http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-3919306-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_75a9b43328a2cbfcf60da8b223a321c7 |
| classificationCPCAdditional | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/Y02P20-582 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C51-42 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/C07C51-42 |
| filingDate | 1972-06-05-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| grantDate | 1975-11-11-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| inventor | http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_99d34fa844b14133301ddc8ccb7c0fae http://rdf.ncbi.nlm.nih.gov/pubchem/patentinventor/MD5_638223fa261df333f49d39b9455671b0 |
| publicationDate | 1975-11-11-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | US-3919306-A |
| titleOfInvention | Purification of recirculated stream for isophthalic acid production |
| abstract | Technical grades of meta xylene employed in manufacturing isophthalic acid generally contain very small amounts of ortho and/or para xylene, leading to the formation of troublesome amounts of orthophthalic acid and terephthalic acid, which are troublesome in the cayalytic oxidation of meta xylene to isophthalic acid in an oxidative reaction zone. The recirculated acetic acid solvent tends to accumulate contaminants such as orthophthalic acid, terephthalic acid, and related impurities. There is the possibility of contamination of the isophthalic acid product by terephthalic acid, benzoic acid, and/or other impurities. Even small amounts of orthophthalic acid are extremely harmful because orthophthalic acid is a catalyst poison. Any troublesome accumulation of contaminants is prevented by the unique combination of steps for purification of the recycled stream. All of the orthophthalic acid (catalyst poison) is removed as the sodium salt in an aqueous filtrate after a precipitate comprising cobalt carbonate has been filtered from a mixture of aqueous sodium carbonate and a stripped bottoms solution. Cobalt acetate is regenerated from the cobalt carbonate precipitate by reaction with a portion of the overhead stream from the flash distillation of the stream from which the isophthalic acid has been removed. Water is desirably removed from the acetic acid prior to its recirculation to the oxidative reaction zone. Only small proportions of make up cobalt acetate and/or make up acetic acid must be added to the recirculated solution because of the high efficiency of the purification of the acetic acid solvent and the high efficiency of the purification of the cobalt acetate catalyst and the satisfactory removal of orthophthalic acid related catalyst poisons from the purified cobalt catalyst. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6657068-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6657067-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-4228091-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-2520796-A http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-7732559-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-2520796-B http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-7541489-B2 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/WO-9831653-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/EP-2356088-B1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/DE-3047478-A1 http://rdf.ncbi.nlm.nih.gov/pubchem/patent/US-6649773-B2 |
| priorityDate | 1970-05-18-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 86.