Question

4) Lactic acid is produced by homolactic bacteria Streptococcus lactis from glucose solution using fed-batch operation. The following data are available: Vo = 101, Xo = 5 g/1. Yxs = 0.12 g X/g S, Yp/s = 0.80 g P/g S. um = 0.2 h-1, Ks = 0.5 g/l, So= 30 g/l, F= 2 1/h. a. How long should the system be operated in order to obtain S=0.5 g/l in the fermenter? b. Determine the biomass concentrations at the end of operation. c. What should be the feed flow rate in order to obtain S = 0.1 g/l after 10 h of operation?

Answer 1

Answer! Given data, Vo = 100; X = 59/1, Yx! 5 = 60!29 x/gs, Yp] 5= 0.809 p19 S, Mm = 0.25?, K5=0.59)], 50 = 309)1, F2 =2 116. 5:0.5911 we know, M:D = Mass-0 D = 0.2X0.5 0.5+0.5 D=00h) We also know that, D=Flv v V- 2016 0.61 V=200 In fed batch, y= VotFt 20=10+2xt gtalo

It=shol 6 At the end of sho operation. Biomifs concentration, xt = X + FXxl Sot 24 = 5+ [zy odbe x30x8] ML = 5+36 [X + = 4 glu poduct concentration, P= Po + yolke * (*+) PE 0+ (0.80) (21) Chest Olxs 's 1P =123918] o Giron 5-0.1 glu D = ums K5+5 0 - 0.2X0) 005 tool DE 0102

D = 0.033h) we know, V=Vo+Ft dividing both sides by Fowe get. Ě V t t 1 / 2 = 1 tott to = 10 +10 0.033 Eta These fose, (F = 0.498157