(61e) On-Purpose Butadiene By Oxidative Dehydrogenation of Butene

Butadiene is an important monomer widely used in rubber and plastics industries. Traditionally, it is produced as a co-product by naphtha steam cracking process. Due to the recent development and utilization of shale gas, on-purpose butadiene via oxidative dehydrogenation (ODH) has generated tremendous interest in both academia and industry. SABIC has developed a high performance catalyst suitable for such a process. In this presentation, we report work focusing on catalyst preparation and catalytic performance.

Zn-Fe-O based mixed metal oxides catalysts have been synthesized via co-precipitation, spray-drying, and solid state reaction methods. It is found that the co-precipitation method yielded the catalyst with best-combined performance and stability. In particular, parameters including starting metal ratio, pH, and aging conditions have been identified as key indicators of catalyst performance. Catalyst life time has been tested through a 4000-hr run which proved high stability under desired conditions. In addition, catalyst deactivation mechanism has been identified and effective regeneration protocol has been developed.   

Catalyst performance evaluation and kinetics studies were carried out in fixed bed reactors. Process variables studied include oxygen to butene ratio, steam to butene ratio, pressure, etc. Key controlling parameters have been identified and new reaction conditions have been discovered which significantly improved the yield reported from previous commercial operation of the technology. Based on results, a semi-empirical kinetic model has been developed which is used in designing a reactor system.