Advanced Low-NOx Cyclone Combustor Development

107 Advanced Low-NOx Cyclone Combustor Development--Energy and Environmental Research Corporation, 18 Mason Street, Irvine, CA 92618-2706; (714) 859-8851 Dr. Roy Payne, Principal Investigator Dr. Thomas J. Tyson, Business Official DOE Grant No. DE-FG03-97ER82400 Amount: $75,000 In the United States, cyclone-fired boilers represent a significant portion of the coal-fired utility boiler population. Due to the very high temperature environment of these boilers, NOx emissions which are higher than wall- or tangentially-fired boilers are generated. Due to limitations of the cyclone combustor design, which arise from the method of fuel and air injection, conventional air staging techniques cannot be used to control NOx emissions without excessive corrosion of the combustor materials. This project will develop a novel means of injecting fuel and air into an existing cyclone combustor which avoids the conventional problems associated with low excess air operation of the cyclone. The technique will use fuel and air staging that is internal to the cyclone combustor in an arrangement which promotes NOx reduction via a combination of air staging and in-situ reburning. The firing scheme will avoid fuel-rich regions near the cyclone combustor walls by taking advantage of the unique aerodynamic characteristics of cyclone flow. Phase I of this project will involve proof-of-concept testing on a small-scale cyclone combustor to demonstrate that the firing concept can reduce NOx emissions without causing corrosion of the cyclone materials and without increasing the emission of unburned carbon. This will involve the design and fabrication of a cyclone test burner, and its installation and testing. After proof-of-concept testing, a pilot-scale burner conceptual design will be prepared. The results of Phase I will be used to develop a pilot-scale combustor for further detailed evaluation in Phase II. Commercial Applications and Other Benefits as described by the awardee: If successful, this project will lead to the development of a novel technique for NOx control on cyclone-fired utility boiler systems. The technique will be easily retrofittable to existing systems, it will cost less than currently available techniques for NOx control on this type of firing system, and it will allow many cyclone boiler operators to meet NOx emissions requirements in a cost effective manner.