Changes in the subfractional composition of heavy oil asphaltenes under aquathermolysis with oil-soluble CO-based catalyst

The asphaltenes extracted from the heavy oil sample and products of non-catalytic and catalytic aquathermolysis in the presence of cobalt-based catalyst precursors and hydrogen donor were investigated. Five fractions of asphaltenes and carbene-carboid were obtained by solvent extraction method. In the products of catalytic aquathermolysis processes, the content of resins and asphaltenes decreased, while the content of light hydrocarbon fractions (saturates and aromatics) slightly increased in contrast with non-catalytic processes. This result is due to intensification of destructive hydrogenation reactions, mostly on the weak -C-S-C- bonds of resins and asphaltenes. This study revealed redistribution phenomenon between the asphaltene fractions and decrease in average molecular mass of all asphaltene fractions under catalyst influence.