NOx Control Options and Integration for US Coal Fired Boilers

Abstract

This is the fourteenth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NO x control strategies and their possible impact on boiler performance for boilers firing US coals. The Electric Power Research Institute (EPRI) is providing co-funding for this program. Using the initial CFD baseline modeling of the Gavin Station and the plant corrosion maps, six boiler locations for the corrosion probes were identified and access ports have been installed. Preliminary corrosion data obtained appear consistent and believable.In situ, spectroscopic experiments at BYU reported in part last quarter were completed. New reactor tubes have been made for BYU's CCR that allow for testing smaller amounts of catalyst and thus increasing space velocity; monolith catalysts have been cut and a small reactor that can accommodate these pieces for testing is in its final stages of construction. A poisoning study on Ca-poisoned catalysts was begun this quarter. A possible site for a biomass co-firing test of the slipstream reactor was visited this quarter. The slipstream reactor at Rockport required repair and refurbishment, and will be re-started in the next quarter. This report describes the final results of an experimental project at Brown University on the fundamentals of ammonia / fly ash interactions with relevance to the operation of advanced NO x control technologies such as selective catalytic reduction. The Brown task focused on the measurement of ammonia adsorption isotherms on commercial fly ash samples subjected to a variety of treatments and on the chemistry of dry and semi-dry ammonia removal processes.iii Table of Our program contains five major technical tasks:• evaluation of Rich Reagent Injection (RRI) for in-furnace NO x control;• demonstration of RRI technologies in full-scale field tests at utility boilers;• impacts of combustion modifications (including corrosion and soot);• ammonia adsorption / removal from fly ash; and • SCR catalyst testing.To date, good progress is being made on the overall program. We have seen considerable interest from industry in the program due to our successful initial field tests of the RRI technology and the corrosion monitor.During the last three months, our accomplishments include the following:• Using the initial CFD baseline modeling of the Gavin Station and the plant corrosion maps, six boiler locations for the corrosion probes were identified and access ports have been installed.• One probe has been collecting data for more than three months and two others have been in service for more than two months; preliminary corrosion data obtained appear consistent and believable.• In situ, spectroscopic experiments at BYU reported in part last quarter were completed; the most significant finding of these investigations was a consistent indication that vanadium does not sulfate during SCR reaction in the presence of gas-phase SO 2 whil...

Industrial Experiment on NOx Reduction by Urea Solution Injection in the Fuel-Rich Zone of a 330 MW Tangentially Pulverized Coal-Fired Boiler

“…The technology of injecting reagents into the fuel-rich zone for NO x reduction has been first applied to utility boilers by the REI Company in the United States, where the technology was called rich reagent injection (RRI). 27 − 29 Based on the test of two existing cyclone-fired utility boilers equipped with over-fire air (OFA), that is, a single wall-fired 130 MW unit (B.L. England Unit 1) and an opposed wall-fired 500 MW unit (Sioux Unit 1), RRI was demonstrated to achieve 30% NO x reduction.…”

“…Through the establishment of a mechanistic model of the ammonia-injected denitrification in a high-temperature reduction zone, Lu et al found that the reaction temperature window of NO x reduction with an NH 3 reagent injected at high temperatures was from 1200 to 1600 °C and the O 2 concentration in the flow gas should be less than 1 vol %. The technology of injecting reagents into the fuel-rich zone for NO x reduction has been first applied to utility boilers by the REI Company in the United States, where the technology was called rich reagent injection (RRI). − Based on the test of two existing cyclone-fired utility boilers equipped with over-fire air (OFA), that is, a single wall-fired 130 MW unit (B.L. England Unit 1) and an opposed wall-fired 500 MW unit (Sioux Unit 1), RRI was demonstrated to achieve 30% NO x reduction.…”