Production acrylamide

The ratio of reactants had to be controlled very closely to suppress these impurities. Recovery of the acrylamide product from the acid process was the most expensive and difficult part of the process. Large scale production depended on two different methods. If soHd crystalline monomer was desired, the acrylamide sulfate was neutralized with ammonia to yield ammonium sulfate. The acrylamide crystallized on cooling, leaving ammonium sulfate, which had to be disposed of in some way. The second method of purification involved ion exclusion (68), which utilized a sulfonic acid ion-exchange resin and produced a dilute solution of acrylamide in water. A dilute sulfuric acid waste stream was again produced, and, in either case, the waste stream represented a... 

Asano, Y, Yasuda, T., Tani, Y, and Yamada, H. 1982. A new enzymatic method of acrylamide production. Agricultural and Biological Chemistry, 46 1183-9. 

Cantarella, M., Spera, A., Cantarella, L., and Alfani, F. 1998b. Acrylamide production in an ultrafiltration-membrane bioreactor using cells of Brevibacterium imperialis CBS 489-74. Journal of Membrane Science, 147 279-90. 

V. Asano, T. Yasuda, Y. Tani, and H, Yamada, A new eirzymatic method for acrylamide production, Agric. Biol. Chem., 46 1183 (1982). 

Figure 3. Comparison of the microbial end conventional chemical processes for acrylamide production.

Phases gas-liquid, gas-liquid catalytic solid, gas-liquid plus catalytic solid minimizes catalyst poisoning, lower pressure than fixed bed. Used for hydrogenation reactions and MTBE and acrylamide production. For example, 90% conversion via reactive distillation contrasted with 70% conversion in fixed-bed option. Liquid with homogeneous catalyst etherification, esterification. Liquid-liquid HIGEE for fast, very fast, and highly exothermic liquid-liquid reactions such as nitrations, sulfonations, and polymerizations. Equilibrium conversion <90%. Use a separate prereactor when the reaction rate at 80% conversion is >0.5 initial rate. The products should boil in a convenient temperature range. The pressure and temperature for distillation and reaction should be compatible. 

Figure 12.1-4. Comparison of the biocatalytic and the conventional chemical process for acrylamide production.

Current acrylamide production at Mitsubishi using bioconversion is around 40 000 tonnes per year. Using a highly improved cobalt-containing nitrile hydratase from Rhodococcus rhodochrous Jl, final product concentrations of around 700 g L"1... 

The hydrolysis of nitriles using nitrile hydratases (for example acrylamide production). 

Biocatalysis on an industrial scale covers a range of reactions, solvents and products, thus extending from the manufacture of large-volume chemicals such as in acrylamide production to numerous syntheses of optically active alcohols, amines, nitriles, peptides and semisynthetic antibiotics, to numerous intermediates. " ... 

Recently, after the discovery of the chemical mechaiusm governing this food-related contaminant, acrylamide production has been described through a series of reactions known as Maillard reaction, between an amino acid, primarily asparagines, and a reducing sugar such as fructose or glucose [21-25] (Figure 13.1). The amino acid... 

Nitrile hydratases (NHases) catalyze the hydration of organic nitriles to amides under very benign reaction conditions (neutral aqueous environment and room temperature) and therefore offer a chemoselective alternative to classical approaches, where functional group compatibility is often limited due to the harsh acidic or basic solutions used [1], Starting with their application in acrylamide production [2,3], this enzyme class is one of the most prominent in industrial processes with respect to production volume (>3 X 10 kg/a for acrylonitrile hydration) [4]. Hence, Lonza (Switzerland) uses a nitrile hydratase to convert 3-cyanopyridine into nicotinamide (6 X 10 tons/year). Very recently, a one-pot industrial protocol for the synthesis of a chiral intermediate for dlastatin was published that employed a nitrile hydratease/amidase approach [5],... 

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