Biocatalytic reduction reactions, environmental

Principle 5—safer solvents and auxiliaries Safe and environmentally acceptable ethyl acetate and butyl acetate are used, together with water, as cosolvent in the biocatalytic reduction reaction and extraction of the hydroxynitrile product. No auxiliaries are needed. 

As mentioned earlier, a major cause of high costs in fine chemicals manufacturing is the complexity of the processes. Hence, the key to more economical processes is reduction of the number of unit operations by judicious process integration. This pertains to the successful integration of, for example, chemical and biocatalytic steps, or of reaction steps with (catalyst) separations. A recurring problem in the batch-wise production of fine chemicals is the (perceived) necessity for solvent switches from one reaction step to another or from the reaction to the product separation. Process simplification, e.g. by integration of reaction and separation steps into a single unit operation, will provide obvious economic and environmental benefits. Examples include catalytic distillation, and the use of (catalytic) membranes to facilitate separation of products from catalysts. 

Comparison of the Environmental Balance of the Chemical and Bioctalytic Processes. The reason for the reduction in production costs is immediately apparent from the reaction sequence shown in Figure 111. Whereas the chemical process requires three intermediate stages, the biocatalytic process occurs in a single synthesis step in water at room temperature with ammonia addition for neutralization. 

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