Wyniki wyszukiwania - BazTech

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Możliwości pozyskiwania organicznych związków tlenowych w wyniku zgazowania węgla

Klimkiewicz R.

Górnictwo Odkrywkowe

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2014

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R. 55, nr 1

90--94

PL

Gaz syntezowy wytwarzany z węgla przez zgazowanie stosowany jest do syntez paliw płynnych i do syntez chemicznych. W wyniku procesu Fischera-Tropscha ubocznie powstają związki tlenowe: głównie alkohole, a także aldehydy, ketony, estry i kwasy organiczne. Część związków tlenowych jest stosowana jako dodatki do paliw. Oksygenaty mogą być też wykorzystywane jako związki pośrednie do produkcji różnych chemikaliów specjalistycznych. Zatem otrzymywanie związków tlenowych w ramach procesu Fischera-Tropscha może być również celowym kierunkiem pozaenergetycznym. Idą za tym możliwości katalitycznych transformacji oksygenatów – dehydratacja, odwodornienie, hydroprzetwarzanie. Alkohole mogą być źródłem wodoru, mogą też podlegać transformacji do innych oksygenatów lub węglowodorów. Jedną z opcji jest dwucząsteczkowa kondensacja alkoholi pierwszorzędowych i/lub aldehydów do ketonów.

EN

The synthesis gas, produced by gasification of coal, is used for the synthesis of liquid fuels and for chemical synthesis. As a result of the Fischer-Tropsch process, oxygenates are formed in a side reactions. primarily alcohols, but also aldehydes, ketones, esters and organic acids. Part of the oxygen containing compounds is used as the fuel additives. Oxygenates can also be used as intermediates in the production of various specialty chemicals. Thus, the preparation of the oxygen containing compounds within the Fischer-Tropsch process can also be, not focused on energy, an intentional direction. Opportunities of catalytic transformation of oxygenates go after: dehydration, dehydrogenation, hydroprocessing. Alcohols can be a source of hydrogen, can also be transformed into other oxygenates or hydrocarbons. One of options is the bimolecular condensation of primary alcohols and/or aldehydes into ketones.

2

Nanocząstki metali przejściowych - synteza i aktywność katalityczna

Gniewek A., Trzeciak A. M.

Wiadomości Chemiczne

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2009

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[Z] 63, 11-12

953-984

EN

Transition metal nanoparticles (also called metal colloids or nanoclusters) are ordered multi-atom sets characterized by a very small size, generally less than 20 nm. They are intermediate species between single atoms and crystals of macroscopic dimensions [1.8]. Nanoparticles have been synthesized by a variety of methods. The most common synthetic procedures involve chemical reduction of transition metal salts or complexes. By the choice of reduction conditions (kind of the reducing agent, type of the stabilizing agent and the elementary reaction parameters like temperature and concentration) it is possible to obtain colloids showing different particle sizes and morphologies. These two factors play a decisive role from the point of view of catalytic activity of nanoclusters. Palladium nanoparticles have been obtained by chemical reduction of PdCl2 aqueous solution using pyrogallol, hydrazine or chromium(II) acetate as the reducing agent. All these systems have demonstrated a very high catalytic activity in important carbon-carbon bond forming reactions (methoxycarbonylation, Heck and Suzuki processes) carried out under mild conditions [48, 49]. Some of the C.C coupling reactions have also been successfully catalyzed by nickel nanoparticles, however they require more harsh conditions [65, 66]. Cobalt and iron nanoparticles present magnetic properties attractive for application of these materials as removable electronic media of high capacity, as well as biosensors or magnetic probes for biological imaging and therapeutic use [9, 18]. The extreme reactivity of nanoparticles, specifically towards oxygen and water, complicates their synthesis, however it is also beneficial in catalytic applications [16, 17]. Conversion of CO/H2 mixture to hydrocarbons, known as Fischer-Tropsch synthesis, representing one of the most important routes to fuels production, is catalyzed very effectively by iron and cobalt nanoparticles. Monometallic and bimetallic cobalt nanoparticles are excellent catalysts of Pauson-Khand type couplings leading to cyclopentanones [17].

3

New generation liquid alternative fuels – development trends

Jęczmionek Ł., Oleksiak S., Skręt I.

Silniki Spalinowe

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2007

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R. 46, nr SC2

11-17

EN

Synthetic hydrocarbon fuels obtained from coal (CTL), natural gas (GTL), biomass (BTL) and via hydroconversion of vegetable oils and their development trends are presented. Although CTL and GTL technologies are used by oil companies (e.g. Sasol and Shell), BTL fuels and fraction obtained by hydroconversion of vegetable oils are relatively less known. In the paper the basic information on synthetic fuels, technologies, perspectives of their development and problems connected with legislation are discussed.