生物分离工程.docx

1、生物分离工程第一讲 绪论 2学时一、通过本章学习应该掌握的内容1、何谓生物分离工程2、生物分离工程的历史及其应用3、生物分离工程在生物技术中的地位？4、生物分离工程的特点5、生物分离工程可分为几大部分，分别包括哪些单元操作？6、在设计下游分离过程前，必须考虑哪些问题方能确保我们所设计的工艺过程最为经济、可靠？二、生物分离工程的发展历史1、概念：从微生物、动植物细胞及其生物化学产品中提取有用物质的技术2、生物分离工程的发展历史已经有几百年的历史了最早的分离技术有蒸馏、过滤等原始方法三、The position of Bioseparation in Biotechnology （生物分离在生物技

2、术中所占位置）By biotechnology, we mean the use of carefully cultured microorganisms, animal cells, and plant cells to produce products useful to humans.（所谓生物技术就是指利用培养微生物、动物细胞、植物细胞来生产对人有用的产品。） By this definition, biotechnology is as old as history, for the earliest known document (4228BC) includes a descri

3、ption of brewing Bread; cheese, and yogurt are other early examples of product which depend on biotechnology.（按上述定义，早在公元前4228年就有了应用生物技术酿酒、制奶酪等的记载。）Today, we restrict biotechnology largely to those areas where chemically defined species are produced .Under this more restricted definition, biotechnolo

4、gy is about 100 year old.（狭义生物技术的产物仅为化学产品，约有100年的历史。）Effective ways to get useful products（获得产品的有效途径）（1）Raw materials（原料）（2）pretreatments（预处理）（3）bioreactions（生物反应）（4）bioseparations（生物分离）（5）products（产品工程）四、生物分离的应用1、医药：抗生素、激素、维生素2、食品：乳酪3、化工：氨基酸4、精细化工：化妆品、香料5、农业：手性农药6、生物：酶五、生物分离过程的特点1、产品丰富A chief chara

5、cteristic of biotechnology is the tremendous variety of products which are produced. This diversity of products spawns the broad spectrum of separation methods used.（产品的多样性导致分离方法的多样性）2、most bioseparation methods come from chemical separations（绝大多数生物分离方法来源于化学分离）3、Bioseparations are more difficult tha

6、n chemical separations.（生物分离一般比化工分离难度大）（1）Complex components（成分复杂）（2）Desired products in dilute suspension（悬液中的目标产物浓度低）青霉素含量为3.6，庆大霉素为0.2，胰岛素仅为0.001（3）Biological activity（生物活性）条件相对温和（4）Biological products require high quality （生物产品要求高质量）（5）Get highly purified dry products（获得高纯度的干燥产品）（6）Sanitation（卫生

7、）因此，生物分离过程往往成本很高，在某些产品的生产过程中，分离成本可能占到总成本的80以上Thus the recovery and the purification processes must be well conceived and well designed.（因此必须仔细考虑和设计产品的回收和纯化过程）We have found that our own designs have been improved by answering the following questions: （设计中应考虑下列问题）（1）What is the value of the product?（产

8、品价值）（2）What is an acceptable product quality?（产品质量）（3）Where is the product in each process stream?（产物在生产过程中出现的位置）（4）Where are the impurities in each process stream?（杂质在生产过程中出现的位置）（5）What are the unusual physicochemical properties of the product and the principal impurities?（主要杂质独特的物化性质是什么？）（6）What a

9、re the economics of various alternative separations?（不同分离方法的技术经济比较）Careful consideration of these questions can provide clues that will lead to optimal processes for the recovery of products of adequate quality coupled with high recovery and minimum effort. （上述问题的考虑将有助于优质、高效产物分离过程的优化）六、生物分离的一般步骤From

10、 our experience, we find that most bioseparations have four similar steps:（生物分离一般分四步）1、不溶物的去除（固液分离）Removal of insolublesfiltration、centrifugation、cell disruption (necessary when the desired product is intracellular.)Relatively little product concentration or improvement of product quality occurs. （提

11、高产物浓度和质量）2、杂质粗分（浓缩）adsorption - ion-exchang（离子交换吸附）extraction（萃取）solvent extraction（溶剂萃取）reversed micelle extraction（反微团萃取） supercritical fluid extraction（超临界流体萃取）aqueous phase extraction（双水相萃取）These steps, which are relatively nonspecific, remove materials of widely divergent properties compared to

12、 the desired product. （以上分离过程不具备特异性，只是进行初分）Appreciable concentration and product quality increases usually occur.（可提高产物浓度和质量）3、纯化chromatography（色谱）electrophoresis（电泳）precipitation（沉淀）These processing technology are highly selective for the product and remove impurities of similar chemical functional

13、ity and physical properties.（以上技术具有产物的高选择性和杂质的去除性）4、精制crystallization（结晶）drying （干燥）七、本章作业1、生物分离工程在生物技术中的地位？2、生物分离工程的特点是什么？3、生物分离工程可分为几大部分，分别包括哪些单元操作？4、在设计下游分离过程前，必须考虑哪些问题方能确保我们所设计的工艺过程最为经济、可靠？第二讲 过滤 2学时一、通过本章学习应掌握的内容1、何谓过滤2、过滤的基本形式3、凝聚和絮凝的区别4、常用的絮凝剂有哪些5、过滤设备分类6、常用过滤设备及其特点二、过滤的基本概念过滤是在某一支撑物上放过滤介质，注入

14、含固体颗粒的溶液，使液体通过，固体颗粒留下，是固液分离的常用方法之一。Filtration separates solid from a liquid by forcing the liquid through a solid support or filter medium. This is a straight forward procedure for well defined crystals. 三、过滤前物料的前处理However the small size of microorganisms make filtration of fermentation beers or oth

15、er biological solutions considerably more complicated. Generally, fermentation beers and other biological solutions are notoriously hard to filter. They are often hard to filter because of high non-Newtonian viscosity or highly compressible cakes. That is to say, we must modified these procedures fo

16、r bio-separations.通常发酵液和生物溶液是高粘度的和非牛顿流体，是很难过滤的，为了加快过滤速度，通常可采用以下方法：1、加热（Heating）降低液体粘度2、凝聚和絮凝（Coagulation and flocculation）在电介质作用下，破坏溶质胶体颗粒表面的双电层，破坏胶体系统的分散状态，使胶体粒子聚集的过程四、影响凝聚作用的主要因素Simple electrolytes act by screening the electrostatic repulsion, which commonly exists between colloidal particles. Whe

17、n this electrostatic repulsion is reduced, attractive London-vander waals forces predominate. The colloids can then coagulate as larger, dense particles which are more easily filtered. (简单电解质降低胶体间的排斥力。从而范德华引力起主导作用，聚合成较大的胶粒，粒子的密度越大，越易分离。)1、无机盐的种类2、无机盐的化合价3、无机盐的用量常用的凝聚剂有：Al2(SO4)3.18(H2O)，AlCl3.6(H2O)

18、，FeCl3，ZnSO4，MgCO3五、絮凝作用(Flocculation)概念：指在某些高分子絮凝剂存在下，在悬浮粒子之间发生架桥作用而使胶粒形成粗大的絮凝团的过程Synthetic polyelectrolytes added as pretreatments can both reduce electrostatic repulsion and adsorb on adjacent particles, forming bridges between them. As a result, the colloidal particles flocculate as large, less

19、dense aggregates which are more easily filtered. These polyelectrolytes can be anionic, cationic or nonionic.（合成助滤剂既降低静电斥力又吸附周围的微粒，形成桥架作用。胶粒过大，就发生絮凝，低密度聚合的胶粒，容易过滤。聚合电解质有阳离子型、阴离子型或非离子型。六、常用的絮凝剂1、天然聚合物多糖类物质、海藻酸钠、明胶等2、人工合成聚合物聚丙烯酰胺类衍生物、聚苯乙烯类衍生物、聚丙烯酸类等七、助滤剂1、目的：助滤剂是一种具有特殊性能的细粉或纤维，它能使某些难以过滤的物料变得容易过滤2、常用的助

20、滤剂：硅藻土（Diatomaceous earths）珍珠岩（Perlites）八、General Theory for FiltrationFluid mechanics for filtration Darcys law （Darcy方程）for incompressible cake, simplest case（适用于不可压缩和简单的可压缩滤饼）for compressible cake, common for bio-separations（普遍使用于生物分离过程。）1、Darcys law（达西定律）V=k P/l (2.1)where Vvelocity of the liqui

21、d kproportionality constant (usually called the Darcys law permeability of the bed) （K比例常数,过滤床渗透性的达西方程参数）Pthe pressure drop across the bed of thickness （压降） viscosity of the liquid （流体粘度）*当Re5时达西定律才成立For batch filtration the velocity is（板框式过滤流速方程） V=(1/A)*dV/dt (2.2)Afiltration area （过滤面积）Vthe total

22、 volume of filtration（滤液总体积）tthe filtration time（过滤时间）有l/k= Rm + Rc （2.3）Rmthe resistance of the filter medium RM （过滤介质的阻力）Rcthe resistance of accumulate cake bio-mass （滤饼的阻力） 2、Incompressible Cakes（不可压缩滤饼）If the cake is in compressible (rigid), the cake thickness is directly proportional to the fil

23、ter area. （不可压缩滤饼厚度正比于过滤的体积） As a result the cakes resistance Rc is Rc=o(V/A) (2.4)where represents the specific cake resistance （滤饼的阻力特性）othe mass of cake solids per volume of filtrate （单位体积滤液含固体滤饼量）3、Compressible cake（可压缩的滤饼）Almost all cakes formed of biological materials are compressible, and so

24、cannot be described with the simple equation just outlined. As these cakes compress, filtration rates drop. （大多数生物滤饼都可压缩，不能仅用作图法描述，滤饼可压缩，则过滤速度降低）=(P)sWherea constant related largely to the size & shape of the particles forming the cake.（与粒子大小和形状相关）S the cake compressibility （s是压缩系数）S=0 a rigid & hig

25、hly incompressible cake （理想的不可压缩s=0）S=1 a highly compressible cake （高度可压缩 s=1）S=0.1-0.8 in practice （变化范围从0到1）Values of S & are most easily determined by plotting the logarithm of versus the logarithm of P as shown in fig.(2.1)（计算s和可用log对logP作图）九、Continuous Rotary Filter 连续旋转式过滤机We analyze the opera

26、tion of these units, a filtration cycle on this filter consists of three chief （过滤有三步组成）1、cake formation（滤饼的形成）2、cake washing to remove either or unwanted solutes（滤饼的洗涤）3、cake discharge（滤饼的卸下）we assume that the resistance of the filter medium Rm is negligible, so that we can use equation (2.5)（假设滤饼阻

27、力不计），the basic expression for filtration(1/A)*dV/dt = P/( Rc)initial condition that（初始条件是）t=0 v=0 Rc = o (V/A) =o(V/A)( P)s tf=(o/(2P1-s)*(Vf/A) tf the cake formation time （滤饼形成时间）Vfthe volume of filtrate collected during that period.（滤液流量）*cake washing（滤饼的洗涤）作用：（1）First, it displays the solution-ri

28、ch broth trapped in pores in the cake.（将滤饼内发酵液洗出）（2）Second, it allows diffusion of solute out of the biomass in the cake. Such diffusion will enhance recovery, if the desired product is in the biomass.（扩散出生物有机体，这对目标产物在生物有机体很有用）八、过滤设备及其结构过滤设备的分类 根据推动力的不同可分为四类（a）重力过滤 自然过滤（b）加压过滤 板框过滤（c）真空过滤 真空过滤器（d）离心

29、过滤 离心过滤器九、过滤介质1、无定形颗粒：颗粒活性炭、沙、无烟煤2、成形颗粒：烧结金属、烧结塑料3、非金属织物：尼龙、玻璃纤维4、金属织物：不锈钢丝网5、无纺品：纸、石棉十、典型的过滤设备1、板框压滤机优点：结构简单、过滤面积大、操作压力高、适用范围广缺点：设备笨重、间歇操作、劳动强度大、辅助时间长2、旋转过滤机可实现连续操作十一、本章作业1、何谓过滤2、过滤的基本形式3、凝聚和絮凝的区别4、常用的絮凝剂有哪些5、过滤设备分类6、常用过滤设备及其特点第三讲 离心与沉降 2学时一、通过本章学习应该掌握的内容1、何谓沉降2、沉降与离心的异同3、沉降与离心的速度方程4、离心设备可分为哪两大类5、常

30、用的离心沉降设备有哪些6、常用的离心过滤设备有哪些二、离心的概念The first step in most industrial bioseparations is the removal of insoluble solids from the fermentation beer. The concentration and size of these in solubles varies widely. （生物分离首先去除不溶物）The size ranges from microorganisms of perhaps 1 um diameter up to insoluble nut

31、rients characteristically 1mm in diameter（粒径从1um的到1mm）When these insolubles are dilute, large & rigid, they can be easily separated by filtration. In the previous chapter, we described filtration, including the use of filter aids. For many beers, these filter aids facilitate filtration. For other beers, filter aids are ineffective.（不溶物浓度小，粒径大，硬度强时用过滤分离。使助滤剂过滤分离，对一些发酵液很有用）When the beers are not easily filtered, they sometimes can be separated by centrifugation, which is the