Patent ID: 7049465

Claim:
A process for recovery of thermal energy from an offgas stream produced in the manufacture of an aromatic carboxylic acid comprising: a) oxidizing an aromatic feedstock with a liquid phase reaction mixture in a reaction zone to form an aromatic carboxylic acid-rich stream and a gaseous mixture; b) removing in a separation zone at least a portion of a solvent from said gaseous mixture to form said offgas stream and a solvent rich stream; and c) recovering said thermal energy from at least a portion of said offgas stream in a heat recovery zone; wherein a portion of said offgas stream is condensed to form a condensed mixture; wherein said condensed mixture is optionally recycled back to said seperation zone; wherein a portion of said thermal energy is recovered in a working fluid; wherein a portion of the enthalpy in said working fluid is recovered in a power cycle comprising an organic rankine cycle or a kalina cycle; and wherein said working fluid is a compound or mixture of compounds that have a normal boiling point between about −100° C. to about 90° C.