Patent ID: 7390921

Claim:
An oxidation process for producing terephthalic acid, said process comprising: (a) introducing a feed stream comprising para-xylene into a reaction zone of a bubble column reactor, wherein at least a portion of said reaction zone is defined by one or more upright sidewalls of said reactor, wherein at least 25 weight percent of said para-xylene enters said reaction zone at one or more locations spaced inwardly at least 0.05 D from said upright sidewalls, wherein said reaction zone has a maximum diameter (D); and (b) oxidizing at least a portion of said para-xylene in a liquid phase of a three-phase reaction medium contained in said reaction zone, wherein said oxidizing forms crude terephthalic acid in said reaction medium, wherein the amount of solids present in said reaction medium is maintained in the range of from about 5 to about 40 weight percent on a time-averaged and volume-averaged basis.