Question $3$: RESIDENCE TIME DISTRIBUTION $(31$ Marks$)$

$3\mathrm{.}1$ It was found that the yield from a chemical reactor at a chemical plant was low. In ordor to understand this problem, a tracer study was conducted on the reactor. An amount of $3\mathrm{.}80kg$ of an inert tracer A was injected into the feed port of the $1\mathrm{.}90-m^3$ reactor. The feed volumetric flow was constant at $3\mathrm{.}1\frac{L}{s}.$ The following tracer response data was measured:

$3\mathrm{.}1\mathrm{.}1$ Calculate values of $E(t),$ the mean residence time $(t_m),$ and ${}^2$ for the flow

$(15)$

through the reactor. A tabular solution is recommended.

$3\mathrm{.}1\mathrm{.}2.$ Sased on the above answer, are you able to identify the problem within the

$(5)$

reactor? Fully explain your answer.

$3\mathrm{.}1\mathrm{.}3$ Construd the $E(t)$ curve and estimate the fraction of the tracer that spent less

$(6)$

than $10$ minutes in the reactor.

$3\mathrm{.}2$ Celculate the conversion obtained in a CSTR for a second order liquid phase

$(5)$

reaction with and $($:$k{C}_{AO}=0\mathrm{.}5mi{n}^{-1}\}$

$31$

$=\frac{V}{\frac{1}{0}}=\frac{1900}{12,9}=612$