A5 Use of the Traditional Packed Bed Bioreactor Model

This section gives advice about the use of the model for the traditional packed-bed bioreactor that was presented in Chap. 24.2. The following steps should be followed.

First use a text editor to edit the input data file. An input data file (text file) has been supplied with the name "input.txt". The contents of this file are shown in Fig. A.3. Change the values as appropriate, save the file (as a text file), and exit the file editor.

Then click twice on "PackedBed". A "DOS window" will appear on the screen. Several questions will appear, one after the other.

• Filename for temperature profile?

• Filename for biomass?

After you answer the last question, the program will run automatically. When the instruction "Press any key to continue" appears, press the space bar.

Inspect the output files. Assuming that you have called the three output files "temp.txt", "biomass.txt", and "echo.txt", respectively:

• temp.txt will have various columns without headings. The number of columns will be 3 greater than the number of "internal collocation points" that was en tered into the file "input.txt". The first column represents the time of the output (h). The other columns represent the temperatures (°C) at the various heights within the bioreactor. The locations of these heights (as a fraction of the total height) are given, in the same order, at the end of the echo file. The number of rows within temp.txt will depend on the values for "Number of times that output is to be reported per hour " and "Time at which the simulation is to finish (h)" that were entered in the input file.

• biomass.txt will have the same organization as "temp.txt". The first column represents the time of the output (h). The entries in the other columns will represent biomass concentrations (kg-biomass kg-substrate-1) at the various fractional heights within the bioreactor.

• echo.txt contains an echo of various input values and other values calculated in the program. The content is self-explanatory.

38.0 Initial bed temperature (deg C)

38.0 Initial inlet air temperature (deg C)

0. K (gain factor that controls the inlet air temperature) 3.0 Superficial velocity of the air (cm/s)

1. Initial biomass (g dry biomass per kg moist solids) 125. Final biomass (g dry biomass per kg moist solids)

.236 Maximum value of the specific growth rate constant (1/h)

38.0 Optimum temperature for growth (deg C)

21 Number of internal points along height

1. Number of times that output is to be reported per hour

101. Time at which the simulation is to finish (h)

Fig A.3. Appearance of the input file (input.txt) for the traditional packed-bed bioreactor model

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