General Electric Company

Stephen L Hung

Kenneth W Beebe

Martin B Cutrone

David Joseph Najewicz

Raul Eduardo Ayala

Alan S Feitelberg

The ammonia content of fuel gas in an IGCC power generation system is reduced through ammonia decomposition, thereby reducing the NO.sub.x emissions from the plant. The power generation system includes a gasifier, a gas turbine and at least one catalytic reactor arranged between the gasifier and the gas turbine. The catalytic reactor may be either a three stage or two stage device. The three stage reactor includes a first catalyst which promotes water-gas-shift, a second catalyst which promotes CO methanation, and a third catalyst which promotes ammonia decomposition. The two stage reactor includes a first catalyst which promotes water-gas-shift and CO methanation and a second catalyst which promotes ammonia decomposition. The plural catalytic stages may be disposed in a single vessel or successively disposed in individual vessels, and the catalysts may be in a pelletized form or coated on honeycomb structures. Alternatively, fluidized bed reactors may be used. The reactions are carried out either adiabatically or non-adiabatically. Heat from the water-gas-shift and CO methanation reactions may be used to generate steam, which can be injected downstream or sent to a steam turbine. Preferably, a second catalytic reactor is provided in parallel with the first reactor so that the two reactors can alternately receive fuel gas from the gasifier.

Staged catalytic ammonia decomposition in integrated gasification

A combustor for a gas turbine includes a diffusion flame combustion zone, a catalytic combustion zone and a post-catalytic combustion zone. At start-up or low-load levels, fuel and compressor discharge air are supplied to the diffusion flame combustion zone to provide combustion products for the turbine. At mid-range operating conditions, the products of combustion from the diffusion flame combustion zone are mixed with additional hydrocarbon fuel for combustion in the presence of a catalyst in the catalytic combustion zone. Because the fuel/air mixture in the catalytic reactor bed is lean, the combustion reaction temperature is too low to produce thermal NO.sub.x. Under high-load conditions, a lean direct injection of fuel/air is provided in a post-catalytic combustion zone where auto ignition occurs with the reactions going to completion in the transition between the combustor and turbine section. In the post-catalytic combustion zone, the combustion temperature is low and the residence time in the transition piece is short, hence minimizing thermal NO.sub.x.

Catalytic combustor with lean direct injection of gas fuel for low

This invention relates to the catalytic reduction of nitrogen monoxide (NO) from highly oxidizing environments. Such catalytic reductions of this type employ the use of small quantities of methane (CH.sub.4) to provide a selective catalytic reduction (SCR) of the NO.

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Waterford, NY, United States of America

Stephen L Hung