Product profiles observed during the pyrolyses of toluene, benzene, butadiene, and acetylene

Conference · Fri Jan 01 04:00:00 EST 1982 · Symp. (Int.) Combust., (Proc.); (United States)

OSTI ID:5719055

Kern, R D; Singh, H J; Esslinger, M A; Winkeler, P W

The thermal decomposition of toluene, benzene, butadiene, and acetylene have been studied by dynamic analysis of the gas from the reflected shock zone with a time-of-flight mass spectrometer. The reacting mixtures were highly dilute and their initial compositions were adjusted to yield a carbon atom shock zone density of (1.0 to 2.2) x 10/sup 17/ atoms cm/sup -3/ over the temperature and total pressure range of (1400 to 2300 K) and (0.21 to 0.57) atm. Concentration profiles were constructed during typical observation times of 700 to 1000 ..mu..s. The major products detected in the pyrolyses of toluene and benzene were acetylene and polyacetylenes up to C/sub 8/H/sub 2/ which were shown to be relatively stable under these reactions conditions. There were no other products recorded with a mass greater than m/e 92 (toluene) or m/e 78 (benzene) in a detection range that extended to m/e 300. Butadiene formed benzene in relatively small amounts during the course of butadiene decay but the benzene decomposed readily to form acetylene and polyacetylenes. Mass balances with respect to observed carbon containing compounds accounted for 70 to 100% of the total carbon atom input. It was concluded that the maximum soot yield was less than 10% for toluene which was much lower than soot yields of approx.80% reported from laser extinction-shock tube experiments. Furthermore, the reaction pathways utilized mostly in the pyrolyses of aromatics are those involving ring fragmentation steps as opposed to ring condensations which occur to a much lesser extent over the temperature and pressure range investigated.

• Research Organization: Univ. of New Orleans, Louisiana
• OSTI ID: 5719055
• Report Number(s): CONF-820801-
• Conference Information: Journal Name: Symp. (Int.) Combust., (Proc.); (United States)
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400301* -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
ACETYLENE
ALKYNES
AROMATICS
BENZENE
BUTADIENE
CHEMICAL REACTIONS
DECOMPOSITION
DIENES
HYDROCARBONS
MASS BALANCE
ORGANIC COMPOUNDS
POLYACETYLENES
POLYENES
PYROLYSIS
PYROLYSIS PRODUCTS
SHOCK TUBES
SHOCK WAVES
SOOT
THERMOCHEMICAL PROCESSES
TOLUENE