Kinetic studies of the partial oxidation of isooctane for hydrogen production over a nickel–alumina catalyst

Abstract

The kinetics of the catalytic partial oxidation of isooctane for hydrogen ( H 2 ) production over a stable Ni / γ - Al 2 O 3 catalyst was investigated at atmospheric pressure in the temperature range of 863–913 K, ratio of weight of catalyst to the molar feed rate of isooctane ( W / F iC 8 o ) in the range of 7.09 – 30.89 kg mol - 1 , and molar feed ratio O 2 / i - C 8 H 18 of 4.0 in a 12.7 mm diameter Inconel micro-reactor housed in an electrically controlled furnace. The developed rate models were based on the Langmuir–Hinshelwood–Hougen–Watson (LHHW) and Eley–Rideal (ER) formulations. Out of the 18 models developed, 10 were eliminated due to poor predictive efficiency. A LHHW mechanism requiring the dissociative adsorption of isooctane and molecular adsorption of oxygen on a single site was the most likely pathway for the partial oxidation of isooctane. The reaction order of 1.5 indicates a strong coverage of nickel by isooctane.