Shell' Research Ltd. Th.wmon Research Cot!ire. P ,'z,. Box 1. ( hestcr ('onlparative ~tudie~ of the pte-I]atne and ignititl.1 behaviours of ethylene, ptopenc, but-I -ene. tq~-bul-2-,:ne, traitshut-2-ene, i'.ohult'ne, hex-I-ene and hexad.5-diene have been made. Moreover. the of real of all thc,c olel/n~ oll tile i:l~lrlbtlstion ill her.anu at di!~2renl oxidation Mage ~, leading to ignition has been studied.
"[he (d~er red lelalive order of case of combustion of some of the olefins is difl~erent from thai ohs,:r red in klborator 3 .iludies by other worker, but agrees with the relative order of knocking tendencies in engine~ It i~ drown lhLlt. H1 general oletins ;ire less prone to oxidative dogradiaion than the conitlgate alkanes, lind not ~iΒ’Β’ vcr,a as ha~ b~2cn presuffled recently in proposals for a new mechanism for the combustion of hydrocarbons.
All tile otel]llS at tidied illilrkedly alleet tile combustion [fl hexane Item I he earliest stage o[ ils oxidat loll 'fhc earliest pre-Ilanle ~dagΒ’ i~. inhil)ited wJlihl the final stage leadillg to ignit iun is prtllllOtl:d. The natttre of Ibe t: l'l'ec I on tbe interveiling stagex, vitriΒ’', w,:lelg, however : ethylene and i.,obutene inhibit, while Ilex-l-ene. Ilextl-1.5-dte ne and but-2-ene~ prOlllOte; propene and btlt-l-elle have a negligible eflΒ’ct.
The results I~leildatt' undcrshlntlillg i)f tile mΒ’charlism of colnhttqion o[ o[Β’lins and of their roll: as mlerllled;Zll0~ !n tile cltlllbtlstion el hydrocarbons ill general. Dlccbanlsnls arc prolx>vd to cxpll, n the variou, observation..