Question

What happens when phathalic anhydride is heated in evaporating dish??

Answer 1

Abstract

CRUDE PHTHALIC ANHYDRIDE PRODUCED BY THE OXIDATION OF O-XYLENE IS CONTINUOUSLY DISTILLED FROM THE SUMP OF A DISTILLATION COLUMN. EVAPORATION OF THE CRUDE PHTHALIC ANHYDRIDE IS EFFECTED IN AN EVAPORATOR WHICH IS IN COMMUNICATION WITH THE SUMP OF THE COLUMN BY NATURAL CIRCULATION FROM THE BOTTOM OF THE SUMP UP THROUGH THE EVAPORATOR AND BACK TO THE SUMP. THE CRUDE PHTHALIC ANHYDRIDE LEAVING THE EVAPORATOR HAS A CONCENTRATION OF AT LEAST FIFTY PERCENT BY WEIGHT OF PHTHLAIC ANHYDRIDE AND TRIMELLITIC ANHYDRIDE. THE EFFECTIVE LEVEL OF THE CRUDE

PHTHALIC ANHYDRIDE IN THE EVAPORATOR IS 30-100% OF THE LENGTH OF THE EVAPORATOR PIPES.