Optimized liquid-phase oxidation
AssigneeEastman Chemical Company
InventorsAlan George Wonders, Gino Georges Lavoie, Charles Edwan Sumner, Jr.
Life of this patent
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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.
Claims32
A 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 said feed stream has one or more of the following characteristics—
- (i) contains meta-xylene in an amount in the range of from about 20 to about 800 parts per million by weight of said para-xylene (ppmwpX),
- (ii) contains meta-xylene, orthoxylene, ethylbenzene, and toluene, in combination, in an amount in the range of from about 50 to about 900 ppmwpX;
- (b) oxidizing at least a portion of said para-xylene in a liquid phase of a multi-phase reaction medium contained in said reaction zone, wherein said oxidizing causes the formation of crude terephthalic acid in said reaction zone;
- and
- (c) oxidizing at least a portion of said crude terephthalic acid in a secondary oxidation reactor to thereby form purer terephthalic acid, wherein said oxidizing in said secondary oxidation reactor is carried out at an average temperature at least 10° C. greater than the average temperature of said oxidizing in said bubble column reactor.
A 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 said feed stream contains meta-xylene in an amount less than 800 parts per million by weight of said para-xylene (ppmwpX), wherein said feed stream contains ortho-xylene in an amount in the range of from about 10 to about 200 ppmwpX, wherein said feed stream contains meta-xylene, orthoxylene, ethylbenzene, and toluene, in combination, in an amount less than 1,600 ppmwpX;
- (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 to thereby form crude terephthalic acid;
- and
- (c) oxidizing at least a portion of said crude terephthalic acid in a secondary oxidation reactor to thereby form purer terephthalic acid, wherein said oxidizing in said secondary oxidation reactor is carried out at an average temperature at least 10° C. greater than the average temperature of said oxidizing in said bubble column reactor.
Dependencies are inferred from the claim text.