Hydrogen and hydrocracking

Major work on zinc chloride catalysts for hydrogenation and hydrocracking of coal has been carried out by Zielke, Gorin, Struck and coworers at Consolidation Coal (now Conoco Coal Development Co.) (1). The emphasis there has been on a full boiling-point range of liquid product, from treatment at temperatures between 385 and 425°C and hydrogen pressures of 140 to 200 bars. 

The relative performances of the two autoclaves were compared by the use of ratios. Three ratios were derived utilising (a) the unconverted phenanthrene, denoted by P (b) the amounts of the various hydro-derivatives of phenanthrene multiplied by the relative number of hydrogens added, eg % tetrahydrophenanthrene 4, denoted by HP (c) the total content of hydrocracked compounds, denoted by C. These ratios would indicate the reactivity of the autoclaves and their relative abilities towards hydrogenation and hydrocracking. 

Rhenium is used in tungsten and molybdenum-based alloys. It is used for filaments for ion gages in mass spectrometers. Rhenium-tungsten alloys are used in thermocouples to measure temperatures up to 2,200°C. Rhenium wire is used in flash bulbs for photography. Rhenium compounds also are used as catalysts in hydrogenation and hydrocracking reactions in petroleum refining. 

The preheated coal slurry (essentially liquefied) is sent to the reactor, where thermal and catalytic cracking, hydrogenation, and hydrocracking take place. These reactions occur rather slowly because fewer reactive bonds are involved in this stage, which produces distillate range small molecules. 

Hydrogenation and hydrocracking activity of iron catalysts has been extensively investigated using coal and model compounds (93 -95). Iron catalysts can hydrogenerate olefinic unsaturated bonds, while they are known to be less active for the hydrogenation of aromatic rings compared with molybdenum-based catalysts. 

In a detailed kinetic study, Sridhar and Ruthven [256], using nickel supported on Kieselghur (58% Ni), alumina (14% and 40% Ni) and silica-alumina (5% Ni), showed that over all four catalysts the rates of both hydrogenation and hydrocracking could be correlated according to the power rate law equation... 

A combination of triflic acid with iodine was shown to be effective to liquefy three types of coal in toluene or tetralin under hydrogen pressure.141 The major role of acid was found to enhance coal depolymerization to asphaltenes, whereas the main function of iodine was to hydrogenate and hydrocrack asphaltenes to oils. The combined catalytic system removed 50% of the nitrogen and 90% of the sulfur of the coals (Illinois No. 6 and Pittsburg seam samples). 

On the metallic membrane side, a well known type of material with this characteristic is Pd and certain Pd alloys. Palladium is known to be catalytic to many reactions including oxidation, hydrogenation and hydrocracking. It has been found that the catalytic activity of selected binary Pd alloys is higher than that of pure Pd. Silver catalyzes a number of oxidation reactions such as oxidation of ethylene and methanol. In addition, nickel is catalytic to many industrially important reactions. 

Alkylbenzenes (BTX) are mainly made from petroleum and coal in the United States. Petroleum refineries produce about 95% of BTX and the rest comes from coal. Coal based BTX is obtained as a by-product from high temperature carbonization of coal employed for the production of metallurgical coke. Carbonization process yields only 2-3 gallons of BTX per ton of coal. BTX can be produced in larger quantities by hydrogenation and hydrocracking of coal (1,2). The organic... 

Sharypov V.I., Kuznetsov B.N., Beregovtsova N.G., Reshetnikov O.L., Baryshnikov S.V. (1996) Modification of iron ore catalysts for lignite hydrogenation and hydrocracking of coal-derived liquids. Fuel, 75, No 1, 39-42. 

Formation of methane and chain lengths of higher molecular hydrocarbons depend on the presence of active hydrogen and are the result of different types of conversions. Secondary polymerizations and depolymerizations (135), as well as hydrogenations and hydrocracking, are important for the final composition of the reaction products. 

H-Oil is a new technique for hydrogenating and hydrocracking residues and heavy oils, developed through the joint efforts of Hydrocarbon Research, Inc. and Cities Service Research Development Co. Several papers have reviewed commercial experience and application studies of this process (2, 3,5,7). 

X 10 bar at 1000°C. Carbon monoxide and carbon dioxide can react with hydrogen in the presence of a catalyst. Depending on the reaction conditions, catalyst and CO H2 ratio a variety ofproducts can be formed. Unsaturated hydrocarbons are converted to saturated or partially saturated hydrocarbons by hydrogenation. In the petroleum industry hydrogenation and hydrocracking reactions are of importance as well as desulfurization and selective hydrogenation (dienes, monoolefins). 

In either mode, the catalyst (or mineral matter) serves to (a) improve the liquid yield, including enhancement in the hydrogenation and hydrocracking rates and (b) improve heteroatom removal. ... 

Lapinas, A.T. Klein, M.T. Gates, B.D. Macris, A. Lyons, J.E. Catalytic Hydrogenation and Hydrocracking of Fluorene Reaction Pathways, Kinetics and Mechanisms, Industrial and Engineering Chemistry Research, 30 (1), 1991,42. 

The main hydrotreating reaction is that of desulfurization, but many others take place simultaneously to various degrees, such as denitrogenation, various hydrogenations and hydrocracking (in some cases deoxidation and dehalogenation) (see Table 1). 

Stepwise ring hydrogenation and hydrocracking of polycyclic aromatics. 

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