جستجوی مقالات مرتبط با کلیدواژه « fixed bed » در نشریات گروه « شیمی »

The aim of this study was investigation the efficiency of the vanadium/Y zeolite shaped catalysts in the combined oxidative-adsorptive desulfurization of model fuel containing 1000 ppm dibenzothiophene (DBT) in a continuous fixed bed reactor. The shaping process was performed by extrusion method using 50 wt.% of boehmite as a binder. Vanadium was impregnated before shaping (VZB(50)) and after shaping (V/ZB(50)). The synthesized catalysts were characterized using different analysis. The obtained results indicated that specific surface area and pore volume of the zeolite decreased after shaping. However the use of boehmite as a binder significantly increased the meso-pore volume. The initial activity of VZB(50) catalyst in the DBT removal was higher than that of V/ZB(50) due to its higher surface area, meso-pore volume and higher acidity. But V/ZB(50) was almost stable during 5 h of reaction, because of more uniform dispersion of vanadium over the support. While vanadium of VZB(50) was leached leading to deactivation. Comparison of the efficiency of catalysts with different geometric shapes also showed the use of extrudes with non-cylindrical cross-section is a good suggestion providing more surface area per unit volume. 82% DBT removal was obtained under mild reaction conditions employed in the combined oxidative-adsorptive desulfurization.