Presentation on theme: "Recovery and Purification of Bio-Products (Chapter 11, M"— Presentation transcript:
1 Recovery and Purification of Bio-Products (Chapter 11, M Recovery and Purification of Bio-Products (Chapter 11, M. Shular, textbook)Strategies to recovery and purify bio-productsSolid-liquid separationCell disruptionSeparation of soluble productsFinishing steps for purification
2 Recovery and Purification of Bio-Products Strategies to recovery and purify bio-productsUnique characteristics of bioseparation products:- the products are in concentration in an aqueous medium. e.g therapeutic protein 0.01mg/l.- The products are usually sensitive.- There is a of products to be separated.- The products can be , often as insoluble inclusion bodies.- The physical and chemical properties of products are similar to contaminants.- Extremely purity and homogeneity may be needed for human care.
3 Recovery and Purification of Bio-Products Strategies to recovery and purify bio-productsFementerSolid-liquid separationRecoveryPurificationSupernatantCellsCell productsCell ruptureCell debrisCrystallization and drying
4 Recovery and Purification of Bio-Products Strategies to recovery and purify bio-productsFementerSolid-liquid separationRecoveryPurificationSupernatantCellsCell productsCell ruptureCell debrisCrystallization and drying
5 Recovery and Purification of Bio-Products Liquid and solid separation- solid particles: mainly cellular mass, specific gravitysize (diameter):bacterial cells: µmyeast cells: µmmold: 5-15 µm in diameter andµm in lengthanimal cells: 10 µmplant cells: 20 µmMethods:
6 Liquid-Solid Separation Filtration Physical separation of solid particles from liquid or gas.a porous medium: allow fluid to pass throughsolid particles to be retained.Slurry flowFiltrateFilter mediumFilter cake
7 Liquid-Solid Separation Filtration .Particle size: greater than 10 µm, yeast, mold, animal or plant cells.i.e. mycelium separation for antibiotics production or waste water treatmentParticle size: µm, bacterial and yeast cells.Size: Å, Cell debris, macromolecules
8 Rotary Vacuum FilterA rotary vacuum filter is a continuous filter partially submergedin the slurry.- A drum is covered with a filter medium.Vacuum is applied to within the drumAs the drum rotates, the solid constituent is separated by retained on the porous mediumThe liquid is drawn through the cakeinto the inner filtrate pipes.Each revolution consists of cake formation,cake washing (if required),drying and cake discharge.
10 Rotary Vacuum FilterThe rate of filtration (the flow of the filtrate) for (vaccum) filtration operation can be determined by (Bennet &Myers, Momentum, Heat and Mass Transfer, 1974, p221, the equation is from the mass balance of the cake.)
14 Rotary Vacuum Filter To design a scaled-up rotary vaccum filter If given a total volume of fermentation broth Vb andrequired time tb to complete the filtration task at the large scale,determine the filter surface area.Based on the results from the smaller filter(incompressible cake: same α, medium & pressure drop):
15 Rotary Vacuum Filter For incompressible cake: constant α. If filtration rate is constant,
16 Liquid-Solid Separation Filtration Rotary vacuum filtrationParticle size: greater than 10 µm, yeast, mold, animal or plant cells.i.e. mycelium separation for antibiotics production or waste water treatmentMicrofiltrationParticle size: µm, bacterial and yeast cells.UltrafiltrationSize: Å, Cell debris, macromolecules(antibiotics, proteins, polysaccharides)
17 Liquid-Solid Separation Filtration Microfiltration & UltrafiltrationUse membrane as porous medium for filtration.Challenge: gel formation on the surface of membrane.Solution: cross-flow (tangential flow filtration)Pressure P1Pressure P2Feed inFeed out
18 Liquid-Solid Separation Filtration Centrifugation- Particle size: µm- more expensive than filtration- limited for scale-up- drive force: centrifugal force
19 ExampleThe following data were obtained in a constant-pressure unit for filtration of a yeast suspension:t(min)V(L)Characteristics of the filter are as follows:A=0.28m2, C=1920kg/m3, μ=2.9X10-3 kg/m-s, α=4m/kgDetermine:a) The pressure drop across the filter.b) The filter medium resistance.c) The size of the filter for the same pressure drop to process 4000L of cell suspension in 20 min.