oa Adsorptive Desulfurization Of Thiophene, Benzothiophene And Dibenzothiophene From Model Fuel By Carbons Derived From Waste Rubber Tires

The removal of sulfur compounds from petroleum is increasingly important. In addition to its contribution to form particulate pollution, sulfur emission may cause some health problems. Regarding the negative impact of sulfur in industry, small amount of sulfur may poison the catalysts or diminish its efficiency. A commonly used method for the removal of sulfur-bearing species from fuel is hydrodesulphurization. However, due to the regulations required removal of sulfur to very low levels, several alternative technologies have also been reported for sulfur removal from liquids such as catalytic oxidation, biological sulfur removal and membrane separation. Desulfurization by adsorption has been regarded as the most promising approach. In this work, porous activated carbon was derived from waste rubber tires. Then, it was characterized by means field emission scanning electron microscopy, energy-dispersive X-ray, X-ray diffraction and Fourier transform infrared spectroscopies. The carbons then were used as adsorbents for adsorptive desulfurization. Model fuel samples with known amounts of thiophene, benzothiophene and dibenzothiophene compounds were prepared and used to test the efficiency of the derived carbons for adsorptive desulfurization. The amount of compounds adsorbed was found to follow the order of dibenzothiophene > benzothiophene > thiophene. Adsorption process was found to well fit pseudo second-order kinetic model. The adsorption mechanism was studied by intraparticle diffusion model. The experimental data were fitted to Langmuir, Freundlich and Temkin isotherm models. Adsorption capacity is governed by chemical interaction and pore volume of the adsorbents. The results revealed that Freundlich isotherm provided a better fit to the experimental data. The developed sorbent exhibited the advantages of being inexpensive and of double benefit to the environment.