Membrane Recycle Reactor for the Acylase Process

Regarding the economical viability of the plant, the retention and stability of acylase are essential features for the process. An ultrafiltration unit retains acylase as the mobile catalyst in the reactor. Alternatively, acylase can be immobilized in a fixed or fluidized bed. A mobile catalyst system is preferred compared to the immobilized form, as the mobile catalyst system avoids mass-transfer limitations. Additionally, regeneration of the catalyst and scale-up of the reactor are much easier as compared to the process with the immobilized acylase. With respect to the deactivation of the catalyst, the thermal as well as the operational stability of acylase has been evaluated extensively [128, 129]. At a pH of 7, acylase appears to be sufficiently stable for L-amino acid manufacture. 

The acylase process is a typical example of reaction and separation by membranes in a sequential mode. The process is fully developed up to industrial scale, yielding high-quality products at good cost effectiveness. 

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