METHANE de-NOX FOR UTILITY PC BOILERS

Abstract

The project seeks to develop and validate a new pulverized coal combustion system to reduce utility PC boiler NO x emissions to 0.15 lb/million Btu or less without post-combustion flue gas cleaning. Work during previous reporting periods completed the design, installation, shakedown and initial PRB coal testing of a 3-million Btu/h pilot system at BBP's Pilot-Scale Combustion Facility (PSCF) in Worcester, MA. Based on these results, modifications to the gas-fired preheat combustor and PC burner were defined, along with a modified testing plan and schedule.During the current reporting period, a revised subcontract was executed with BBP to reflect changes in the pilot testing program. Modeling activities were continued to develop and verify revised design approaches for both the Preheat gas combustor and PC burner. Reactivation of the pilot test system was begun with BBP personnel. A presentation on the project results to date was given at the NETL-sponsored 2002 Conference on SCR and SNCR for NOx Control on May 15-16, 2002 in Pittsburgh PA. EXECUTIVE SUMMARY Project Objectives:The overall project objective is the development and validation of an innovative combustion system, based on a novel coal preheating concept prior to combustion, that can reduce NO x emissions to 0.15 lb/million Btu or less on utility pulverized coal (PC) boilers. This NO x reduction should be achieved without loss of boiler efficiency or operating stability, and at more than 25% lower levelized cost than state-of-the-art SCR technology. A further objective is to make this technology ready for full-scale commercial deployment in order to meet an anticipated market demand for NO x reduction technologies resulting from the EPA's NO x SIP call.

Numerical and Experimental Study on Preheating Burner Characteristics for Peak Shaving

“…Preheating is a cost-effective low-NO x combustion method. In the 1980s, the All-Russian Research Institute of Thermal Engineering [16] proposed, for the first time, a method of natural gas preheating in combination with the air staged combustion technology, which divides the pulverized coal combustion process into three zones: pyrolysis, reduction, and combustion zones. When the preheating temperature reaches 1000 K, NO x emission is reduced by 80% to 138 mg/Nm 3 at 6% O 2 .…”

Experimental Investigation on NOx Reduction Potential of Gas-Fired Coal Preheating Technology

“…A gas-fired coal preheating (GFCP) method is that a pulverized coal (PC) stream enters the chamber where flue gas from gas combustion is used to heat the PC stream to high temperature before coal combustion. The GFCP method developed for utility PC boilers by the All-Russian Thermal Engineering Institute (VTI) has been verified to be an effective de-NO x method. − This approach also increases the degree of the freedom of NO x control strategies, since it can be used with conventional combustion de-NO x techniques such as air staging, low NO x burner, reburning, and moderate and intensive low-oxygen dilution (MILD).…”