Patent ID: 7357911

Claim:
A process for generating hydrogen by the water-gas shift reaction in the presence of a Pt—Re based water-gas shift catalyst, comprising operating the water-gas shift reaction at a temperature of about 150 to 450° C.; a feed gas comprising up to about 20 vol % CO and steam; a gas space velocity, of the feed gas, at about 4500 to 50,000 h −1 , and reducing catalyst aging by controlling temperature, vol % CO, gas space velocity so as to meet the following formula: Δ T (50) 20h =(5.51+4.40×10 −5 [VHSV ×Pt(g/l)/7.4]−0.015× T+ 0.049×% CO) 2 −1.65 wherein T is Temperature in degrees C. (% CO) is the CO content of the dry process gas (without steam) in volume percent, VHSV is the gas hourly space velocity for a catalyst containing 7.4 g Pt per liter, Δ T(50) 20h is the difference of the temperatures at 50% CO conversion, i.e., Δ T (50) aged 20 hours-T (50) fresh, and ΔT (50) 20h is less than 7.0.