Recovery of metal and bromine catalysts components from residue of aromatic acid produced by and recovered from catalytic liquid phase oxidation

Claim 2

In the production of iso- or terephthalic acid by the liquid phase oxidation of m- or p-xylene with molecular oxygen in the presence of acetic acid solution of components of catalysis comprising manganese and/or cobalt and a source of bromine, wherein such phthalic acid product is first separated as a solid and then acetic acid is removed from the fluid oxidation effluent leaving a residue containing said components of catalysis, at least iron as contaminant metal, and acidic and neutral organic compounds; the recovery of said components of catalysis from said residue for recycle to said oxidation by the treatment of said residue with water and lithium carbonate by the method comprising: a. leaching such residue with water at a temperature from ambient temperature to 100*C with an amount of water in the range of from 1 to 10 weight parts per weight part of residue, b. separating the aqueous extract from insolubles, c. adjusting the pH of said aqueous extract to pH in the range of 8.0-8.2 by the addition of lithium carbonate whereat said pH range iron-free catalyst metal carbonate precipitates, d. separating the catalyst metal carbonate precipitate from the aqueous mother liquor, e. dissolving at a temperature of 50*-100*C the separated catalyst metal carbonate in aqueous acetic acid of 50-60 weight percent acetic acid content in an amount thereof from 1-1.3 times the stoichiometric requirement for conversion of catalyst metal carbonate to catalyst metal acetate and recycling said catalyst metal acetate to said oxidation process, f. incinerating said aqueous mother liquor to ash containing LiBr and oxides of contaminant metal, g. leaching said ash at a temperature from ambient temperature to 100*C with an amount of water to dissolve the lithium bromide content of said ash, and h. separating from said metal oxides the aqueous solution of lithium bromide and recycling the aqueous solution to the oxidation process.

Claim 3

IN THE PRODUCTION IS ISO- OR TEREPHTHALIC ACID BY LIQUID PHASE OXIDATION OF M-OR P-XYLENE WITH MOLECULAR OXYGEN IN THE PRESENCE OF ACETIC ACID SOLUTION OF COMPONENTS OF CATALYSIS COMPRISING MANGANESE AND/OR COBALT AND A SOURCE OF BROMINE, WHEREIN SUCH PHTHALIC ACID PRODUCT IS FIRST SEPARATED AS A SOLID AND THEN ACETIC ACID IS REMOVED FROM THE FLUID OXIDATION EFFLUENT LEAVING A RESIDUE CONTAINING SAID COMPONENTS OF CATALYSIS, ATLEAST IRON AS CONTAMINANT METAL, AND ACIDIC AND NEUTRAL ORGANIC COMPOUNDS; THE RECOVERY OF SAID COMPONENTS OF CATALYSIS FROM SAID RESIDUE FOR RECYCLE TO SAID OXIDATION BY THE TREATMENT OF SAID RESIDUE WITH WATER AND LITHIUM CARBONATE BY THE METHOD COMPRISING: A. LEACHING SAID RESIDUE WITH WATER AT AMBIENT TEMPERATURE TO 100*C IN THE PRESENCE OF AN AMOUNT LITHIUM CARBONATE FROM 1 TO 2 TIMES THE AMOUNT INDICATED BY THE ACID NUMBER IN MG KOH PER GRAM OF THE RESIDUE TO CONVERT TO LITHIUM SALTS THE ACIDIC ORGANIC MATERIAL IN SAID RESIDUE AND WITH AN AMOUNT OF WATER TO DISSOLVE SUCH LITHIUM SALTS, B. SEPARATING SUCH AQUEOUS SOLUTION FROM INSOLUBLES CONSISTING ESSENTIALLY OF CATALYST METAL CARBONATE,IRON CARBONATE AND THE NEUTRAL ORGANIC MATERIALS CONTENT OF THE RESIDUE C. REMOVING AND COLLECTING SAID NEUTRAL ORGANIC MATERIALS FROM SAID INSOLUBLES BY STEAM DISTILLATION THEREOF, D. DISSOLVING SAID NEUTRALS-FREE INSOLUBLES AT A TEMPERATURE FROM 50*-100*C AQUEOUS ACETIC ACID CONTAINING 50-60 WEIGHT PERCENT ACETIC ACID IN AN AMOUNT THEREOF FROM 1.0-1.3 TIMES THE STOICHIOMETIC AMOUNT REQUIRED TO CONVERT THE METAL CARBONATES TO DISSOLVED METAL ACETATES, E. HEATING SAID SOLUTION OF METAL ACETATES TO REMOVE ACETIC ACID AND OBTAIN A SOLUTION PH OF 4.5 TO 55.5 WHEREAT AN INSOLUBLE FORM OF IRON PRECIPITATES F. SEPARATING SAID PH 4.5 TO 5.5 SOLUTION FROM SAID PRECIPITATE AND RECYCLING SAID SEPARATED SOLUTION TO THE OXIDATION PROCESS G. INCINERATING TO A LITHIUM BROMIDE-CONTAINING ASH A MIXTURE OF SAID AQUEOUS SOLUTION OF LITHIUM SALTS AND SAID REMOVED AND COLLECTED NEUTRAL ORGANIC MATERIALS, H. LEACHING SAID ASH AT AMBIENT TEMPERATURE TO 100*C WITH WATER IN AN AMOUNT TO DISSOLVE THE LITHIUM BROMIDE CONTENT OF SAID ASH, AND I. SEPARATING FROM THE UNDISSOLVED PORTION OF SAID ASH THE AQUEOUS SOLUTION OF LITHIUM BROMIDE AND RECYCLING THE SEPARATED SOLUTION TO THE OXIDATION PROCESS.

Claim 4

IN THE PRODUCTION IS ISO- OR TEREPHTHALIC ACID BY LIQUID PHASE OXIDATION OF M-OR P-XYLENE WITH MOLECULAR OXYGEN IN THE PRESENCE OF ACETIC ACID SOLUTION OF COMPONENTS OF CATALYSIS COMPRISING MANGANESE AND/OR COBALT AND A SOURCE OF BROMINE, WHEREIN SUCH PHTHALIC ACID PRODUCT IS FIRST SEPARATED AS A SOLID AND THEN ACETIC ACID IS REMOVED FROM THE FLUID OXIDATION EFFLUENT LEAVING A RESIDUE CONTAINING SAID COMPONENTS OF CATALYSIS, ATLEAST IRON AS CONTAMINANT METAL, AND ACIDIC AND NEUTRAL ORGANIC COMPOUNDS; THE RECOVERY OF SAID COMPONENTS OF CATALYSIS FROM SAID RESIDUE FOR RECYCLE TO SAID OXIDATION BY THE TREATMENT OF SAID RESIDUE WITH WATER AND LITHIUM CARBONATE BY THE METHOD COMPRISING: A. LEACHING SAID RESIDUE WITH WATER AT AMBIENT TEMPERATURE TO 100*C IN THE PRESENCE OF AN AMOUNT LITHIUM CARBONATE FROM 1 TO 2 TIMES THE AMOUNT INDICATED BY THE ACID NUMBER IN MG KOH PER GRAM OF THE RESIDUE TO CONVERT TO LITHIUM SALTS THE ACIDIC ORGANIC MATERIAL IN SAID RESIDUE AND WITH AN AMOUNT OF WATER TO DISSOLVE SUCH LITHIUM SALTS, B. SEPARATING SUCH AQUEOUS SOLUTION FROM INSOLUBLES CONSISTING ESSENTIALLY OF CATALYST METAL CARBONATE,IRON CARBONATE AND THE NEUTRAL ORGANIC MATERIALS CONTENT OF THE RESIDUE C. REMOVING AND COLLECTING SAID NEUTRAL ORGANIC MATERIALS FROM SAID INSOLUBLES BY STEAM DISTILLATION THEREOF, D. DISSOLVING SAID NEUTRALS-FREE INSOLUBLES AT A TEMPERATURE FROM 50*-100*C AQUEOUS ACETIC ACID CONTAINING 50-60 WEIGHT PERCENT ACETIC ACID IN AN AMOUNT THEREOF FROM 1.0-1.3 TIMES THE STOICHIOMETIC AMOUNT REQUIRED TO CONVERT THE METAL CARBONATES TO DISSOLVED METAL ACETATES, E. HEATING SAID SOLUTION OF METAL ACETATES TO REMOVE ACETIC ACID AND OBTAIN A SOLUTION PH OF 4.5 TO 55.5 WHEREAT AN INSOLUBLE FORM OF IRON PRECIPITATES F. SEPARATING SAID PH 4.5 TO 5.5 SOLUTION FROM SAID PRECIPITATE AND RECYCLING SAID SEPARATED SOLUTION TO THE OXIDATION PROCESS G. INCINERATING TO A LITHIUM BROMIDE-CONTAINING ASH A MIXTURE OF SAID AQUEOUS SOLUTION OF LITHIUM SALTS AND SAID REMOVED AND COLLECTED NEUTRAL ORGANIC MATERIALS, H. LEACHING SAID ASH AT AMBIENT TEMPERATURE TO 100*C WITH WATER IN AN AMOUNT TO DISSOLVE THE LITHIUM BROMIDE CONTENT OF SAID ASH, AND I. SEPARATING FROM THE UNDISSOLVED PORTION OF SAID ASH THE AQUEOUS SOLUTION OF LITHIUM BROMIDE AND RECYCLING THE SEPARATED SOLUTION TO THE OXIDATION PROCESS.

Claim 5

The method of claim 1 wherein the undissolved portion of the leached ash is used in leaching step (a) to provide at least a portion of the lithium carbonate requirement.