Abstract
In the present study, a number of phosphorus modified HZSM-5(Si/Al = 250) zeolite as MTO catalyst were prepared and characterized by various methods. A kinetic model for MTO process over PZSM-5 catalyst was developed based on data obtained from a differential fixed bed reactor within the temperature range of 360–425°C and 1 bar pressure applying the Langmuir-Hinshelwood formulation. The kinetic parameters were evaluated from the experimental data using genetic algorithm. It was found that the predicted data from the model were well correlated with the experimental results, indicating that ethylene and propylene are primary olefins.
NOMENCLATURE
kr,0 | = | Arrhenius constant for dimethyl ether production |
ke,0 | = | Arrhenius constant for ethylene production |
kp,0 | = | Arrhenius constant for propylene production |
Kd,0 | = | Equilibrium constant for dimethyl ether production |
Km,0 | = | Equilibrium constant for methanol production |
kL1, kL2 | = | Arrhenius constants for C+4 production |
Er,0 | = | Activation energy for dimethyl ether production, kJ/mol |
Ee,0 | = | Activation energy for ethylene production, kJ/mol |
Ep,0 | = | Activation energy for propylene production, kJ/mol |
ΔHm0 | = | Enthalpy of adsorption for methanol, kJ/mol |
ΔHd0 | = | Enthalpy of adsorption for dimethyl ether, kJ/mol |
EL1,0, EL2,0 | = | Activation energy for C+4 production, kJ/mol |
Nres | = | Number of components |
Nexp | = | Number of experiments |
W | = | Weight of catalyst, g |
F | = | Molar flow rate, mol/h |
R | = | Rate of reaction, mol/g catalyst/h |
α | = | Stoichiometric coefficient |
SUBSCRIPT
Exp | = | Experimental |
Calc | = | Calculated |
i | = | ith component |
j | = | jth reaction |
k | = | kth experiment |