Eastman Chemical Company

Grupo Petrotemex S.a. De C.v.

Raymond Elbert Fogle, Iii

Alan George Wonders

Ronald Buford Sheppard

Timothy Alan Upshaw

Martin De Boer

Thomas Earl Woodruff

Kenny Randolph Parker

Lee R Partin

Marcel De Vreede

Philip Edward Gibson

The invention provides improved energy content in and shaft power recovery from off-gas from xylene oxidation reactions while at the same time minimizing wastewater treatment cost. More shaft power is produced using off-gas than is required to drive the main air compressor, even with preferred, relatively low oxidation temperatures. Simultaneously, an amount of wastewater greater than byproduct water from oxidation of xylene is kept in vapor form and treated along with off-gas pollutants in a self-sustaining (self-fueling) gas-phase thermal oxidative destruction unit. Optionally, off-gas is combined from multiple xylene oxidation reactors, comprising primary and/or secondary oxidation reactors and forming TPA and/or IPA. Optionally, air compressor condensate and caustic scrubber blowdown are used in a TPA process or as utility water, effectively eliminating normal flow of liquid wastewater effluent from a TPA plant. Optionally, PET off-gas containing the water of PET formation is treated in a shared thermal oxidative destruction unit, effectively eliminating normal flow of liquid wastewater effluent from a combined pX-to-TPA-to-PET plant.

Dicarboxylic acid production with self-fuel oxidative destruction

Dicarboxylic acid production with direct fired off-gas heating

Dicarboxylic acid production with enhanced energy recovery

Dicarboxylic acid production with minimal wastewater generation

The invention provides improved energy content in and shaft power recovery from off-gas from xylene oxidation reactions while at the same time minimizing wastewater treatment cost. More shaft power is produced using off-gas than is required to drive the main air compressor, even with preferred, relatively low oxidation temperatures. Simultaneously, an amount of wastewater greater than byproduct water from oxidation of xylene is kept in vapor form and treated along with off-gas pollutants in a self-sustaining (self-fueling) gas-phase thermal oxidative destruction unit. Optionally, off-gas is combined from multiple xylene oxidation reactors, comprising primary and/or secondary oxidation reactors and forming TPA and/or IPA.

Integrated co-production of dicarboxylic acids

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. 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.

Growing community of inventors

Johnson City, TN, United States of America

Raymond Elbert Fogle, Iii