Eastman Chemical Company

Martin De Boer

Alan George Wonders

Ronald Buford Sheppard

Raymond Elbert Fogle, Iii

Thomas Earl Woodruff

Marcel De Vreede

Kenny Randolph Parker

Lee R Partin

Robert Lin

Philip Edward Gibson

Johannes Wilhelmus Sluijmers

Disclosed is an optimized system for more efficiently and economically producing terephthalic acid. The system includes a multi-stage oxidative digestion system for processing an improved initial slurry from primary oxidation. The multi-stage digestion system is capable of adequately purifying the improved initial slurry without requiring significant liquor exchange between primary oxidation and oxidative digestion.

Polycarboxylic acid production system employing enhanced multistage oxidative digestion

Disclosed is an optimized system for more efficiently and economically producing terephthalic acid. The system employs an evaporative removal step downstream of oxidative digestion. The evaporative removal step removes a portion of the liquid phase and promotes precipitation of certain aromatic impurities. By promoting precipitation of certain aromatic impurities, the amount of the precipitated impurities in the recycled solvent is advantageously reduced.

Polycarboxylic acid production system employing enhanced evaporative concentration downstream of oxidative digestion

Disclosed is an optimized system for more efficiently and economically producing terephthalic acid. The system minimizes or eliminates the need for liquor exchange upstream of oxidative digestion and/or upstream of substantial cooling of the TPA-containing slurry.

Polycarboxylic acid production system employing oxidative digestion with reduced or eliminated upstream liquor exchange

Disclosed is an optimized system for more efficiently and economically producing terephthalic acid. The system includes an optimized post-digestion cooling stage that provides a TPA product having enhanced purity, while minimizing costs associated with removing impurities from recycled solvent.

Polycarboxylic acid production system employing hot liquor removal downstream of oxidative digestion

The present invention relates to a process for oxidizing a slurry composition in a post oxidation zone in the presence of added steam. More specifically, the present invention relates to a process for oxidizing a crude terephthalic acid composition in a post oxidation zone in the presence of added steam in a process for the production of a crystallized post oxidation composition.

Method for oxidizing a slurry composition in a post oxidation zone in the presence of added steam

Disclosed is an optimized system for more efficiently and economically producing terephthalic acid. A solvent purification system is employed to remove of at least one aromatic impurity present in a solvent purification feed. At least about 20 weight percent of the solvent purification feed originates from a cooled, post-digestion, TPA-containing slurry.

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Barendrecht, Netherlands

Martin De Boer