| abstract |
LIQUID PHASE OXIDATION OF P-XYLENE WITH MOLECULAR OXYGEN-CONTAINING GAS (E.G., AIR OR COMMERCIAL OXYGEN) IN PRESENC OF ACETIC ACID PRODUCES FLUID OXIDATION EFFLUENT WHICH IS SUBJECTED FIRST TO SIMULTANEOUS TEREPHTHALIC ACID CRYSTALLIZATION AND ACETIC ACID DISPLACEMENT BY CONTACT WITH A COUNTERCURRENT FLOW OF WATER AND SECOND TO SIMULTANEOUS WATER DISPLACEMENT BY AND TEREPHTHALIC SLURRY FORMATION IN METHANOL BY ITS COUNTERCURRENT CONTACT WITH THE FIRST FORMED SLURRY OF TEREPHTHALIC ACID IN WATER FROM ACETIC ACID DISPLACEMENT. THIS PROVIDES A SLURRY OF TEREPHTHALIC ACID IN METHANOL AS FEED TO ESTERIFICATION FROM WHICH A LIQUID ESTERIFICATION EFFLUENT IS SUBJECTED TO SIMULTANEOUS DMT CRYSTALLIZATION AND METHANOL MOTHER LIQUOR DISPLACEMENT BY COUNTERCURRENT CONTACT WITH COOLER FRESH METHANOL THEREBY PRODUCING A SLURRY OF PRECIPITATED DMT IN FRESH METHANOL. |