SCALE-UP OF STIRRED AND AERATED BIOENGINEERING (TM) BIOREACTOR BASED ON CONSTANT MASS TRANSFER COEFFICIENT

The scale-up studies based on the constant oxygen transfer coefficient, k(L)a from 16 l to 150 l of aerated and agitated bioreactor were performed. By employing the static gassing out techniques, the k(L)a values were calculated at different sets of impeller speeds and air flow rates performed in various viscosities and temperatures in the 16 l and 150 l Bioengineering (TM) stirred bioreactor. Empirical correlation was employed to correlate and investigate the dependence of k(L)a on specific power input and superficial air velocity. In maintaining a constant k(L)a upon scale-up from 16 l to 150 l, the specific power input and the superficial air velocity cannot be maintained, thus an adjustment has to be done. From the experimental results at 150 l, it was discovered that the specific power input from 0.0001 to 4.2 kW/m(3) and superficial air velocity within the range of 9 x 10(-4) m/s to 7 x 10(-3) m/s employed gave a comparable k(L)a values achieved at 16 l scale. Hence, the calculated scaling-up factor for impeller speed and air flow rate were 0.28 and 3.1, respectively. The comparable results obtained from both scales confirmed that the scale-up protocol developed works.