Viscosity reduction of heavy crude oil using ultrasonication assisted by SiFe nanoparticles

Heavy crude oil viscosity reduction is essential for the petroleum industry because of its high density and viscosity, elevated concentration of asphaltene, and limited mobility. The primary aim of this investigation is to decrease the viscosity of Sharqy Baghdad heavy crude oil with 20.32 API by ultrasonic irradiation using Fe₂O₃-functionalized silica nanoparticles (SiFe). SiFe of an average size of 67.11 nm and 426.12 m²/g surface area were created by the incipient wetness technique with Fe₂O₃ over SiO₂ nanoparticles, prepared by the sol–gel method using local sand. The X-ray diffraction analysis (XRD) indicates the presence of an amorphous silica with α-Fe₂O₃. Scanning electron microscopy analysis (SEM) showed that SiFe nanoparticles tend to agglomerate. Energy dispersive X-ray analysis (EDX) reveals the presence of Si, O, Al, and Fe elements. Fourier transform infrared spectra (FTIR) exhibit the presence of siloxane, silanol groups, and the Fe–O stretching mode of Fe₂O₃. A low total weight loss of 8.23% is revealed by thermogravimetric analysis (TGA), which validates the thermal stability of SiFe nanoparticles. The optimal outcomes were observed when the ultrasound exposure time was set at 2 min, 30% power intensity, 0.8 duty cycle, 35 °C, with 1000 mg/L SiFe nanoparticles, resulting in a reduction in viscosity of 33.74%, asphaltene concentration reduced from 6.379 to 4.119 wt%, and sulfur content decreased from 4.68 to 3.85 wt%. These findings demonstrated the effectiveness of employing nanoparticles and ultrasonic waves to increase the light components in crude oil compared to ultrasonication alone, and this plays a significant role in facilitating oil transportation through pipelines and enhancing the production of lighter fractions of high economic and industrial value during oil refining.