公开(公告)号：GB719673A

公开(公告)日：1954-12-08

申请号：GB1943452

申请日：1952-07-31

Applicant: STANDARD OIL DEV CO

Inventor： JONE THOMAS GARRETT

Abstract: Cyclopentadiene and methyl cyclopentadiene are separated from the vapour phase products of cracking a hydrocarbon fraction by quenching and segregating a vapour phase stream containing C1-C9 hydrocarbons, substantially no dimers of the cyclopentadienes being formed, compressing and cooling this stream to condense out most of the C6+hydrocarbons together with some C5 and a small amount of lower, stripping the lower hydrocarbons from the C6+, passing the latter to a dimerization zone, fractionating from the C10 and C12 dimers, C5-9C hydrocarbons to recover a concentrate of cyclopentadiene and methyl cyclopentadiene dimers which is dedimerized and the resulting monomers separated by fractionation. Gas oil, kerosine or naphtha boiling between 250 DEG and 700 DEG F. is cracked in admixture with 50-90 mol. per cent of steam at 1000-1600 DEG F. and 1-10 atm. total pressure for a period of 1-5 secs. The product, at a pressure of about 0-100 p.s.i.g., is quenched to about 350-650 DEG F. by injection of water and cycle oil and fed to a fractionator operating at about 0-10 p.s.i.g. giving an overhead of C1 to C9 containing nearly all the cyclopentadiene and homologue, a cycle oil condensate, and a bottom tar stream. The overhead is cooled rapidly to 90-135 DEG F. to condense C10+ hydrocarbons, and steam, and then further compressed and cooled to about 40-210 p.s.i.g. and 90-135 DEG F. to condense further water and C6+ hydrocarbons, including most of the methyl cyclopentadiene. The remaining vapours containing cyclopentadiene and mainly C1-C5 hydrocarbons may be purified and dried before compressing and cooling, e.g. with liquid propene or ammonia, to liquify C5+ hydrocarbons, andfr actionating at about 80-90 p.s.i.g. to give a bottom C5+ liquid which may be soaked at 150-250 DEG F. to dimerize the cyclic dienes, and fractionated to recover cyclopentadiene dimer. Alternatively, the C5+ liquid may be processed together with the C6+ condensate containing most of the methyl cyclopentadiene. This condensate is first stripped to remove C3-C5 hydrocarbons, soaked to dimerize cyclic dienes, and fractionated to recover a dimer concentrate. The homologous dienes are separated from the conconcentrates by dedimerizing at 300-650 DEG F. and fractionation of the vapours.