Centrifugal Separations in Biotechnology


  • Wallace Woon-Fong Leung, Chair Professor of Innovative Products and Technologies, Department of Mechanical Engineering; Director, Research Institute of Innovative Products and Technologies, The Hong Kong Polytechnic University, Hong Kong

This book is the first devoted to centrifugal separation in biotechnology. It is of value toprofessionals in the chemical, bioprocess, and biotech sectors, and all those concerned with bioseparation, bioprocessing, unit-operations and process engineering.Key topics covered include a full introduction to centrifugation, sedimentation and separation; detailed coverage of centrifuge types, including batch and semi-batch centrifuges, disk-stack and tubular decanter centrifuges; methods for increasing solids concentration; laboratory and pilot testing of centrifuges; selection and sizing centrifuges; scale-up of equipment, performance prediction and analysis of test results using numerical simulation.
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chemical engineers, process & mechanical engineers, bioengineering professionals, pharmaceutical chemists, process industry R & D


Book information

  • Published: July 2007
  • ISBN: 978-1-85617-477-0

Table of Contents

1Introduction1.1 Introduction 1.2 Centrifugal Separation and Filtration 1.2.1 Sedimenting Centrifuge1.2.2 Filtering centrifuges1.3 Pros and Cons of Filtration versus Centrifugation1.4 Generic Flow Sheet for Biopharmaceutical Process1.5 Other Centrifugal Separations1.6 Inputs and Outputs of Centrifuge1.7 Separation Metrics1.7.1 Protein Yield 1.7.2 Centrate Suspended Solids. 1.7.3 Throughput Rate1.7.4 Cell Viability 1.8 Summary2Principles of Centrifugal Sedimentation2.1 Introduction2.2 Non-intuitive Phenomena2.2.1 Pressure Distribution2.2.2 Coriolis Effect2.3 Intuitive Phenomena2.3.1 Centrifugal Acceleration2.3.2 Fluid in a Centrifuge Bowl not at Solid-Body Motion2.3.3 Regimes of Sedimentation2.3.4 Stokes’ Law2.3.5 Settling with Concentrated Solids2.4 Process Functions2.5 Summary 3.Batch and Semi-Batch Centrifuges3.1 Spintube3.2 Centrifugal Filter 3.3 Ultracentrifuges 3.3.1 Analytical Ultracentrifuge3.3.2 Preparative Ultracentrifuge3.3.3 Centrifugal Elutriation3.4 Tubular Centrifuge 3.4.1 General Tubular Bowl Geometry3.4.2 Ribs and Solids Scraper 3.4.3 Plunger Cake Discharge3.4.4 Submerged Hub 3.5 Summary4.Disk Centrifuge4.1 Lamella/Inclined Plate Settler4.1.1 Inclined Plate Settler Principle4.1.2 Complications in Inclined Plate Settler4.2 Disk Stack Centrifuge 4.2.1 General Disk Geometry4.2.2 Disk Angle 4.2.3 Disk Spacing4.2.4 Process Functions of Disk Centrifuge4.2.5 Feed Solids4.2.6 Manual Disk Centrifuge4.2.7 Intermittent Discharge4.2.8 Chamber Bowl4.2.9 Nozzle Discharge4.2.10 Liquid Discharge4.3 Feed Inlet and Accelerator4.3.1 Introduction to Low Shear4.3.2 Hydro-Hermetic Feed Design4.3.3 Power Loss4.3.4 Feed Acceleration Visual and Quantitative Testing4.3.5 Improved Feed Accelerator4.4 Other Considerations4.5 Examples of commercial disk stack centrifuge4.6 Summary5. Decanter Centrifuge5.1 Solid Bowl or Decanter centrifuge5.2 Feed Rate5.3 Pool Depth5.4 Rotation Speed and G-force5.5 Differential Speed5.6 Sedimentation Enhancement using Chemicals5.7 Three-Phase Separation5.8 Cake Conveyance 5.8.1 Dry Beach 5.8.2 Hydraulic Assist 5.9 Summary6. Commercial Applications of Centrifugation in Biotechnology6.1 Generic Flow Sheet of Biopharmaceutical6.2 Mammalian Cell6.3 Yeast Processing6.4 Hormones Processing 6.5 Insulin Production6.6 Biotech Separation of Inclusion Bodies6.7 Vaccines Processing6.7.1 Concentrated Cell based Product6.7.2 Serum Product6.8 Enzymes Processing6.8.1 Extracellular Enzymes6.8.2 Intracellular Enzymes6.9 Ethanol Production6.10 Other Biotech Processing 6.10.1 Recovery of Coagulation Factors from Blood Plasma6.10.2 Tissue from Animal Cells6.10.3 Lab Concentration and Buffer Exchange using centrifugal Filter6.11 Summary7. Concentrating Solids by Centrifugation7.1 Introduction7.2 Concentrating underflow7.3 Compaction7.4 Expression or Percolation7.5 Compaction Testing7.6 Compaction Pressure 7.7 Recommendations for Increasing Solid Concentration in Underflow7.8 Summary8. Lab and Pilot Testing8.1 Process Objectives 8.2 Solid, Liquid and Suspension Properties8.2.1 Solids Properties8.2.2 Mother Liquid Properties8.2.3 Feed Slurry Properties8.3 Bench-Scale Testing8.3.1 Separability8.3.2 Flocculant and Coagulant in Bench Tests8.3.3 Test Variables8.3.4 Material Balance8.3.5 Acceleration and Deceleration Time Duration8.3.6 Settling Velocity8.4 Pilot Testing8.4.1 Material Balance Consideration for Pilot/Production Scale8.4.2 Product (Protein) Yield8.4.3 Pilot Test Factors8.5 Summary9. Selection and Sizing of Centrifuges9.1 Selection9.1.1 Introduction9.1.2 Tubular Centrifuge Selection9.1.3 Disk Centrifuge Selection9.1.4 Centrifuge Comparison9.2 Centrifuge Sizing9.2.1 Sizes and Rates9.2.2 Dimensionless Le Number9.2.3 Spintube (bottle) Centrifuge 9.2.4 Sizing for Disk Centrifuge 9.2.5 Sizing for Tubular, Chamber and Decanter Centrifuge9.3 Feed Particle Size Distribution9.4 Summary10. Troubleshoot and Optimization10.1 Troubleshooting10.1.1 Time Scale of Occurrence10.1.2 Mechanical or Process Problem10.1.3 Process Problems10.1.4 Mechanical Problem10.2 Optimization10.2.1 Separation Metrics10.2.2 Monitored Variables10.2.3 Controlled Variables10.2.4 A Simple Optimization Scheme10.3 Summary11. Flow Visualization and Separation Modeling of Tubular Centrifuge11.1 Flow Visualization11.2 Improved Moving Layer Flow Model 11.3 Effect of Velocity Profile11.4 Effect of Friction within the Flow Layer11.5 Dimensionless Le Parameter11.6 Quantitative Prediction 11.6.1 Total Solids Recovery in Cake11.6.2 Total solids Recovery in the Centrate11.6.3 Particle Size Distribution of Supernatant/Overflow 11.6.4 Cumulative Size Recovery 11.7 Sedimentation Tests11.7.1 Experiments on Sedimentation in Rotating Bowl Centrifuge11.8 Summary12. Disk Stack Modeling 12.1 Disk Model12.1.1 Continuous Phase12.1.2 Dispersed Phase12.2 Model Validation12.3 Complications12.4 Summary13. Performance Projection of Centrifuges in Bioseparation13.1 Disk Centrifuge13.1.1 Baseline Case (400-mm Disk)13.1.2 Effect of Fine Size Distribution (400-mm Disk)13.1.3 Effect of G-Force (580-mm disk)13.1.4 Effect of Efficiency h (580-mm Disk)13.1.5 Disk Centrifuge for Yeast Processing (500-mm disk)13.1.6 Disk Centrifuge for Inclusion Body Separation (260-mm Disk)13.1.7 Enzymes (580-mm Disk)13.2 Tubular Centrifuge 13.2.1 High-G Tubular (100- & 300-mm)13.2.2 Lower-G Tubular (100- & 300-mm)13.3 Decanter13.4 Spintube 13.5 Strategy of Developing Drug using Numerical Simulations13.6 Summary14. Rotating Membrane in Bioseparation14.1 Membrane 14.1.1 Osmotic Pressure Resistance14.1.2 Gel Resistance14.1.3 Membrane Fouling and Cake Formation14.1.4 Two Scenarios of Rotational Effect on Membrane Filtration 14.2 Rotating Disk Membrane with surface parallel to the G-Force14.2.1 Dimensionless Numbers14.2.2 Governing Equations and Solution14.2.3 Gel Concentration14.2.4 Determining Diffusivity14.2.5 Parametric Effects14.3 Rotating Membrane with Membrane Perpendicular to the G-Force 14.3.1 Spintube Equipped with Membrane Module - Centrifugal Filter14.3.2 Model on Swinging Bucket Equipped with UF Membrane14.3.3 Comparing Test Results with Predictions14.4 Summary