Additional Exercises

1:

Data for a specific growth rate coefficient as a function of substrate concentration for a biochemical reactor are shown below x2, g/liter 0 0.1 0.25 0.5 0.75 1 1.5 3 5 m, hr-1 0 0.38 0.54 0.63 0.66 0.68 0.70 0.73 0.74 Estimate the parameter values for a Monod-specific growth rate model. The production rate of cells is Dx1. Find the steady-state value of the dilution rate that maximizes the production rate of cells. The substrate feed concentration is 5 g/liter. Find the steady-state concentration of biomass and substrate at this dilution rate. Find the linear state space model at this dilution rate, with dilution rate and substrate feed concentration as the input variables. Also, find the transfer function relating dilution rate to biomass concentration. Simulate the responses (using the nonlinear dynamic model) of the concentration of biomass and substrate to step increases and decreases of 10% in the dilution rate (changes are from the dilution rate found in question b.). Compare these results with those of the linear system (remember to convert deviation variables back to physical variables).

2:

Literature search: Perform a literature review (using Current Contents, EI Compendex, or some other professional search package, and NOT an Internet-based search engine) on the control of fermentation processes. Select one or two articles that are most interesting to you and discuss the importance of this particular process. Example: What is a typical annual production rate?