Synthesis of zinc oxide nanoparticles for wax deposition control and oil upgrading: effect of drying temperature

Wax deposition becomes a major problem in the transportation of crude oil. During the transportation and production also they encounter problem due to the characteristic of the crude oil which was high specific gravity and high viscosity. Therefore, to encounter the problems occurred, nanotechnology had been introduced by performing synthesis of zinc oxide (ZnO) nanoparticles using sol-gel method. To obtain an efficient result in overcome the problems, an optimum drying temperature during the synthesized was investigated since it gave different sizes of nanoparticles. Hence, synthesized of ZnO nanoparticles using sol-gel method were performed and the drying temperature was varied from 80ºC to 200ºC to identify which temperature gave smaller size of nanoparticles as the smaller size gave better reduction in viscosity. By varying the drying temperature during the synthesized of ZnO nanoparticles also can show its effect to the surface morphology. Then, the crystalline phase and size of the ZnO nanoparticles were determined using X-ray Diffraction (XRD) and the surface morphology by using Field Emission Scanning Electron Microscopy (FE-SEM). While for the elemental composition determined using energy dispersive X-ray spectroscopy (EDX) shows that the nanoparticles contain Zinc (Zn) and Oxygen (O) only. As for the oil upgrading, the ZnO nanoparticles had been used as the viscosity reducer at different sizes, different shear rate and temperature using electronic rheometer and it shows that the smaller size of nanoparticles which is 10.87nm gave the highest viscosity reduction with range 50%. Also, for wax deposition, the smaller size of ZnO nanoparticles gave the higher percentage of ZnO efficiency and reduces more wax compared to bigger size with efficiency 78%. Therefore, the oil upgrading can be done by the addition of ZnO nanoparticles and the 200ºC of drying temperature gave the greatest effect.