Apparent Kinetics Of Water Gas Shift Reaction Over Co-Mo Catalysts Under Atmospheric Pressure And Pressurized Conditions

The Co-Mo catalyst is a relatively new catalyst developed for the water gas shift reaction(WGSR).This kind of catalyst has a higher catalytic activity in a sulfur-containing atmosphere,which is suitable for the WGSR of raw sulfur-containing syngas to produce hydrogen and other chemicals.In this thesis,the WGSR kinetics of an industrial Co-Mo catalyst under atmospheric pressure and pressurized condition were studied.The main contents are included as follows.The sulfurization experiment of the Co-Mo catalyst was carried out on a fixed-bed reactor,and the time required for the catalyst to complete the sulfurization was obtained.WGSR kinetics experiments were carried out at a near atmospheric pressure(150 kPa).The result showed that the reaction rate was the most sensitive to changes of the CO mole fraction.The atmospheric pressure kinetic model is:(?)The results of WGSR kinetics experiments conducted under a pressurized condition(2 MPa)showed that the increase in pressure can significantly promote the reaction rate.The pressurized kinetic model is:(?)Statistical tests showed that the effect of H2 on the reaction rate in the model was insignificant so that the pressurized kinetic model was simplified by ignoring the parameter for H2.After applying the two kinetic models for calculating the catalytic activities at different temperature and pressure,it was found that the activity of the Co-Mo catalyst varied with pressure.The catalysts before and after sulfurization were characterized by N2 adsorption,X-ray diffraction and X-ray photoelectron spectroscopy.It was found that the specific surface area and pore structure of the catalyst changed after sulfurization.Co and Mo are distributed on the y-Al2O3 support as amorphous low-valence sulfides.A plausible catalytic reaction mechanism is proposed,which can elucidate the higher CO reaction order obtained from the experiment.