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Hydrocarbons, cracking, catalytic

For environmental reasons, burning should be smokeless. Long-chain and unsaturated hydrocarbons crack in the flame producing soot. Steam injection helps to produce clean burning by eliminating carbon through the water gas reaction. The quantity of steam required can be as high as 0.05—0.3 kg steam per kg of gas burned. A multijet flare can also be used in which the gas bums from a number of small nozzles parallel to radiant refractory rods which provide a hot surface catalytic effect to aid combustion. [Pg.59]

Chromium zeolites are recognised to possess, at least at the laboratory scale, notable catalytic properties like in ethylene polymerization, oxidation of hydrocarbons, cracking of cumene, disproportionation of n-heptane, and thermolysis of H20 [ 1 ]. Several factors may have an effect on the catalytic activity of the chromium catalysts, such as the oxidation state, the structure (amorphous or crystalline, mono/di-chromate or polychromates, oxides, etc.) and the interaction of the chromium species with the support which depends essentially on the catalysts preparation method. They are ruled principally by several parameters such as the metal loading, the support characteristics, and the nature of the post-treatment (calcination, reduction, etc.). The nature of metal precursor is a parameter which can affect the predominance of chromium species in zeolite. In the case of solid-state exchange, the exchange process initially takes place at the solid- solid interface between the precursor salt and zeolite grains, and the success of the exchange depends on the type of interactions developed [2]. The aim of this work is to study the effect of the chromium precursor on the physicochemical properties of chromium loaded ZSM-5 catalysts and their catalytic performance in ethylene ammoxidation to acetonitrile. [Pg.345]

In 1962 Mobil Oil introduced the use of synthetic zeolite X as a hydrocarbon cracking catalyst In 1969 Grace described the first modification chemistry based on steaming zeolite Y to form an ultrastable Y. In 1967-1969 Mobil Oil reported the synthesis of the high silica zeolites beta and ZSM-5. In 1974 Henkel introduced zeolite A in detergents as a replacement for the environmentally suspect phosphates. By 2008 industry-wide approximately 367 0001 of zeolite Y were in use in catalytic cracking [22]. In 1977 Union Carbide introduced zeolites for ion-exchange separations. [Pg.4]

Like the paraffins, naphthenes do not appear to isomerize before cracking. However, the naphthenic hydrocarbons (from C9 upward) produce considerable amounts of aromatic hydrocarbons during catalytic cracking. Reaction schemes similar to that outlined here (page 131) provide possible routes for the conversion of naphthenes to aromatics. [Pg.158]

Hydrocarbon cracking catalysts comprising a USY zeolite and discrete particles of alumina dispersed in an inorganic oxide matrix are known. It has been investigated that catalytic cracking process utilizing catalysts comprising zeolites that have been pre-... [Pg.223]

The objective of this work is to identify relationships between structure and catalytic performance in the specific case of hydrocarbon cracking over dealuminated Y zeolites. Dealuminated zeolites are prepared using chemical and hydrothermal methods and the effect of dealumination method on structure-performance... [Pg.31]

Today much of the propylene used in the world is produced by the catalytic hydrocarbon cracking in fluid cat-cracking and similar operations . [Pg.50]

Reaction of Steam on Hydrocarbons. The catalytic interaction of steam and hydrocarbons has been used commercially on a large scale. The thermal cracking of hydrocarbons is an important part of petroleum refining and produces a large amount of hydrogen. The reaction of steam on methane from natural gas at about 1100 °C is... [Pg.1603]

J. N. Beltramini, Catalytic Properties of heteropolyacids Supported on MCM-41 Mesoporous Silica for Hydrocarbon Cracking Reactions, Stud. Surf. Sci. Catal, 146, 653-656 (2003). [Pg.71]

The poor selectivity of the thermal decomposition of polyolefins has promoted the development of catalytic cracking. Catalytic cracking lowers the pyrolysis process temperature and lowers the boiling temperature range of the resultant liquid products. The use of molecular sieves and amorphous silica-alumina catalysts for the cracking of waste polymers into a range of hydrocarbons has been widely studied (see Chapters 3-5, 7, 8). [Pg.386]

The information about synthetic mordenite properties was obtained in 1961 when Keough and Sand (7) found that H- and other forms of this crystalline aluminum silicate display high activity and selectivity in the reactions of hydrocarbon cracking and ethanol dehydration. Later this zeolite was shown (J, 2, 5, 7, 8, 10-13, 15, 16) an active catalyst in the reactions of isomerization, cracking, and alkylation of hydrocarbons and alcohol dehydration. However, the catalytic properties of mordenite have been studied insufEciently, compared with those of other zeolites. [Pg.442]

Le et al. 5232580 03.08.93 Catalytic Process for Hydrocarbon Cracking Using Synthetic Mesoporous Crystalline Material... [Pg.35]

Catalytic properties of mesoporous crystalline MCM-41 and related materials for hydrocarbon cracking... [Pg.389]

The accepted papers cover every aspect of catalysis on microporous materials. A significant number of contributions describe the synthesis, modification, instrumental and chemical characterisation of zeolites and other micro- and mesoporous materials. Catalytic reactions involve hydrocarbon cracking, nucleophilic aromatic substitution, methanol to hydrocarbon conversion, hydration of acetylene, various alkylation reactions, redox transformations, Claisen rearrangement, etc. A whole range of appealing chemistry can be enjoyed by reading the contributions. [Pg.804]

Dimerization and codimerization reactions are widely used on an industrial scale either to provide chemicals of high added value or to upgrade by-product olefinic streams coming from various hydrocarbon cracking processes (steam or catalytic cracking) or hydrocarbon forming processes (Fischer-Tropsch synthesis or methanol condensation) (e. g., according to eq. (1)). [Pg.253]

A preferred embodiment of this concept is the catalytic plate reactor, which consists of catalytically coated metal plates so that exothermic and endothermic reactions take place in alternate channels. In addition to minimizing the heat transfer resistances, this reactor facilitates mass transfer to the catalytic surface by reducing the diffusion length. Catalytic plate reactors can find applications in steam reforming, dehydrogenation, and hydrocarbon cracking which are strongly endothermic processes. In recent years those reactors have received considerable attention as steam reformers for fuel cell applications. " ... [Pg.369]

It seems more interesting to utilize the discovered mechanisms of methane conversion into higher hydrocarbons for catalytic cracking of methane into carbon and hydrogen. [Pg.734]


See other pages where Hydrocarbons, cracking, catalytic is mentioned: [Pg.1560]    [Pg.88]    [Pg.152]    [Pg.566]    [Pg.349]    [Pg.220]    [Pg.275]    [Pg.189]    [Pg.5]    [Pg.8]    [Pg.539]    [Pg.127]    [Pg.97]    [Pg.162]    [Pg.100]    [Pg.220]    [Pg.1382]    [Pg.1584]    [Pg.737]    [Pg.364]    [Pg.163]    [Pg.315]    [Pg.109]    [Pg.593]    [Pg.22]    [Pg.23]    [Pg.371]    [Pg.878]    [Pg.1042]    [Pg.48]   


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Hydrocarbons, cracking

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