Study On Controlling The Yield Of Tar In The Processes Of Oxidation Of Phenol And 4-tert-bytyi Phenol Oxidiation By Fenton Reagent

Pyrocatechol and hydroquinone , as important raw material intermediates in fine chemical industries, are used in many fields.The catalytic hydrogenation of phenol by hydrogen peroxide is the advanced technology that produces pyrocatechtechol and hydroquinone. The produced phenol hydroxylation mixture's moisture content of tar is very high ,there well be a big improvement to find the way to control the yield of tar. The catalytic hydrogenation of 4-tert-butyl-phenol by hydrogen peroxide is a new green way to produces 4-tert-butyl-pyrocatechol. It is very important to used Fenton catalytic to increase the yield of 4-tert-butyl-pyrocatechol.The standard working curve of phenol, catechol, hydrochinone, and water were measured by external reference method of gas phase chromoatography. The percentage composition of tar was calculated in the reaction system. The accuracy of percentage composition of tar was proved high by coefficient of recovery and interfering experiments.Through a series of experiments based on the characteristic of phenol hydroxylation produced tar obtained that: the initial stages of phenol hydroxylation can produces small benzoquinone.At the beginning stage add small benzoquinone can minish the time of the biggest quantity benzoquinone, but can not minish the inducement time. In the phenol hydroxylation mixture the benzoquinone can not be reductive to pyrocatechol or hydroquinone. The ph have obvious effect on the yield of tar, the ferrous can oxidized to ferric iron, but the valency charge has no effect on the react. The rule of pyrocatechol or hydroquinone oxidized is obtained.The papers measured the best technology of Fenton catalytic 4-tert-bytyi phenol hydroxylation: the temperature,react time,pH, ferrous sulfate , feet rate,hydrogen peroxide drops mode etc.The initial generation rates of TBC from catalytic 4-tert-bytyi phenol oxidated by hydrogen peroxide was experimentally studied in a homogenous system .The kinetics equation was obtained..According to the experimental results, the mechanism of catalytic 4-tert-bytyi phenol oxidated by hydrogen peroxide was proposed, and the control items of reaction rates were determined was obtained by the method of Bodenstein.