Relevant bibliographies by topics / Selective non-catalytic reduction (SNCR)

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  1. Journal articles
  2. Dissertations / Theses
  3. Book chapters
  4. Conference papers
  5. Reports

Academic literature on the topic 'Selective non-catalytic reduction (SNCR)'

Author: Grafiati
Published: 4 June 2021
Last updated: 1 February 2022

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Journal articles on the topic "Selective non-catalytic reduction (SNCR)"

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Xu, Bo Yan, Hai Ying Tian, Jie Yang, De Zhi Sun, and Shao Li Cai. "A System of Selective Non Catalytic Reduction of NOx for Diesel Engine." Advanced Materials Research 201-203 (February 2011): 643–46. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.643.

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SNCR (Selective Non Catalytic Reduction) system is proposed, with 40% methylamine aqueous solution as reducing agent to reduce NOx in diesel exhaust gas. The effect of injection position and volume on the reduction efficiency through the test bench is systematically researched. A three-dimensional model of a full-sized diesel SNCR system generated by CFD software FIRE is used to investigate the reduction efficiency under different temperatures. The simulated results have a good agreement with the test results, and it can be used to optimize SNCR system. The results can indicate the practical application of this technology.
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He, Fengshuo, Xiumin Yu, Yaodong Du, Zhen Shang, Zezhou Guo, Guanting Li, and Decheng Li. "Inner Selective Non-Catalytic Reduction Strategy for Nitrogen Oxides Abatement: Investigation of Ammonia Aqueous Solution Direct Injection with an SI Engine Model." Energies 12, no. 14 (July 17, 2019): 2742. http://dx.doi.org/10.3390/en12142742.

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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.
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Zhang, Qian, Rui Ma, You Ning Xu, Jun Rui Shi, and Feng Yi Guan. "Comparison and Analysis on Flue Gas Denitrification Technology in Coal Fired Boiler Retrofit." Advanced Materials Research 781-784 (September 2013): 2497–501. http://dx.doi.org/10.4028/www.scientific.net/amr.781-784.2497.

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The widely used technologies of Selective Catalytic Reduction (SCR), Non-selective Catalytic Reduction (SNCR) and hybrid SNCR-SCR for coal-fired boiler in China are reviewed. The technical characteristics of different processes and transformation methods are compared. Analysis is made about the advantages of each technology and the major problems in the retrofitting. The proposal for the corresponding problems is presented. Reference is provided for coal-fired boiler denitrification transformation in China.
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Zheng, Minggang, Yuankun Zhang, and Lei Shi. "Research on selective non-catalytic NOx reduction (SNCR) for diesel engine." International Journal of Heat and Technology 36, no. 3 (September 30, 2018): 981–86. http://dx.doi.org/10.18280/ijht.360326.

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Cao, Qing Xi, Hui Liu, Shao Hua Wu, Wen Yan Wu, Sui Ying Yu, Zhen Zhong Li, and Chun Hui Yang. "Numerical Study of Selective Non-Catalytic Reduction Process in Large Utility Boiler." Advanced Materials Research 732-733 (August 2013): 258–64. http://dx.doi.org/10.4028/www.scientific.net/amr.732-733.258.

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To provide a theoretical guidance for the application of selective non-catalytic reduction (SNCR) in a large capacity utility boiler, numerical study of SNCR process in a 600 MW utility boiler was performed based on computational fluid dynamics (CFD) code Fluent. Good agreement of the calculation results with the industrial test data confirms the reliability of the calculation model. It is found that the NO removal efficiency is low and NH3-slip is high, because the injected reducing agent could not mix with the flue gas adequately, and the furnace temperature is not uniform in utility boiler with large furnace size. Aiming at this problem, the commissioning scheme for reducing agent injection system was optimized, and CO was added together with the reducing agent. As a result, NO removal efficiency increases from 19% to 27%, and NH3-slip decreases from 59 ppm to 13 ppm.
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Buinevičius, Kestutis, and Egidijus Puida. "REDUCTION OF NOX CONCENTRATIONS IN BOILER FLUE GAS BY INJECTING SELECTIVE REAGENTS." JOURNAL OF ENVIRONMENTAL ENGINEERING AND LANDSCAPE MANAGEMENT 13, no. 2 (June 30, 2005): 91–96. http://dx.doi.org/10.3846/16486897.2005.9636851.

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Present EU regulations promote search for efficient means of reducing environmental pollution caused by fuel‐burning equipment. Primary means of NOx reduction are of a limited efficiency. The aim of this study is investigation and development of Selective Non‐Catalytic Reduction (SNCR) for NOx Control. This method can be applied in the existing boilers that have no external flue gas cleaning equipment, and that is the main advantage of the method. Experimental investigation of the influence of various reagent solutions on NOx concentration was carried out in a stand simulating a boiler furnace. Reagents and their operation conditions were selected, desirable efficiency of SNCR method was determined. The experimental results indicated positive application perspectives of this method. Reduction of NOx concentration by 40 % was reached. It was determined that improperly selected SNCR technology can even increase NOx concentration.
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Wielgosiński, Grzegorz, Justyna Czerwińska, Olga Szymańska, and Janusz Bujak. "Simultaneous NOx and Dioxin Removal in the SNCR Process." Sustainability 12, no. 14 (July 17, 2020): 5766. http://dx.doi.org/10.3390/su12145766.

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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.
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Blejchař, Tomáš, Jaroslav Konvička, Bernd von der Heide, Rostislav Malý, and Miloš Maier. "High Temperature Modification of SNCR Technology and its Impact on NOx Removal Process." EPJ Web of Conferences 180 (2018): 02009. http://dx.doi.org/10.1051/epjconf/201818002009.

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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.
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Park, Poong-Mo, Young-Kwon Park, and Jong-In Dong. "Reaction Characteristics of NOx and N2O in Selective Non-Catalytic Reduction Using Various Reducing Agents and Additives." Atmosphere 12, no. 9 (September 13, 2021): 1175. http://dx.doi.org/10.3390/atmos12091175.

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Artificial nitrogen oxide (NOx) emissions due to the combustion of fossil fuels constitute more than 75% of the total NOx emissions. Given the continuous reinforcement of NOx emission standards worldwide, the development of environmentally and economically friendly NOx reduction techniques has attracted much attention. This study investigates the selective non-catalytic reduction (SNCR) of NOx by methane, ammonia, and urea in the presence of sodium carbonate and methanol and the concomitant generation of N2O. In addition, the SNCR mechanism is explored using a chemical modeling software (CHEMKIN III). Under optimal conditions, NOx reduction efficiencies of 80–85%, 66–68%, and 32–34% are achieved for ammonia, urea, and methane, respectively. The N2O levels generated using methane (18–21 ppm) were significantly lower than those generated using urea and ammonia. Addition of sodium carbonate and methanol increased the NOx reduction efficiency by methane to ≥40% and 60%, respectively. For the former, the N2O level and reaction temperature further decreased to 2–3 ppm and 850–900 °C, respectively. The experimental results were well consistent with simulations, and the minor discrepancies were attributed to microscopic variables. Thus, our work provides essential guidelines for selecting the best available NOx control technology.
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Krawczyk, Piotr. "Experimental investigation of N2O formation in selective non-catalytic NOx reduction processes performed in stoker boiler." Polish Journal of Chemical Technology 18, no. 4 (December 1, 2016): 104–9. http://dx.doi.org/10.1515/pjct-2016-0078.

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Abstract Stoker fired boiler plants are common throughout Eastern Europe. Increasingly strict emission standards will require application of secondary NOx abatement systems on such boilers. Yet operation of such systems, in addition to reducing NOx emissions, may also lead to emission of undesirable substances, for example N2O. This paper presents results of experimental tests concerning N2O formation in the selective non-catalytic NOx emission reduction process (SNCR) in a stoker boiler (WR 25 type). Obtained results lead to an unambiguous conclusion that there is a dependency between the NOx and N2O concentrations in the exhaust gas when SNCR process is carried out in a coal-fired stoker boiler. Fulfilling new emission standards in the analysed equipment will require 40–50% reduction of NOx concentration. It should be expected that in such a case the N2O emission will be approximately 55–60 mg/m3, with the NOx to N2O conversion factor of about 40%.
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Dissertations / Theses on the topic "Selective non-catalytic reduction (SNCR)"

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Nárovec, Jiří. "Moderní metody denitrifikace uhelných kotlů." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2015. http://www.nusl.cz/ntk/nusl-231795.

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V současnosti musí velké energetické podniky k dodržení emisních předpisů, zejména pak vyžadovaných limitů NOx, uplatňovat denitrifikační metody. Tématem předkládané diplomové práce jsou moderních denitrifikační metody a jejich praktické uplatnění v lokálních poměrech uhelného kotle s parním výkonem 640 t.h-1 v elektrárně Počerady. Práce obsahuje rešerši moderních denitrifikačních metod používaných velkými uhelnými kotli se zaměřením zejména na sekundární denitrifikační metody. Jsou uvažovány dvě možné varianty denitrifikace – varianta 1 využívá selektivní katalytickou redukci (SCR) a varianta 2 selektivní nekatalytickou redukci (SNCR) společně s nízkoemisními hořáky a stupňovaným přívodem spalovacího vzduchu. Pro výběr vhodné denitrifikační metody jsou studovány investiční náklady jednotlivých variant – nižší investiční náklady (o 19.4%) slibuje varianta 2. Při srovnávání SCR se SNCR vyšlo najevo, že investiční náklady metody SNCR jsou 5krát nižší než metody SCR. V souladu s investičními náklady, s dispozicí kotle a se složitostí jeho instalace je pro navazující studium problematiky využita varianta 2. Stěžejní část práce se zabývá stanovením optimálního tzv. teplotního okna pro konkrétní metodu SNCR. Těžištěm práce je tepelný výpočet ohniště a části deskového přehříváku pro stanovený rozsah paliv a výkon kotle v rozmezí 60-100%. S uvažováním výsledků z výpočtu jsou navrženy dvě vstřikovací roviny, které mají zaručit vysokou efektivitu denitrifikačního procesu při uvažovaných provozních podmínkách kotle. Diplomová práce rovněž diskutuje obecnou vhodnost instalace SNCR a SCR ve stávajících uhelných kotlích.
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Kozlová, Romana. "Možnosti využití popílků po SNCR pro výrobu portlandského cementu." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2016. http://www.nusl.cz/ntk/nusl-240583.

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The Master thesis deals with utilization possibilities of fly ash after selective non-catalytic reduction (SNCR) process for Portland cement preparation as a correction component to the raw material with regard to contaminated fly ash by ammonium sulphate or ammonium hydrogensulfate that is one of the products from SNCR process. Presented thesis was focused on behaviour of raw meal with ammonia hydrogensulfate contaminated fly ash after SNCR during burning of Portland clinker in simulated kiln conditions. The thesis deals with Portland clinker preparation from this kind of raw mix and it studies mainly clinker quality, clinker phases and structure. Quantitative phase composition of prepared samples of clinker was performed by optical microscopy measurements using point counting method and XRD analysis (Rietveld method). Hydration heat flow of prepared clinker was measured by Isothermal Calorimetry. TG-DTA analysis of prepared raw meal was studied due to better comparison of prepared samples and better understanding of processes during burning process.
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Timpanaro, Anthony. "Reduction of NOx Emissions in a Single Cylinder Diesel Engine Using SNCR with In-Cylinder Injection of Aqueous Urea." UNF Digital Commons, 2019. https://digitalcommons.unf.edu/etd/876.

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The subject of this study is the effect of in-cylinder selective non-catalytic reduction (SNCR) of NOx emissions in diesel exhaust gas by means of direct injection of aqueous urea ((NH2)2CO) into the combustion chamber. A single cylinder diesel test engine was modified to accept an electronically controlled secondary common rail injection system to deliver the aqueous urea directly into the cylinder during engine operation. Direct in-cylinder injection was chosen in order to ensure precise delivery of the reducing agent without the risk of any premature reactions taking place. Unlike direct in-cylinder injection of neat water, aqueous urea also works as a reducing agent by breaking down into ammonia (NH3) and Cyanuric Acid ((HOCN)3). These compounds serve as the primary reducing agents in the NOx reduction mechanism explored here. The main reducing agent, aqueous urea, was admixed with glycerol (C3H8O3) in an 80-20 ratio, by weight, to function as a lubricant for the secondary injector. The aqueous urea injection timing and duration is critical to the reduction of NOx emissions due to the dependence of SNCR NOx reduction on critical factors such as temperature, pressure, reducing agent to NOx ratio, Oxygen and radical content, residence time and NH3 slip. From scoping engine tests at loads of 40 percent and 80 percent at 1500 rpm, an aqueous urea injection strategy was developed. The final injection strategy chosen was four molar ratios, 4.0, 2.0, 1.0 and 0.5 with five varying injection timings of 60, 20, 10, 0, and -30 degrees after top dead center (ATDC). In addition to the base line and aqueous urea tests, water injection and an 80-20 water-glycerol solution reduction agent tests were also conducted to compare the effects of said additives as well. The comparison of baseline and SNCR operation was expected to show that the urea acted as a reducing agent, lowering NOx emissions up to 100% (based on exhaust stream studies) in the diesel exhaust gas without the aid of a catalyst. The data collected from the engine tests showed that the aqueous urea-glycerol solution secondary had no effect on the reduction of NOx and even resulted in an increase of up to 5% in some tests. This was due to the low average in-cylinder temperature as well as a short residence time, prohibiting the reduction reaction from taking place. The neat water and water-glycerol solution secondary injection was found to have a reduction effect of up to 59% on NOx production in the emissions due to the evaporative cooling effect and increased heat capacity of the water.
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Park, Yong Hun. "An investigation of urea decomposition and selective non-catalytic removal of nitric oxide with urea." Texas A&M University, 2004. http://hdl.handle.net/1969.1/279.

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The use of urea (NH2CONH2) to remove nitric oxide (NO) from exhaust streams was investigated using a laboratory laminar-flow reactor. The experiments used a number of gas compositions to simulate different combustion exhaust gases. The urea was injected into the gases as a urea-water solution. The decomposition processes of the urea-water solutions and urea powder were examined. For both the nitric oxide removal and the urea decomposition experiments, a Fourier transform infrared (FTIR) spectrometer was used to determine the concentrations of the product species. The products from the decomposition were examined every 50 K from 500 K to 800 K. The dominant products were ammonia (NH3), isocyanuric acid (HNCO) and carbon dioxide (CO2). In case of urea-water solution decomposition, for gas temperatures between 550 and 650 K, the highest concentrations were for NH3 and HNCO. On the other hand, the concentrations of CO2 were highest for gas temperatures of about 500 - 550 K. For temperatures above about 650 K, the amount of these three dominant prod-ucts slightly decreased as temperature increased. ivFor the nitric oxide removal (SNCR) experiments, the gas mixture was heated to temperatures between 800 K and 1350 K. Depending on the temperature, gas composition, residence time, and urea feed rate, removal levels of up to 95% were obtained. Other by-products such as N2O were detected and quantified. The effects of the urea/NO (beta) ratio were determined by varying the urea concentration for a constant NO con-centration of 330 ppm. The effects of the levels of oxygen (O2) in the exhaust gases and the residence time also were investigated. Increasing the urea/NO ratio and residence time resulted in higher NO removal and increased the temperature window of the nitric oxide removal.
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Bargagli, Dei Conti Stoffi Matilde. "Stato dell'arte e definizione di parametri progettuali per abbattitori a umido e abbattitori degli ossidi d'azoto." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.

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Il fine della presente tesi è quello di definire parametri di riferimento progettuali e di controllo sul funzionamento degli abbattitori ad umido e degli abbattitori degli ossidi di azoto dalle emissioni industriali, utili ad una valutazione preventiva del progetto di impianto ed alla gestione dello stesso, da proporre come rappresentativi dello stato dell’arte per questi abbattitori. E’ innanzitutto effettuata una breve disamina sui composti inorganici quali inquinanti atmosferici: da quali fonti deriva la loro presenza in aria, quali sono gli effetti sull’ambiente, quantificazione delle emissioni antropiche per questa categoria di inquinanti e quali obiettivi di riduzione si pone la Regione Emilia Romagna. Viene quindi affrontata una breve sintesi della legislazione nazionale e regionale necessaria a comprendere dove si innesta la necessità di definire questi parametri di riferimento, con il confronto di disposizioni normative vigenti sull’argomento a livello nazionale e delle regioni Lombardia ed Emilia Romagna per giungere infine ad una proposta aggiornata. Si passa poi ad una descrizione accurata degli abbattitori ad umido e, di seguito, degli abbattitori degli ossidi di azoto, fornendo il discrimine tra le diverse tipologie presenti sul mercato e concretamente utilizzate in campo; inoltre grazie allo studio di due impianti presenti nel territorio di Modena viene fornita una comprensione più approfondita dei parametri tecnici di progettazione e funzionamento. L’analisi ha interessato: - parametri tecnici costruttivi; - parametri di funzionamento; - efficienza di abbattimento. La proposta conclusiva rappresenta la sintesi di confronto tecnico con esperti costruttori/installatori di impianti di depurazione dell’aria, di una dettagliata analisi conoscitiva delle caratteristiche e delle rese di abbattimento di impianti autorizzati, installati e controllati, presenti nel territorio della regione Emilia Romagna.
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Wolfram, Kyle Martin. "Characterization of air to fuel ratio control and non-selective catalytic reduction on an integral compressor engine." Thesis, Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/742.

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Book chapters on the topic "Selective non-catalytic reduction (SNCR)"

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Nussbaumer, Thomas. "Selective Catalytic Reduction and Selective Non-Catalytic Reduction of Nitric Oxides for Wood Firings." In Advances in Thermochemical Biomass Conversion, 708–19. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1336-6_54.

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Pels, J. R., and M. J. F. M. Verhaak. "Selective Catalytic Reduction of Nitrous Oxide with Hydrocarbons using a SO2 Resistant Fe/zeolite Catalyst." In Non-CO2 Greenhouse Gases: Scientific Understanding, Control and Implementation, 359–64. Dordrecht: Springer Netherlands, 2000. http://dx.doi.org/10.1007/978-94-015-9343-4_57.

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Taber, Douglass F. "C–C Bond Construction: The Zhu Synthesis of Goniomitine." In Organic Synthesis. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780190646165.003.0023.

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Non-enolizable β-keto esters such as 3 are fragile and difficult to prepare. Karl J. Hale of Queen’s University Belfast devised (Org. Lett. 2013, 15, 370) soft enolization con­ditions for methoxycarbonylation of 1 with 2. Zheng Huang of the Shanghai Institute of Organic Chemistry coupled (Org. Lett. 2013, 15, 1144) 4 with 5 under Ir catalysis to make 6. Tomoya Miura and Masahiro Murakami of Kyoto University combined (Angew. Chem. Int. Ed. 2013, 52, 3883) the diazo precursor 8 with the allylic alco­hol 7 to give 9, the product of Claisen rearrangement. Tsuyoshi Satoh of the Tokyo University of Science showed (Tetrahedron Lett. 2013, 54, 2533) that the combina­tion of the carbenoid 10 with a ketone enolate 11 led to the cyclopropanol (not illus­trated). Jin Kun Cha of Wayne State University found (Org. Lett. 2013, 15, 1780) that such cyclopropanols coupled with an acid chloride 12 under Pd catalysis to give the diketone 13. Christopher J. O’Brien of Dublin City University established (Chem. Eur. J. 2013, 19, 5854) conditions for the catalytic Wittig reaction of 14 with 15 to give 16, with in situ reduction of the phosphine oxide. Amir H. Hoveyda of Boston College showed (Org. Lett. 2013, 15, 1414) that the allene of 17 underwent selective borylation, lead­ing after coupling with 18 to the triene 19. Damian W. Young of the Broad Institute demonstrated (Org. Lett. 2013, 15, 1218) that ring-closing metathesis gave the alkenyl silane 20 with high geometric control. Halogenation to give 21 could then proceed with either retention or inversion of alkene geometry. Jianwei Sun of the Hong Kong University of Science and Technology and Zigang Li of the Shenzen Graduate School of Peking University condensed (J. Am. Chem. Soc. 2013, 135, 4680) the alkyne 22 with 23 to give the trisubstituted alkene 24 with high geometric control. The condensation worked equally well with medium and large ring ethers. Hua-Jian Xu of the Hefei University of Technology combined (Org. Lett. 2013, 15, 1472) the bromo alkyne 25 with the carboxylate 26 to give the nitrile 27.
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Conference papers on the topic "Selective non-catalytic reduction (SNCR)"

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Zhang, Bo, Hongjie Xu, Xiangyu Zhang, Xiaofeng Xiang, Ning Gao, and Xu Lu. "Study on Optimization of Selective Non-Catalytic Reduction for W-Flame Boiler." In ASME 2017 Power Conference Joint With ICOPE-17 collocated with the ASME 2017 11th International Conference on Energy Sustainability, the ASME 2017 15th International Conference on Fuel Cell Science, Engineering and Technology, and the ASME 2017 Nuclear Forum. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/power-icope2017-3110.

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For the optimal design of the selective non-catalytic reduction (SNCR) for a 600MW W-flame boiler, the SNCR process was simulated through method of chemical kinetics analysis and fluid dynamics analysis. The design temperature, de-nitrification efficiency in theory, position of spray gun and other parameters were determined and 46% de-nitrification rate was finally obtained. Chemical kinetics analysis, without considering the effect of reducing agent mixed with NOx, the theoretical efficiency is higher. Fluid dynamics analysis, taking into account the effect of mass transfer, the de-nitrification efficiency is lower than the theoretical value. In practical engineering, the mixed mass transfer is an important factor affecting the efficiency of SNCR. (CSPE)
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Swanson, Larry, Wei Zhou, David Moyeda, and Christopher Samuelson. "Enhanced Selective Non-Catalytic Reduction (SNCR) for Refinery Applications: Pilot-Scale Test Data With a Hydrogen Promoter." In ASME 2011 International Mechanical Engineering Congress and Exposition. ASMEDC, 2011. http://dx.doi.org/10.1115/imece2011-62038.

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Selective non-catalytic reduction technology (SNCR) is an effective and economical method of reducing NOX emissions for a wide range of industrial combustion systems. It is widely known that the traditional SNCR temperature window is centered around 1,200 to 1,255 K [1]. However, for some applications, the flue gas temperatures in boilers, oxidizers, and heaters range from 950 to 1150 K. At these lower temperatures, injection of an amine reagent into flue gas no longer actively reduces NOX, but instead passes through the system and exits as ammonia slip. Earlier studies have shown that at lower temperatures, hydrogen and other promoters can be added to the system to shift the SNCR window to a lower temperature range, enhancing or promoting SNCR NOX reduction performance [2–5]. This extended abstract describes pilot-scale test results for an enhanced SNCR process (ESNCR) that uses hydrogen as the SNCR promoter. The impacts of flue gas temperature, hydrogen concentration, CO concentration, and SO2 concentration on ESNCR NOX reduction performance are presented.
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Sereika, Titas, Kęstutis Buinevičius, and Adolfas Jančauskas. "Comparison of NOx Emissions Decreasing Methods for Biofuel Boilers." In Environmental Engineering. VGTU Technika, 2017. http://dx.doi.org/10.3846/enviro.2017.047.

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The main idea of research is to figure out the emissions of nitrogen oxides reduction using various type of reduction methods. In experiments were used NOx reduction methods: high CO emissions generation, flue gas recirculation, water and water vapor supply, selective non-catalytic reduction (SNCR), and SNCR with flammable additive. This study presents emission and combustion results obtained burning furniture production waste which generates higher rate of NOx emissions. The result of research shows, that CO emission has the biggest impact factor -on reducing NOx emission. Burning fuel in combustion zone with first and secondary air ratio (40/60) and using methods for higher generation CO emissions reached 3.000 mg/m3 which reduces NOx emissions up to 83%. Using selective non-catalytic reduction with traditional and flammable additives reduction of NOx emissions reached up to 55%.
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Zhenzhen Guan and Dezhen Chen. "NOx removal in the selective non-catalytic reduction (SNCR) process and combined NOx and PCDD/Fs control." In 2011 IEEE Power Engineering and Automation Conference (PEAM). IEEE, 2011. http://dx.doi.org/10.1109/peam.2011.6134838.

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Koralewska, Ralf. "NOx Reduction: The Challenge for Innovative Concepts in Europe." In 19th Annual North American Waste-to-Energy Conference. ASMEDC, 2011. http://dx.doi.org/10.1115/nawtec19-5438.

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During combustion, most of the waste’s nitrogen content is transferred to the flue gases as nitrogen oxide, NOx. The EU Waste Incineration Directive defines a maximum emission limit value for NOx of 200 mg/Nm3 as a daily average value referred to 11% O2. Based on National Emission Ceilings (NEC) defined by the Gothenburg Protocol, it can be expected that the limit values for NOx in the EU will become even more stringent. In some European countries (e.g. The Netherlands, Austria, Switzerland) a lower emission limit has already been introduced. Selective Catalytic Reduction (SCR) technologies are used in many cases to achieve the above-mentioned NOx limits. However, there are drawbacks to SCR systems such as high investment cost. Operation cost is also quite high due to the energy consumption necessary for the reheating of the flue gas as well as the increased pressure loss. Innovative technologies are therefore required to make it possible to reconcile both requirements: reduced emissions and increased energy efficiency. Selective Non-Catalytic Reduction (SNCR) systems are based on the selective reaction of ammonia or urea injected into the upper furnace. In many cases SNCR technologies are limited by the ammonia slip which increases in case of more stringent NOx requirements. According to the relevant BREF document, an ammonia slip limit of 10 mg/Nm3 is generally required at the stack. In order to achieve reduced NOx values, it is necessary to implement measures to reduce ammonia slip, by means of either a wet scrubber or a High-dust catalytic converter. EfW plants in Mainz (Germany) and Brescia (Italy) are examples of operational plants combining SNCR with such a catalytic converter type. In addition R&D activities are carried out on the development of simplified reaction mechanisms to be implemented in Computational Fluid Dynamics (CFD) codes. With these tools it will be possible to describe the interaction between turbulent mixing, radiation and chemical reaction rates. Another option to achieve low NOx values (below 100 mg/Nm3) is the reduction of NOx by so-called primary measures, e.g. the Very Low NOx process (VLN), which has been developed by MARTIN jointly with its cooperation partners. The VLN process is based on a grate-based combustion system. The “VLN gas” is drawn off at the rear end of the grate and is reintroduced into the upper furnace in the vicinity of the SNCR injection positions. NOx will be reduced significantly, ensuring low NOx emission values at the stack as required, at low values for ammonia slip. The new EfW plant in Honolulu (USA) will be equipped with the VLN process. In Coburg (Germany), the VLN process will be retrofitted in an existing installation. This paper documents the potential and the limitations of different measures for NOx reduction as well as examples of recent innovative EfW plants in Europe using MARTIN technologies successfully.
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Zhou, Hao, Guiyuan Mo, and Kefa Cen. "The Large Capacity Pulverized Coal Fired Utility Boiler and the Low NOx Combustion Technology Developments in China in Response to Environmental Challenges." In ASME 2011 Power Conference collocated with JSME ICOPE 2011. ASMEDC, 2011. http://dx.doi.org/10.1115/power2011-55473.

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Large capacity pulverized coal fired utility boiler technology is in quick developments in China, hundreds of super critical boilers have been constructed in the last several years which can achieve high efficiency and low pollutants emissions. The different types of super critical boilers are introduced in this paper, they include the single-furnace with double fireball corner fired furnace, the wall fired furnace and the tower-type furnace. The low NOx combustion technologies have been widely used to face the environmental challenges. The low NOx technologies employed in pulverized-coal boilers consist of the combustion modification and post-combustion technology. The low NOx combustion modification technology includes the low NOx burner, close coupled over fire air (CCOFA) and separated over fire air (SOFA). The post-combustion technology consists of selective non-catalytic reduction (SNCR) and selective catalytic reduction (SCR) technologies. Zhejiang University develops integrated low NOx technology, including the low NOx combustion system, SNCR system and SCR system. This integrated technology can reduce the NOx emissions to be lower than 50 mg/Nm3.
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Timpanaro, Anthony, and John Nuszkowski. "Reduction of NOx in a Single Cylinder Diesel Engine Emissions Using Selective Non-Catalytic Reduction (SNCR) with In-Cylinder Injection of Aqueous Urea." In 14th International Conference on Engines & Vehicles. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2019. http://dx.doi.org/10.4271/2019-24-0144.

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8

Van Durme, Robert E. "Spray Technology is Critical in Helping a Plant Achieve Optimal Performance." In ASME 2009 Power Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/power2009-81054.

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Spray nozzles are used in several locations inside a powerplant and have intimate contact with the processes in the plant. Nozzles are used for inlet fogging, humidification, Wet and Semi-Dry FGD (Flue Gas Desulphurization) applications using open spray towers, CFB (Circulating Fluidized Bed) and SDA (Spray Dry Absorber) scrubbers, NOx using SCR (Selective Catalytic Reduction) and SNCR (Selective Non-catalytic Reduction) technologies. As plants try to achieve optimum efficiency, spray nozzles need to be designed, installed, and maintained properly. In addition, operators and designers need to be aware when a spray nozzle needs to be cleaned or replaced. A defective spray nozzle will have an adverse affect on plant performance. Several factors are to be considered in selecting the proper nozzle. These include material of construction, flowrate, spray angle, operating pressure, placement, droplet size, maximum free passage, spray angle, and many more. New developments in spray nozzle technology are allowing powerplants to have better control and achieve/maintain the tighter regulations on key emissions in the plants. Examples of nozzle type, their application, and recent installations/retrofits will be discussed.
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Sigg, Fred, Roland Halter, and Peter Chromec. "DyNOR™ DeNOx Performance Confirmed in Further MSW Plants." In 18th Annual North American Waste-to-Energy Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/nawtec18-3504.

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Von Roll Inova’s innovative new SNCR process is up to the task. This new approach takes the well known Selective non-catalytic reduction process to new heights (lows). By monitoring process conditions very closely and implementing a quick-reacting, highly precise mechanical system for distribution of the reducing agent, emissions can be limited to levels comparable to those demonstrated by SCR. Von Roll Inova’s DyNOR™ (Dynamic NOx Reduction) process takes advantage of fast and precise infrared pyrometer measurements in the exact locations where reagent is needed. Coupled with a patented distribution system, reagent injection is continuously directed to the optimal location in the furnace. The system is capable of responding to changes in a matter of seconds and thus can correct for uneven temperature profiles which are typical in combustion systems with inhomogeneous waste fuel such as MSW. Good combustion control can limit uncontrolled NOx emissions to less than 200 ppmv and forms the platform upon which secondary NOx reduction measures should build. The conventional Von Roll Inova SNCR process limits NOx emissions to 100 ppmv. DyNOR™ pushes the envelope further towards 70 ppmv NOx and less than 10 ppmv ammonia slip and closes the gap towards capital intensive catalytic systems. Long term trials at a full scale industrial installation have demonstrated emission levels well below 75 ppmv with ammonia slip below 15 ppmv. Now this process has successfully been implemented as a retrofit in a commercial unit. Results confirm that these levels can be safely achieved without compromising furnace air distribution and residence time.
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Bases, Gary J. "Water Gauge, Flue Plate Stiffeners, and Insulation Systems Design Considerations." In 11th North American Waste-to-Energy Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/nawtec11-1671.

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Tremendous money is wasted due to the lack of attention to the water gauge and flue plate stiffeners, and their impact on the insulation and lagging design. The design and installation of an insulation and lagging system will depend heavily upon the flue or duct stiffener arrangement. The stiffener arrangement is determined by many factors including the water gauge of the flue or duct plate design. The stiffener pattern and size is the first thing you consider when designing an insulation and lagging system. Therefore, it is imperative to understand how the size, shape and pattern of the external stiffeners are developed. The stiffener sizing of yesterday was based on a much lower water gauge pressure and allowed the insulation to be placed between the stiffeners without having to cut-to-fit. The stiffeners being designed today are quite large and much farther apart. This is due in part to the water gauge number being used in the design calculations and because they have not considered the required insulation thickness and application. A well designed and installed insulation and lagging system will save money and energy at a rate that is essential for an efficient plant operation. This is especially true when adding a selective catalytic reduction system (SCR) or a selective non catalytic reduction system (SNCR) to the back end of a steam-generating unit. The insulation and lagging system is critical for these air pollution systems to operate correctly.
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Reports on the topic "Selective non-catalytic reduction (SNCR)"

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Urbas, Jerry B. HYBRID SELECTIVE NON-CATALYTIC REDUCTION (SNCR)/SELECTIVE CATALYTIC REDUCTION (SCR) DEMONSTRATION FOR THE REMOVAL OF NOx FROM BOILER FLUE GASES. Office of Scientific and Technical Information (OSTI), May 1999. http://dx.doi.org/10.2172/789208.

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2

Engineering development of coal-fired high performance power systems, Phase 2: Selective non-catalytic reduction system development. Office of Scientific and Technical Information (OSTI), February 1997. http://dx.doi.org/10.2172/510672.

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