Kinetics of Methanol Transformation into Hydrocarbons on a HZSM-5 Zeolite Catalyst at High Temperature (400−550 °C)

Abstract

A kinetic model of seven lumps has been established which allows the quantification of the product distribution (oxygenates, n-butane, C2−C4 olefins, C2−C4 paraffins (without n-butane), C5−C10 fraction, methane) in the transformation of methanol into hydrocarbons at high temperature (400−550 °C) on a HZSM-5 zeolite catalyst (SiO2/Al2O3 = 30) with high acidic strength (>120 kJ (mol of NH3)−1) and agglomerated with bentonite and alumina. The kinetic model fits well the experimental data obtained in a fixed bed reactor, from small values of space time in which the formation of hydrocarbons is incipient, to a space time of 2.4 (g of catalyst) h (mol CH2) −1 for a complete conversion of methanol. The rise in temperature increases the yield of C2−C4 olefins, so that the maximum value (∼50%) is obtained at the ceiling temperature for the hydrothermal stability of the HZSM-5 (550 °C) and space times between 0.6 and 1 (g of catalyst) h (mol CH2)−1.