| Catechol and hydroquinone were made from the hydroxlation of phenol and hydrogen peroxide. The effects of kinds of catalyst, catalyst concentration and composition, reaction temperature, phenol /H2O2 mole ratio, reaction time, pH value, phenol initial concentration, hydrogen peroxide feeding mode on conversion and selectivity were investigated by using the orthogonal tests in the paper. The key factors and the optimal parameters of hydroxlation of phenol by hydrogen peroxide were obtained accounting to the analysis of range and the analysis of variance. Single factor tests were studied based on the results of the orthogonal tests. The optimal experimental conditions were obtained: phenol concentration was 12%, phenol:H2O2=1.33:l, optimal reaction temperature was 45℃, dropping rate of hydrogen peroxide was 0.30g/min. Under the optimal experimental conditions, conversion of phenol was 40%, dihydroxybenzene selectivity was 83-85%, catechol/hydroquinone mole ratio was 1.6-1.8.A novel tubular reactor and the experimental flowsheet were designed and built in lab. model scale based on the results of the orthogonal tests and single factor tests. The continuous operation of the hydroxlation of phenol and hydrogen peroxide was made in this tubular reactor. The effects of the operation parameters on conversion and selectivity were studied. The highest dihydroxybenzene selectivity was 71.35%, lower than 12% in the results of small scale test. The difference and problems between the above two scale tests were pointed out. It showed the direction for the future research.
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