Document Type : Research Article
School of Chemistry, College of Science, University of Tehran, Tehran, I.R. IRAN
Hydrotreating heavy naphtha using highly active NiMo catalysts on walnut shell activated carbon (NiMo-WAC) nanocatalysts is a new technology for clean fuel production. In this research, pyrolysis of the walnut shell as a scalable, low-cost, and high-yield method was used to synthesize chemically activated carbon in the presence of ZnCl2, as activating agent. To enhance the catalytic conversion, walnut shell active carbon was functionalized with HCL, HNO3, and H2SO4 to prepare NiMo-WAC1, NiMo-WAC2, and NiMo-WAC3 respectively. These nanocatalysts were synthesized through the incipient wetness impregnation method and characterized by X-Ray Diffraction (XRD), Fourier Transform InfraRed (FT-IR) spectroscopy, Inductively Coupled Plasma-atomic emission (ICP) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), Brunauer–Emmett–Teller (BET) surface area, Temperature-Programmed Desorption (TPD) and Temperature-Programmed Reduction (TPR) techniques. CHNS (Eager 300 for EA1112) was used to study elemental analysis of the walnut shell feedstock used for active carbon synthesis. Different operating parameters including temperature, pressure, LHSV, and H2/feed (heavy naphtha) ratio for hydrodesulfurization (HDS) reactions were explored by evaluating NiMo-WAC nanocatalysts catalytic activity. HDS of heavy naphtha with 2491 ppm of sulfur in the operation condition of temperature: 290 °C, pressure: 30 bar, H2/oil: 100 NL/L, and LHSV: 3.3 h-1 showed considerably higher activity of NiMo-WAC2 nanocatalyst, less than 10 ppm in the product, than NiMo-γAl2O3 as a commercial and reference catalyst, maximum 104 ppm in the product, and this is economically valuable.