Studies on Deactivation of Naphtha Reforming Catalyst

Abstract

This work presents the radial flow reactor model for simulation of reforming process having four reactors. To begin with naphtha is considered as three lumps of naphthenes, paraffins and aromatics to enable comparing with reported results as a bench mark so that feed lumps can be easily extended to individual carbon numbers in later stage. Four major reforming reactions are considered for the model. The model integrates differential material and energy balance equations to generate concentration and temperature profiles as a function of reactor radius for each reactor for a given input of feed and recycle gas composition and flow rates, H2/HC ratio, inlet temperature and pressure. The model predicted values matched well with the reported values. The kinetics are taken from literature. Thermodynamics data for carbon number 6 is considered for paraffin, naphthene and aromatic lumps of feed. Thermodynamic data is obtained from ChemCAD. The simulation results based above models agree very well with Experimental results. Experiments were carried out in fixed bed reactor to study deactivation kinetics. The work involves accelerated ageing runs. Accelerated ageing runs require operation of the process at high severity so that catalyst life can be reduced to 3-4 days. Analysis of temperature-time data to find deactivation kinetics.Isothermal run experiment carried out for estimation of deactivation constant. Temperature-activity data from model simulation. Experimental data was used to find the deactivation kinetics parameters of the model. Similarly primary reaction and deactivation reaction rate parameters were estimated from conversion-time data generated in the experiments at different temperatures. Gas and liquid samples are analyzed once in 2 hrs. Find surface area, chloride content, and coke in all runs.