低碳烷烃循环流化床脱氢工艺条件优化

Optimization of operation conditions for low-carbon alkane dehydrogenation process in a circulating fluidized bed

针对PBD型脱氢催化剂,采用循环流化床中试装置对低碳烷烃(丙烷、异丁烷、正丁烷)单独脱氢以及不同配比混合低碳烷烃进行了较为系统的工艺条件优化研究。结果表明,反应温度和空速对低碳烷烃脱氢过程的影响至关重要,不同脱氢原料具有不同的适宜操作工况,其中丙烷脱氢在600℃和1 700 h^(-1)条件下,转化率为39%,丙烯收率达33%;异丁烷脱氢在580℃和1 700 h^(-1)条件下,转化率为48%,异丁烯收率为45%;正丁烷脱氢在580℃和1 700 h^(-1)条件下,转化率为40%,丁烯收率高达32%。PBD型催化剂对于不同配比混合低碳烷烃具有较高的催化活性。最终获得的不同脱氢原料适宜的操作工况下,可以为循环流化床低碳烷烃脱氢装置的工程设计与放大和工业装置的生产调优提供基础数据与理论支持。

Optimization studies on operation conditions for the dehydrogenation process of low-carbon alkanes( propane,iso-butane,n-butane and their mixtures) are carried out by employing a pilot-scale circulating fluidized bed( CFB) unit.PBD,a catalyst developed by Yantai University,is used in this study.Experimental findings indicate that the reaction temperature( T) and the gas hourly space velocity( GHSV) have great influences on the dehydrogenation process of low-carbon alkanes.Proper operation conditions are different according to different feedstocks.Under conditions of T =600℃ and GHSV = 1 700 h-1,the conversion rate of propane can reach 39% and the yield of propylene can achieve 33%.Under the conditions of T = 580℃ and GHSV = 1 700 h-1,the conversion rate of iso-butane can reach 48% and the yield of iso-butylene can achieve 45%. Under the conditions of T = 580℃ and GHSV = 1 700 h-1,the conversion rate of nbutane can reach 40% and the yield of n-butylene can achieve 32%.Additionally,the catalyst PBD shows high catalytic performances in dehydrogenation of low-carbon alkane mixtures with different ratios.Finally,the obtained proper operation conditions for different feedstocks can provide with fundamental data and theoretical support for engineering design and scale up of circulating fluidized bed( CFB) dehydrogenation units,as well as the control and optimization of industrial CFB dehydrogenation plant.