Hydrogen is produced in the steam reforming of propane:

The water–gas shift reaction also takes place in the reactor, leading to the formation of additional hydrogen:

The reaction is carried out over a nickel catalyst in the tubes of a shell-and-tube reactor. The feed to the reactor contains steam and propane in a 6:1 molar ratio at 125°C, and the products emerge at 800°C. The excess steam in the feed assures essentially complete consumption of the propane. Heat is added to the reaction mixture by passing the exhaust gas from a nearby boiler over the outside of the tubes that contain the catalyst. The gas is fed at 4:94 m³/mol C₃H₈, entering the unit at 1400°C and 1 atm and leaving at 900°C. The unit may be considered adiabatic.

(a) Calculate the molar composition of the product gas, assuming that the heat capacity of the heating gas is 0.040 kJ/(mol ∙ °C).

(b) Is the reaction process exothermic or endothermic? Explain how you know. Then explain how running the reaction in a reactor–heat exchanger improves the process economy.

Transcribed Image Text:

C3Hg(g) + 3H,O(v) → 3CO(g)+ 7H2(g)