Selective Non-catalytic Reduction Technology Research Articles

The reaction characteristics and mechanism of polymer non-catalytic reduction (PNCR) for NOx removal

To overcome the defects of the traditional selective non-catalytic reduction (SNCR) process (e.g., low efficiency, narrow temperature range), a new modified SNCR technology based on the solid complex polymer reducing agents, also called polymer non-catalytic reduction (PNCR), was investigated both in the laboratory and pilot scale to reveal its reaction characteristics and mechanism. The PNCR process demonstrates excellent removal efficiency (about 90%) of NO in furnace in the wide temperature range (850–1150 °C), and possesses promising application feasibility with an average NOx emission concentration of 68.72 mg·m−3 even on unstable industrial operating conditions. The NO removal behaviors influenced by O2, temperature, or water steam illuminate the unique O2-independent and H2O-promoted reaction characteristics of PNCR in the wide temperature range. The thermogravimetric infrared spectra/mass spectrometry (TG-IR/MS) results further reveal a pyrolysis-assisted formation mechanism of active NH2/NH free radicals without the requirement of O2 and high temperature, which avoids the overoxidation of active radicals and accounts for the wide denitrification temperature window, low oxygen compliance and high denitrification efficiency of PNCR process. The excellent NO removal performance as well as the unique reaction characteristics/mechanism of PNCR forebode its broad industrial application prospect in the field of flue gas cleaning.

Research of coupling technologies on NOx reduction in a municipal solid waste incinerator

The controlling of NOx emission remains the focus and motivates research in municipal solid waste incineration nowadays. The denitrification process in municipal solid waste incinerator based on coupling technologies of flue gas recirculation, over-fired air and selective non-catalytic reduction were conducted by numerical simulation in this work. The effects of different flue gas recirculation ratios, two paths of applying flue gas recirculation and application of coupling technologies on NOx emission and combustion characteristics were studied. The results indicated approximately 23.54% of initial NOx was reduced with flue gas recirculation ratio of 20% (injected through path 1), and the boiler efficiency was increased gradually from 80.16% to 83.78 %, as the flue gas recirculation ratio increased from 13% to 20%. The improvement of NOx removal efficiency was maintained at about 16% when flue gas recirculation ratio was 13% to 20% (injected through path 2). Moreover, the NOx removal efficiency was 33.68% when selective non-catalytic reduction technology was applied separately but increased by 13.51% when over-fired air technology was combined. With coupling technologies applied, the total NOx removal efficiency reached the highest of 76.48%, indicating flue gas recirculation coupling with over-fired air and selective non-catalytic reduction technologies is feasible to achieve lower NOx emission in municipal solid waste incineration.

Simultaneous NOx and Dioxin Removal in the SNCR Process

Nitrogen oxides, polychlorinated dibenzo-p-dioxins, and polychlorinated dibenzofurans are pollutants formed during thermal processes, in particular during the combustion of various fuels, including waste. They are classified as dangerous and highly toxic environmental pollutants whose emissions are strictly regulated. Many methods for reducing their emissions are known, but all involve additional production costs. For this reason, effective and cheap methods for removing these pollutants from exhaust gases are still sought. Selective non-catalytic reduction of nitrogen oxides is one of the more effective and cheaper methods for reducing these emissions. However, an alternative to expensive methods for dioxin and furan removal (catalysis, adsorption, etc.) may include using dioxin synthesis inhibitors. The authors propose a method for the simultaneous removal of both pollutants from flue gases using selective non-catalytic reduction technologies with dioxin synthesis inhibitors used as reducing agents.

Numerical Study on the Denitrification Efficiency of Selective Noncatalytic Reduction Technology in Decomposing Furnace

In order to reduce the nitrogen oxide emission of cement plant, the denitrification of decomposing furnace is studied in this paper. Based on Fluent software platform, the 2500 t/d new dry-process cement kiln decomposing furnace of a plant is modeled and simulated by using air fractional combustion technology combined with selective noncatalytic reduction technology. The model and simulation methods are verified by the field test. The effects of the urea injection position and ammonia-nitrogen molar ratio on NO, NH3, and denitrification efficiency are studied by numerical simulation. The results show that the optimal injection position of the urea solution is 12 m, the optimal ammonia/nitrogen molar ratio is 1.8, and the optimal injection velocity of the urea solution is 40 m/s. The simulation results obtained under the optimal parameters are as follows: NO concentration is 187.60 mg/m3, NH3 escape is 32.40 mg/m3, and denitrification efficiency is 74.75%.

Modeling of SNCR denitration system based on adaptive weight particle swarm optimization

In view of the improvement of NOX emission control requirements for coal-fired units, traditional PID controllers have been unable to effectively control large delay, large inertia, nonlinear, time-varying SNCR denitration systems, and most advanced control algorithms are often object-based models. Therefore, a model of SNCR denitration system based on adaptive weight particle swarm optimization algorithm is established. A 2×200MW heating steam turbine generator set equipped with a 2×705t/h circulating fluidized bed boiler was used as the test unit, and the selective non-catalytic reduction technology denitration system was analysed. The particle swarm optimization algorithm with adaptive weights was used to model the relationship between the urea flow rate and the NOX concentration at the chimney outlet of the SNCR denitration system under working conditions of 140 MW, 170 MW and 200 MW, respectively, to provide a process for the automatic control of the SNCR denitration systemmodel. Apply the actual data from the field to verify the model. The results show that the error between the output of the model and the actual operational data is within the allowable range, which verifies the validity of the model. This result opens up a new path for the particle swarm optimization algorithm to model the SNCR denitration process, and promotes the application of intelligent algorithms in other industrial processes.

Field test of SNCRDeNOxtechnology in building ceramic industry and the process optimization

Ceramic industry accounts for considerable amount of NOx emission of industrial sources in China. With stricter air protection act imposed by the Chinese government, many ceramic plants have to install deNOx devices. Among all the de-NOx technologies, selective non-catalytic reduction (SNCR) is barely used in the NOx burning area process-control. In this study, a number of first-hand data focusing on burning area NOx control by using SNCR technology of ceramic roller-hearth kiln were shared, the spraying rate, temperature range, the quantity and arrangement mode of spray guns were studied.Besides, a continuous experiment was carried out. When the spraying rate was 60 L/min, the temperature range was 900-950 °C, and two spray guns were used and arranged as opposite spraying mode, the NOx concentration after purification kept below 25 mg/m3, the removal efficiency was steadily higher than 40% with the average about 50%, and the ammonia escape met relevanttechnical specification.

Application of A High Efficiency Composite Denitration Agent in Ceramic Roller Kiln Flue Gas Treatment: A Case Study

With the increasing stringent environment pollution emission standards, the ceramic industry is facing a great challenge of NOx control. The research and application of highly efficiency deNOx technologies for ceramic roller kiln are benefit both to ceramic industry and environmental protection. Selective non-catalytic reduction (SNCR) is among the leading edge of the hotspot of NOx control. However, most of the reported investigations were laboratory scale study, which were limited to representing the performance of SNCR denitration agent at real application. In this study, we compared the performance of a self-made denitration agent with traditional ones, and the effect of spraying rate and position on NOx removal efficiency were investigated at a 20000 m2/h ceramic product line. Besides, a continuous experiment was carried out. By the work conducted in a real gas, a number of first-hand data focusing on SNCR technology for deNOx of ceramic roller kiln and its possibility of coupling with existed wet absorption process were shared in this paper.

Inner Selective Non-Catalytic Reduction Strategy for Nitrogen Oxides Abatement: Investigation of Ammonia Aqueous Solution Direct Injection with an SI Engine Model

This study contributes to a method based on an aqueous solution of ammonia direct injection for NOx emissions control from internal combustion engines. Many previously published studies about deNOx technology are based on selective catalytic reduction (SCR), but only few deal with inner selective non-catalytic reduction (inner SNCR) technology, which is an intensive improvement of selective non-catalytic reduction (SNCR) applied in the in-cylinder purification procedure. Before numerical calculations were carried out, the computational fluid dynamic (CFD) simulation model was validated with steady-state experimental results. The main results revealed that with the increasing concentration of aqueous solution of ammonia, nitrogen oxides gradually decrease, and the largest decline of NOx is 65.1% with little loss of cylinder peak pressure. Unburned hydrocarbon (UHC) and carbon monoxide (CO) may increase using inner SNCR, and soot emissions show a decreased tendency. However, there is little change when ammonia content varies. Ulteriorly, refining the direct injection phase is of great help to inner SNCR technology to enhance the reduction of NOx and reduce NH3 oxidation and NH3 slipping.

High Temperature Modification of SNCR Technology and its Impact on NOx Removal Process

SNCR (Selective non-catalytic reduction) Technology is currently being used to reach the emission limit for nitrogen oxides at fossil fuel fired power plant and/or heating plant and optimum temperature for SNCR process is in range 850 - 1050°C. Modified SNCR technology is able to reach reduction 60% of nitrogen oxides at temperature up to 1250°C. So the technology can also be installed where the flue gas temperature is too high in combustion chamber. Modified SNCR was tested using generally known SNCR chemistry implemented in CFD (Computation fluid dynamics) code. CFD model was focused on detail simulation of reagent injection and influence of flue gas temperature. Than CFD simulation was compared with operating data of boiler where the modified SNCR technology is installed. By comparing the experiment results with the model, the effect on nitrous oxides removal process and temperature of flue gas at the injection region.

NOx removal by NH3 and flammable additives in the selective non-catalytic reduction (SNCR) process

Reducing nitrogen oxides (NOx) emissions is becoming much more difficult and expensive for stricter environmental requirements. NOx emission restriction could not be achieved only by primary NOx reduction methods. This paper presents results of experimental research work of NOx removal by selective non-catalytic reduction (SNCR) technology. Experiments were performed in the temperature range of 1000–1200 oC to investigate the effects of additives (NH3, CH4, C2H2 and mixture of C3H8/C4H10). Comparing additives effects of NOx reduction while burning furniture production waste received that with NH3 additive reduces 56% of primary NOx. Flammable additives can reduce up to 76 % NOx emissions in exhaust gasses. Results showed that SNCR technology with flammable additives can change traditional NOx reduction additives and this technology can be easily installed in existing boilers.DOI: http://dx.doi.org/10.5755/j01.mech.23.5.16331

Coupling sorghum biomass and wheat straw to minimise the environmental impact of bioenergy production

The reform of the European sugar market in 2006 paved the way for the development of new agricultural value chains in the Po Valley (Italy). A value chain based on the use of biomass sorghum (Sorghum bicolor (L.) Moench) to produce electricity in a medium-scale power plant was investigated. A Life Cycle Assessment was carried out to explore the environmental impact and energy performance of power generation from three biomass sorghum genotypes characterized by different earliness (early, medium-late and late) in the Po Valley (Italy). To fully cover the plant needs, sorghum was complemented by winter wheat straw. Productivity and losses of sorghum for the past 39 years as simulated in Serra et al. (2017) were used to produce a probability distribution of environmental impacts. Soil organic carbon change relative to the straw removal and sorghum incorporation in soil as well as indirect land use change CO2 emissions for the substitution of sugar crops with energy crops were also accounted for. To test the influence of the assumptions an extensive sensitivity analysis over several parameters was performed. The lowest average GHG emissions (68.9 g CO2eq.MJ−1) were achieved with the late genotype while medium-late and early genotypes emitted 73.5 g CO2eq. MJ−1 and 76.8 g CO2eq.MJ−1, respectively. Despite the conservative assumptions, the bioenergy system contributed on average 47.7% less GHG than a natural gas power plant. In the lowest productivity years the sorghum based energy system emitted 52% less GHG than the Italian electricity mix.Overall, when harvesting and bailing failed due to unfavourable weather conditions, the lowest GHG emissions were found, thanks to the increased replacement of sorghum with straw. In fact, soil incorporation of sorghum biomass resulted in more nutrients added to the soil than with incorporation of wheat straw. Considering that GHG emissions decreased linearly when sorghum biomass yield increased, the highest reductions of GHG were found with late genotypes, that produced the highest yields. The lowest GHG emissions were found when harvesting failed, as the fertilizer debit of straw is lower than the fertilizer credit of sorghum. However, since carbon and nutrients storage in the soil is not rewarded monetarily, this option will not correspond to an optimal profit as the risk of failures are highest with late genotype.All other environmental impacts assessed were higher for the sorghum based system than for the fossil alternatives. It was found that the presence of DeNOx SNCR (Selective Non-Catalytic Reduction) technology achieved the expected mitigation of acidification potential and photochemical oxidant formation but at the expenses of an increased climate change impact, due to additional N2O emissions.

Simplified method for calculating SNCR system efficiency

SNCR (Selective Non-Catalytic Reduction) technology is aimed at reducing NOx emissions. SNCR efficiency is appropriately high only for the reaction temperature range called ‘the SNCR temperature window’. It is a narrow temperature range defined in various ways in the literature, which makes it difficult to evaluate the DeNOx system’s efficiency. Therefore, this study attempts to approximate the relationship between SNCR system efficiency and the flue gas temperature. The approximation was performed on the basis of literature data and verified using data from an experiment. Measurements were performed in a Polish boiler with a maximum continuous rating of 230 t/h. The verified, evaluated function could be used to forecast efficiency of SNCR systems in existing units that use urea or ammonia as a reagent. The approximation results are polynomial functions that depend on flue gas temperature, which fit the literature data with the coefficient of determination R2 = 0.83-0.86. Therefore, these equations could be used by the designer or operator of the boiler for preliminary determination of current SNCR system efficiency.

Potentials for Denox in Chinese Cement Industry with the Life Cycle Assessment Method

To explore NOx mitigation strategies in Chinese cement industry systematically, a material flow analysis was developed. The realistic output of cement production in China were identified and quantified. The inventory data of Chinese cement production were selected without denitration technology applications at that time. Then the life cycle impact assessment (LCIA) results were calculated with the principal of ISO 14040 and ISO 14044 of Life Cycle Assessment. The impact categories of global warming potential (GWP), acidification potential (AP), eutrophication potential (EP), photochemical oxidant formation potential (POCP), and human toxicity potential (HTP) were used to calculate environmental impact. The results showed that the NOx emission was the major environmental damages and the following was CO2 emission. This argument disagreed with the view that CO2 emission was the major contributor of environmental load. The reason is that the NOx emission is far over the international level due to few denitration technology applications. In the assumption of selective non-catalytic reduction (SNCR) technology applications, there is still large emission mitigation potential according to the target scenario analysis. The application of selective catalytic reduction (SCR) technology with higher deNOx efficiency and the roadmap of deNOx of Chinese cement industry were also discussed. The SNCR technology with the auxiliary of SCR development over the coming decades will be decisive for the roadmaps of Chinese cement industry to reach deeper NOx emission cuts.

Scenario Analysis of Denitration for Chinese Coal-Fired Power Generation

The environmental loads are made due to the natural resources and fossil fuels use and pollutants emissions by Chinese thermal power industry. To explore the realistic coal-fired power generation and its denitration strategies, the input and output of coal-fired power generation in China were identified and quantified. The scope of this paper is defined in the boundary of coal-fired electricity generation system all over China. The methodology follows the principal of ISO 14040 and ISO 14044. The functional unit is “1 kWh of electricity generated”. The inventory data of Chinese coal-fired power generation in 2009 without denitration technology applications were measured. The output data include the CO, N2O, CH4, CO2, NOx, PM and SO2 emissions. NOx emissions are the major contributor of acidification and photochemical in China. To avoid catastrophic environmental damages, the air pollution especially NOx emissions from coal-fired power plants are advised to be cut. For scenario analysis, in the assumption of 100%of selective non-catalytic reduction (SNCR) technology applications, China still has denitration potential. In the coming several decades, the SNCR technology will be decisive for the Chinese coal-fired power industry to reach deeper NOx emission reductions. However, the reduction agents of ammonia and urea usage bring ammonia slip, and extra natural resource and fossils consumption. The urea use also brings extra CO2 emissions. This limits the applications of SNCR technology to reduce NOx emissions.

Numerical Simulation on Improving NO<sub>x</sub> Reduction Efficiency of SNCR by Regulating the 3-D Temperature Field in a Furnace

The optimum temperature within the reagent injection zone is between 900 and 1150°C for the NOX reduction by SNCR (selective non-catalytic reduction) in coal-fired utility boiler furnaces. As the load and the fuel property changes, the temperature within the reagent injection zone will bias from the optimum range, which will reduces significantly the de-NOX efficiency, and consequently the applicability of SNCR technology. An idea to improve the NOX reduction efficiency of SNCR by regulating the 3-D temperature field in a furnace is proposed in this paper. In order to study the new method, Computational fluid dynamics (CFD) model of a 200 MW multi-fuel tangentially fired boiler have been developed using Fluent 6.3.26 to investigate the three-fuel combustion system of coal, blast furnace gas (BFG), and coke oven gas (COG) with an eddy-dissipation model for simulating the gas-phase combustion, and to examine the NOX reduction by SNCR using urea-water solution. The current CFD models have been validated by the experimental data obtained from the boiler for case study. The results show that, with the improved coal and air feed method, average residence time of coal particles increases 0.3s, burnout degree of pulverized coal increases 2%, the average temperature at the furnace nose decreases 61K from 1496K to 1435K, the NO emission at the exit (without SNCR) decreases 58 ppm from 528 to 470 ppm, the SNCR NO removal efficiency increases 10% from 36.1 to 46.1%. The numerical simulation results show that this combustion adjustment method based on 3-D temperature field reconstruction measuring system in a 200 MW multi-fuel tangentially fired utility boiler co-firing pulverized coal with BFG and COG is timely and effective to maintain the temperature of reagent injection zone at optimum temperature range and high NOX removal efficiency of SNCR.

Energy from Waste – Clean, efficient, renewable: Transitions in combustion efficiency and NOx control

Traditionally EfW (Energy from Waste) plants apply a reciprocating grate to combust waste fuel. An integrated steam generator recovers the heat of combustion and converts it to steam for use in a steam turbine/generator set. This is followed by an array of flue gas cleaning technologies to meet regulatory limitations.Modern combustion applies a two-step method using primary air to fuel the combustion process on the grate. This generates a complex mixture of pyrolysis gases, combustion gases and unused combustion air. The post-combustion step in the first pass of the boiler above the grate is intended to “clean up” this mixture by oxidizing unburned gases with secondary air.This paper describes modifications to the combustion process to minimize exhaust gas volumes and the generation of noxious gases and thus improving the overall thermal efficiency of the EfW plant. The resulting process can be coupled with an innovative SNCR (Selective Non-Catalytic Reduction) technology to form a clean and efficient solid waste combustion system.Measurements immediately above the grate show that gas compositions along the grate vary from 10% CO, 5% H2 and 0% O2 to essentially unused “pure” air, in good agreement with results from a mathematical model. Introducing these diverse gas compositions to the post combustion process will overwhelm its ability to process all these gas fractions in an optimal manner. Inserting an intermediate step aimed at homogenizing the mixture above the grate has shown to significantly improve the quality of combustion, allowing for optimized process parameters. These measures also resulted in reduced formation of NOx (nitrogenous oxides) due to a lower oxygen level at which the combustion process was run (2.6vol% O2,wet instead of 6.0vol% O2,wet).This reduction establishes optimal conditions for the DyNOR™ (Dynamic NOx Reduction) NOx reduction process. This innovative SNCR technology is adapted to situations typically encountered in solid fuel combustion. DyNOR™ measures temperature in small furnace segments and delivers the reducing reagent to the exact location where it is most effective. The DyNOR™ distributor reacts precisely and dynamically to rapid changes in combustion conditions, resulting in very low NOx emissions from the stack.

The energy consumption and environmental impacts of SCR technology in China

Energy and environment are drawing greater attention today, particularly with the rapid development of the economy and increase consumption of energy in China. At present, coal-fired power plants are mainly responsible for atmospheric air pollution. The selective catalytic reduction (SCR) technology is a highly effective method for NO X control. The present study identified and quantified the energy consumption and the environmental impacts of SCR system throughout the whole life cycle, including production and transportation of manufacturing materials, installation and operation of SCR technology. The analysis was conducted with the utilization of life cycle assessment (LCA) methodology which provided a quantitative basis for assessing potential improvements in the environmental performance of the system. The functional unit of the study was 5454 t NO X emission from an existing Chinese pulverized coal power plant for 1 year. The current study compared life cycle emissions from two types of de-NO X technologies, namely the SCR technology and the selective non-catalytic reduction (SNCR) technology, and the case that NO X was emitted into atmosphere directly. The results showed that the environmental impact loading resulting from SCR technology (66810 PET 2000) was smaller than that of flue gas emitted into atmosphere directly (164121 PET 2000) and SNCR technology (105225 PET 2000). More importantly, the SCR technology is much more effective at the elimination of acidification and nutrient enrichment than SNCR technology and the case that NO X emitted into atmosphere directly. This SCR technology is more friendly to the environment, and can play an important role in NO X control for coal-fired power plants as well as industrial boilers.

Design and Test of a Selective Noncatalytic Reduction (SNCR) System for Full-Scale Refinery CO Boilers To Achieve High NOxRemoval

Selective noncatalytic reduction technology (SNCR) is an effective and economical method of reducing NOx emissions from a wide range of industrial combustion systems. It is widely known that the SNCR process is primarily effective in a narrow temperature window, around 900−1000 °C, and that high CO concentrations can both shift the temperature window and limit its effectiveness. While the application of SNCR on a utility boiler is challenging because of a number of factors that can have negative impacts on SNCR NOx reduction performance, the implementation of SNCR technology on an industrial or refinery boiler has unique challenges intrinsic to these boiler designs and fuels fired. This paper describes the design and test of SNCR technology on two refinery CO boilers. The work presented consisted of (1) baseline testing, (2) process analysis, (3) computational fluid dynamics (CFD) simulations, and (4) optimization testing. A three-dimensional full-scale CFD model was constructed for the boiler and was calibrated using baseline test data to simulate the flow characteristics, temperature profile, and oxygen/combustibles distribution of the boiler. The CFD model was also used to design and optimize a reagent injection system that resulted in fast and effective distribution of the reagent in the flue gas of the boiler. The CFD model, which incorporates a reduced SNCR chemistry model, was further applied to predict NOx reduction efficiency and ammonia slip. After installation and commissioning of the SNCR system, a series of parametric optimization tests were performed on both units. The final performance tests showed that the application of SNCR technology could reduce NOx emissions by at least 50%, with less than 5 ppm of ammonia slip, at a nitrogen stichiometric ratio (NSR) of 1.5. The test results are shown in the paper for a comparison to the model predictions made during the design phase.

Experimental Study on the Effect of Urea and Additive Injection for Controlling Nitrogen Oxides Emissions

Selective noncatalytic reduction (SNCR) for nitrogen oxides (NOx) abatement, using urea (the NOxOUT process) as an N-agent was conducted experimentally on a multifunctional combustion facility. Results showed that the NOxOUT process resulted in 90.1% NO reduction at 1,273 K if the N-agent-to-NO mole ratio (NSR) varied between 1.5 and 2. Also, oxygen concentration of the inlet gas clearly impacted the process. NOx reduction was reduced by 17.1% when oxygen concentration was increased from 2.7 to 3.6%. If the concentration was increased further, decline of NOx reduction would become smooth. At the same time, ample residence time must be guaranteed, and a minimum value of 1.2 s was required for a thorough NOx reduction. The temperatures where 90% of the maximum reductions are achieved in low and high temperature zones are seen as the lower and upper limit temperature, respectively. The range between the lower and upper limit temperature is defined as a “temperature window.” Different reagents lead to different maximum reductions and the “temperature window” changes accordingly. Based on these findings, synergistic effect of additives was studied to broaden the narrow “temperature window” of SNCR. Sodium carbonate, ethanol, glycerol, and acetic acid, with a concentration of 200 ppm, respectively, were selected as additives, and the “temperature window” was broadened by 40–80 K. Different additives presented different characteristics. Sodium carbonate simultaneously broadened the “temperature window” toward low and high temperature zones and slightly compromised the maximum NOx reduction. The organic compounds mainly showed effect in low temperature zone and reduced the maximum NOx reduction by 11–14%. This investigation is performed from operating parameters to additive injection, which makes the effect of additive obvious. It is hoped that the conclusions of this work could further ascertain the NOxOUT process and make a contribution to the industrialization of the SNCR technology.

Development and Implementation of Numerical Simulation for a Selective Noncatalytic Reduction System Design

Selective noncatalytic reduction (SNCR) technology is an effective and economical method of reducing NOx emissions from a wide range of industrial combustion systems. It is widely known that the SNCR process is primarily effective in a narrow temperature window, around 1200−1255 K, and that high CO concentrations can both shift the temperature window and limit the process’ effectiveness. To ensure proper design and application of SNCR technology, it is critical to understand the flow and temperature fields, SNCR kinetics, and species concentrations in the combustion system and to design an injection system that provides good mixing and distribution of the reagent with the furnace gases. The work summarized in this article developed and incorporated a reduced SNCR chemical mechanism into a commercial computational fluid dynamics (CFD) model. Three main results are reported: (1) the reduced mechanism is validated by comparisons to a detailed mechanism using a plug-flow reactor and a perfectly stirred reactor, (2) the SNCR modeling approach with the reduced mechanism is validated by comparing the three-dimensional modeling results with test data from a pilot-scale combustion furnace, and (3) the integrated CFD modeling approach is applied to designing an SNCR system for an industrial furnace. The SNCR system was installed and has been in operation for several years. The NOx reduction and ammonia slip performance for the full-scale system agreed well with the CFD predictions.