Patent ID: 7589231

Claim:
A process for producing terephthalic acid, said process comprising: (a) introducing a feed stream comprising an p-xylene into a reaction zone of a bubble column reactor; (b) introducing a first oxidant stream comprising molecular oxygen into said reaction zone via one or more lower oxidant openings; and (c) introducing a second oxidant stream comprising molecular oxygen into said reaction zone via one or more upper oxidant openings, wherein said reaction zone has a maximum diameter (D), wherein said upper oxidant openings are located at least 1D above said lower oxidant openings, wherein said first and second oxidant streams each contain less than 50 mole percent molecular oxygen, wherein at least 10 mole percent of the total amount of molecular oxygen introduced into said reaction zone is introduced via said lower oxidant openings, wherein at least 10 mole percent of the total amount of molecular oxygen introduced into said reaction zone is introduced via said upper oxidant openings, and wherein said oxidizing causes at least 10 weight percent of solid oxidizable compound to form solids in said reaction medium.