An experimental investigation of the ignition properties of hydrogen and carbon monoxide mixtures for syngas turbine applications

Ignition studies of simulated syngas mixtures of hydrogen (H-2), carbon monoxide (CO), oxygen (02), nitrogen (N-2) and carbon dioxide (CO2) were performed using a rapid compression facility. Experiments were conducted using pressure time-histories and high-speed imaging to measure ignition delay times (tau(ign)), over a broad range of conditions relevant to current and proposed gas-turbine technologies, and which included fuel compositions consistent with typical gasification facilities. Specifically, the tau(ign) data spanned pressures from P=7.1 to 26.4 atm, temperatures from T=855 to 1051 K, equivalence ratios from phi=0.1 to 1.0, oxygen mole fractions from chi(O2)=15% to 20% and H-2:CO ratios from H-2:CO=0.25 to 4.0 (mole basis). Regression analysis yielded the following best-fit to the composite data set: tau(ign)=3.7x10(-6)P(-0.5)phi(0.4)chi(-5.4)(O2) exp(12, 500/R[cal/mol/K]T) In this expression, tau(ign) is the ignition delay time [ms], P is pressure [atm], T is temperature [K], phi is the equivalence ratio (based on the H-2 and CO to O-2 molar ratio), and chi(O2) is the oxygen mole fraction. The uncertainty in the measured values for tau(ign) is estimated as less than 30%. The experimental data are in good agreement with model predictions based on a recently proposed detailed reaction mechanism for H-2 and CO. (c) 2006 The Combustion Institute. Published by Elsevier Inc. All rights reserved.