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Physicochemical properties and NH3-SCR catalytic performance of intercalated layered aluminosilicates

Szymaszek-Wawryca Agnieszka, Díaz Urbano, Samojeden Bogdan, Motak Monika

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 4

art. no. 171381

EN

The representative of natural layered clays, bentonite, was modified according to two routes and tested as a new catalyst for selective catalytic reduction of nitrogen oxides with ammonia (NH3-SCR). The natural acid-activated clay was ion-exchanged with Na+ or remained in H-form and pillared with metal oxides. In order to limit the number of synthesis steps, iron as an active phase was introduced simultaneously with Al2O3 during the intercalation procedure. Additionally, the samples were doped with 0.5 wt% of copper to promote low-temperature activity. It was found that the performed modifications resulted in disorganization of the ordered layered arrangement of bentonite. Nevertheless, acid activation and pillaring improved structural and textural parameters. The results of catalytic tests indicated that the samples containing Fe2O3 pillars promoted with Cu exhibited the highest NO conversion of 85% at 250°C (H-Bent-AlFe-Cu) and 75% at 300°C (Na-Bent-AlFe-Cu). What is important, activity of the protonated samples in the high-temperature region was noticeably affected by the side reaction of ammonia oxidation, correlated with the production of NO and resulting in N2O emission during the process comparing to Na-Bentonite catalysts.

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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.

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Selective catalytic reduction of NO with ammoniaat low temperature over Cu-promotedand N-modified activated carbon

Saad Marwa, Białas Anna, Grzywacz Przemysław, Czosnek Cezary, Samojeden Bogdan, Motak Monika

Chemical and Process Engineering

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2020

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Vol. 41, nr 1

59–-67

EN

Catalytic properties of activated carbons oxidized, treated with N-compounds, and promoted withcopper were studied in selective catalytic reduction NOXby ammonia (NH3-SCR). The modificationof the catalysts consisted of a series of steps (pre-oxidation of activated carbon, impregnation with urea,impregnation with copper). The physicochemical properties of the obtained samples were determinedusing X-ray diffraction, FT-IR spectroscopy, and low-temperature N2sorption. The modification withcopper improved the catalytic activity and stability of the catalysts. All the functionalized carbon dopedwith copper reached more than 90% of NO conversion and CO2did not exceed 240 ppm at 220◦C.The sample doped with 5 wt.% Cu had the maximum NO conversion of 98% at 300◦C. The maximum N2O concentration detected for the same sample was only 55 ppm, which confirmed its selectivity.

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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.