Using the oil-soluble copper-based catalysts with different organic ligands for in-situ catalytic upgrading of heavy oil

Abstract

Oil-soluble copper-based catalysts with different organic ligands (octanoate, decanoate, oleate, and stearate) were proposed in this work for improving the upgrading processes. All of the upgrading experiments were carried out using a batch reactor at temperatures of 250 and 300 °C, and 24 h of reaction time. The changes in the physical properties and chemical compositions of the oil samples before and after upgrading were studied including viscosity, SARA analysis, and GC analysis of evolved gases as well as the distribution of carbon number in saturates. In addition, TG-FTIR and XRD techniques were used to evaluate the in-situ transformation of used catalysts. Used catalysts were mainly transformed into particles of copper oxide, sulfide, and pure metal which acted as a catalytic phase during upgrading of heavy crude oil. Introducing proposed catalysts as additives to the upgrading system resulted in viscosity reduction and reached their maximum value at 300 °C in presence of copper-oleate (50.31%). Moreover, an increase in the content of saturates (especially with light alkanes C10-C20), decreasing the content of heavy fractions including resins and asphaltenes as well as removal of sulfur were observed. The best catalytic performance was provided by copper oleate. The low cost and availability of proposed catalysts combined with good catalytic performance make them promising and potential catalysts for improving in-situ upgrading of heavy oil.