Methanol $($CH$3$OH$)$ is produced by the reaction of carbon dioxide $($CO$2)$ and

hydrogen $($H$2).$ The feed to the reactor is made up of $30\%$ by volume CO$2$ and

$70\%$ by volume H$2$ where a fractional conversion of the hydrogen of $0\mathrm{.}60$ is

achieved. The product gas consisting of methanol and water, and unreacted

hydrogen and carbon dioxide is passed to a condenser which separates the

products of the reaction from the unreacted gases.

a$.$ Write down a balanced stoichiometric equation for the above reaction.

$[5\%]$

b$.$ Prepare a neat process flow diagram and fill in all of the known$/$unknown

flow rates and compositions. $[5\%]$

c$.$ Conduct a Degree$-$of$-$Freedom analysis on the reactor, condenser

and overall process and show that it is necessary to specify one other

process variable to allow you to balance the PFD$.[20\%]$

d$.$ Assuming a basis of $100$ mol$/$h feed to the reactor determine the flow

rates and compositions of all streams in the process. $[30\%]$

e$.$ Express the composition of the exit gas stream from the reactor in

mass fractions. $[10\%]$

f$.$ The single pass mode of operation is very wasteful of the feed

gases. If the exit gas from the condenser is recycled and mixed with a

fresh feed stream such that the reactor feed stream remains unchanged,

determine the molar flow rate and composition of the fresh feed to the

process. $[20\%]$

g$.$ What modification to the process described in $($f$)$ would be required if the

input stream contained $0\mathrm{.}004\%$ by volume of an inert gas. $[5\%]$

h$.$ If it is required to design a process to produce $160$ kmol$/$h of methanol

what quantity of fresh feed gas would be required.