Chemical manufacture reaction velocity

In Chapters 13 and 14 of this book the applications of conventional chemical catalysts were described. The use of enzymes or whole cells as catalysts for chemical transformations is well known. They can bring about various reactions at ambient temperature and pressure and afford high reaction velocities. In fact, enzymatic reaction sequences may be designed to give the ideal efficiency embodied in the second law of thermodynamics. Thus, hundreds of compounds that are very difficult to prepare by purely chemical methods may be obtained quite readily and economically with the help of enzymes. Until recently, most laboratory investigations and manufacturing processes employed soluble enzymes in dilute aqueous solutions. Before use, the required enzyme must be obtained from biological sources as a concentrated extract. It is not uncommon for a particular type of cell to contain many proteins in addition to the one desired. Therefore, the purification and concentration of enzymes in preparation for use is a very cumbersome process. When used in solution, enzyme catalysts are invariably lost after each batch operation. The use of immobilized enzymes and whole cells has been proposed as a means that could eliminate such losses and preserve hard won stocks of specialized enzymes. 

A BR has several advantages in the realization of industrial reactions. It is flexible, allowing the same reactor to be used for multiple, chemically different reactions. This is a clear advantage for the manufacture of an assortment of fine chemicals the production can be adjusted and rearranged according to market demand. Different reactions often require very different reaction times (batch time), since reaction velocities vary considerably. For a BR, this is, however, a minor problem the reaction time can easily be altered, as required, by allowing a longer or a shorter reaction time until the desired product distribution is obtained. 

Droplets distribution of the dispersed phase in size to the formation of fine homogeneous systems in the confiisor-diffuser channels is narrowed by increasing speed of immiscible fluid streams. Increase in volumetric flow velocity co and the number of diffuser confused sections 1 to 4 leads to reduction of the volume-surface diameter of droplets of the dispersed phase and, consequently, to increase in the specific surface of the interface, which in the case of fast chemical reactions intensify flie total process. Inadvisability of using the apparatus with the number of diffuser sections iV confused over 5 1, making these devices simple and inexpensive to manufacture and operate as well as compact, for example, length does not exceed 8-10 caliber (L/d ). 

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