http://rdf.ncbi.nlm.nih.gov/pubchem/patent/GB-658449-A
Outgoing Links
| Predicate | Object |
|---|---|
| assignee | http://rdf.ncbi.nlm.nih.gov/pubchem/patentassignee/MD5_043c6a4e90e797f67a0e5cb252d30c56 |
| classificationCPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentcpc/C07C7-177 |
| classificationIPCInventive | http://rdf.ncbi.nlm.nih.gov/pubchem/patentipc/C07C7-177 |
| filingDate | 1949-05-13-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationDate | 1951-10-10-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| publicationNumber | GB-658449-A |
| titleOfInvention | Process for the separation of dienes and the products thus obtained |
| abstract | The separation of an aliphatic conjugated diene and its closely related alicyclic conjugated diene from a hydrocarbon mixture comprising them is effected by subjecting to a dimerization treatment wherein the alicyclic diene is converted to dimer, separating a monomeric fraction comprising the aliphatic diene and a dimerized fraction, heating the latter at about 150-450 DEG C. to convert the alicyclic diene dimer to monomer, separating from the resulting mixture a fraction comprising alicyclic diene monomer and a fraction comprising unaffected dimers, heating the latter to above about 500 DEG C. to convert remaining dimers to monomers, and separating a fraction comprising said monomers which may be recycled to the dimerization. The initial mixture may comprise isoprene, with or without piperylene, and cyclopentadiene. Other aliphatic dienes which may be separated are trans-1,3-pentadiene, trans-2 (or 3)-methyl-1,3-pentadiene, 2 - isopropyl - 1,3 - butadiene, trans - 1,3 - hexadiene, and 2 - butyl - 1,3 - pentadiene. Other alicyclic dienes are alkyl cyclopentadienes such as 5-methyl-1,3-cyclopentadiene. The first pyrolysis of dimerized fraction is preferably effected at 350-450 DEG C., the second at 550-700 DEG C., in the presence of steam, and with residence times of 0.2-4, preferably 0.5-2, seconds. The initial dimerization may be effected by heating at about 50-130 DEG C. An equation for obtaining the time required is given. Solvents or diluents and a blanket of inert gas may be present. Separation of dimers is preferably by fractionation. The stripped monomer may be purified by extractive distillation or complex formation with heavy metal cations. Unconverted dimers remain in the residue after distillation of the product of the second pyrolysis treatment and may be recycled. Examples describe the treatment of mixtures obtained by distilling a cracked gasoline or petroleum or from destructive distillation of coal to recover isoprene or 1,3-pentadiene and cyclopentadiene. |
| isCitedBy | http://rdf.ncbi.nlm.nih.gov/pubchem/patent/DE-1084717-B |
| priorityDate | 1948-05-17-04:00^^<http://www.w3.org/2001/XMLSchema#date> |
| type | http://data.epo.org/linked-data/def/patent/Publication |
Incoming Links
Total number of triples: 27.