The Determination of Rate-Limiting Steps during Soot Formation

Abstract : A single-pulse shock tube has been used to examine the pyrolysis and rich oxidation of cyclopentadiene as well as its pyrolysis in the presence of acetylene, biacetyl, and benzene. In addition, mixtures of benzene and hydrogen have been copyrolyzed. These fuels have been diluted in argon and shock heated over the temperature range of 1200 to 2000K and at total pressures of ten to thirteen atmospheres. Dwell times were about 500-600 microseconds. Collected gas samples were analyzed using gas chromatography for hydrogen, carbon oxides and C1 to C14- hydrocarbons. Experimental results and preliminary chemical kinetic modeling lead to mechanistic proposals on the decomposition of C5-rings as well as isomerization processes between C5- and C6-rings. In addition, data on cyclopentadiene indicates that this fuel has a sooting tendency comparable to that of benzene. Keywords: Pyrolysis, Cyclopentadiene, Benzene, Hydrogen addition, Ring formation, Ring isomerization, Soot formation, Soot modeling, Single-pulse shock tube.