Upgrade of heavy crude oil via aquathermolysis over several types of catalysts

Abstract

A solid NaY zeolite catalyst was synthesized from raw materials using a hydrothermal method. The NH4Y and HY forms of the catalyst were then prepared using multistage ion-exchange and calcination processes, respectively. Cobalt and Zinc as transition metals were loaded into the HY structure through impregnation method. The synthesized Zn/HY and Co/HY zeolites along with ZnO and CoO nanoparticles were all used as catalysts for aquathermolysis. The catalysts were characterized using X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy-energy-dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller surface area and pore volume analysis. A stainless-steel autoclave operated at 45 bar and 250 °C for 24 h was employed for upgrading heavy crude oil samples extracted from the East Baghdad oilfield using toluene as the hydrogen donor. The reaction products were analyzed by evaluating the changes in their viscosity, API gravity, density, pour point, and flash point. The results indicated that the efficiency of the catalysts decreased as follows: Zn/HY zeolite > Co/HY zeolite > nano CoO > nano ZnO > HY zeolite > in the presence of the hydrogen donor only = in the absence of catalysts or the hydrogen donor. The decrease in the S-content of the products was also evaluated. The results indicated that the efficiency of the catalysts decreased as follows: Co/HY zeolite > Zn/HY zeolite > nano CoO > nano ZnO > HY zeolite > in the presence of the hydrogen donor only > in the absence of catalysts or the hydrogen donor. The S-content of the products obtained over the Co/HY zeolite catalyst decreased the most (by 65.63%). Moreover, the viscosity of the crude oil obtained over the Zn/HY zeolite catalyst decreased the most (by 63.69%).