http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-1204184-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_8857d9285f4a393618523d052bf765df |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C51-56 http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C51-265 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C51-265 http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C51-56 |
| filingDate | 1967-09-19-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1970-09-03-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-1204184-A |
| titleOfInvention | Manufacture of trimetallitic anhydride |
| abstract | 1,204,184. Trimellitic acid and anhydride. STANDARD OIL CO. 19 Sept., 1967 [19 Sept., 1966], No. 42674/67. Heading C2C. A process for the recovery of trimellitic acid and/or anhydride from an oxidation effluent obtained by the liquid phase air oxidation of pseudocumene in the presence of a heavy metal catalyst, said effluent being at a temperature of 325-450‹ F. and a pressure of 170-410 p.s.i.g. and containing trimellitic acid and a solvent consisting of 91-72% by wt. acetic acid and 9-28% by wt. water, there being 177-336 part by wt. solvent per 100 parts by wt. trimellitic acid, comprises the steps of (1) cooling and depressurizing the oxidation effluent in a first crystallization zone operated at superatmospheric pressure to crystallize 5-30% by wt. of the trimellitic acid and to form a suspension of crystals; (2) introducing the suspension from (1) to a second crystallization zone operated at a subatmospheric pressure and a temperature such that additional trimellitic acid is crystallized; (3) separating the effluent from (2) into a mother liquor and a crystalline product; (4) washing the crystalline product with 95- 98% wt. cone. acetic acid; (5) combining the mother liquor from (3) with the wash liquor from (4); (6) stripping acetic acid and water from the combined liquors from (5); (7) recycling trimellitic acid and/or anhydride present in the stripper bottoms from (6) to the first or second crystallization zone; and (8) recovering the washed crystals from (4) optionally followed by conversion of the trimellitic acid content thereof to the anhydride. In a preferred embodiment step (1) is operated at 320-285‹ F. and 24-45 p.s.i.g.; step (2) at 120-140‹ F. and 75-115 mm. Hg absolute and in step (6) the amount of acetic acid and water stripped off is equivalent to the amount of acetic acid and water used in step (4) and 65-95% by wt. of the acetic acid and water of the mother liquor from (3). The stripping step (6) may be effected at 448-500‹ F. and 0-10 p.s.i.g. to convert the trimellitic acid in the combind liquors to the anhydride and the stripper bottoms are flashed at 420- 600‹ F. and 5-20 mm. Hg absolute to remove 80-85% by wt. of the anhydride formed during stripping (6) as an overhead vapour which is condensed and recycled to the first or second crystallization zones. The washed product recovered at (4) is converted to the intramolecular anhydride by feeding the crystals to a pool of molten trimellitic anhydride at 400-500‹ F and 200 mm. Hg absolute atmospheric pressure. Crude anhydride is withdrawn from this pool and, optionally after filtering flashed at 425-575‹ F. and 10-55 mm. Hg absolute. The vaporized anhydride is condensed to give a product of high purity. Acetic acid and water obtained as overhead vapours from the crystallization zones and from step (6) may be reconcentrated and used as solvent for the oxidation process, washing liquor for step (4) or fed to the crystallization to maintain a flowable suspension. The process is illustrated by examples and schematic flow diagrams (not shown). |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/WO-0153246-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6562997-B2 |
| priorityDate | 1966-09-19-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
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Total number of triples: 24.