Abstract
The optimum condition for vapor phase catalytic chlorination reaction of ο-phthalonitrile in the presence of activated carbon catalyst was investigated. When the reaction temperature was 250-300°c, the velocity of feeding of ο-phthalo-nitrile 0.2-0.5 × 10-3 mol/g.hr and Cl2/PN, (ο-phthalonitrile) above 6 moles, the yield of tetrachlorophthalonitrile above 90 mole % and that of hexachlorobenzene below 3 mole % were obtained. The change of activity of activated carbon catalyst during the reaction time was investigated up to 110 hrs, but no decreasing activity was observed. The relation between the condition for preparation of activated carbon and its chlorination activity was investigated. For obtaining activated carbon catalyst of high chlorination activity, it was necessary to keep steaming temperature above 750°c with enough time. With the progress of activation by steaming, the time required for preliminary chlorinating treatment can be shortened and the rate of increase in weight of catalyst after the reaction is increased. The mechanism of chlorination of o-phthalonitrile was considered to proceed through the route of ο-phthalonitrile → 4-monochlorophthalonitrile → 4, 5-dichlorophthalonitrile →tetrachlorophthalonitrile.
