Commodity chemical acrylamide

The degradation of nitriles by nitrilases (EC 3.5.5.1) has been the subject of intense study, especially as it relates to the preparation of the commodity chemical acrylamide. Nitrilases catalyze the hydrolysis of nitriles to the corresponding acid plus ammonia (Figure 1 reaction 5), whereas nitrile hydratases (EC 4.2.1.84) add water to form the amide. Strains such as Rhodococcus rhodo-chrous Jl, Brevibacterium sp., and Pseudomonas chlororaphis have been used to prepare acrylamide from acrylonitrile, which contain the hydratase and not nitrilase activity [12]. A comparison of these strains has been discussed elsewhere [98]. Other uses of nitrilases, however, have primarily been directed at resolution processes to stereoselectively hydrolyze one enantiomer over another or regiose-lectively hydrolyze dinitriles [99-101]. 

Synthesis of the Commodity Chemical Acrylamide Catalyzed by Nitrile Hydratase from Rhodococcus rodochrous (E.C. 4.2.1.84)t10 -112 ... 

Synthesis of the Commodity Chemical Acrylamide Catalyzed by Nitrile... 

Biocatalysts tend to be used for the production of speciality (performance) chemical products, rather than for the manufactnre of bnlk (commodity) chemicals. Good examples of commodity chemicals prodnced by biocatalysts do exist, snch as acrylamide and glucose syraps. Other products from bioreactions, such as HFCS s and 6-APA, have, due to their success, also acquired the status of commodity chemicals. 

Acrylamide is one of the most important commodity chemicals and is used in coagulators, soil conditioners, and petroleum recovering agents. Conventional... 

Production of acrylamide (Fig. 13) by hydration of acrylonitrile under the action of the intracelluar nitrile hydratase in Rhodococcus rhodochrous (Nitto Chemical Industry Co., Ltd., fed-batch process). The annual production amounts to >30000 tons (see also Table 6). Acrylamide is one of the most important commodity chemicals and is required in large quantities as the pre-polymer of polyacrylamide that is widely used in polymer and floccu-lent applications. The advantages of this hydratase approach in comparison with the classical chemical nitrile hydration are higher product end concentration, quantitative yields, no formation of acrylic acid, no need for copper catalyst, and only five chemical/technical operations instead of seven [73,112,113,171]. An analogous process for nicotinamide is being commercialized by Lonza (see also section 6). 

Acrylamide is one of the most important commodity chemicals for the synthesis of various polymers and is produced in an amount of about 200,000 t/year worldwide. In its conventional synthesis, the hydration of acrylonitrile is performed with copper catalysts. However, the preparative procedure for the catalyst, difficulties in its regeneration, problems associated with separation and purification of the formed acrylamide, undesired polymerization and over-hydrolysis are serious drawbacks. Using whole cells of Brevibacterium sp. [658, 659], Pseudomonas chlororapis [660, 661] or Rhodococcus rhodochrous [662] acrylonitrile can be converted into... 

In recent years, the attempts to apply Immobilized enzymes or microorganisms to the production of commodity chemicals have been steadily Increasing. Hlgh-fructose corn-syrup (22), acrylamide (23), ethanol (24) and soap (25) are notable examples of this tendency. With respect to oleochemlstry, four types of reactions are worth mentioning ... 

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... 

Acrylamide monomer is an important chemical commodity produced on a multihundred thousand ton scale for the production of polymers and copolymers. The preferred manufacturing process is by the catalytic hydration of acrylonitrile at 70-120 °C using reduced Raney copper as the catalyst the initial concentration of acrylonitrile being around 4 m. There are several shortcomings to this process, among which are the high level of acrylic acid formed and byproduct formation12, 3). 

Acrylic acid is an important chemical building block used in the manufacture of polyacrylates and commodity acrylates. Commodity acrylates, such as methyl, ethyl, n-butyl, and 2-ethylhexyl acrylate, are utilized in various industrial applications, including coatings, adhesives and sealants, textiles and fibers, polymer additives/impact modifiers, and films. Polyacrylates are extensively used as super absorbent polymers. Bio-based acrylic acid can be obtained through the fermentation of carbohydrates to 3-hydroxypropionic acid (3-HPA), and further dehydration of 3-HPA gives acrylic acid. 3-HPA could also be used as a precursor to other important chemical building blocks, such as PDO, acrylonitrile, and acrylamide. Via another route, glycerol can be chemically converted to acrylic acid, either by dehydration to acrolein followed by oxidation to the final product or in a one-step oxydehydration. 

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