Catalytica, Inc.

Catalytica Energy Systems, Inc.

Tanaka Kikinzoku Kogyo K.k.

Other

Sarento George Nickolas

Ralph Albert Dalla Betta

David Yee

Kazunori Tsurumi

Nobuyasu Ezawa

James C Schlatter

Marco Antonio Velasco

Robert Anthony Corr, Ii

Toru Shoji

Jon McCarty

Ralph Dalla Betta

Mark A Spencer

Timothy J Caron

Walter Wiley

Fabio H Ribeiro

A control system for a catalytic combustion system on a gas turbine includes a flame preburner, a fuel injector positioned downstream of the preburner and a catalyst positioned downstream of the fuel injector. In such systems, a portion of the fuel combusts within the catalyst itself and the remainder of the fuel combusts in a homogeneous combustion process wave downstream of the catalyst. A sensor in communication with the control system monitors the homogeneous combustion process wave and adjusts the gas temperature at the catalyst inlet to a preferred value based on a predetermined schedule that relates the catalyst inlet gas temperature to operating fundamentals such as adiabatic combustion temperature or the gas turbine's exhaust gas temperature.

Control strategy for flexible catalytic combustion system

The present additional control strategy has been developed to allow the gas turbine to operate at lower load or at other conditions where the total fuel required by the gas turbine is not optimum for full combustion of the fuel. The present invention manages air that bypasses the catalytic combustor and air that bleeds off of the compressor discharge. The bypass system changes the fuel air ratio of the catalytic combustor without affecting the overall gas turbine power output. The bleed system also changes the fuel air ratio of the catalytic combustor but at the cost of reducing the overall gas turbine efficiency. The key advantage of a catalytic combustor with a bypass and bleed system and the inventive control strategy is that it can maintain the catalyst at optimum low emissions operating conditions over a wider load range than a catalytic combustor without such a system.

Design and control strategy for catalytic combustion system with a wide operating range

Methods and apparatus, both devices and systems, for control of Zeldovich (thermal) NOx production in catalytic combustion systems during combustion of liquid or gaseous fuels in the post catalytic sections of gas turbines by reducing combustion residence time in the HC zone through control of the HC Wave, principally by adjusting the catalyst inlet temperature. As the fuel/air mixture inlet temperature (to the catalyst) is reduced, the HC Wave moves downstream (longer ignition delay time), shortens the residence time at high temperature, thereby reducing thermal NOx production. The countervailing increase in CO production by longer ignition delay times can be limited by selectively locating the HC Wave so that thermal NOx is reduced while power output and low CO production is maintained. NOx is reduced to on the order of <3 ppm, and preferably <2 ppm, while CO is maintained <100 ppm, typically <50 ppm, and preferably <5-10 ppm.

Method of thermal NOx reduction in catalytic combustion systems

Methods and apparatus for control of NO in catalytic combustion systems, and more particularly to control of thermal or/and prompt NO produced during combustion of liquid or gaseous fuels in the combustor sections of catalytic combustor-type gas turbines, by controlled injection of water in liquid or vapor form at selected locations, orientations, amounts, rates, temperatures, phases, forms and manners in the compressor and combustor sections of gas turbines. The ratio of thermal NO ppm reduction to water addition, in weight %, is on the order of 4-20, with % NO reduction on the order of up to about 50-80% and NO of below 2 ppm. Liquid water, steam or superheated steam can be used to reduce NO in combustion systems operating at reaction zone temperatures above 900&deg; C., preferably 1400&deg; C. to 1700&deg; C. The amount of water added is sufficient to provide a concentration of water in the range of from about 0.1% to about 20% by weight of the total air and fuel mixture flowing into the post catalyst reaction zone. Water is introduced simultaneously or sequentially in a plurality of locations, at selected rates, amounts, temperatures, forms, and purity, preferably in accord with a suitable control algorithm.

Process and apparatus for control of NOx in catalytic combustion systems

An improved catalytic reactor for high temperature reactions having a reaction chamber and a monolithic catalyst structure disposed in the reaction chamber is disclosed wherein the catalyst structure has a multiplicity of longitudinally disposed channels formed by thin metal substrate walls which expand on exposure to the heat generated in high temperature reactions and reactor also includes a monolithic open cellular support structure disposed in the reaction chamber having a multiplicity of longitudinally disposed passageways formed by strips of high temperature resistant metal or ceramic material with the support structure being secured on its outer periphery to the wall of the reaction chamber to limit movement along the longitudinal axis, and being positioned at and abutting against the outlet end of the catalyst structure. The improved structure also includes: (a) an annular space between the outer periphery of the catalyst structure and the wall of the reaction chamber which is sized to accommodate the thermal expansion of the catalyst structure which occurs during the high temperature reaction without allowing the catalyst structure to be deformed by pressing against the reaction chamber wall; (b) a plurality of flexible flanges which extend from the outer peripheral surface of the catalyst structure to the inner surface of the reaction chamber tubular wall to substantially block the flow of reaction gas mixture through the annular space; (c) a radial centering assembly which includes cooperating struts and splines mounted on the chamber wall and the support structure to permit thermal expansion of the support structure; (d) an optional centering support structure for transferring a portion of the force from the flow of gases onto a second support structure positioned on the inlet side of the catalyst structure; and (e) an outer metal band for the support structure having slots formed therein to provide sufficient flexibility for thermal expansion of the support structure while providing additional support therefor.

Support structures for a catalyst

This invention is a catalyst structure having integral heat exchange surfaces and a method for using the structure in highly exothermic processes, such as a combustion process, while maintaining the catalyst and the structure wall at a temperature below the adiabatic combustion temperature.

Catalyst structure having integral heat exchange

This invention is a comparatively high pressure combustion process having a two stages in which a fuel is stepwise combusted using specific catalysts and catalytic structures and, optionally, having a final homogeneous combustion zone. The choice of catalysts and the use of specific structures, including those employing integral heat exchange, results in an overall catalyst structure which is stable due to its comparatively low temperature. The product combustion gas is at a temperature suitable for use in a gas turbine, furnace, boiler, or the like, but has low NO.sub.x content.

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San Jose, CA, United States of America

Sarento George Nickolas