PT

$4-$CBA

TA

where TALD is $p-$tolualdehyde, PT is $p-$toluic acid, and $4-$CBA is $4-$carboxybenzaldehyde. The rate of

reaction $i$ is $r_i=k_i{C}_i^{n_i}$ where $k_i$ is the rate constant, $C_i$ is the concentration of species $i,$ and $n_i$ is the

order of the reaction. Note that consumed oxygen and produced water are missing from the reaction

scheme above. At industrial conditions, $15$ bar, all reactions are zero$-$order with respect to oxygen. The

kinetic parameters of reactions $1-4$ at $195C$ are given below $[2]$:

A full design requires simultaneously solving a system of governing equations. We will use ChemCAD to

model the full reaction network, but first we will do some manual calculations using only reaction $1.$

a$)$ Using reaction $1$ only, estimate the reactor volumes and residence times needed to achieve

conversion $x_{Px}=0\mathrm{.}99$ with a feed of $C_{P{x}_0}=3\mathrm{.}8M$ and $F_{P{x}_0}=10$ tonnes$/$hr for two CSTRs in series

of equal volume. The reactor temperature and pressure are $T=195C$ and $P=15$ bar. The liquid

densities of $p-$xylene and acetic acid at this temperature are $691\mathrm{.}5$ and $834\mathrm{.}4k\frac{g}{m^3},$

respectively.