Chapter 9, Problem 9.18P

Carbon monoxide at 25°C and steam at 150°C are fed to a continuous water-gas shift reactor. The product gas, which contains 40.0 mole% H₂, 40.0% CO₂, and the balance H₂O(v), emerges at 500°C at a rate of 3.50 SCMH (standard cubic meters per hour) and goes to a condenser. The gas and liquid streams leaving the condenser are in equilibrium at 15°C and 1 atm. The liquid may be taken to be pure water (no dissolved gases).

1. Calculate the percent excess steam fed to the reactor and the rate of condensation of the water (kg/h).

Calculate the rate (kW) at which heat must be transferred from the condenser.

Taking atomic species at 25°C as references, prepare and fill in an inlet-outlet enthalpy table and calculate the required rate of heat transfer (kW) to or from the reactor.

It has been suggested that the carbon monoxide feed stream could pass through a heat exchanger prior to entering the reactor and the reactor product gas could pass through the same heat exchanger before entering the condenser. Sketch and label a flowchart of the heat exchanger and state economic benefits that might result from its use. (Hint: Heating and cooling operations are both expensive.)