Hydrogen and carbon monoxide are produced by a reacion between steam $($water

vapor$)$ and propane $(C_3{H}_8).$ Carbon monoxide also reacts with the steam, leading to the

formation of additional hydrogen and $C{O}_2\mathrm{.}100mo\frac{l}{m}in$ of propane at $125C$ is

combined with $50\%$ excess steam at $200C$ to form a fresh feed. The feed is joined by a

recycle and the combined streams are fed to the reactor. The products, which are at

$300C,$ are sent to a separator where $80\%$ of the steam and propane are recycled back

to join the fresh feed, and the rest of the products exit. If the overall conversion of

propane is $85\%$ and the selectivity of $CO$ to $C{O}_2$ is $5$ :