Slide 1Graham Watt Jackie Ankomah Dilmini Peiris Bryan Cawthorn Slide 2Background of centrifugation – purpose Centrifuge designs – different requirements Disc stack centrifuge technology Our centrifuge – process Design choice and sizing Costing analysis Slide 3Downstream processing is a major consideration in industry - separation of products/byproducts/wastes -separation of multiple phases, liquids/solids Specific to our application, removal of biomass from production stream -can be achieved through application of centripetal force -similar principles to use of settling tank, accelerated Slide 4Slide 5Filters – low solids concentration Disc stack centrifuge – increasing concentration Decanter centrifuge – higher concentration Slide 6Courtesy Alfa-Laval, 2008 Our Process - 1% solids ** - 1micron diameter Slide 7Subjecting the material to high centrifugal forces denser solids outwards -causes separation of solid and liquids phases -allows removal of solids manually, intermittently, or continuously Courtesy Alfa-Laval, 2008 Slide 8Centrifugation systems are very sensitive to changes in material composition - liquid media viscosity will impact settling rate (Stokes Law) - liquid flowrate through centrifuge - particle size (flocculation interactions) - cell integrity - rate limiting steps in process – fermentation of 12 days Slide 9Recommendation courtesy Stanley Foster, Alfa Laval Alfa Laval Culturefuge 400 - Designed to limit cell disruption - Hermetic seal preventing air/liquid interface - Allows for necessary throughputs Courtesy Elsevier, 2008 Slide 10Liquid Viscosity – 1.5cP Particle Diameter – 1micron Throughput – 63.7L/h Outer disk radius- 0.75m Inner disk radius- 0.5m Number of disks- 10 Centrifugation time- 10 days Cost estimation- $80,000 Slide 11Courtesy Alfa-Laval, 2008 Slide 12?