Optimized liquid-phase oxidation

Abstract

Disclosed is an optimized process and apparatus for more efficiently and economically carrying out the liquid-phase oxidation of an oxidizable compound. Such liquid-phase oxidation is carried out in a bubble column reactor that provides for a highly efficient reaction at relatively low temperatures. When the oxidized compound is para-xylene and the product from the oxidation reaction is crude terephthalic acid (CTA), such CTA product can be purified and separated by more economical techniques than could be employed if the CTA were formed by a conventional high-temperature oxidation process.

1 - 15 . (canceled) 
     
     
         16 . In a bubble column reactor for reacting a predominately gas-phase stream and a predominately liquid-phase stream in a multi-phase reaction medium contained in a reaction zone, wherein said bubble column reactor includes a primary pressure-containing vessel shell having one or more upright sidewalls and presenting one or more upright inner surfaces that define at least a portion of said reaction zone, the improvement comprising:
 one or more internal members disposed in said reaction zone and presenting one or more upright outer surfaces for contacting said reaction medium, wherein the total upright outer surface area of said internal members accounts for at least about 10 percent of the combined upright inner surface area of said sidewalls and said internal members; and   one or more gas openings for introducing said gas-phase stream into said reaction zone, wherein at least a substantially portion of said gas openings are located below a substantial portion of said internal members in a manner such that the natural buoyancy of said gas-phase stream in said reaction medium causes at least a portion of the gas-phase stream to rise through the reaction medium adjacent at least a portion of substantially all of said upright outer surfaces of said internal members.   
     
     
         17 . The bubble column reactor of  claim 16  wherein the total upright outer surface area of said internal members accounts for in the range of from about 15 to about 600 percent of the combined upright inner surface area of said sidewalls and said internal members. 
     
     
         18 . The bubble column reactor of  claim 16  wherein the total upright outer surface area of said internal members accounts for in the range of from about 25 to about 400 percent of the combined upright inner surface area of said sidewalls and said internal members. 
     
     
         19 . The bubble column reactor of  claim 16  wherein said reaction zone as a maximum height (L) of at least about 10, a maximum diameter (D) of at least about 1 meters, and an L:D ratio of at least about 6:1. 
     
     
         20 . The bubble column reactor of  claim 19  wherein said L is at least about 30 meters, said D is at least about 2.5 meters, and said L:D ratio is in the range of from about 8:1 to about 20:1. 
     
     
         21 . The bubble column reactor of  claim 16  wherein said one or more sidewalls is a single substantially cylindrical sidewall. 
     
     
         22 . The bubble column reactor of  claim 16  wherein said upright surface area is presented by surfaces extending upwardly within about 30 degrees of vertical. 
     
     
         23 . The bubble column reactor of  claim 16  wherein said upright surface area is presented by surfaces extending upwardly within about 15 degrees of vertical. 
     
     
         24 . The bubble column reactor of  claim 16  wherein said reaction zone presents a normally-lower end and a normally-upper end separated by a distance (L), wherein at least about 50 percent of the cumulative open area defined by all of said gas openings is located closer said normally-lower end than are said internal members. 
     
     
         25 . The bubble column reactor of  claim 24  wherein substantially all of the cumulative open area defined by all of said gas openings is located closer said normally-lower end than are said internal members. 
     
     
         26 . The bubble column reactor of  claim 24  wherein a majority of the cumulative open area defined by all of said gas openings are located within about 0.25L of the normally-lower end of said reaction zone. 
     
     
         27 . The bubble column reactor of  claim 16  wherein said bubble column reactor further comprises one or more liquid openings for introducing said liquid-phase stream into said reaction zone, wherein said reaction zone presents a normally-lower end and a normally-upper end separated by a distance (L), wherein at least about 50 percent of the cumulative open area defined by all of said liquid openings is located closer said normally-lower end than are said internal members. 
     
     
         28 . The bubble column reactor of  claim 27  wherein substantially all of the cumulative open area defined by all of said liquid openings is located closer said normally-lower end than are said internal members. 
     
     
         29 . The bubble column reactor of  claim 28  wherein at least about 50 percent of the cumulative open area defined by all of said feed openings is located within about 0.22L of the oxidant opening located closest to said normally-lower end. 
     
     
         30 . The bubble column reactor of  claim 16  wherein said gas openings are configured in a manner such that when said reaction zone is theoretically partitioned into 4 vertical quadrants of equal volume by a pair of intersecting vertical planes, not more than about 80 percent of the cumulative open area defined by all of said gas openings is located in a common one of said vertical quadrants. 
     
     
         31 . The bubble column reactor of  claim 30  wherein not more than 40 percent of the cumulative open area defined by all of said gas openings is located in a common one of said vertical quadrants. 
     
     
         32 . The bubble column reactor of  claim 16  wherein said internal members are not configured to provide substantial heating or cooling of the contents of said reactor. 
     
     
         33 - 34 . (canceled)