Wyniki wyszukiwania - Biblioteka Nauki

1

Enthalpy of isopropanol adsorption on zeolite

100%

Jabłoński M. , Dzienisz A. , Sawicka M. , Wróblewska E. , Lubkowski K. , Dąbrowska G. , Piz M. , Sreńscek-Nazzal J.

Polish Journal of Chemical Technology

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2019

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tom Vol. 21, nr 4

58--65

EN

The enthalpy of isopropanol adsorption on ZSM-5 (Zeolite Socony Mobil Framework Type MFI) was determined by the static adsorption method at the temperature range from 20°C to 100°C. Langmuir and Huttig models of equilibrium adsorption have been used to calculate the enthalpy of isopropanol adsorption at these conditions. Adsorption isotherms determined by the flow method at 20°C and 30°C have been also used in the calculations. The obtained values of isopropanol adsorption enthalpy were compared with the values of isopropanol evaporation enthalpy and with the results obtained from isopropanol and water desorption measurements with thermogravimetry and differential scanning calorimetry methods.

2

Effect of hydrothermal treatment on the structure of an aluminosilicate polymer

100%

Melar J. , Bednarik V. , Slavik R. , Pastorek M.

Open Chemistry

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2013

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tom 11

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nr 5

782-789

EN

The effect of hydrothermal treatment on the structure of an aluminosilicate polymer prepared by a polycondensation reaction between silicate and hydroxoaluminate in alkaline aqueous solution was studied. The structural changes were investigated using X-ray diffraction analysis, Fourier-transform infrared spectroscopy, scanning electron microscopy imaging and thermogravimetric analysis. The results indicated that the amorphous aluminosilicate polymer transformed into a crystalline product during the hydrothermal treatment at 145°C. The crystalline phase was identified as a mineral of the zeolite group, most likely phillipsite. This transformation required an alkaline environment during the hydrothermal treatment. [...]

3

Dual function adsorbent-catalyst CuO-CeO2/NaX for temperature swing oxidation of benzene, toluene and xylene

100%

Urbutis A. , Kitrys S.

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nr 4

492-501

EN

A less common cyclic process of decontamination of benzene, toluene and o-xylene (BTX) using a dual function adsorbent-catalyst, referred to as the temperature swing oxidation, is introduced and discussed in this research. Preparation technique and characterization of the dual function adsorbent-catalyst CuO-CeO2/NaX are presented. The temperature swing oxidation of BTX consists of two stages: adsorption of the VOC from the stream saturating the adsorbent-catalyst at different levels and catalytic oxidation of concentrated VOC induced by raising bed temperature at different flow rates of regenerative air. The results indicate that at lower saturation levels and lower flow rates of regenerative air a complete oxidation performance is better. The highest obtained values of the overall conversion of toluene, o-xylene and benzene into CO2 and H2O were 99.3, 99.8 and 77.5%, respectively, proving that the temperature swing oxidation using a dual function adsorbent-catalyst is a promising VOC decontamination technique under properly selected operating conditions.

4

New hydrodewaxing catalysts JSC “AZKiOS” for processing of waxy oil and diesel fuel

86%

Kiseleva T. P. , Reznichenko I. D. , Tselyutina M. I. , Posokhova O. M. , Skornikova S. A.

Catalysis for Sustainable Energy

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2012

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tom 1

71-74

EN

JSC “Angarsk catalysts and organic synthesis plant” has the modern hydrodewaxing catalysts for production of the EURO diesel fuel and transformer oil. New generation of hydrodewaxing catalysts are the result of complex research. Researches of JSC “AZKiOS” performed optimization of ZSM-5 zeolite synthesis technology; the stage of promotor introduction in zeolite is performed. Increase of activity of the catalysts as a result of introduction in the promoted zeolite is established. As a result it has become possible to carry out the process at a lowered temperature, which leads to the increase in selectivity and operation cycle time.

5

The effect of electron irradiation on the optical properties of the natural armenian zeolite-clinoptilolite

86%

Yeritsyan H. , Harutiunian V. , Gevorkyan V. , Grigoryan N. , Hakhverdyan E. , Nikoghosyan S. , Sahakyan A. , Gevorgyan R. , Sargisyan H. , Keheyan Y.

Open Physics

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2005

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tom 3

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nr 4

623-635

EN

Infrared (IR) absorption and luminescence in chemically and radiation-modified natural Armenian Zeolite (clinoptilolite) samples have been studied. The luminescence was studied in 390–450 nm and 620–710 nm wavelength bands, and the IR measurements were carried out in the 400–5400 cm−1 range. It is shown that the luminescence intensity depends on the content of pure clinoptilolite in the samples and, probably on the distribution of “passive” luminescence centers over Si and Al sites that became “active” under radiation or chemical treatment. The samples of electron irradiated clinoptilolite have higher luminescence intensity than the chemically and thermally treated ones. A decrease in the intensity of IR absorption bands at 3550 cm−1 and 3650 cm−1 was found after irradiation.

6

Dielectric properties and specific conductivity of armenian natural clinoptilolite irradiated by electrons

86%

Yeritsyan H. , Sahakyan A. , Nikoghosyan S. , Harutiunian V. , Gevorkyan V. , Grigoryan N. , Hakhverdyan E. , Keheyan Y. , Gevorgyan R. , Sargisyan H.

Open Physics

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2005

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tom 3

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nr 4

610-622

EN

The results of dielectric properties and direct current specific electric conductivity measurements in Armenian natural clinoptilolite samples are presented. Electron irradiation with energy 8 MeV and thermal treatment of samples are performed to elucidate possible enhancement mechanisms of clinoptilolite parameters. The results are discussed on the basis of new point structural defects formation and recombination of initial ones in samples. It was shown that the irradiation dose of 3·1016 el/cm2 is critical for natural zeolite structural change, which is manifested by significant changes in dielectric properties and other characteristics. The samples subjected to high temperature heating after electron irradiation, in comparison with an unquenched one, have a significantly higher (about an order of magnitude) value of specific conductivity.