Catalytic aquathermolysis of Mackay River bitumen with different types of Mo-based catalysts

In the present work, the catalytic aquathermolysis of Mackay River bitumen with 12 Mo-based catalysts were investigated. Thereinto, 6 catalysts were commercially available chemicals, while another 6 were lab-made polyoxometallate (POM) type catalysts. The catalytic aquathermolysis was carried out at 250 degrees C for 24 h and the properties including viscosity, SARA compositions of the bitumen after aquathermolysis have been measured. All the catalysts could improve the heavy fraction conversion ratio and decrease the viscosity of the bitumen. Soluble molybdates, (NH4)(6)Mo7O24 and (NH4)(2)MoS4, exhibited relatively higher catalytic activity on the bitumen aquathermolysis than insoluble MoO3, H2MoO4 and MoS2. The catalytic activities of the Keggin-type POMs was similar to soluble molybdates. Anderson-type POMs with long alkyl chains, such as [(C18H37)(2)(CH3)(2)N](4)NiMo6O24H6, showed considerably high activity in the catalytic aquathermolysis of the bitumen, which benefited from the two octadecyl chains of its quaternary ammonium cation and the Ni active center of the Anderson-type POM. This kind of Anderson-type POMs was applicable for the heavy oil reservoirs with relatively high requirements for viscosity reduction. We hope that the study will provide guiding principle for catalyst development for the catalytic aquathermolysis of Mackay River bitumen and other heavy oils.

Automated summary

Different Mo-based catalysts, including commercially available chemicals and lab-made POMs, were studied for the catalytic aquathermolysis of Mackay River bitumen. Anderson-type POMs with long alkyl chains showed considerable high activity in heavy fraction conversion and viscosity reduction, indicating potential application in heavy oil reservoirs with high requirements for viscosity reduction.