Analysis of NOx Formation in a Hydrogen-Fueled Gas Turbine Engine

A commercially available natural gas fueled gas turbine engine was operated on hydrogen. Three sets of fuel injectors were developed to facilitate stable operation while generating differing levels of fuel/air premixing. One set was designed to produce near uniform mixing while the others have differing degrees of non-uniformity. The emissions performance of the engine over its full range of loads is characterized for each of the injector sets. In addition, the performance is also assessed for the set with near uniform mixing as operated on natural gas. The results show that improved mixing and lower equivalence ratio decreases NO emission levels as expected. However, even with nearly perfect premixing, it is found that the engine, when operated on hydrogen, produces a higher amount of NO than when operated with natural gas. Much of this attributed to the higher equivalence ratios that the engine operates on when firing hydrogen. However, even at the lowest equivalence ratios run at low power conditions, higher NO was observed. Analysis of the potential NO formation effects of residence time, kinetic pathways of NO production via NNH, and the kinetics of the dilute combustion strategy used are evaluated. While no one mechanism appears to explain the reasons for the higher NO, it is concluded that each may be contributing to the higher NO emissions observed with hydrogen. In the present configuration with the commercial control system operating normally, it is evident that system level effects are also contributing to the observed NO emission differences between hydrogen and natural gas. ASME Turbo Expo 2008: Power for Land, Sea, and Air Volume 3: Combustion, Fuels and Emissions, Parts A and B Berlin, Germany, June 9–13, 2008 Conference Sponsors: International Gas Turbine Institute ISBN: 978-0-7918-4313-0 | eISBN: 0-7918-3824-2 Copyright © 2008 by ASME

[1]  N. Laurendeau,et al.  Laser-Induced fluorescence measurements and modeling of nitric oxide in premixed flames of CO+H2+CH4 and air at high pressures: I. Nitrogen fixation , 2001 .

[2]  K. P. Lim,et al.  Rate constants for the N2O reaction system: Thermal decomposition of N2O; N+NO→N2+O; and implications for O+N2→NO+N , 1992 .

[3]  Thomas Sattelmayer,et al.  Operation Characteristics of a Premixed Sub-ppm NOx Burner With Periodical Recirculation of Combustion Products , 2005 .

[4]  Giovanni Lozza,et al.  Using Hydrogen as Gas Turbine Fuel , 2003 .

[5]  R. Yetter,et al.  Flow reactor studies and kinetic modeling of the H2/O2 reaction , 1999 .

[6]  Josh Mauzey,et al.  Characterization and Reduction of Pollutant Emissions From a Landfill and Digester Gas Fired Mictroturbine Generator , 2005 .

[7]  James A. Miller,et al.  A chemical kinetic model for the selective reduction of nitric oxide by ammonia , 1981 .

[8]  R. Yetter,et al.  Kinetic modeling of the CO/H2O/O2/NO/SO2 system: Implications for high-pressure fall-off in the SO2 + O(+M) = SO3(+M) reaction , 2000 .

[9]  A. Konnov,et al.  Nitric oxide formation in premixed flames of H2+CO+CO2 and air , 2002 .

[10]  J. Seitzman,et al.  Characteristics of Combustion Processes in a Stagnation Point Reverse Flow Combustor , 2006 .

[11]  Josh Mauzey,et al.  Evaluation of a Low Emission Gas Turbine Operated on Hydrogen , 2006 .

[12]  Thomas Sattelmayer,et al.  Lean Blowout Limit and NOx-Production of a Premixed Sub-ppm NOx Burner With Periodic Flue Gas Recirculation , 2004 .

[13]  K. Hatori,et al.  Hydrogen combustion test in a small gas turbine , 1981 .

[14]  A. Lefebvre.  Gas Turbine Combustion , 1983 .

[15]  J. Wunning,et al.  Flameless oxidation to reduce thermal no-formation , 1997 .

[16]  G. S. Samuelsen,et al.  Fuel Injection and Emissions Characteristics of a Commercial Microturbine Generator , 2004 .

[17]  J. De Ruyck,et al.  NO formation rates for hydrogen combustion in stirred reactors , 2001 .

[18]  T. Turányi,et al.  An investigation of important gas-phase reactions of nitrogenous species from the simulation of experimental measurements in combustion systems , 2001 .

[19]  Michael J. Pilling,et al.  Evaluated Kinetic Data for Combustion Modelling , 1992 .

[20]  F. Shum,et al.  Combustion performance of hydrogen in a small gas turbine combustor , 1985 .

[21]  Zhenwei Zhao,et al.  An updated comprehensive kinetic model of hydrogen combustion , 2004 .

[22]  A. Dean,et al.  O + NNH: A possible new route for NOX formation in flames , 1995 .

[23]  Yoshimichi Hino,et al.  Heat transfer improvement and NOx reduction by highly preheated air combustion , 1997 .

[24]  A. Hayhurst,et al.  Evidence for a New Way of Producing NO via NNH in Fuel-Rich Flames at Atmospheric Pressure , 1998 .

[25]  M. Katsuki,et al.  Chemical kinetic study on the reduction of nitric oxide in highly preheated air combustion , 2002 .

[26]  Y. Neumeier,et al.  Ultra Low Emissions Combustor with Non-Premixed Reactants Injection , 2005 .