Upgrading of Omani heavy oil with bimetallic amphiphilic catalysts

Upgrading of Omani heavy oil was studied under aquathermolytic conditions in the presence of amphiphilic catalysts of NiMo, CoMo and their mixture of 1:1 wt ratio. The optimum reaction parameters were 300 degrees C, 5wt% water concentration and 2wt% catalyst concentration. For viscosity reduction, the catalyst efficiency follows the trend (CoMo+NiMo)> NiMo>CoMo. The maximum viscosity reduction observed at optimum conditions was 95% after 24 h of reaction on CoMo+NiMo mixture. Upgrading products distribution showed an increase in <C14 components and a reduction in >C21 components - suggesting cracking of longer carbon chains. Fourier Transform-Infrared Spectroscopy (FT-IR) confirmed the formation of alkenes as well as shortening of CH2 bonds following upgrading. Nuclear Magnetic Resonance (NMR) confirmed the occurrence of dealkylation reactions as well as cleavage of side chains on aromatics. X-ray fluorescence (XRF) indicated a reduction in sulfur content of up to 15% and confirmed the importance of C-S bond cleavage and hydrogenation in reduction of heavy oil viscosity. Results obtained indicated that amphiphilic catalysts are useful in the upgrading of Omani heavy oil, which will lead to an increase in recovery of higher value hydrocarbons. (C) 2016 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.