A SHOCK-TUBE INVESTIGATION OF THE RATE OF SOOT FORMATION FOR BENZENE, TOLUENE, AND TOLUENE-N-HEPTANE MIXTURES

The rate of soot formation during the pyrolysis and oxidation of rich mixtures of toluene and benzene, and the pyrolysis of tolune/n-heptane mixtures has been determined using a reflected shock technique over the temperature range of 1500-1950K and for pressures between 2. 6 and 3. 6 multiplied by 10**5 Pa. A laser beam attenuation technique was used to determine soot concentrations using helium-neon lasers at 632. 8 and 1152. 0 nm. The test gas mixtures were diluted with at least 98 mol% argon and for the pyrolysis experiments the hydrocarbon concentrations did not exceed 0. 35 mol m** minus **3. The oxidation experiments employed fuel rich mixtures with equivalence ratios between 6 and 11. Rates of soot formation and soot yields exhibited an Arrhenius dependence and could be expressed by a correlation equation in a form which is also suitable for the prediction of soot limits.