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Możliwości technologiczne ograniczenia emisji związków toksycznych z kotłów rusztowych poprzez zastosowanie technologii NewEcoTube wspartej systemami FGR oraz SPDR

Szewczyk Dariusz, Chmielewski Jan

Instal

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2020

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nr 2

16--18

PL

W niniejszym artykule omówiono najnowsze technologie umożliwiające optymalizację procesu spalania oraz redukcję emisji NOx, CO (przy zachowaniu niskiej zawartości O2 oraz NH3 ) do poziomów wymaganych przez obowiązujące dyrektywy IED [1], MCP [2] oraz opublikowane konkluzje BAT [3] dla kotłów rusztowych małej i średniej mocy. Przedstawiono również możliwości technologiczne pracujących już instalacji redukcji tlenków azotu dostarczonych przez Spółkę ICS S.A., opartych na technologii NewEcoTube wspartej przez systemy FGR oraz SPDR.

EN

This article discusses the latest technologies enabling optimization of the combustion process and reduction of NOx and CO emissions (while maintaining low O2 and NH3 content) to the levels required by the IED [1], MCP [2] directives, and the published BAT conclusions [3] for low and medium power stoker-fired coal boilers. Also, it presents technological possibilities of the already operating NOx reduction installations provided by ICS S.A. based on NewEcoTube technology and supported by FGR and SPDR systems.

2

The influence of holmium on catalytic properties of Fe or Cu-modified vermiculites

Samojeden Bogdan, Grzybek Teresa, Kowal Joanna, Szymaszek Agnieszka, Jabłońska Magdalena, Gläser Roger, Motak Monika

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1484--1495

EN

Natural layered clay, vermiculite, was modified and tested as catalyst for the selective catalytic reduction of NOx with ammonia (NH3-SCR). Its modification included the application of the blowing agent (azodicarbonamide), acid treatment and pillaring with Al2O3. Active phase (transition metals: Cu or Fe) was introduced via impregnation. The obtained materials were characterized by N2 sorption (texture), XRD (structure), DR-UV-Vis (oxidation state and aggregation of the active phase), H2-TPR (reducibility of the active phase), in situ DRIFTS (types of adsorbed species due to contact of the sample NH3) and NH3-TPD (type/strength of the acidic sites). The initial modification procedures (treatment with azodicarboamide) resulted in the increase of specific surface area of vermiculite. The introduction of transition metal ions provided a significant amount of acidic sites. The promoting impact of holmium was confirmed by the increased strength of the sites. The highest catalytic activity was exhibited by the sample Fe-containing vermiculite and doped with Ho.

3

Numerical simulation of O3 and NO reacting in a tubular flow reactor

Modliński N., Kordylewski W.K., Jakubiak M.P.

Chemical and Process Engineering

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2013

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Vol. 34, nr 3

361--373

EN

A process capable of NOx control by ozone injection gained wide attention as a possible alternative to proven post combustion technologies such as selective catalytic (and non-catalytic) reduction. The purpose of the work was to develop a numerical model of NO oxidation with O3 that would be capable of providing guidelines for process optimisation during different design stages. A Computational Fluid Dynamics code was used to simulate turbulent reacting flow. In order to reduce computation expense a 11-step global NO - O3 reaction mechanism was implemented into the code. Model performance was verified by the experiment in a tubular flow reactor for two injection nozzle configurations and for two O3/NO ratios of molar fluxe. The objective of this work was to estimate the applicability of a simplified homogeneous reaction mechanism in reactive turbulent flow simulation. Quantitative conformity was not completely satisfying for all examined cases, but the final effect of NO oxidation was predicted correctly at the reactor outlet.

4

Pilot-scale studies on NOx removal from flue gas via NO ozonation and absorption into NaOH solution

Jakubiak M.P., Kordylewski W.K.

Chemical and Process Engineering

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2012

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Vol. 33, nr 3

345-358

EN

The paper presents results of experimental studies on removal of NOx from flue gas via NO ozonation and wet scrubbing of products of NO oxidation in NaOH solutions. The experiment was conducted in a pilot plant installation supplied with flue gas from a coal-fired boiler at the flow rate 200 m3/h. The initial mole fraction of NOx,ref in flue gas was approx. 220 ppm, the molar ratio X = O3/NOref varied between 0 and 2.5. Ozone (O3 content 1-5% in oxygen) was injected into the flue gas channel before the wet scrubber. The effect of the mole ratio X, the NaOH concentration in the absorbent, the liquid-to-gas ratio (L/G) and the initial NOx concentration on the efficiency of NOx removal was examined. Two domains of the molar ratio X were distinguished in which denitrification was governed by different mechanisms: for X > 1.0 NO2 undergoes further oxidation to higher oxides being efficiently absorbed in the scrubber. At the stoichiometric conditions (X = 1) the effectiveness of NO oxidation was better than 90%. However, the effectiveness of NOx removal reached only 25%. When ozonation was intensified (X >/= 2.25) about 95% of NOx was removed from flue gas. The concentration of sodium hydroxide in the aqueous solution and the liquid-to-gas ratio in the absorber had little effect on the effectiveness of NOx removal for X > 2.

5

The effect of ozone feeding mode on the effectiveness of NO oxidation

Jakubiak M., Kordylewski W.

Chemical and Process Engineering

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2011

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Vol. 32, nr 3

229-239

EN

The influence of ozone injection mode on the effectiveness of nitrogen monoxide oxidation to nitrogen dioxide by ozone in a flow reactor was investigated experimentally in laboratory apparatus. Nitrogen monoxide was diluted to the mole fraction 100 ppm in air which served as the carrier gas flowing through the tube of the diameter D = 60 mm into which ozone was injected. The effects of a number of ozone injecting nozzles and their configuration on the effectiveness of NO oxidation were examined. In the closest vicinity from the injection site the counter-current injection mode appeared to be superior to the co-current injection mode, but in areas located further from the injection site both injection systems were almost equally effective.

6

Combined DPF+SCR systems for retrofitting in the VERT quality verification tests

Czerwinski J., Zimmerli Y., Mayer A., Bunge R., Heeb N., Lemaire J., Jauss F.

Journal of KONES

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2008

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Vol. 15, No. 3

89-101

EN

New Diesel exhaust gas aftertreatment systems, with DPF*) and deNOx (mostly SCR) inline application are very important step towards zero emission Diesel fleet. Solid quality standards of those quite complex systems are urgently necessary to enable decisions by several authorities. The Swiss Federal Office of the Environment BAFU and the Swiss Federal Roads Office ASTRA decided to support further activities of VERT to develop appropriate testing procedures and to define the quality criteria. The present report informs about the international network project VERT *) dePN (de-activation, de-contamination, disposal of particles & NOx), which was started in Nov. 2006 with the objective to introduce the SCR-, or (DPF+SCR)-systems in the VERT verification procedure. Examples of results with some investigated systems are given. The most important statements are: - the investigated combined aftertreatment systems (DPF+SCR) for dynamic engine application efficiently reduce the target emissions with deNOx-efficiency up to 92% (if operated in the right temperature window) and filtration efficiency based on particle count up to 100%, - the average NOx conversion rate at transient operation (ETC) depends strongly on the exhaust gas temperature profile and the resulting urea dosing control, - the NP filtration efficiency, which is verified at stationary engine operation is perfectly valid also at the transient operation. The present results will be confirmed in the further project activities with other systems and with different testing cycles. A special attention will be paid to the operational profiles, which are representative for low emissions zones LEZ.

7

Wpływ obecności SO2 w gazie odlotowym na budowę i właściwości katalityczne (DeNOx) montmorillonitów promowanych Mn

Grzybek T., Olszewska D.

Chemia i Inżynieria Ekologiczna

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2002

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Vol. 9, nr 5/6

589-592

PL

Modyfikowany kwasem solnym montmorillonit z Jelsowego Potoku interkalowano oligokationami cyrkonu i promowano jonami Mn2+. Zbadano wpływ obecności S02 na aktywność katalityczną tak przygotowanego katalizatora w reakcji selektywnej redukcji tlenków azotu amoniakiem (DeNOx.). Stwierdzono, że obecność ditlenku siarki prowadzi do trwałego zatruwania badanych katalizatorów, dlatego ich użycie jest możliwe w układach zawierających dwa złoża, przy czym pierwsze służy do eliminacji S02 z gazów odlotowego.

EN

Montmorillonites modified with HCl was pillared with Zr oligocations and promoted with Mn. Its catalytic activity in DeNO reaction with ammonia was determined in the presence and absence of S02. It was found that the S02 presence leads to irreversible deactivation of catalysts and thus their use is possible in two-bed systems, the first of which should remove S02 from the stack gases.

8

On the catalytic removal of nitrogen oxides.

Wojciechowska M.

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje

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1999

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Vol. 9, nr 56

55-66

EN

From the viewpoint of environmental protection there has been increasing demand for cleaner exhaust and better fuel economy. Atmospheric emissions of NOx not only have detrimental effects on human health, but also have adverse effects on the ecosystems in which we live. This review reports on progress in studies of catalytic processes to promote nitrogen oxide decomposition as well as catalytic NO reduction by some selective argents. The particular attention it is directed towards the activities of supported noble metals, transition metal oxides supported on zeolites, metal oxides and magnesium fluoride. Also the current ideas on the mechanism of catalytic reduction of nitrogen oxides are discussed.

PL

Tlenki azotu są silnie toksycznymi związkami stanowiącymi potencjalne zagrożenie dla środowiska naturalnego. Emitowane są one głównie z gazów odlotowych silników samochodowych jak i zakładów przemysłowych. Najbardziej efektownymi metodami usuwania tlenków azotu są metody katalitycznej redukcji NOx. Niniejsza praca przedstawia obecny stan badań nad katalitycznymi procesami rozkładu tlenków azotu jak i katalitycznej redukcji NO dla niestacjonarnych źródeł jego emisji. Przedyskutowano aktywności różnych katalizatorów: od metalicznych do tlenków metali przejściowych osadzonych na zeolitach, tlenkach i fluorku magnezu. Przedstawiono również aktualne poglądy na temat mechanizmu katalitycznej redukcji tlenku azotu za pomocą węglowodorów.