Laminar Flame Speed Measurements of Hydrogen/Natural Gas Mixtures for Gas Turbine Applications

Abstract

Due to the increasingly challenging carbon emission reduction targets, hydrogen-containing fuel combustion is gaining the energy community’s attention, as highlighted recently in the U.S. Department of Energy’s (DOE) Hydrogen Program Plan [1]. Though fundamental and applied research of hydrogen-containing fuels has been a topic of research for several decades, there are knowledge-gaps and unexplored fuel blend combustion characteristics at conditions relevant to modern gas turbine combustors. Hydrogen will be burned directly or as mixtures with natural gas (NG) and/or ammonia (NH3) in these devices. Fundamental research on the combustion of hydrogen (H2) containing fuels is still essential, especially to overcome or accurately predict challenges such as nitrogen oxides (NOx) reduction and flashback and develop fuel flexible combustors for a prosperous hydrogen economy. We focused our investigation on a natural gas and hydrogen mixture. Measurements of laminar burning velocity (LBV) are necessary for these fuels to understand their applicability in the turbines and other engines. In this study, the maximum rate of pressure rise and LBV of methane (CH4), CH4/H2, natural gas, and natural gas/H2 mixture were measured in synthetic air. The experimental conditions were at an initial pressure of 1 atm and an initial temperature of 300 K. A realistic natural gas composition from the field was used in this study and consisted of CH4 and other alkanes. The experimental data were compared with simulations carried out with detailed chemical kinetic mechanisms.