Calculation of combustion properties and flame stability analysis for limit gas 65% CH4 + 35% H2

Abstract

The world energy demand enhances the environmental and operational benefits of natural gas as an energy alternative, due to its composition, mainly methane (CH4), it has low polluting emissions and benefits in energy systems and combustion; hence the search for mixtures of natural gas with other fuels, such as hydrogen (H2), to further enhance its properties. In the present work, some properties were determined numerically and experimentally for the mixture 65% CH4 + 35% H2 at atmospheric conditions of the city of Medellín, Colombia, properties related to the structure, stability of the flame, and autoignition. Numerical simulations and experimental measurements of the laminar deflagration velocity were carried out for dosages between 0.9 and 1.4. In general, the laminar deflagration speed adjusts well to the numerical results, the maximum value of the deflagration speed corresponds to a value of 51.38 cm / s for a dosage of 1.1. Flame instabilities occur for a dosage of 0.75. Additionally, it was found that the optimum operating range of the burner operating with this limit gas is in the range of relative dosages between 0.9 <- 0 <-1.4.

Keywords

• pollutant emissions
• flame instabilities
• laminar deflagration rate
• delay time to ignition