Catalytic Performance of Modified HZSM-5 on Synthesis of Ethyl Phenol: A Kinetic Study

Abstract

The selective synthesis of p-ethylphenol from vapor phase alkylation of phenol with ethanol was investigated in a fixed bed reactor on cerium modified zeolite HZSM5 at temperature 693K. A series of CeZSM-5 were prepared by modifying with 4%, 6%, 8% and 10% cerium ammonium nitrate solution. ZSM-5 exchanged with 10% cerium nitrate solution was proved to be the best of all the catalyst used. The modified catalyst were further characterized by SEM, XRD. Phenol reacted with ethanol to form ethylphenyl ether by O-alkylation, and p- and o-ethylphenol by C-alkylation; secondary products were m-ethylphenol and dialkylated compounds. Reactions were carried out in the temperature 623K-693K, phenol to ethanol reactant mole ratio 1-10 over both cerium modified ZSM-5 modified. From the study of the effects of various parameters, the optimum operating condition for maximum selectivity of p-ethyl phenol were obtained at space time-0.0384kgh/kmol, phenol to ethanol reactant mole ratio of 1:3, nitrogen to feed mole ratio, 0.16. 1 atm pressure. A systematic and detailed kinetic study were carried out for the alkylation reaction. From the product distribution pattern, a kinetic model was developed following Langmuir–Hinshelwood approach. The kinetic and adsorption parameters of the rate equation were determined by non-linear regression analysis. From the kinetic analysis of the experimental data, the apparent activation energy for the reaction was determined to be 43.27 kJ/mol.