E. coli have a maximum respiration rate, qO2max, of about 240-mg O2/g-dry wt-h. It is desired to achieve a cell mass of 20 g dry wt/l. The kLa is 120 h-1 in a 1000-l reactor (800 l working volume). A gas stream enriched in oxygen is used (i.e., 80% O2) which gives a value of C* = 28 mg/L. If oxygen becomes limiting, growth and respiration slow; for example,

                                     

   where CL is the dissolved oxygen concentration in the fermenter. What is CL when the cell mass is  at 20 g/l?

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#Question id: 27052

#Section 4: Fundamentals of Biological Engineering

A membrane is used for separation of gases from waste. If the feed stream contains 20% CO2 and 80% SO2 and the product contains 25% CO2 and 75% SO2. Assume that the waste stream amounts to 80% of the input stream. What is the composition of CO2 in waste stream?

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#Question id: 27053

#Section 4: Fundamentals of Biological Engineering

To obtain a 100 Kg of 40 % N2 solution, how much nitrogen must be added to a 20% nitrogen solution?

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#Question id: 27054

#Section 4: Fundamentals of Biological Engineering

For the given distillation column 1000 Kg of feed is given to the column and the efficiency of the column is 10%.  What is the amount of product?   

    

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#Question id: 27055

#Section 4: Fundamentals of Biological Engineering

What is the enthalpy of 150 g formic acid at 70°C and 1 atm relative to 25°C  and 1 atm? 

(Cp for formic acid is 0.524 cal g-1 °C-1)

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#Question id: 27056

#Section 4: Fundamentals of Biological Engineering

15 J is the latent heat for melting of ice, what is the heat of transition from 0oC ice to 15oC water if heat of transition from 0oC water to 15oC water is 10 J?

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#Question id: 27057

#Section 4: Fundamentals of Biological Engineering

50 g benzaldehyde vapour is condensed at 179°C. What is the enthalpy of the liquid relative to the vapour? 

(Standard latent heat for vaporisation for benzaldehyde is 38.40 kJ gmol-1)