Production of olefins via oxidative de-hydrogenation of C3‒C4 fraction by CO2 over Cr‒Mo/MCM‒41

The present study investigates the oxidative de-hydrogenation of propane-butane (C3-C4) fraction over mono (Cr, Mo) and bi-metal (Cr-Mo) loaded MCM–41catalysts. The catalysts were prepared by sequential impregnation method at 500oC calcination temperature. Experiments were performed by feeding C3-C4 fraction and CO2 into a continuous flow quartz reactor at atmospheric pressure (P = 1 atm.), reaction temperatures between 500 – 650oC, gas hourly space velocity within 100 – 400 h-1, and at reaction time (tr) = 2h. The physicochemical properties and performance of catalysts were evaluated by BET, XRD, H2–TPR, and NH3–TPD characterization techniques. The major products are ethylene, propylene, isobutylene, butylene. This paper reports that the total yield of olefins (Ʃ C2-C4) = 71.6 % was achieved at 89.5 % conversion level of C3–C4 at 630oC. The results indicate that the addition of Mo to Cr/MCM–41 modifies its catalytic activity. The Cr/MCM–41 and Mo/MCM–41 catalysts were prepared for comparison purposes.