydrogen, and may also contain propylene, polypropylene, mesityl oxide, diisopropyl ether, acetaldehyde, propionaldehyde, and many other hydrocarbons and carbon oxides (25,28). 

Diisopropjibenzenes (DIPB) are readily obtained via Eriedel-Crafts alkylation of benzene or cumene by propylene. This reaction inhquid phase has not evolved drastically since 1980 with the exception of the large variety of heterogeneous acid catalysts that are now being used, mainly zeoHtes, type HZSM-12, giving a para/meta ratio = 0.7 (4). In fact, propylene can also be replaced by isopropyl alcohol coming from the hydrogenation of acetone that... 

Other by-products include acetone, carbonaceous material, and polymers of propylene. Minor contaminants arise from impurities in the feed. Ethylene and butylenes can form traces of ethyl alcohol and 2-butanol. Small amounts of / -propyl alcohol carried through into the refined isopropyl alcohol can originate from cyclopropane [75-19-4] in the propylene feed. Acetone, an oxidation product, also forms from thermal decomposition of the intermediate sulfate esters, eg. 

After flashing the propylene, the aqueous solution from the separator is sent to the purification section where the catalyst is separated by a2eotropic distillation 88 wt % isopropyl alcohol is obtained overhead. The bottoms containing aqueous catalyst solution are recycled to the reactor, and the light ends are stripped of low boiling impurities, eg, diisopropyl ether and acetone. A2eotropic distillation yields dry isopropyl alcohol, and the final distillation column yields a product of more than 99.99% purity. 

Isomerization and Hydrogenolysis. lsomeri2ation of propylene oxide to propionaldehyde and acetone occurs over a variety of catalysts, eg, pumice, siUca gel, sodium or potassium alum, and 2eohtes (80,81). Stronger acid catalysts favor acetone over propionaldehyde (81). AHyl alcohol yields of 90% are obtained from use of a supported lithium phosphate catalyst (82). 

Carbonyl Compounds. Cychc ketals and acetals (dioxolanes) are produced from reaction of propylene oxide with ketones and aldehydes, respectively. Suitable catalysts iaclude stannic chloride, quaternary ammonium salts, glycol sulphites, and molybdenum acetyl acetonate or naphthenate (89—91). Lactones come from Ph4Sbl-cataly2ed reaction with ketenes (92). 

Cmde propylene oxide separated from the epoxidation reactor effluent is further purified by a series of conventional and extractive distillations to reduce the content of aldehydes, ethylbenzene, water, and acetone (182,183). 

The oxidation step is similar to the oxidation of cumene to cumene hydroperoxide that was developed earlier and is widely used in the production of phenol and acetone. It is carried out with air bubbling through the Hquid reaction mixture in a series of reactors with decreasing temperatures from 150 to 130°C, approximately. The epoxidation of ethylbenzene hydroperoxide to a-phenylethanol and propylene oxide is the key development in the process. 

AH commercial processes for the manufacture of caprolactam ate based on either toluene or benzene, each of which occurs in refinery BTX-extract streams (see BTX processing). Alkylation of benzene with propylene yields cumene (qv), which is a source of phenol and acetone ca 10% of U.S. phenol is converted to caprolactam. Purified benzene can be hydrogenated over platinum catalyst to cyclohexane nearly aH of the latter is used in the manufacture of nylon-6 and nylon-6,6 chemical intermediates. A block diagram of the five main process routes to caprolactam from basic taw materials, eg, hydrogen (which is usuaHy prepared from natural gas) and sulfur, is given in Eigute 2. 

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