Types of Bioreactor • Stirred tank bioreactor • Airlift bioreactor • Loop reactor • Immobilized system • Membrane Reactors • Bubble Column • Photobioreactors Airlift Bioreactor
A disposable bioreactor A pilot plant bioreactor Immobilized bioreactor
Advantages of continuous culture • Growth rate can be controlled and maintained. • Effect of changes in physical or chemical parameters can be examined. • Biomass concentration can be maintained by varying the dilution rate. Find out more on the advantages.
Dilution Rate, D • D = F/V, the number of culture volumes passing through the reactor per hour. • dX/dt=-DX + X = X(-D) • During steady state, dX/dt = 0 consequently = D • So, by varying the medium supply, growth rate can be varied. • This holds until D m • Under these condition, the nutrient is no longer limiting • Therefore, the expression (-D) becomes -ve
Critical Dilution Rate • The lowest dilution rate at which wash out occurs. • Dc is approximately equal to m. • At dilution rates approaching Dc, the chemostat becomes less stable since slight fluctuations in the flow rate. • A major drawback of chemostat is that they work best at lower dilution rates where the changes in X and S are small.
Assignment 1Discuss 2 types of axial flow impeller and radial flow impeller with respect to their power drawn under aerated and non aerated conditions.
Describe the flow patterns for axial flow impeller and radial flow impeller. Give examples for the types of impeller for both pattern.