Hydrodesulphurization of thiophene over a NiO‐MoO 3 ‐Al 2 O 3 catalyst

NiO‐MoO 3 ‐Al 2 O 3 based hydrodesulphurization catalysts appear to be of long term interest in the processing of Athabasca bitumen to eliminate organo‐bonded sulphur and nitrogen‐containing groups. This study employs such a catalyst (NALCO NM 502: 2% NiO, 14.0% MoO 3 , and γ‐Al 2 O 3 ) in rate measurements of the vapor‐phase reaction of thiophene with hydrogen using an integral fixed‐bed reactor operated at about atmospheric pressure and in the temperature range, 270 to 350°C. Both power‐law and mechanistic models were fitted to the data; discrimination amongst the later being based upon consistency with physicochemical observations and the power‐law behaviour. The kinetic parameters for these models were contrasted with those obtained by a number of other workers for primarily Co‐Mo‐Al 2 O 3 catalysts.