Methods and Apparatus for Enhanced Gas Distribution

A reactor defining a reaction zone therein, said reactor comprising:

• a sparger disposed in said reaction zone for introducing fluid into said reaction zone,
• wherein said sparger comprises one or more fluid distribution conduits defining in the range of from 20 to 300 fluid discharge openings,
• wherein when said sparger is theoretically partitioned into four annular regions of equal area, the cumulative discharge opening area of the fluid discharge openings located in one of said annular regions is within 25 percent of the cumulative discharge opening area of the fluid discharge openings located in at least one other of said annular regions,
• wherein said sparger has a total flow-through open area of at least 25 percent,
• wherein said fluid discharge openings have an average mean diameter in the range of from about 0.5 to about 2.0 mm,
• wherein greater than 50 percent of said fluid discharge openings are positioned to discharge said fluid in a normally downward direction,
• wherein said sparger has a maximum diameter in the range of from about 0.5 to about 6 meters,
• wherein said sparger has a maximum diameter that is at least 90 percent of the diameter of said reaction zone at the elevation where said sparger is disposed.

A system for at least partially oxidizing an oxidizable compound by contacting at least a portion of said oxidizable compound with a gas-phase oxidant, said system comprising:

• a first oxidation reactor;
• a second oxidation reactor in downstream fluid-flow communication with said first oxidation reactor;
• a bubble column reactor in downstream fluid-flow communication with said second oxidation reactor and defining a reaction zone;
• and
• a sparger disposed within said reaction zone and configured to discharge at least a portion of said gas-phase oxidant into said reaction zone,
• wherein said sparger comprises one or more fluid distribution conduits defining a plurality of fluid discharge openings,
• wherein when said sparger is theoretically partitioned into four annular regions of equal area, the cumulative discharge opening area of the fluid discharge openings located in one of said annular regions is within 25 percent of the cumulative discharge opening area of the fluid discharge openings located in at least one other of said annular regions,
• wherein said sparger has a total flow-through open area of at least 25 percent,
• wherein said sparger has a maximum diameter that is at least 90 percent of the diameter of said reaction zone at the elevation where said sparger is disposed.

A method for producing a dicarboxylic acid, said method comprising:

• (a) contacting an oxidizable compound with a first gas-phase oxidant thereby forming a crude dicarboxylic acid slurry;
• (b) purifying at least a portion of said crude dicarboxylic acid slurry thereby forming a purified dicarboxylic acid slurry;
• and
• (c) contacting at least a portion of said purified dicarboxylic acid slurry with a second gas-phase oxidant in a reaction zone of a bubble column reactor, wherein at least a portion of said second gas-phase oxidant is introduced into said reaction zone via a sparger disposed in said reaction zone,
• wherein said sparger comprises one or more fluid distribution conduits defining a plurality of fluid discharge openings,
• wherein when said sparger is theoretically partitioned into four annular regions of equal area, the cumulative discharge opening area of the fluid discharge openings located in one of said annular regions is within 25 percent of the cumulative discharge opening area of the fluid discharge openings located in at least one other of said annular regions,
• wherein said sparger has a total flow-through open area of at least 25 percent,
• wherein said sparger has a maximum diameter that is at least 90 percent of the diameter of said reaction zone at the elevation where said sparger is disposed.