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Show SECOND GENERATION ADVANCED REBURNING FOR HIGH EFFICIENCY NOx CONTROL Vladimir M. Zamansky·, Loc Ho, Peter M. Maly and W. Randall Seeker Energy and Environmental Research Corporation 18 Mason, Irvine, CA 92718 Phone: (714) 859-8851; Fax: (714) 859-3194 E-mail: 75113.2675@compuserve.com ABSTRACT Energy and Envirorurental Research Corporation (EER) is developing a family of high efficiency and low cost NOx control technologies for coal fired utility boilers based on Advanced Rebuming (AR), an integration of conventional reburning with injection of a nitrogen agent (N-agent) for enhanced NOx control. The second generation systems incorporate two improvements over conventional AR: • N -agent Promotion There are additives which considerably enhance the NOx control from N-agent injection. These promoters are water soluble inorganic salts which can be added to aqueous nitrogen agents. • N-agent Injection into the Reburning Zone In conventional AR, the N-agent is injected along with the overfire air. However, the N-agent can also be injected into the reburning zone. This allows two stages of N-agent injection for deeper NOx control. Experimental and kinetic modeling results on integrating these improvements with AR are presented. These results show that NOx control can be increased to over 90%. These second generation AR systems are intended for post-RACf applications in ozone non-attainment areas where NOx control in excess of 80% is required. INTRODUCTION Reburning, a fuel staging method for NOx control, was suggested by Wendt et al. [1]. This is a three stage trethod which involves combustion of a fuel in two stages. In the main combustion zone 80-90% of the fuel is burned with a nonnal amount of air (about 10% excess). The combustion process fonns a definite amount of NOx' Then, in the second stage. the rest of the fuel (reburning fuel) is added at temperatures of about 1400-1700K into the secondary combustion zone, called the reburning zone, to maintain a fuel-rich envirorurent. In a specific range of conditions (stoichiometric * Corresponding author |