Question

A first order irreversible reaction to convert compound X to compound Y in solution is planned to be carried out at 55ºC in three CSTRs placed in series, each of a different volume: the 1st tank is 200 cm^3 , the 2nd is 300 cm^3 and the 3rd is of 500 cm^3 . The 1st order rate constant of this reaction is 0.09 h^-1 . For the total holding time (tau) across all three tanks of 24 hours, what will be the conversion of X at the outlet from the 3rd tank?

Answer 1

An important/key observation in this problem is that the flow rate would remain same through the three reactors. Hence the flow rate can be calculated as the ratio of total volume of the three reactors upon total holdup time = 1000 cm^3/24 hours = 125/3 cm^3/hour.

Therefore, the holdup times in the three reactors are 24/5 hours or 36/5 hours and 12 hours respectively.

4 200 mL 300ML 5oomL । Comb = 1 am) ; rate= dla =-kCA k=0,09ht, holding time (total)= Trate = 24hs.s. As described above, the holdup times of the there reactals would be in the eatio of their volumes, such that they add upto Trotal = 24 kus. tizay we; ła= 6 h. & 73=60 4. OR 1268. Governing equations for the steady state operation of the 3 ESTR (for first order reaction) would be Reactor 0 Reactal @ Reactor ③ | C - CAO Itkti CALE CAI HKTz CA 3= CA2 ltkez . CA3= CAO itky)(1+kZy)(1+k?) TX I (conversion at the outlet of tauk3) T= 1- CA3 i X= ! (tkr) () (1tk) (1+0.08424) 0.7963 = |-* fire) / 900) 1X 2074323 762