Question

Consider a reaction of species A to form product B in a constant-density isothermal system. The rate of disappearance of A is given by a second-order rate, that is, (-r_A) = kC_A². A process plant carries out the reaction using a single PFR with 95% conversion of A. To increase production, a second reactor is added. The second reactor is to have the same volume as the first one, and the overall conversion from the system of two reactors is to remain at 95%. Four scenarios are imagined, as given in the following. For each case, determine by what factor the plant can increase production of B. Justify you answer using the appropriate mathematics or impeccable logic.
a) The second reactor is also a PFR and is operated in parallel.
b) The second reactor is a PFR and is operated in series.
c) The second reactor is a CSTR in series placed before the PFR.
d) The second reactor is a CSTR in series placed after the PFR.

Answer 1