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Hydroizomeryzacja długołańcuchowych węglowodorów n-parafinowych na katalizatorach dwufunkcyjnych

Fedyna M., Jaroszewska K., Masalska A., Trawczyński J.

Przemysł Chemiczny

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2017

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T. 96, nr 11

2331--2338

PL

Przedstawiono aktualny stan wiedzy na temat dwufunkcyjnych katalizatorów selektywnej hydroizomeryzacji wielkocząsteczkowych n-alkanów. Uwagę skoncentrowano na właściwościach powierzchni katalizatorów, takich jak kwasowość (moc i dystrybucja centrów kwasowych), rodzaj i stopień dyspersji fazy metalicznej oraz struktura porowata nośnika. Przedyskutowano również zagadnienie równowagi pomiędzy funkcją uwodorniająco-odwodorniającą katalizatora a jego funkcją kwasową określoną przez stosunek liczby dostępnych centrów metalicznych do liczby centrów kwasowych (cMe/cH+) oraz odległość pomiędzy centrami metalicznymi i kwasowymi (nas), które bezpośrednio decydują o aktywności i selektywności.

EN

A review, with 53 refs., of properties of bifunctional metal/ acid catalysts used for selective hydroisomerization of long-chain n-alkanes (surface acidity strength and distribution of the acid sites, type of metallic phase and its dispersion as well as support porous structure). The effect of balance between metal and acid sites and degree of their intimacy on the activity and selectivity of the catalysts was taken into consideration.

2

Glinokrzemofosforany i ich wybrane zastosowania

Łużny R., Walendziewski J.

Wiadomości Chemiczne

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2006

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[Z] 60, 1-2

47-74

EN

At the end of 20-th century B.M. Lok et al. discovered and next patented a new class of solids. They called it silicoaluminophosphates (abbreviation - SAPO) because of the chemical constitution of these molecular sieves. These new materials consist of tetrahedral units of silicon, aluminium and phosphorous oxides arranged in a manner that can be regarded as silicon substitution into hypothetical aluminophosphate (AlPO4) framework. SAPOs are prepared under mild hydrothermal conditions from gel containing precursors of phosphorous, aluminium, silicon oxide and a structure directing template (mostly amines and quaternary ammonium compounds). Unique properties of SAPO molecular sieves such as possibility of acidity control of solids in a wide range during synthesis and shape selectivity of catalyst based on silicoaluminophosphate aroused interest of scientists, who started research of the SAPO's properties, new applications and new, improved methods of synthesis of these molecular sieves. In this paper article we have described properties of silicoaluminophosphates molecular sieves, mechanism of Si incorporation into hypothetical AlPO4 framework and have described known classic methods of the SAPO's synthesis presented by Lok et al. as well as improved ("rapid" method, non-aqueous medium, with surfactant and dry gel conversion). At the end we have presented two of many possible applications . hydroisomerization of n-paraffins and synthesis of olefins using "Methanol To Olefin Process".

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Conceptual processes for zeolite membrane based hydroisomerization of light alkanes

Maloncy M. L., Gora L., Jansen J. C., Maschmeyer Th.

Ars Separatoria Acta

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2003

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No. 2

18-28

EN

A zeolite membrane reactor concept for the hydroisomerization of n-hexane was applied experimentally. The results indicate separation selectivities with factors close to 20 for n-, mono- and dibranched components in a gas mixture, as well as nhexane conversions up to equilibrium values. The research octane number calculated for the product stream of the different experiments indicates numbers as high as 85. For the hydroisomerization of C7 alkanes, a concept of two reactors and a zeolite membrane was proposed and an industrial scale process was simulated. A high octane number product containing tribranched, and a part of dibranched, C7 isomers is predicted. Although the product yield was calculated to be only 24% of the process feed, there was an improvement in a research octane number from 57 for the feed to 92 for the product. Both processes show that the application of zeolite membranes in the hydroisomerization of light alkanes can results in a octane number higher, than in the "state of the art" processes. The membrane unit, however, is the main cost driver of the processes, thus, the economical feasibility of industrial scale light alkanes hydroisomerization processes using zeolite membranes is restricted to its further commercial development.

4

Selectivity of zeolites in n-paraffins hydroisomerization process.

Walendziewski J., Pniak B., Grzechowiak J.

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

329-335

EN

The hydroisomerization of the cetane fraction of n-paraffins over a series of prepd. zeolite-based platinum catalysts was studied. The hydrocracking activity of dealuminated H-b and ZSM-5 zeolites was too high. H-mordenite, NiNaY, and SAPO-11 containing catalysts gave better isomerization selectivities.

5

Hydroconversion of cetane fraction over molybdenum catalysts.

Walendziewski J., Pniak B., Sayag C., Grzechowiak J.

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

355-360

EN

Carbonization with methane-H2 mixturure and/or hydrogen reduction of 32% MoO3/Al2O3 catalysts gives low activity isomerization catalysts of moderate selectivity, by far lower than it was found for non-supported catalysts described in literature. The main products of isomerization process in the presence of carbonized and reduced catalysts molybdenum catalysts are mono-branched isomers. The hypothetical reason of considerably lower activity of alumina supported molybdenum catalysts in isomerization reaction in comparison to the non-supported ones is reaction of molybdenum compounds with alumina and therefore lower susceptibility of molybdenum for carbonization.