(189c) Simulation of Propane Dehydrogenation (Catofin) Process

Propylene is mainly produced as a byproduct of steam cracking of naphtha and catalytic cracking. However, steam cracker feedstocks shift to light material and it decreases production of propylene. To solve the supply and demand gap of propylene, on-purpose methods for the propylene production are suggested. Among them, propane dehydrogenation (PDH) method is the most used method. PDH is an endothermic equilibrium reaction with catalysts such as platinum or chromium in higher temperature and lower pressure. It is known that PDH has high selectivity to propylene from the propane of 85~92wt%. Because PDH reactors usually operated with 500 to 700â?? temperature range, cokes are generated in the surface of catalysts. It decreases activity of catalysts and deactivated catalysts make low conversion of propane and low selectivity to propylene. Therefore, the key factors to be considered for the PDH reaction are temperature, pressure and coke. Catofin process is a continuous PDH process which uses the cyclic operation of multiple fixed bed reactor. Each reactor has its cycle of reaction and catalyst regeneration. During the reaction step, propane feed is dehydrogenated to propylene, and also cokes are generated in the surface of catalysts. At regeneration step, the hot air regenerates catalysts by removing cokes.

This study aims to simulate Catofin process which has 4 fixed bed reactor system. Through the sensitivity analysis, optimization problem of reactor model is developed. When temperature and pressure goes higher, conversion of propane increases while selectivity to propylene decreases. Therefore, the optimization of reaction temperature and pressure condition for maximize propylene recovery is conducted. With optimized reaction condition, whole process simulation is conducted. Suggested process produces 99wt% propylene with 10.9kg/s rate.