Wyniki wyszukiwania - Biblioteka Nauki

1

Wpływ warunków preparatyki i obróbki na właściwości fizykochemiczne i katalityczne układu Ru/CeO2-Al2O3

100%

Rynkowski J. , Lewicki A. , Szynkowska M. I. , Lenik M. , Kazimierski K. K.

Zeszyty Naukowe. Chemia / Politechnika Łódzka

|

1998

|

tom Z. 46

205-217

PL

W pracy przedstawiono wyniki badań katalizatorów rutenowych naniesionych na binarne nośniki CeO2-Al2O3. Katalizatory otrzymano przez impregnację lub wytrącanie. Temperatura utleniania tlenem wynosiła 370°C. Redukcję wodorem wykonywano w temperaturze określonej przez badania temperaturowo programowanej redukcji. Badane katalizatory charakteryzowano metodami TPR, TPO, XRD. Redukcja układu RuO2/CeO2-Al2O3 ma złożony charakter. Badania TPR wskazują na przebieg redukcji RuO2 z maksymalną szybkością w temperaturze 120-145°C. Obecność rutenu przyspiesza redukcję CeO2. Badania XRD wybranych katalizatorów kalcynowanych oraz redukowanych w różnych temperaturach w zakresie 120-900°C pozwoliły na określenie składu fazowego badanych układów. Określono także wpływ temperatury na wielkość krystalitów CeO2 i naniesionego rutenu. Wykonano testy aktywności katalitycznej badanych układów w reakcji uwodornienia CO2 w zakresie temperatury 50-300°C.

EN

This work presents the results of studies on ruthenium catalysts supported on binary supports CeO2-Al2O3. The catalysts were obtained by impregnation or precipitation. The catalysts under study were characterised by TPR, TPO and XRD methods. The reduction of RuO2/CeO2-Al2O3 system is complex. The reduction of RuO2 is complete already at the low temperatures 120-145°C. Ru promotes the reduction of surface CeO2. XRD studies of chosen catalysts calcined and reduced at different temperatures in the range 120-900°C allowed to identify phase composition of the investigated systems. An influence of temperature on the size of CeO2 crystallites and ruthenium support was also determined. Catalytic activity tests of studied systems in CO2 hydrogenation reaction in temperature range 50-300°C were carried out.

2

Influence of Microstructure and Heat Transfer Surface on the Thermal Power of Cast Iron Heat Exchangers

86%

Mróz M. , Orłowicz A. W. , Tupaj M. , Lenik M. , Kawiński M. J. , Kawiński M.

Archives of Foundry Engineering

|

2021

|

tom Vol. 21, iss. 4

93--96

EN

The paper presents the results of calorimetric tests of segment elements of fireplace inserts. The aim of the work was to optimize their thermal power by replacing the previously used gray cast iron with flake graphite with gray iron with vermicular graphite and replacing the existing geometry of the heat transfer surface with a more developed one. It turned out that the thermal power of the test segments made of cast iron with vermicular graphite was higher compared to the segments of the same shape made of gray cast iron with flake graphite. It was found that the use of segments made of vermicular cast iron with a ferritic matrix allowed for an increase in the thermal power value by dozen percent, compared to segments of the same shape made of vermicular cast iron with a pearlitic matrix. The test results showed that the thermal power of the test segments depends on the variant of the development of both the heat receiving surface and the heat giving off surface. The highest value of the thermal power was obtained when ribbing in the form of a lattice was used on both of these surfaces, and the lowest when using flat surfaces.

3

The Effect of Sulphur Content on the Microstructure of Vermicular Graphite Cast Iron

86%

Mróz M. , Orłowicz A. W. , Tupaj M. , Lenik M. , Kawiński M. , Kawiński M.

Archives of Foundry Engineering

|

2022

|

tom Vol. 22, iss. 1

18--22

EN

The application of ferritic-matrix vermicular graphite cast iron in the production of fireplace fireboxes improves their thermal output, but the consumer market for these products prioritises their price. Given this consideration, this work concerns a comparison of the quality of vermicular graphite cast iron types produced from 0.025%S pig iron (a less expensive material) and 0.010%S pig iron (a more expensive material) in terms of the number and shape of vermicular graphite precipitates varying with the magnesium level in the alloy. It turned out that the vermicular graphite cast iron made with the 0.025%S pig iron demonstrated a slightly lower number of vermicular graphite precipitates. For both vermicular graphite cast iron melts, 0.028%Mg and 0.020%Mg in the alloys provided a vermicular graphite precipitate share of approx. 50% and 95%, respectively.

4

Influence of Microstructure and Heat Transfer Surface on the Thermal Power of Cast Iron Heat Exchangers

81%

Mróz M. , Orłowicz A. W. , Tupaj M. , Lenik M. , Kawiński M. , Kawiński, M.. , Mróz M. , Orłowicz A. W. , Tupaj M. , Lenik M. , Kawiński M. , Kawiński, M..

|

nr 3