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1
Content available remote Zastosowanie czynnika R600a w sprężarkowych układach chłodniczych
Dudar A.
Instal
|
2018
|
nr 7/8
25--32
PL
Artykuł zawiera informacje dotyczące izobutanu jako czynnika chłodniczego. Przedstawiono możliwości jego wykorzystania w sprężarkowych układach chłodniczych jako substytutu czynników syntetycznych. Zamieszczone zostały również jego własności fizyko-chemiczne, ekologiczne oraz użytkowe na tle klasycznych, szeroko dotychczas stosowanych, czynników chłodniczych z grupy HCFC, HFC, CFC i HFO.
EN
The article contains information on isobutane as a refrigerant. Presented are the possibilities of its use in compressor cooling systems as a substitute for synthetic refrigerants. Their physical-chemical, ecological and functional properties have also been included in comparison with the classic, widely used refrigerants from the HCFC, HFC, CFC and HFO groups.
2
Content available Numerical modelling of ejector operating with isobutane
Śmierciew K., Butrymowicz D., Gagan J., Pietrowicz S.
Zeszyty Energetyczne
|
2017
|
T. 4
51--62
EN
The rapid growth of various applications of the ejection refrigeration systems could be observed recently. Because of possibility of the application of solar or waste energy to supply the motive energy they can be thought as a real alternative to compression devices in air-conditioning technologies. Ejection system can effectively compete with absorption system under temperature of the motive heat source lower than 80°C. The paper deals with CFD numerical simulation along with experimental investigations carried out on a specially constructed prototype/stand for the case of isobutane as a working fluid under motive vapour temperature below 75°C. The numerical and experimental results of entrainment ratio were compared. A good accuracy between numerical and experimental results was observed. The divergent of the results are lower than 20% for tested series. The exemplary pressure and velocity field were presented. Also it was shown that predicted by numerical simulation pressure distribution at ejector wall fits well with experimental pressure distribution.
3
Badania eksperymentalne pracy dwufazowej pompy strumienicowej pracującej z izobutanem
Przybyliński T., Butrymowicz D., Karwacki J., Śmierciew K., Kwidziński R.
Chłodnictwo : organ Naczelnej Organizacji Technicznej
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2014
|
R. 49, nr 1
6--10
PL
W artykule przedstawiono wyniki badań eksperymentalnych pracy dwufazowej pompy strumienicowej w zastosowaniu do układów chłodniczych. Badania przeprowadzono dla strumienicy pracującej z izobutanem. W artykule przedstawiono opis stanowiska badawczego oraz wyniki eksperymentów w postaci charakterystyk pracy strumienicy oraz współczynnika wnikania ciepła.
EN
Paper deals with experimental investigation of two-phase vapour-liquid injector as a liquid pump in refrigeration systems. The experiment results for the injector are presented for the case of isobutane as working fluid. Experimental data was shown as the operation characteristics of the injector as well as heat transfer coefficient.
4
Alternatywne do R 134a czynniki proponowane jako płyny robocze w klimatyzacji samochodowej i innych instalacjach chłodniczych o małej wydajności. Część 2
Andrzejczyk R.
Technika Chłodnicza i Klimatyzacyjna
|
2012
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nr 6-7
283-288
PL
Kolejny etap „ekologicznej polityki UE” znalazł swój wyraz w dyrektywie 2006/40/EU, na mocy której we wszystkich nowo produkowanych urządzeniach chłodniczych i klimatyzacjach zastosowanie mogą mieć tylko czynniki o wskaźniku GWP nie większym niż 150. Oznacza to, że również stosowany powszechnie w motoryzacji oraz w niewielkich urządzeniach chłodniczych czynnik R134a odejdzie do historii. Proces ten trwa, bowiem wspomniana dyrektywa obowiązuje już od 1 stycznia 2011 roku. Wydawałoby się, że naturalnymi zamiennikami dla wycofywanego czynnika R134a mogą być czynniki naturalne, już obecnie szeroko stosowane w urządzeniach chłodniczych i klimatyzacyjnych, np. dwutlenek węgla (R744), propan (R290), czy izobutan (R600a). W pierwszej części artykułu („TCHK” nr 5/2012, s. 212) autor porównał właściwości obecnie proponowanych zamienników dla R134a, między innymi nowego płynu roboczego o oznaczeniu HFO-1234yf. W części drugiej przedstawił analizę efektywności energetycznej małej instalacji chłodniczej, w której zastosowano omawiane płyny niskowrzące
EN
Another stage of 'proecological strategy" in European Union is reflected by the Directive 2006l40/EU. It states that only refrigerants with GWP not higher than 150 may be used in new refrigerating and air conditioning plants. It means that very popular in mobile and other low capacity unlls R 134a wilt become a history. Statements of the Directive are valid from the 1st of January 2011. The replacement of R 134a with natural refrigerants could be possible. Fluids like carbon dioxide (R 744), propane (R 290) or isobutane (R 600a) are already videly used in refrigerating and air conditioning plants. In the first part of/he paper (.TCHKź nr 512012, p. 212)the properties of offered alternative refrigerants have been compared and the special attention is paid to the new fluid HFO-1234yf. In the second part energetic efficiency of a small refrigerating system with analysed refrigerants is compared
5
Modelowanie CFD strumienicy gazowej pracującej z izobutanem
Kołodziejczyk M., Butymrowicz D., Śmierciew K.
Technika Chłodnicza i Klimatyzacyjna
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2010
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nr 10
434-438
PL
W artykule przedstawiono wybrane zagadnienia dotyczące modelowania numerycznego strumienic stosowanych w urządzeniach chłodniczych. Publikacja stanowi kontynuację wcześniejszego cyklu artykułów opublikowanych w „TCHK” (nr 9, 10 i 12/2008), w których przedstawiono metody obliczania strumienic za pomocą modeli o parametrach skupionych. Prezentowana publikacja poświęcona jest modelom numerycznym z zastosowaniem technik CFD w odniesieniu do strumienicy gazowej pracującej z izobutanem
EN
The paper deals with chosen problems of numerical modeling of injectors used in refrigerating plants. This is the continuation of previous papers published in JCHK'(nr 9. l0,and 12/2008). In this paper the use of CFD techniques for isobutane injector modeling is presented.
6
Selective Oxidation of Isobutane and Isobutene over Hydrothermally Synthesized Mo-V-Te-Ce–O Mixed Oxide Catalyst
Guan J. Q., Wu S. J., Shao Y. Q., Ma Y. Y., Shang F. P., Yu X. F., Liu J., Kan Q. B.
Polish Journal of Chemistry
|
2009
|
Vol. 83, nr 4
605-613
EN
MoV0.3Te0.23 and MoV0.3Te0.23Ce0.2 catalysts were prepared by a hydrothermal synthesis method and tested for the oxidation of isobutane and isobutene. Characterization results (XRD, FT-IR, TPR, BET, and XPS) showed that the structure and properties of the Mo–V–Te-based catalysts are relatively different depending on the presence of Ce element. Catalytic tests showed that the selectivity to methacrylic acid can comparatively be improved by the addition of Ce into the MoV0.3Te0.23 catalyst for the selective oxidation of isobutane.
7
Preparation of Mo-V Catalysts for Selective Oxidation of Isobutane
Guan J. Q., Wu S. J., Jing S. B., Xu C., Wang Z. Q., Shang F. P., Kan Q. B.
Polish Journal of Chemistry
|
2009
|
Vol. 83, nr 10
1831-1836
EN
A series of Mo-V-O catalysts for the selective oxidation of isobutane were prepared by a hydrothermal method and by a solution reaction. The synthesis method, catalyst composition and calcination temperature have great effect on the catalytic behavior. Catalytic tests showed that MoV0.3 catalyst prepared by a hydrothermal method exhibited the best catalytic behavior. Using this catalyst 10.7 per cent selectivity to methacrolein and 15.3 per cent selectivity to methacrylic acid can be achieved at an isobutane conversion of 10.4 per cent at 380 graduate C.
8
Zeolites as the Modern Catalysts for the High Octane Gasoline Component Production
Patrylak K. I., Patrylak L. K., Ionin V. O., Voloshyna Y. G., Skubiszewska-Zięba J., Repetskyi I. A.
Polish Journal of Chemistry
|
2008
|
Vol. 82, nr 1-2
101-106
EN
Processes of isobutane with butenes alkylation with the purpose of obtaining the high octane gasoline component (alkylate), being environmentally detrimental due to use of concentrated H2SO4 or HF acids as catalysts, are nevertheless of great industrial importance supplying the world market with approximately 80 mln tons of alkylate yearly. The perspective of zeolite catalysts as the substitutes of the above concentrated acids in the modern alkylation process has been considered. The most effective today’s solid alkylation catalyst of the narrow acid spectrum has been found. Such acidity spectrum is considered to be responsible for the essential prolongation of the effective catalyst lifetime.
9
Selective Oxidation of Isobutane and Isobutene over Mo-Te Mixed Oxide Catalysts
Guan J. Q., Wu J. S., Shao Y. Q., Xu H. Y., Yang Y., Xu L., Zhen K. J., Kan Q. B.
Polish Journal of Chemistry
|
2008
|
Vol. 82, nr 8
1571-1571
EN
A series of TeMox (x = 3–6) mixed oxides were prepared and investigated for the selective oxidation of isobutane and isobutene. Both the characterization results and the catalytic properties of the samples are quite different, depending on the composition of the calcined samples. Among them, TeMo3 catalyst showed the best total selectivity to methacrolein and methacrylic acid (as high as 46%), and their yield reached 10.1% at 400°C in the selective oxidation of isobutane. How ever, TeMo4 catalyst showed the best catalytic performance in the selective oxidation of isobutene, in which 73% selectivity to methacrolein and 9% selectivity to methacrylic acid can be obtained at 77.5% isobutene conversion at 440 graduate C.
10
Oxidative Dehydrogenation of Isobutane on VOx/Oxide Support Catalysts: Effect of the Potassium Additive
Samson K., Grzybowska-Świerkosz B.
Polish Journal of Chemistry
|
2007
|
Vol. 81, nr 7
1345-1354
EN
Effect of the potassium additive on physicochemical and catalytic properties in oxidative dehydrogenation (ODH) of isobutane has been studied for a series of vanadia-based catalysts supported on different oxides (SiO2, Al2O3, TiO2, MgO). The catalysts (denoted as VS where S is a cation of a support), containing 1 or 1.5 monolayer (mnl) of V2O5 were prepared by impregnation method, characterized by BET, XPS, isopropanol decomposition (probe reaction for acido-basic properties) and tested in isobutane ODH in the temperature range 250-450_C. For all the catalysts the K additive decreased the acidity and increased the basicity, decreased the total acitivity, and increased (with the exception of VMg catalyst) the selectivity to isobutene. The increase in the selectivity was attributed to the decrease in acidity and increase in basicity of the catalysts. For VMg, different distribution of carbon oxides and different kinetic scheme were observed (dominance of CO2 formed by a consecutive path over CO formed by a parallel route) as compared with other catalysts (dominance of CO over CO2). These facts suggest, that the decrease in the selectivity to isobutene by the K additive observed for VMg catalyst is due to modification by K of other than acido-basic properties (most probably interaction of the catalysts with oxygen), which control the selectivity in this case.
11
Content available remote Odwodornienie izobutanu do izobutenu w obecności ditlenku węgla na katalizatorze wanadowym naniesionym na węgiel aktywny
Ogonowski J., Skrzyńska E.
Czasopismo Techniczne. Chemia
|
2007
|
R. 104, z. 1-Ch
117-121
PL
W niniejszym artykule przedstawiono badania dotyczące aktywności katalizatora wanadowego naniesionego na powierzchnię węgla aktywnego w reakcji odwodornienia izobutanu do izobutenu w obecności ditlenku węgla oraz w atmosferze gazu inertnego. Wyniki porównano z rezultatami reakcji Boudouarda oraz gazu wodnego, co pozwoliło stwierdzić, że badany proces przebiega zgodnie z modelem dwustopniowym.
EN
The activity of the vanadium oxide supported on active carbon catalyst was tested in the reaction of isobutane dehydrogenation reaction in the presence and absence of carbon dioxide. The data were compared with the results obtained in the Boudouard and reverse water gas shift reactions. It has been found that isobutane dehydrogenation process proceeds via two-step reaction pathway.
12
Selective Oxidation and Oxidative Dehydrogenation of Isobutane on Mo-V-Te-P Mixed Metal Oxide Catalysts
Guan J., Wang G., Jing S., Wang Z., Kan Q.
Polish Journal of Chemistry
|
2006
|
Vol. 80, nr 8
1397-1405
EN
MoV0.3Te0.23Px (x = 0-0.5) catalysts have been prepared and tested in the selective oxidation of isobutane. Among them, MoV0.3Te0.23P0.3 catalyses the direct oxidation of isobutane to methacrolein and methacrylic acid with 33% selectivity, and a total dehydrogenation (olefin plus methacrolein andmethacrylic acid) selectivity up to 63%at 400 graduate C.
13
Content available remote Odwodornienie izobutanu w obecności ditlenku węgla - analiza termodynamiczna procesu
Ogonowski J., Sikora E., Skrzyńska E.
Nafta-Gaz
|
2005
|
R. 61, nr 3
120-124
PL
W pracy przeprowadzono analizę termodynamiczną procesu odwodornienia izobutanu w obecności CO2 dla modelu stechiometrycznego obejmującego sześć reakcji liniowo niezależnych: reakcję odwodornienia izobutanu do izobutenu, reakcję gazu wodnego oraz reakcje termicznego krakingu izobutanu do niższych węglowodorów.
EN
In the work thermodynamic consideration of dehydrogenation of isobutane to isobutene in the presence of carbon dioxide was performed. Stoichiometric model established six linear independent reactions: dehydrogenation isobutane to isobutene, reverse water gas shift reactions and thermal cracking reactions of isobutane to light hydrocarbons.
14
Dehydrogenation of Isobutane to Isobutene over V2O5/gamma-Al2O3 Catalysts: Effects of the Extent of Catalyst Reduction on Catalytic Performance
Ma H., Fu Y.-H., Li Y., Wang Z. -L., Zhu W. -C., Wang G.-J.
Polish Journal of Chemistry
|
2003
|
Vol. 77 / nr 7
903-908
EN
V2O5/_-Al2O3 catalysts for the dehydrogenation of isobutane to isobutene were prepared by impregnation and characterized by BET,H2-TPR, ESR and XPS. Based on our studies of the effects of the extent of catalyst reduction on catalytic performance, we conclude that the V2O5/_-Al2O3 catalytic activity for the dehydrogenation of isobutane is related to the valence state of vanadium present in the catalyst, in the order of V4+> V3+. Furthermore, V4+ species are the main active sites of this reaction under the present reaction conditions.
15
Mg-Al hydrotalcite modified with V3+ and/or V5+ cations as precursors of catalysts for oxidative.
Węgrzyn A., Kuśtrowski P., Rafalska-Łasocha A., Dziembaj R.
Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje
|
2002
|
Vol. 10, nr 57
253-258
EN
The chemical composition of Mg-Al hydrotalcite was modified either by introduction of V3+ cations into the brucite-like sheets of double layered hydroxide or by exchange of the interlayer NO3- and CO32- anions with polyoxovanadate species. Pyrovanadate (V2O74-) and decavanadate (V10O286-) intercalated into Mg-Al hydrotalcite were obtained from the parent aqueous NH4VO3 solution by adjustment of pH to the value of 9.5 or 4.5, respectively. All the as-synthesized samples were characterized with respect to their structure by powder x-ray diffraction and IR spectroscopy. The calcined materials were used as catalysts in oxidative dehydrogenation of iso-butane performed in the excess of oxygen.
16
Effect of Potassium Modification of Structure and Reactivity of V2O5/gamma-Al2O3 for Isobutane Dehydrogenation to Isobutene
Ma H., Wang Z. -L., Zhu W. -C., Jing S. -B., Ji D. -H., Wang G.-J.
Polish Journal of Chemistry
|
2002
|
Vol. 76 / nr 12
1733-1738
EN
Undoped and K-doped V2O5/ -Al2O3 catalysts for the dehydrogenation of isobutane to isobutene were prepared by impregnation and characterized by means of BET, H2-TPR, NH3-TPD, XPS and ESR. It is found that potassium addition changes acidic and electric properties of V2O5/ -Al2O3 and results in a better spreading of V2O5 over -Al2O3 surface. Small addition of potassium toV2O5/ -Al2O3 catalyst (K:V = 0.05), consisting of 12 wt% V2O5, increased the activity and selectivity in dehydrogenation of isobutane to isobutene.
17
Oxidative dehydrogenation of isobutane on chromium oxide-titania catalysts
Grzybowska B., Słoczyński J., Grabowski R., Wcisło K., Kozłowska A., Stoch J., Serwicka E.
Polish Journal of Chemistry
|
1998
|
Vol. 72, nr 9
2159-2171
EN
Oxidative dehydrogenation of isobutane has been studied at 250 degreeC for a series of chromium oxide-TiO2 (anatase) samples containing 5-50 Cr at per nm(2) of the support surface and for pure chromia. The catalysts have been characterized by XPS, Raman, ESR spectroscopies and by probe reactions for acido-basic properties and the catalyst oxygen reactivity. The maximum activity and selectivity to isobutene have been observed for a catalyst containing 1 theoretical monolayer of the chromia phase on titania. Higher selectivity to isobutene for this catalyst as compared with unsupported chromia or catalysts with higher Cr loading has been ascribed to lower acidity and lover reactivity of oxygen.
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