Sooting tendency of n-heptane/anisole blends in laminar counter-flow flames with oxygen enrichment

Anisole has been recognized as a potential alternative fuel to lower soot emission in internal combustion engines. Thus, in the present study, soot formation by n-heptane/anisole blends in a counter-flow laminar diffusion flame have been measured by using the Line of Sight Attenuation (LOSA). Several main factors related to the sooting tendency were analyzed in detail, including the anisole proportion, oxygen content, and fuel and oxidant flow velocities. Increasing the anisole proportion (0-30% in mole fraction) and oxygen content (30-40% in volume fraction) in oxidant promoted soot formation in the flame, and the maximum soot volume fraction could be fitted as an exponential function of the anisole proportion. Higher fuel and oxidant flow velocities resulted in greater strain rates and a shorter residence time for the reaction mixture, which ultimately inhibited soot formation.