Corn-steep liquor contains 2.5 % invert sugars and 50% water; the rest can be considered solids. Beet molasses containing 50% sucrose, 1% invert sugars, 18% water and the remainder solids, is mixed with corn-steep liquor in a mixing tank. Water is added to produce a diluted sugar mixture containing 2% (w/w) invert sugars. 125 kg corn-steep liquor and 45 kg molasses are fed into the tank.

What is the concentration of solids in the final mixture?

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#Question id: 14625

#Section 5: Bioprocess Engineering and Process Biotechnology

Monod kinetics are considered in a CSTR with an organism growing with an initial substrate concentration of 50 g1^-1 and kinetic parameters of Ks = 2 g1^-1 and umax = 0.5 h^-1 . (a) What would be the maximum dilution rate for 100% yield of biomass with maximum rate? 

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#Question id: 14626

#Section 5: Bioprocess Engineering and Process Biotechnology

A bacterial fermentation was carried out in a reactor containing broth with average density 1200 kg/m³ and viscosity 0.02 N.s/m² . The broth was agitated at 90 rpm and air was introduced through the sparger at a flow rate of 0.4 vvm. The fermenter was equipped with two sets of flat blade turbine impellers and four baffles. The dimensions of vessel, impellers and baffle width were: tank diameter, Dt =4 m; impeller diameter, Di = 2 m; baffle width, Wb = 0.4 m; also, the liquid depth was H = 6.5 m 

Determine ungassed power, P; 

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#Question id: 14627

#Section 5: Bioprocess Engineering and Process Biotechnology

In a batch production of penicillin, 40 m³ capacity of the plant, sterile air is required to be supplied. The bioreactor requires 1 vvm (volume of air/volume of broth. min). The incoming air contains 3000 cells/m³of air, for 100 hours operation. Calculate the depth of filter if the penetration of bacteria is 1 in 1 million. 

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#Question id: 14628

#Section 5: Bioprocess Engineering and Process Biotechnology

Microbial cells are separated from a culture broth at a flow rate of 3.35 x10^-3m3/5. Assume the cells are spherical with average diameter of 111m. Select a centrifuge that can perform this separation. Given data: p_cell =1.1, P_water,=997 kgm^-1 at 25 °C; P_broth = 3p_water, and the viscosity of water is 0.9 x 10^-3 N.s/m² 

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#Question id: 14629

#Section 5: Bioprocess Engineering and Process Biotechnology

Microbial cell recovery is carried out in a continuous disc-stack centrifuge. The centrifuge is operated at 5000 rpm for separation of baker's yeast. At a feed rate of 60 1/min, 50% of the cells are recovered. At constant speed, solid recovery is inversely proportional to flow rate. What flow rate is required to recover 90% of cells if the centrifuge speed is fixed at 5000 rpm? 

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#Question id: 14630

#Section 1: Engineering Mathematics

The series whose n^th term is sin 1/n is