Reducing Gas Turbine Emissions Through Hydrogen-Enhanced, Steam-Injected Combustion

Abstract

The Potential for reducing emissions from gas turbines by injecting steam for Nox control and hydrogen for Co control is evaluated through laboratory-scale combustion experiments. Results showed that hydrogen addition into a steam-injected diffusion combustor at hydrogen/fuel molar ratios of approximately 20 percent was associated with somewhat increased NOx production and reduced CO emissions. Both effects are attributed to an increase in the local stoichiometric flame temperature. However, the decrease in CO was greater than the increase in NOx, resulting in a net emissions benefit, or a shifting of the NOx–CO curve toward the origin. Consequently, a greater range of NOx/CO emissions targets could be achieved when hydrogen was available. Additional experiments on premixed systems with hydrogen injection showed a significant increase in operability. Cost estimates for producing hydrogen with a conventional fired steam reformer suggested high capital costs unless ample steam, is already available. Hence, the technology is particularly well suited for turbines that use steam for power augmentation. Alternate reforming technology, such as catalytic partial oxidation, offers the potential for reduced capital costs.

Hydrogen injection as additional fuel in gas turbine combustor. Evaluation of effects

“…By the other way, the use of hydrogen as only fuel [22], or the injection in small quantities to lean primary zones operating with fossil fuels [23][24][25][26][27], can reduce greatly the unburned hydrocarbons and CO emissions, and furthermore the substitution of a fossil fuel by hydrogen contributes to the reduction of CO 2 emissions and the anthropogenic greenhouse effect, because the hydrogen can be produced from renewable sources, gasification of biomass, solar insolation and water (photoelectrochemical and photochemical), or solar insolation, biological organism and water (photobiological).…”

The Effect of Discrete Pilot Hydrogen Dopant Injection on the Lean Blowout Performance of a Model Gas Turbine Combustor

“…Both will, in principle, sustain the reaction under decreasingly lean operation. The increase in OH concentrations from hydrogen doping can also enhance CO burnout rates as observed by Maughan, Bowen, and Kimura (1993).…”

Feasibility Analysis of Hydrogen as Additional Fuel in Aircraft Propulsion

“…A technological option for smooth transition from kerosene to hydrogen in aviation is the injection, as supplemental fuel of small quantities of hydrogen in a kerosene fuelled gas turbine, as it has been suggested by some previous studies (Norgren and Ingebo, 1974;Maughan et al, 1996;Juste, 2006). The use of limited quantities of hydrogen does not cause the problems associated with the use of 100% H 2 .…”