Multiphase Bioreactor Design

surface tension between water and dodecane 0.040 N/m

diameter gel bead 2.76 mm

diffusion coefficient substrate 10 –9 m/s

diffusion coefficient product 10 –9 m/s

distribution coefficient simulation depended

Hydrodynamics

hold-ups 3-phase fluidised bed simulation depended

Number of tanks per m reactor

3-phase fluidised bed 3

2-phase fluidised bed 13

Richardson and Zaki constants 2-phase fluidisation

n 2.35

v∞ 0.0377 m/s

Kinetics

Michaelis-Menten constant 1 mol/m^3

toxic product concentration simulation depended mol/m^3

maximum substrate conversion rate simulation depended mol/(m^3 s)

Operation parameters

medium flux simulation depended m/s

dodecane flux simulation depended m/s

initial substrate concentration 1000 mol/m^3

initial product concentration 0 mol/m^3

of substrate is reached. However, a combination of parameters is easily

found for which the substrate is not completely converted, hence substrate

concentration inside the gel bead is not equal to zero. Substrate will be

converted to product, as long as the product concentration at any place

inside the gel bead is less than the toxic product concentration.

Figure 12.9b:

As substrate is converted, product is formed. Early in the process little

product is present. Gradually product appears throughout the whole gel

bead. As product is initially formed near the surface of the gel bead,

product not only diffuses out of the gel bead but also towards the centre;

consequently a maximum concentration is found

Multiphase bioreactor design 368