Document Type : Original Article
Petrochemicals Department, Egyptian Petroleum Research Instituts, Nasr City, Cairo 11727, Egypt
Processes Development Department, Egyptian Petroleum Research Institute, Cairo, Egypt
Used Oil Department, Petrotrade Company, Ministry of Petroleum & Mineral Resources, Cairo 11727, Egypt
Basic Science Department, Faculty of Technology and Education, Helwan University, Cairo 11727, Egypt
Waste lubricating engine oils are categorized as one of the most dangerous hazardous wastes. Herein, zeolite Y was synthesized from natural kaolin via the ultrasonic-assisted hydrothermal technique for the first time. The natural kaolin and the synthesized zeolite Y were characterized by x-ray diffraction, Fourier transformed infrared spectroscopy and scanning electron microscopy. The synthesized zeolite is then applied for the recycling of the waste lubricant engine oil. The recycled engine oil parameters such as flashpoint, dynamic viscosity, kinematic viscosity, viscosity index, pour point, sulfur content, heavy metals content, sulfur content, ash content and carbon residue were analyzed and compared to those of the virgin and waste oils. The results reveal that zeolite Y adsorbent efficiently removed heavy metals, particularly chrome, copper, iron, lead, and zinc that were in the waste engine oil. A removal efficiency of 35.71% Cr3+, 66.67 % Cu2+, 92.17 % Fe2+, 63.02 % Pb2+ and 95.24 % Zn2+ are obtained for Zeolite Y at 25 ºC whilst 47.14 % Cr3+, 76.19 % Cu2+, 92.93 % Fe2+, 70.70 % Pb2+ and 96.31 % Zn2+ were obtained for Zeolite Y at 40 ºC. The viscosity index of the waste oil treated with zeolite Y was reduced to 327 as compared to the viscosity index of the virgin and waste oils which were 326 and 336, respectively. These results showed that the waste engine oil can be recycled using the synthesized low-grade zeolite Y adsorbent. Additionally, the physical properties of the recycled oil indicate that it has good efficiency and can be reused.