Carbon monoxide at 25C and saturated steam at 150C are fed to a continuous water
ID: 1068365 • Letter: C
Question
Carbon monoxide at 25C and saturated steam at 150C are fed to a continuous water-shift reactor. The product gas, which contains 40.0 mole% H2, 40.0 mole% CO2 and the rest H2O(v) emerges at 500C at a rate of 100 moles/h, and goes to a condensor, where all of the H2O is condensed. The gas and liquid streams leaving the condensor are at equilibrium at 25C and 1 atm. The liquid leaving the condensor can be assumed to be pure water (no dissolved gases), and there is no water vapour in the exiting gas stream from the condensor.
a) Calculate the % excess steam fed to the reactor and rate of condensation of the water (kg/h) leaving the condensor.
b) Calculate the rate (kW) at which heat must be removed from the condensor.
c) Calculate the rate of heat transfer (kW) to or from the reactor (state which it is).
Explanation / Answer
Basis:
Assume that 1m3 of carbon monoxide feed to the reactor.
CO + H2O (saturated steam) = H2 + CO2
According to stiochiometry
1m3 of CO consumes 0.643 m3 of steam
0.643 m3 of steam react with CO to produce 0.1 m3 of Hydrogen
As per problem statement the production of hydrogen is 2.4 m3
so steam requirement to produce 2.4 m3 is =15.66 m3
From that excess of steam used in the reaction = 15.66-0.643/15.66 * 100 = 95.92% excess of steam is used.
The rate of condensation of water (kg/h) = 5.5 kg/hr
2) Q = mcp dt
Q = 5.5 * 7.48* 475
= 19541 kW
3) Q = 118608 kW