Combustion chemistry of ternary blends of hydrogen and C₁–C₄ hydrocarbons at atmospheric pressure

Interest in the combustion chemistry of multifuel blends is motivated by the need to study the combustion of natural gas, which is known to be a mixture of alkanes. The present study performed using molecular beam mass spectrometry and numerical modeling has shown that the width of the zones of hydrogen and methane consumption in the H₂/CH₄/C₃H₈/O₂/Ar flame and the width of the zones of methane and propane consumption in the CH₄/C₃H₈/C₄H₁₀/O₂/Ar flame differ significantly from each other. The causes of this phenomenon were determined by analyzing the modeling results. It has been found that in the presence of heavier compounds, lighter fuels, such as H₂ and CH₄, are formed, which reduces the total rate of their consumption and, hence expands the zone of their consumption in the flame. The influence of the presence of hydrogen in the fuel mixture on the concentration of C₂ hydrocarbons has also been studied. It has been established that the addition of hydrogen reduces the maximum concentration of ethane, ethylene, and acetylene in the flame, and the fraction of unsaturated C₂ hydrocarbons with respect to saturated ones also decreases.