화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.56, No.45, 13110-13125, 2017
Propane Oxidative Dehydrogenation Using Consecutive Feed Injections and Fluidizable VOx/gamma Al2O3 and VOx/ZrO2-gamma Al2O3 Catalysts
Propane oxidative dehydrogenation (PODH) was studied using VOx/gamma Al2O3 and VOx/ZrO2-gamma Al2O3 catalysts and consecutive propane injections. These catalysts were synthesized with 2.5, 5, and 7.5 wt % vanadium (V) loadings. Temperature programmed reduction by hydrogen displayed one reduction peak for VOx/gamma Al2O3 and two for VOx/ZrO2-gamma Al2O3 (5 and 7.5 wt % vanadium). Temperature-programmed desorption of ammonia (NH3-TPD) and pyridine Fourier transform infrared spectroscopy showed that zirconia on gamma Al2O3 reduces the catalyst acidity. NH3-TPD kinetics gave for VOx/ZrO2-gamma A(2)O(3) higher desorption activation energies than those for VOx/gamma Al2O3. PODH runs in the Chemical Reactor Engineering Center Riser Simulator were developed under an oxygen-free atmosphere at 550 degrees C, close to 1 atm, 20 s, and a 42.0 catalyst/propane weight ratio (g/g). PODH runs for the 7.5% V/ZrO2-gamma Al2O3 showed (a) 93% propylene selectivity and 25% propane conversion (based on propane converted into gaseous carbon-containing products), (b) 85% propylene selectivity at 28% propane conversion (based on propane converted including coke). The COx selectivity remains at 2%. This makes the 7.5% V/ZrO2-gamma Al2O3 catalyst a promising one for anticipated PODH industrial applications.