The water gas shift reaction equilibrates rapidly at temperatures above about 450 °C. At high temperatures this reaction favors the formation of carbon monoxide, while at low temperatures more hydrogen is formed. When hydrogen is the desired product, the shift reaction is promoted at lower temperatures by using an excess of steam and providing a medium- or low-temperature shift catalyst.
In an auto thermal reforming process, 1000 kmol/h of methane at 20 °C is compressed to 10 bar, mixed with 2500 kmol/h of saturated steam, and reacted with pure oxygen to give 98% conversion of the methane.
The resulting products are cooled and passed over a medium-temperature shift catalyst that gives an outlet composition corresponding to equilibrium at 350 °C.
i. How much heat is required to vaporize the steam?
ii. How much oxygen is needed?
iii. What is the temperature at the exit of the auto thermal reforming reactor? iv. What is the final molar flow rate of each component of the synthesis gas?