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Third Semester B.Tech. Degree Examination, November 2009(2008 Scheme)

BIOPROCESS CALCULATIONS (B)

Time : 3 Hours Max. Marks : 100

PART – A

Answer all questions from Part A.

1. Schematically represent processes with recycle by-pass and purge stream.

2. Explain the concept of theoretical oxygen demand.

3. Estimate the theoretical growth and product yield coefficients for ethanol

production. Given Y X/ATP = 10.5 gdw/mol ATP.

4. What are the factors affecting the transport of O2 across cell membrane ?

5. Explain briefly the biomass productivity in a continuous culture.

6. Explain the ATP consuming and ATP generation steps in glycolysis.

7. Define power number and Nussult number.

8. Write notes on Boyle’s law and Avogadro’s principles.

9. If 8 ml of distilled water are added to 2 ml of 95% ethanol, what is the concentration

of the diluted ethanol solution ?

10. Explain the rate controlling reactions in glycolysis. (4×10=40 Marks)

Reg. No. : ....................................

Name : .........................................

P.T.O.

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PART – B

Answer any one from each Module.

MODULE – I

11. a) Calculate the molar volume of isobutene at 428 K and 86.2 bar using

- The Vander Waals equation

- The Lydersen method.

The critical pressure and temperature of isobutene are 36.48 bar and 408.1 K.

The critical compressibility factor and acentric factors are 0.2627 and 0.282

respectively. 10

b) Stefan Boltzmann law states that emissive power is proportional to the fourth

power of absolute temperature stated mathematically4

b TE

where Eb is the emissive power in Btu / ft2h, is the Stefan Boltzmann

constant, and T is the temperature in °K. What is the value of in W/m2K4,

if its value in FPS unit is 0.171 × 10–8 Btu / ft2 h°K4 ? 10

12. a) A natural gas has the following composition by volume CO2 : 0.8%, N2 : 3.2%

and CH4 : 96%. Calculate

a) The composition in weight percent

b) The average mol. wt.

c) The density at standard conditions. 10

b) Calculate the volume occupied by one mole of O2 at 300 K and 100 bar

using

a) The ideal gas law

b) The Vander Waals equation

Take a = 0.1378 Nm4/mol2, b = 3.18×10–5 m3/mol. 10

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MODULE – II

13. a) At one hour intervals, 0.75 ml sample from culture are withdrawn, their opticaldensities are determined as given below :

Hours after inoculation OD550 Cells/ml

0 0.008 2.1×107

1 0.020 4.5×107

2 0.052 1×108

3 0.135 2.6×108

4 0.200 4×108

5 0.282 5.8×108

6 0.447 9.6×108

Calculate the growth constant K and the generation time for the given culture. 10

b) Serratia Marcescens is cultured in minimal medium in a small stirred fermenter.Oxygen consumption is measured at a cell concentration of 22.7 g/l dryweight.

Time O2 concentration (m mol/l)

0 0.25

2 0.23

5 0.21

8 0.20

10 0.18

12 0.16

a) Determine the rate constant for O2 uptake.

b) If the cell concentration is reduced to 12 g/l, what is the value of the rateconstant ? 10

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14. a) The following reaction catalyzed by phosphoglucomutase occurs during

breakdown of glycogen.

Glucose - 1 - Phosphate glucose 6 - phosphate.

A reaction is started by adding phosphoglucomutase to 0.04 mol glucose

1-phosphate in 1 litre solution at 25ºC. The reaction proceeds to equilibrium atwhich the concentration of glucose - 1- phosphate is 0.002 M and theconcentration of glucose - 6 - phosphate is 0.038 M.

a) Calculate the equilibrium constant

b) What is the theoretical yield ?

c) What is the yield based on amount of reactant supplied ? 10

b) Explain the method for determination of KLa (Oxygen mass transfer

coefficient). 10

MODULE – III

15. a) Explain the various modes of membrane transport. 5

b) The maximum growth yield coefficient for Bacillus Subtilis growing on

methanol is 0.4 g × 1 gs. The heat of combustion of cells is 21 kJ / g cellsand for substrate, it is 73 Kcal/g. Determine the metabolic heat generated by

the cells per unit mass of methanol consumption. 15

16. a) What are the major steps in aerobic metabolism of hydrocarbons ? What are

the end products ? 10

b) Steam is used to heat nutrient medium in a continuous flow process saturatedsteam at 150ºC enters a coil on the outside of the heating vessel and is completelycondensed. Medium enters the vessel from the jacket to the surroundings areestimated as 0.22 KW. If the flow rate of medium is 3250 Kg/hr and the heatcapacity is CP = 0.9 Cal/g/ºC how much steam is required ? 10

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