CBE 654 : BIOREACTOR ENGINEERING SEM 2 SESSION 2013/14ASSIGNMENT 3 : QUESTION

(SUBMISSION DATELINE 4pm FRIDAY 20/6/2014)

A single stage stirred tank continuous bioreactor of working volume 50m3 has been

filled with a medium containing 30 kg/m3 of sugar which can be used for yeast production. Determine the maximum productivity that can be achieved by this system and predict the medium feed rate for it.

Experiments in the laboratory have shown that the shortest doubling time for this yeast are 3 hours. In a medium that contains 500 g/m3 of the same sugar, the doubling time of this yeast is 6 hours, and to produce 1g dry weight (gdw) of yeast biomass, 2 kg of this sugar is needed.

State clearly all assumptions made. (3 Marks)