Wyniki wyszukiwania - BazTech

1

Development of a mechnistic model for sorption selective mixed-matrix membranes for gas separation

Kramer V., Hülagü D., Kraume M.

Czasopismo Techniczne. Mechanika

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2012

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R. 109, z. 1-M

125--135

EN

In this article a new, mechanistic model for mass transport in mixed-matrix membranes (MMM) is introduced. It was developed for sorption selective MMMs taking into account sorption characteristics, morphological parameters and operation conditions. Model structure, equations and input parameters are discussed. Investigations of different determining factors on permeability are shown for permeation of n-butane through mixed-matrix membranes made of PDMS and activated carbon. The results are compared with the Maxwell model to prove plausibility of the new concept.

PL

W artykule niniejszym wprowadzono nowy, mechaniczny model przenoszenia masy w membranach wielomatrycowych (MMM). Został on opracowany dla selektywnych MMM sorpcyjnych z uwzględnieniem charakterystyki sorpcji, parametrów morfologicznych oraz warunków pracy. W artykule omówiono strukturę modelu, równania i parametry wejściowe, a także przedstawiono badanie różnego rodzaju czynników decydujących o przenikalności w zakresie przenikania n-butanu przez membrany wielomatrycowe wykonane z PDMS i węgla aktywowanego. Aby udowodnić wykonalność nowej koncepcji, wyniki porównano z modelem Maxwella.

2

n-Butan – metoda oznaczania

Jeżewska A.

Podstawy i Metody Oceny Środowiska Pracy

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2010

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Nr 1 (63)

107--112

PL

Metoda polega na adsorpcji n-butanu na węglu modyfikowanym, desorpcji n-heksanem i analizie chromatograficznej (GC-FID) otrzymanego roztworu. Oznaczalność metody wynosi 190 mg/m3.

EN

Determination of a worker’s exposure to airborne n-butane is made by using an Anasorb CMS tube (400/200 mg sections). Samples are collected at a maximum flow rate of 1.5 L/h until a max-imum collection volume of 3 L is reached. After sampling, the Anasorb CMS tube is desorbed in n-hexane. The obtained solution is analyzed with gas chromatography (GC-FID). The working range is 190 ÷ 3800 mg/m3 for a 3-L air sample.

3

Selective Oxidation of Light Alkanes on Transition Metal Promoted Vanadyl Pyrophosphate (VPO) Catalysts

Haber J., Stoch J., Zazhigalov V. A., Bacherikova I. V., Cheburakova E. V.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 9

1839-1852

EN

Vanadyl diphosphate (Identical to vanadyl pyrophosphate) promoted with Bi, Cs, Co and Te was studied as catalyst in the oxidation of propane, n-butane and n-pentane. The additives modified the surface P/V ratio as determined by XPS, and Br?nsted and Lewis acidity, determined by TPD of ammonia and transformation of 2-methyl-3-butyn-2-ol. The specific rate of the oxidation of hydrocarbons correlated with the nucleophilicity of surface oxygenions. With in crease of Lewis acid ity the se lec tiv ity to maleic an hydride in oxidation of n-bu tane increased, whereas in oxidation of n-pentane the selectivity to phthalic an hydride increased and that to maleic an hydride decreased. The mechanism is discussed.

4

n-Butane Conversion on Differently Pretreated Supported Palladium Catalysts

Bonarowska M., Karpiński Z.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 11

1821-1828

EN

Metal-support interactions in silica- and alumina-supported palladium cata lysts have been re-investigated by using n-bu tane converion as a test reaction. High temperature reduction at 600°C results in a consider able in crease in the isomerization selectivity, i.e. a similar effect as in the case of previously studied rea tions of 2,2-dimethylpropane and C6-alkanes. There fore, changes in the selectivity for isomerization and also in the activation energy can be re garded as use ful diagnostic parameters to wards determining whether or not palladium interacts with a support.

5

Oxidative dehydrogenation of n-butane over transition metal containing hydrotalcite derived catalysts.

Kuśtrowski P., Chmielarz L., Węgrzyn A., Surman J., Dziembaj R.

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

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2002

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Vol. 10, nr 57

247-252

EN

Mg-Al layered double hydroxides containing carbonates and nitrates in theinterlayer gallery were used as parent materials for anion exchange. NO-3 and CO2-3 anions were exchanged with oxoanions containing vanadium, chromium, molybdenum and tungsten. Ion-exchange in basic solution led to introduction of V2O 4-7, CrO2-4, MoO2-4 and WO2-4 anions, while V10O286-, Cr2O2-7, Mo7O6-24 and W7O6-24 forms were intercalated in acidic solution. The intercalation was confirmed by X-ray diffraction and FTIR spectroscopy. Oxidative dehydrogenation of n-butane was carried out over hydrotalcite-derived catalysts. The catalysts obtained by thermal decompn. of V2O4-7-contg. Hydrotalcites appeared to be the most active ones in a prodn. of 1,3-butadiene. However, the highest yield of butenes was achieved over Mg-Al-Cr oxides catalyst in the low temp. range (Ł550C).