Jr. Maughan et al., REDUCING GAS-TURBINE EMISSIONS THROUGH HYDROGEN-ENHANCED, STEAM-INJECTED COMBUSTION, Journal of engineering for gas turbines and power, 118(1), 1996, pp. 78-85
The potential for reducing emissions from gas turbines by injecting st
eam for NOx control and hydrogen for CO control is evaluated through l
aboratory-scale combustion experiments. Results showed that hydrogen a
ddition into a steam-injected diffusion combustor at hydrogen/fuel mol
ar ratios of approximately 20 percent was associated with somewhat inc
reased NOx production and reduced CO emissions. Both effects are attri
buted 20 an increase in the local stoichiometric flame temperature. Ho
wever, the decrease in CO was greater than the increase in NOx, result
ing in a net emissions benefit, or a shifting of the NOx-CO curve towa
rd the origin. Consequently, a greater range of NOx/CO emissions targe
ts could be achieved when hydrogen was available. Additional experimen
ts on premixed systems with hydrogen injection showed a significant in
crease in operability. Cost estimates for producing hydrogen with a co
nventional fired steam reformer suggested high capital costs unless am
ple steam is already available. Hence, the technology is particularly
well suited for turbines that use steam for power augmentation. Altern
ate reforming technology, such as catalytic pal tial oxidation, offers
the potential for reduced capital costs.