Accession Number : AD0685160

Title :   TECHNIQUE FOR TRAPPING INTERMEDIATE SPECIES OF HIGH-TEMPERATURE REACTIONS,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Cook,Eileen ; Siegel,Bernard

Report Date : NOV 1968

Pagination or Media Count : 26

Abstract : A technique is described that offers promise for use in high-temperature syntheses and in the study of mechanisms of high-temperature reactions. The electrical explosion of metal wires into surrounding gases initiates high-temperature reactions, but instead of confining the reactants to a reactor of fixed volume, temperature quenching is augmented by rapid adiabatic expansion of the heated gases. The explosion chamber that contains the initial reactants is separated from an expansion chamber that is either initially evacuated or filled with an inert gas. The two chambers are separated by a thin diaphragm, which is ruptured by the wire explosion. The technique leads to the trapping of intermediate species that would otherwise react further. The pyrolyses of methane and isobutane were used as model systems in this study. In the methane pyrolysis, the expansion technique leads to the isolation of ethane molecules, which are formed in the earliest stages of the mechanism of methane pyrolysis. In the isobutane pyrolysis, one also isolates ethane molecules formed in the earliest stages of the pyrolysis, and one tends to isolate the reaction C4H10 to CH4 + C3H6, which is an early step in the pyrolytic sequence. A later reaction, C3H6 to C2H2 + CH4, is effectively suppressed. (Author)

Descriptors :   (*PYROLYSIS, *EXPLODING WIRES), (*METHANE, PYROLYSIS), (*BUTANES, PYROLYSIS), CHEMICAL REACTIONS, HIGH TEMPERATURE

Subject Categories : Organic Chemistry
      Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE