Shock tube studies of pyrolyses pertinent to soot formation
A shock tube coupled to a time-of-flight mass spectrometer is utilized to investigate the chemical kinetics of reactions pertinent to soot formation. Three projects are covered. 1. High temperature pyrolyses of acetylene and diacetylene. The acetylene decomposition mechanism is developed further by incorporating new thermodynamic and chemical kinetic parameters. A sub-mechanism valid for the experimental conditions is derived, revealing several kinetic features for the pyrolyses of acetylene and diacetylene. A value of 111 kcal/mol for the heat of formation of C[sub 4]H[sub 2] is supported by these experiments. 2. The mechanism of pyrolyses of propargyl chloride, propyne and allene. In mixtures of propargyl chloride dilute in neon, benzene is not detected as an expected product of reactions involving C[sub 3]H[sub 3] radicals. However, in mixtures of C[sub 3]H[sub 3]Cl containing H[sub 2], benzene is observed. Benzene production is also recorded in the mixtures of C[sub 3]H[sub 3]Cl + allene and C[sub 3]H[sub 3]Cl + propyne. Two initial parallel reactions for propargyl chloride decomposition C[sub 3]H[sub 3]Cl [yields] C[sub 3]H[sub 3] + Cl, C[sub 3]H[sub 3]Cl [yields] c-C[sub 3]H[sub 2] + HCl are proposed to account for the ratio of HCl/DCl measured in the pyrolysis of a C[sub 3]H[sub 3]Cl - D[sub 2] mixture. A primary mechanism with 36 reactions is proposed which yields satisfactory agreement between the calculational and experimental results. Mixtures containing allene or propyne were investigated in order to compare the respective benzene yields. 3. High temperature dissociation of toluene. One of the current disputes in the high temperature dissociation of toluene was studied; the relative dominance of two initiation reactions. C[sub 7]H[sub 8] [yields] C[sub 7]H[sub 7] + H, C[sub 7]H[sub 8] [yields] C[sub 6]H[sub 5] + C[sub 3]H. The theory of unimolecular reactions was employed to explore the relative dominance and falloff behavior for these two reactions.
- Research Organization:
- New Orleans City Government, LA (United States)
- OSTI ID:
- 6958748
- Resource Relation:
- Other Information: Thesis (Ph.D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETYLENE
COMBUSTION KINETICS
PYROLYSIS
ALLENE
PROPYNE
SOOT
PRODUCTION
TOLUENE
ALKYLATED AROMATICS
ALKYNES
AROMATICS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DECOMPOSITION
DIENES
HYDROCARBONS
KINETICS
ORGANIC COMPOUNDS
POLYENES
REACTION KINETICS
THERMOCHEMICAL PROCESSES
400800* - Combustion
Pyrolysis
& High-Temperature Chemistry