Pro ble m 2 In bioreactors, the growth is generally autocatalytic in that the more cells you have, the greater the growth rate Cells + nutrients cells + more cells + product The cell growth rate, r, and the rate of nutrient consumption, r, are directly proportional to the concentration of cells for a given set of conditions. A Levenspiel plot of (1/- r.) as a function of nutrient conversion X, = (Cso - Cs)/Cso is given below in Figure P2-8. Cso 0.8 0.6 - * (orygon) dm3 0.4 Nutrients CO2, H20 Products ... 0.2 .. 0 0.2 0.4 0.6 Cell Wall Cell Membrane Cytoplasm Cell Nuclear region Ribosome 0.8 . Figure P2-8: Levenspiel plot for bacteria growth, Problem 1. For a nutrient feed rate of 1 kg/hr with Cso = 0.25 g/dm', what chemostat (CSTR) size is necessary to achieve: (d) How could you arrange a CSTR and PFR in series to achieve 80% conversion with the minimum total volume? Repeat for two CSTRs in series. Pro ble m 2 In bioreactors, the growth is generally autocatalytic in that the more cells you have, the greater the growth rate Cells + nutrients cells more cells + product The cell growth rate, r, and the rate of nutrient consumption, r, are directly proportional to the concentration of cells for a given set of conditions. A Levenspiel plot of (1/- r.) as a function of nutrient conversion Xs = (Cso - Cs)/Cso is given below in Figure P2-8. 0.8 1 0.6 Cs V (dm3 = ") 0.4 Nutrients CO2, H2O Products 0.2 0 0.2 0.4 Cell Wall Cell Membrane Cytoplasm Cell Nuclear region Ribosome 0.8 0.6 . Figure P2-8: Levenspiel plot for bacteria growth, Problem 1