Dehydrogenation of C3-C4 paraffin's to corresponding olefins over slit-SAPO-34 supported Pt-Sn-based novel catalyst

The objective of this work is to discuss the performance of Pt-Sn/slit-SAPO-34 novel catalyst for selective C-3-C-4 dehydrogenation to corresponding light olefins. The metallic contents, acidity, active metallic sites and metallic dispersion were determined using a number of physico-chemical techniques as it gives a justification for superior catalytic activity for dehydrogenation reaction. The Pt-Sn/slit-SAPO-34 catalyst was analyzed for dehydrogenation activity under optimized operating conditions; at atmospheric pressure, hydrogen to alkane (feed) molar ratio is 0.2, weight hourly space velocity 5 h(-1) and temperature 585 degrees C. Around 40% light alkane conversion and above 95% of total olefins selectivity with 94% propene, 92% n-butene and about 84% iso-butene selectivity were achieved over Pt-Sn/slit-SAPO-34 novel catalyst. The catalyst was parametrically characterized over the above said operating conditions and effects of operating conditions on product distribution were discussed. The coke formation was inherently related to catalyst activity in dehydrogenation reaction and related to surface intermetallic ensemble effects; and ultimately the prominent stakeholder in catalyst deactivation. The novel catalysts also showed very good hydrothermal stability in a continuous reaction-regeneration cycles due to silica-based acidic structure of support. The results obtained over Pt-Sn/slit-SAPO-34 novel catalyst were compared with other Pt-Sn-based ZSM-5 and SAPO-34 supported catalysts of similar active metallic content under identical operating conditions. (c) 2012 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.