Soot formation in ethylene pyrolysis with furan and tetrahydrofuran additives

Effect of furan $(\mathrm{C}_4\mathrm{H}_4\mathrm{O})$ and tetrahydrofuran $(\mathrm{C}_4\mathrm{H}_8\mathrm{O})$ additives in a mixture of ethylene $(\mathrm{C}_2\mathrm{H}_4)$ with argon on soot formation during pyrolysis behind reflected shock waves in a pressure range $p_5=2.1 -4.4$ atm and a temperature range $T_5=1600-2580$ K is studied. Temperature dependences for the volume fraction of the condensed phase and the sizes of forming carbon nanoparticles in the studied mixtures are obtained by laser extinction and laser-induced incandescence. It is revealed that adding these furans increases the volume fraction of soot and expands the temperature range of its formation. The effect of furan turns out to be more pronounced than that of tetrahydrofuran. It is shown by the kinetic modeling of ethylene pyrolysis processes with the selected additives that alternative pathways for the production of $\mathrm{C}_3\mathrm{H}_3$ propargyl are formed in the presence of $\mathrm{C}_4\mathrm{H}_4\mathrm{O}$ and $\mathrm{C}_4\mathrm{H}_8\mathrm{O}$, which is the reason why soot formation improves.