Production of dimethyl terephthalate

Claim 1

A CONTINUOUS PROCESS FOR THE PREPARATION OF DIMETHYL TEREPHTHALATE FROM TEREPHTHALIC ACID WHICH COMPRISES CONDUCTING THE FOLLOWING CONTINUOUS PROCESS OPERATIONS: (1) INTRODUCTING TEREPHTHALIC ACID INTO A HEATED REACTION ZONE MAINTAINED AT A PRESSURE NO GREATER THAN ABOUT 300 P.S.I.G., (2) MAINTAINING AN AMOUNT OF DIMETHYL TEREPHTHALATE IN SAID REACTION ZONE IN AN AMOUNT CONTINUOUSLY IN EXCESS OF 50% BY WEIGHT OF THE CONTENTS THEREOF AND AT A LEVEL SUFFICIENT FOR A SUBSTANTIAL PROPORTION OF SAID DIMETHYL TEREPHTHALATE TO REACT WITH SAID TEREPHTHALIC ACID WHEREBY SAID EXCESS IS CONTINUOUSLY CONVERTED INTO METHYL HYDROGEN TEREPHTHALATE, (3) INTRODUCING METHANOL INTO A REACTON ZONE MAINTAINED AT A PRESSURE NO GREATER THAN ABOUT 300 P.S.I.G. CONTAINING SAID METHYL HYDROGEN TEREPHTHALATE WHEREBY A SUBSTANTIAL PROPORTION THEREOF IS CONVERTED INTO DIMETHYL TEREPHTHALATE, (4) REMOVING A SUBSTANTIAL PROPORTION OF SAID DIMETHYL TEREPHTHALATE FROM THE LATTER REACTION ZONE AS A VAPOR, AND (5) MAINTAINING AT LEAST THE LATTER REACTION ZONE AT A TEMPERATURE ABOVE ABOUT 250*C.