Simulation On The Industrial Dehydrogenation Of Long Chain Paraffin

In recent years, due to the increasing global demand of olefins, the process of paraffins dehydrogenation to mono-olefins has attracted considerable attention. In an axial or radial adiabatic industrial reactor, the dehydrogenation process is usually performed under the pressure 0.2Mpa and the temperature 465～495℃. Different catalysts are used, usually containing platinum deposited on alumina or zeolite. Dehydrogenation is accompanied with isomerization, cracking, dimerization and other side reactions, and the side productions like diene and aromatics will reduce the catalyst activity and shorten the cycle time. Therefore, the activity, selectivity and stability of the dehydrogenation catalyst can affect the production cost and quality of mono-olefins.In this study, the dehydrogenation reaction of long chain paraffin on industrial reactor was simulated based on the material balance and heat balance equations derived from one-dimensional homogenous adiabatic radial reactor model and dehydrogenation kinetic model. The trends of catalyst activity during two cycles were determined by solving the dehydrogenation reaction equations of long chain paraffin on industrial reactor. The results showed that the catalyst deactivation rate was 0.00047h-1, the deactivation degree was 2.47 in cycle 1; and the catalyst deactivation rate was 0.00039h-1, the deactivation degree was 2.58 in cycle 2. The average relative deviations of cycle 1 and cycle 2 were 7.24% and 6.55% respectively. The fitting effect of experimental values and calculated values was good. In addition, the influences of the process conditions on reactions and catalyst were predicted to provide support for the operation optimization of industrial dehydrogenation.