Biochemical engineering recycle

FIG. 24-23 Continuous culture with recycle. (A. E. Humphrey, Biochemical Engineering in Encyclopedia of Chemical Processing and Design, -ool. 4, July 1977,pp. 359A 94.)... 

Kargupta K., Siddhartha D. and Sanyal S.K. Analysis of the performance of a continuous membrane bioreactor with cell recycling during ethanol fermentation. Biochemical Engineering Journal 1 (1) (1998) 31-37. 

The second part deals with applications of solvent extraction in industry, and begins with a general chapter (Chapter 7) that involves both equipment, flowsheet development, economic factors, and environmental aspects. Chapter 8 is concerned with fundamental engineering concepts for multistage extraction. Chapter 9 describes contactor design. It is followed by the industrial extraction of organic and biochemical compounds for purification and pharmaceutical uses (Chapter 10), recovery of metals for industrial production (Chapter 11), applications in the nuclear fuel cycle (Chapter 12), and recycling or waste treatment (Chapter 14). Analytical applications are briefly summarized in Chapter 13. The last chapters, Chapters 15 and 16, describe some newer developments in which the principle of solvent extraction has or may come into use, and theoretical developments. 

Biochemical transformations that are mediated by microorganisms are characterized by autocatalytic behavior. The fact that the rates of these reactions increase as the concentration of the organism increases provides opportunities for engineers to consider a variety of modes of operation to enhance the performance (and productivity) of a CSTBR facility. One fruitful approach is to do a partial separation and concentration of the cells contained in the efQnent from the CSTBR (see Figure 13.8) and recycle the resnlting process stream back to a point where it is mixed with the contents of the CSTBR. 

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