Process Calculations GATE-2011
Q 1: Ammonia is synthesized at 200 bar and 773 K by the reaction N_2+3H_2\rightleftharpoons2{\mathrm{NH}}_3 . The yield of ammonia is 0.45 mol/mol of fresh feed. The flow sheet for the process (along with available compositions) is shown below.
The single pass conversion for H2 in the reactor is 20 %. The amount of H2 lost in the purge as a percentage of H2 in fresh feed is
Q 2: The following combustion reactions occur when methane is burnt.
{\mathrm{CH}}_4+2O_2\rightarrow{\mathrm{CO}}_2+2H_2O
2{\mathrm{CH}}_4+3O_2\rightarrow2CO+4H_2O
20 % excess air is supplied to the combustor. The conversion of methane is 80 % and the molar ratio of CO to CO2 in the flue gas is 1:3. Assume air to have 80 mol % N2 and the rest O2. The O2 consumed as a percentage of O2 entering the combustor is