Resorcinol Cleaner Synthesis Process

Resorcinol, an important fine organic intermediate, has been widely used formany fields. With a higher requirement for quality of resorcinol an the more focus onenvironmental protection, the research on new techniques of resorcinol having betterenvironmental effects is very needed.Many factors were discussed in the traditional technics for the preparations ofresorcinol using meta-phenylenediamine(MPDA) hydrolysis reaction with sulfuricacid. The optimum conditions of synthesize resorcinol were as folloWing: the reactiontemperature must between about 220℃to 250℃, a molar ratio of about 1.6 to 2.0moles sulfuric acid to about 1.0 moles MPDA, a reaction time within 6 to 10 hours.By orthogonal test the better resorcinol yield of 91.2% was achieved when the molarratio of H₂SO₄, MPDA and H₂O was 2.0/1/60, the reaction temperature was 250℃,the reaction time was 6 hours.In this paper some solid acids were used as alternatives of liquid acids in theprocess of MPDA hydrolysis reaction. The types of solid acids, the reaction time andthe reaction hours had effect on the yield of resorcinol. Zeolites H-ZSM-5 with lowacidity gave bad resorcinol yields, which were less than 10%. The external surfaceacid sites didn't change greatly. Solid superacid with higher acidity such asSO₄^2-/ZrO₂. SO₄^2--/TiO₂ andα-Zirconium Phosphate could improve the resorcinol yieldobviously. Especially the presence of solid superacid SO₄^2-/ZrO₂ gave good resorcinolyield of 41.3% in the conditions of the reaction temperature 270℃and the reactiontime 8 hours. It can be concluded that solid acids would be a better substitute forliquid acids due to cleaner and more regenerable properties.