METHYLATION OF PHENOL TO 2,6-DIMETHYLPHENOL ON A MANGANESE OXIDE CATALYST

Phenol methylation and methanol cracking were studied on a chemically promoted manganese oxide catalyst. The rate of phenol disappearance and the rate of 2,6-dimethylphenol formation were found to exhibit first-order dependences on the phenol concentration and on the o-cresol concentration, respectively. In addition, the rates of three simultaneously occurring methanol cracking reactions were found to be first-order with respect to the methanol concentration. In the temperature range 400-470-degrees-C, the activation energies of phenol disappearance and 2,6-dimethylphenol formation were calculated as 116 and 156 kJ/mol, respectively. The activation energies of the three methanol cracking reactions were in the range 200-262 kJ/mol. The rate equations obtained were used to simulate an adiabatic tubular reactor for phenol methylation Model predictions agreed well with experimental data from a pilot-scale adiabatic reactor and demonstrated the feasibility of using adiabatic reactors for the synthesis of 2,6-dimethylphenol.