生物分离工程课件1.ppt

Bioseparation Engineering Chapter 1 Introduction §1.1 Downstream processing in biotechnology The producing process of a biotechnological product is termed bioprocess, that can be divided into two processes as follows Upstream processing：strain development and bioreaction （enzyme catalyze reaction, microbial fermentation, plant/mammalian cell culture, etc） Downstream processing：the isolation and purification of biotechnological products The complexity of downstream processing is determined by the required purity of the product, in turn determined by its application. The downstream processing scheme normally can be divided into the following stages §1.2 Demands on the  downstream processing Strictly monitor the DSP steps for keeping the activity of the product; Rapidly remove those impurities can affecting the stability of the final product; Generally it is necessary to apply special efficient methods to the purification of the product; Since many products are applied to food, pharmaceutical, and cosmetics, those substances harmful to mankind health must be removed; Since the product concentration is low in the culture broth, it is necessary to concentrate the broth for removing large amounts of water. Because those of unit operations are costly, the cost of DSP is increased observably. §1.3 Separation mechanism and unit operation According to different separation principles the unit operations can be sorted into two groups： Mechanical separation Object：unhomogeneous phase system Mechanism：separation based on the difference of substances’ size and density Unit operation：filtration, settling, centrifugation, etc. Mass transfer separation Object：homogeneous phase system Transport/velocity separation Mechanism：separation based on the migration velocity difference of solutes drove by bearing a applied force Unit operation：ultrafiltration, reverse osmosis, electrophoresis, etc. Diffusion/equilibrium separation Mechanism：separation based on t