Simulation and sensitivity analysis of a multitubular fixed bed catalytic reactor to produce Phtalic anhydride
Advancing the chemical engineering fundamentals
Chemical Reaction Engineering (T2-2P)
Keywords: phtalic anhydride, multitubular reactor, pseudohomogeneous model, heterogeneous model
Simulation and sensitivity analysis of a multitubular fixed bed catalytic reactor to produce Phtalic anhydride
Orozco G.A.*, Durán A. E **
Department of Chemical Engineering.
Universidad Nacional de Colombia
Bogotá D.C. – Colombia
Phtalic anhydride is a petrochemical used as intermediate or feedstock for production of plastifiers, specially PVC and polyesthers. O-xylene oxidation to anhydride phtalic is carried out in a multitubular fixed bed reactor packed with vanadium and titanium catalyst. This reaction have been well studied because of it is a strongly exothermic process and its sensivity to little changes in the feed conditions (temperature, composition). In this work was developed the simulation for this reactor using several models: unidimensional pseudohomogeneous without axial dispersion, bidimensional pseudohomogeneous and unidimensional heterogeneous; models were numerically evaluated by orthogonal collocation method and false transient. Modelling was performed using a kinetic that follows redox mechanism proposed by Calderbank and the parameters adjusted by Anastasov for an industrial catalyst. Transport and physicochemical parameters were calculated with empirical correlations reported in literature. Temperature profiles found on unidimensional pseudohomegeneous model without axial dispersion and bidimensional pseudohomogeneous model differ in 20 Kelvin degrees near to hot-spot and 4% for composition in feed stream at real operating conditions in an industrial situation. The results obtained with a bidimensional pseudohomegeneous model gave better results with respect to the experimental temperature profiles of an industrial reactor; this suggest the possibility of use bidimensional models for next studies of stability in the reactor.
* gaorozcoa@unal.edu.co
** haduranp@unal.edu.co
Presented Tuesday 18, 13:30 to 15:00, in session Chemical Reaction Engineering (T2-2P).
