An engineering and economic evaluation of the methane de-NOX{sup SM} technology

The Institute of Gas Technology (IGT) and Ogden Martin Systems, Inc. (OMS) are conducting joint engineering and economic evaluation of IGT`s METHANE de-NOX{sup SM} technology for its application to new, as well as retrofit, municipal waste combustors (MWCs). It is anticipated that this new technology offers a technically and economically attractive alternative to existing selective noncatalytic reduction (SNCR) systems for new facilities, as well as in retrofit applications. Consequently, IGT and OMS are considering pursuing a long-term demonstration of this technology on an OMS MWC. The METHANE de-NOX approach was developed based on extensive full-scale MWC infurnace characterization and pilot-scale testing using simulated combustion products. The approach involves injection of natural gas, together with recirculated flue gases (for mixing), above the grate to provide oxygen-deficient combustion conditions that promote the destruction of NO{sub x} precursors, as well as NO{sub x}. Extensive pilot-scale testing, using both simulated combustion products and actual municipal waste (MW), showed that significant NO{sub x} reduction could be achieved. The results were used to define the key operating parameters for a field evaluation of the process. A full-scale METHANE de-NOX system was designed and retrofitted to a 100-ton/day Riley/Takuma mass burn system at the Olmsted County Waste-to-Energymore » facility for this field evaluation. The results of the field evaluation tests demonstrated the reduction of up to 60% in NO{sub x} emissions and up to 50% in CO emissions. Further benefits included a reduction of up to 50% in excess air requirements and boiler efficiency improvements. This paper describes the METHANE de-NOX technology and discusses the results to date of the IGT/OMS engineering and economic study. The focus is on the discussion of the benefits and drawbacks of this new technology in comparison with existing SNCR systems.« less