System for continuous preparation of terephthalic acid

Claim 1

APPARATUS FOR MAKING PURIFIED TEREPHTHALIC ACID THROUGH OXIDIZING A FEEDSTOCK CONSISTING ESSENTIALLY OF PARAXYLENE WITH MOLECULAR OXYGEN IN THE PRESENCE OF DEHYDRATED SATURATED MONOCHARBOYLIX ACID HAVING FROM TWO TO EIGHT CARBON ATOMS, INCLUSIVE, IN THE MOLECULE, HEAVY METAL OXIDATION CATALYST, AND A BROMINE-AFFORDING SUBSTANCE ALL OF WHICH COMPRISE MIXTURE FOR REACTION; WHICH COMPRISES: AN OXIDATION VESSEL FABRICATED FROM CORROSION RESISTANT METAL HAVING MEANS FOR RECEIVING MIXTURE FOR REACTION, REMOVING LIUQID REACTION MIXTURE CONTAINING TEREPHTHALIC ACID SOLIDS, AND MEANS FOR REMOVING VAPORS AND GASES THEREFROM; A CONDENSER; TRANFER MEANS FOR CONDUCTING SAID VAPORS AND GASES TO SAID CONDENSER; TRANSFER MEANS FOR RETURNING CONDENSATE TO SAID OXIDATION VESSEL; SOLID-LIQUID PHASE SEPARATION MEANS FOR SEPARATING CRUDE TEREPHTHALIC ACID CRYSTALS FROM THE LIQUID PORTION OF THE REACTION MIXTURE; DISTILLATION MEANS FOR SEPARATING SAID LIQUID PORTION INTO A WATER OVERHEAD FRACTON, A DEHYDRATED SATURATED MONOCARBOXYLIC ACID FRACTION, AND A DISTILLATION BOTTOMS FRACTION CONTAINING CATALYST AND ACIDIC REACTION BYPRODUCTS AND INTERMEDIATES; MEANS FOR WASHING THE CRUDE TEREPHTHALIC ACID CRYSTALS WITH DEHYDRATED SATURATED MONOCARBOXYLIC ACID, CONNECTIONS FOR SUPPLYING SAID DEHYDRATED ACID TO SAID MEANS FOR WASHING THE CRUDE TEREPHTHALIC ACID CRYSTALS, AND CONNECTIONS FOR CYCLING THE DEHYDRATED ACID AFTER WASHING TO THE OXIDATION VESSEL; AND MEANS FOR DRYING THE WASHED TEREPHTHALIC ACID CRYSTALS TO RECOVER A PURIFIED AND DRIED TEREPHTHALIC ACID PRODUCT.