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TLS Online TPP Program

#Question id: 14319

Both Saccharomyces cerevisiae yeast and Zymomonas mobilis bacteria produce ethanol from glucose under anaerobic conditions without external electron acceptors. The biomass yield from glucose is 0.11 g g-1 for yeast and 0.05 g g-I for Z. mobilis. In both cases the nitrogen source is NH3. Both cell compositions are represented by the formula CH1.800.5N0.2. What is the yield of ethanol from glucose by Saccharomyces cerevisiae yeast?

#Section 5: Bioprocess Engineering and Process Biotechnology
  1. 1.72gmol gmol-1
  2. 1.82gmol gmol-1  
  3. 1.90gmol gmol-1 
  4. 1.50gmol gmol-1                                    
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TLS Online TPP Program

#Question id: 14222

#Section 5: Bioprocess Engineering and Process Biotechnology

A stirred-tank reactor is to be scaled down from 10 m3 to 0.1 m3. The dimensions of the large tank are: Dt = 2 m; Di = 0.5 m; N = 100 rpm.Determine the dimensions of the small tank (Dt , Di , H) by using geometric similarity?
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TLS Online TPP Program

#Question id: 14223

#Section 5: Bioprocess Engineering and Process Biotechnology

A furnace wall is constructed of firebrick 15-cm thick. The temperature inside the wall is 700⁰C the temperature outside is 80⁰C. If the thermal conductivity of the brick under these conditions is 0.3 W m-1 K^-1, what is the rate of heat loss through 1.5 m2 of wall surface?
TLS Online TPP Program

#Question id: 14224

#Section 5: Bioprocess Engineering and Process Biotechnology

Heat is transferred from one fluid to a second fluid across a metal wall. The film coefficients are 1.2 and 1.7kW m^-2 K^- 1. The metal is 6-mm thick and has a thermal conductivity of 19 W m^-1 K^-1. On one side of the wall there is a scale deposit with a fouling factor estimated at 19 W m^-1 K^-1. What is the overall heat-transfer coefficient?
TLS Online TPP Program

#Question id: 14225

#Section 5: Bioprocess Engineering and Process Biotechnology

A fermenter is maintained at 35⁰C by water circulating at a rate of 0.5 kg s^-1 in a cooling coil inside the vessel. The inlet and outlet temperatures of the water are 8⁰C and 15⁰C respectively. The length of the cooling coil is increased by 50%. In order to maintain the same fermentation temperature, the rate of heat removal must be kept the same. Determine the new cooling-water flow rate and outlet temperature by carrying out the following calculations. The heat capacity of the cooling water can be taken as 4.18 kJ kg^- 1 o C^- 1. From a steady-state energy balance on the cooling water, calculate the rate of cooling with the original coil ___________________.
TLS Online TPP Program

#Question id: 14226

#Section 5: Bioprocess Engineering and Process Biotechnology

A fermenter is maintained at 35⁰C by water circulating at a rate of 0.5 kg s^-1 in a cooling coil inside the vessel. The inlet and outlet temperatures of the water are 8⁰C and 15⁰C respectively. The length of the cooling coil is increased by 50%. In order to maintain the same fermentation temperature, the rate of heat removal must be kept the same. Determine the new cooling-water flow rate and outlet temperature by carrying out the following calculations. The heat capacity of the cooling water can be taken as 4.18 kJ kg^- 1 o C^- 1. Determine the mean temperature difference with the original coil.
TLS Online TPP Program

#Question id: 14227

#Section 5: Bioprocess Engineering and Process Biotechnology

A fermenter is maintained at 35⁰C by water circulating at a rate of 0.5 kg s^-1 in a cooling coil inside the vessel. The inlet and outlet temperatures of the water are 8⁰C and 15⁰C respectively. The length of the cooling coil is increased by 50%. In order to maintain the same fermentation temperature, the rate of heat removal must be kept the same. Determine the new cooling-water flow rate and outlet temperature by carrying out the following calculations. The heat capacity of the cooling water can be taken as 4.18 kJ kg^- 1 o C^- 1. Evaluate UA for the original coil. ________________