Acrylonitrile industrial preparation

One oxidation reaction that is of large industrial relevance is the oxidative dehydrogenation of light alkanes to the corresponding alkene (Scheme 3.20). This reaction has been reported to be promoted by r-GO as catalyst [29]. The importance of this reaction type is particularly high for the industrial preparation of propene from propane and butenes from butanes. Both reactions are carried out industrially in very large scale, because propene is the monomer of polypropene and also the starting material of propylene oxide, acrylonitrile, and other base chemicals. Butenes are mainly used for the preparation of 1,3-butadiene that is one of the major components of rubbers and elastomers. 

An important nitrile is acrylonitrile H2C=CHCN It is prepared industrially from propene ammonia and oxygen m the presence of a special catalyst Polymers of acryl omtrile have many applications the most prominent being their use m the preparation of acrylic fibers... 

PROPENE The major use of propene is in the production of polypropylene. Two other propene-derived organic chemicals, acrylonitrile and propylene oxide, are also starting materials for polymer synthesis. Acrylonitrile is used to make acrylic fibers (see Table 6.5), and propylene oxide is one component in the preparation oi polyurethane polymers. Cumene itself has no direct uses but rather serves as the starting material in a process that yields two valuable industrial chemicals acetone and phenol. 

A synthesis of great industrial interest is the electrochemical anodic reductive dimerisation of two molecules of acrylonitrile to give adiponitrile, from which adipic acid and 1,6-hexanediamine are prepared by hydrolysis and reduction, respectively, of the two nitrile groups. Polycondensation of the resulting products leads to Nylon 66 (Scheme 5.27). 

During the history of a half century from the first discovery of the reaction (/) and 35 years after the industrialization (2-4), these catalytic reactions, so-called allylic oxidations of lower olefins (Table I), have been improved year by year. Drastic changes have been introduced to the catalyst composition and preparation as well as to the reaction process. As a result, the total yield of acrylic acid from propylene reaches more than 90% under industrial conditions and the single pass yield of acrylonitrile also exceeds 80% in the commercial plants. The practical catalysts employed in the commercial plants consist of complicated multicomponent metal oxide systems including bismuth molybdate or iron antimonate as the main component. These modern catalyst systems show much higher activity and selectivity... 

The industrial process for the preparation of acrylonitrile from propylene and ammonia uses a bismuth molybdate catalyst (equation 91). 

Acrylamide with a demand of 200,000 tons year" is one of the most important commodities in the world. It is used for the preparation of coagulators, soil conditioners, stock additives for paper treatment, and in leather and textile industry as a component of synthetic fibers. Conventional chemical synthesis involving hydration of acrylonitrile with the use of copper salts as a catalyst has some disadvantages rate of acrylic acid formation higher than acrylamide, by-products formation and polymerization, and high-energy inputs. To overcome these limits since 1985, the Japanese company Nitto Chemical Industry developed a biocatalyzed process to synthesize... 

Since polyamines are industrially available compounds, we returned to our first successful cacade synthesis in 19781 where we produced dendritic oligoamines. It seemed attractive to pursue this synthesis with new preparative and analytical methods, which then were limited. As starting materials, we selected the commercially available tris(2-ami-noethyl)amine (TREN) due to its inherently branched structure. The synthesis was accomplished in a manner identical to that conducted 16 years ago, affording a 90% yield of the first-generation dendrimer 46 by reaction of TREN with acrylonitrile and catalytic amounts of acetic acid (Scheme 10). 

Di-n-propylamine can be produced in industrial scale by the alkylation of ammonia with n-propanol on Ba(OH)2 modified Ni/Al203 catalyst [2], by the reductive amination of propionaldehyde over a cobalt-containing catalyst [3] or by the hydrogenation acrylonitrile in n-exane on Ni/Al203 catalyst [4,5]. However, only scare data is available about the alkylation of ammonia or i-butylamine with i-butanol [6-10]. Di-i-butylamine was prepared from i-butanol over alumina at 370-380 C with 28 % yield [7]. 20 wt% Co - 5 wt% Ni catalyst supported on alumina was used to prepare di-i-butylamine fi"om i-butanol and i-butylamine at 200 °C with a yield of 60. 6 [10]. Aliphatic mixed secondary amines prepared from a pimary amine and an alcohol were usually obtained on copper-containing catalysts at 190-200 C with 30-50 % yields [11-13]. 

Amides can be made by the enzymatic hydrolysis of nitriles. Nitto Chemical Industry of Japan uses Rhodococcus rhodocrous to prepare acrylamide from acrylonitrile... 

Solvent Manufacture and Preparation. 1,3-Dicyanobutane is a new material which can be produced at low cost by a process developed in the laboratories of U. S. Industrial Chemicals Co. (6, 7,14). The catalytic dimerization of acrylonitrile produces methyleneglutaronitrile which is readily hydrogenated to give methylglutaronitrile, also called 1,3-dicyanobutane. Thus,... 

The polymer may be prepared readily by free-radical mechanisms in bulk, emulsion, and suspension the latter technique is usually preferred on an industrial scale. Copolymers of vinylidene chloride with vinyl chloride, acrylates, and acrylonitrile are also produced. 

Most comonomers differ from styrene in polarity and reactivity. A desired copolymer composition can be achieved, however, through utilization of copolymerization parameters based on kinetic data and on quantum-chemical considerations. This is done industrially in preparations of styrene-acrylonitrile, styrene-methyl methacrylate, and styrene-maleic anhydride copolymers of different compositions. 

Polyacrylonitrile copolymers are also used in barrier resins for packaging. One such resin contains at least 70% acrylonitrile and often methyl acrylate as the comonomer. The material has poor impact resistance and in one industrial process the copolymer is prepared in the presence of about 10% butadiene-acrylonitrile rubber by emulsion polymerization. The product contains some graft copolymer and some polymer blend. In another process the impact resistance of the copolymer is improved by biaxial orientation. The package, however, may have a tendency to shrink at elevated temperature, because the copolymer does not crystallize. 

Discuss industrial polymers and copolymers of acrylonitrile and methacrylonitrile. How are they prepared and used ... 

While the hydrodimerization of acrylonitrile to adiponitrile has been the most successful commercial organic process, a few other organic compounds are known to be prepared by electrolysis on an industrial scale. Many more possible processes have been examined on a pilot-plant scale and some of these may also have been extended to commercial operation. In addition, the literature describing laboratory-scale organic electrosynthesis is now very extensive. 

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