Kinetics and mechanisms of the catalytic thermal cracking of asphaltenes adsorbed on supported nanoparticles

The production of heavy and extra-heavy oil is challenging because of the rheological properties that crude oil presents due to its high asphaltene content.The upgrading and recovery processes of these unconventional oils are typically water and energy intensive,which makes such processes costly and environmentally unfriendly.Nanoparticle catalysts could be used to enhance the upgrading and recovery of heavy oil under both in situ and ex situ conditions.In this study,the effect of the Ni-Pd nanocatalysts supported on fumed silica nanoparticles on post-adsorption catalytic thermal cracking of n-Casphaltenes was investigated using a thermogravimetric analyzer coupled with FTIR.The performance of catalytic thermal cracking of n-Casphaltenes in the presence of NiO and PdO supported on fumed silica nanoparticles was better than on the fumed silica support alone.For a fixed amount of adsorbed n-Casphaltenes(0.2 mg/m~2),bimetallic nanoparticles showed better catalytic behavior than monometallic nanoparticles,confirming their synergistic effects.The corrected OzawaFlynn-Wall equation(OFW) was used to estimate the effective activation energies of the catalytic process.The mechanism function,kinetic parameters,and transition state thermodynamic functions for the thermal cracking process of n-Casphaltenes in the presence and absence of nanoparticles are investigated.