Analysis on premixed combustion of H2–CH4 mixed fuels for SiO2 particle preparation

The combustion of premixed H2 and CH4 fuels to prepare SiO2 nanoparticles was analyzed numerically. The commercial CFD-code Fluent was used to calculate the profiles of gas velocities, temperature, species concentrations and reaction rates for various process conditions in the premixed flame reactor. To understand the effect of CH4 addition to H2 fuel, the CH4 mole fraction was changed from 0% to 10%, while keeping the H2 concentration constant. With the increase of CH4 concentration, flame temperature increases, which will affect the properties of SiO2 particles prepared in premixed flame reactor. Using the data of gas temperatures and velocities extracted from Fluent, the trajectories and temperature histories of SiO2 particles were calculated inside the premixed flame reactor. This study shows that particles starting at different initial positions move inside the reactor with different particle trajectories and have different temperature histories, and the properties of SiO2 nanoparticles prepared in the premixed flame reactor will depend on those process variables significantly.

• The SiO2 nanoparticle synthesis by H2-CH4 combustion was analyzed numerically. • The profiles of velocity, temperature, species concentrations etc. were calculated. • Increase of CH4 concentration affects the properties of SiO2 particles. • The trajectories and temperature histories of SiO2 particles were calculated.