Hydrocarbons aromatic, catalytic

Fetzer, J. C., The Production of Large Polycyclic Aromatic Hydrocarbons During Catalytic Hydrocracking, in Catalysts in Petroleum Refining and Petrochemical Industries, 1996. Kuwait, Studies in Surface Science and Catalysis, Elsevier. 100 pp. 263-271. 

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. 

THE PRODUCTION OF LARGE POLYCYCLIC AROMATIC HYDROCARBONS DURING CATALYTIC HYDROCRACKING... 

Tapp et al. ° used SAPO-5 and CoAPO-5 to convert methanol to hydrocarbons. The catalytic experiments were carried out at 360 C, 1 bar total pressure, and LHSV=2. The typical hydrocarbon fraction contained 45 wt% of light olefins, 15 wt% of higher aliphatics, 40 wt% of aromatics, and less than 1% of methane. The main aromatics were penta- and hexa-methylbenzene. SAPO-5 remained active for approximately 300 g methanol/g catalyst, while CoAPO-5 remained active for only 30 g methanol/g catalyst. The lower stability of CoAPO-5 with respect to SAPO-5 is in agreement with that observed in small-pore SAPO and MeAPO molecular sieves. The methanol transformation on AIPO4-5 mainly yielded dimethylether and water. 

Figure 1 shows the yields of conversion and the products distribution (Cj Cg hydrocarbons, aromatic, polyaroioatics and tar) as a function of reactor temperature for pure cyclopentanone over Il-ZSM-5/bentonite (80/20 Wt.%) catalyst. The conversion is completed at 350 C. The main reaction is a ther.nal decarbonylation of cyclopentanone, giving hydrocarbon fragment that reacts further on the catalytic bed to produce aliphatic, aromatic and polyaroiaatic hydrocarbons. Cyclopentenone which is partially deoxygenated (32%) over H-ZSM-5/bentonite (80/20 Wt.%) at 450 C, can be completely converted... 

Many different substrates can undergo oxidative carbonylations, such as unsaturated and saturated hydrocarbons, aromatic and heteroaromatic derivatives, alcohols, phenols, and amines, giving a number of carbonyl compounds in a regio- and stereocontrolled fashion and with high degree of chemoselectivity. Oxidative car-bonylation reactions have been recently and carefully reviewed [10-13]. In this section a general overview of the most recent developments in oxidative carbonylations mediated by catalytic palladium(II) compounds and directed toward the synthesis of heterocyclic compounds is presented. As already reported in the introduction, the cyclocarbonylation reactions ending with the synthesis of simple lactones and lactams are reported in the chapter that discusses the carbonylation of alcohols and amines and are recently been reviewed [7,9,79]. 

Zhao, Y., Fu, Y., Guo, Q.-X., 2012. Production of aromatic hydrocarbons through catalytic pyrolysis of y-valerolactone from biomass. Bioresource Technology 114, 740—744. 

Du, Z., et al., 2013. Production of aromatic hydrocarbons by catalytic pyrolysis of microalgae with zeolites catalyst screening in a pyroprobe. Bioresource Technology 139 (0), 397-401. 

We shonld also utilize liquid hydrocarbons, which frequently accompany natural gas. These so-called natural gas liquids currently have little use besides their caloric heat value. They consist mainly of saturated straight hydrocarbons chains containing 3-6 carbon atoms, as well as some aromatics. As we found (Chapter 8), it is possible by superacidic catalytic treatment to upgrade these liquids to high-octane, commercially usable gasoline. Their use will not per se solve our long-... 

Acetyl chlotide reacts with aromatic hydrocarbons and olefins in suitably inert solvents, such as carbon disulfide or petroleum ether, to furnish ketones (16). These reactions ate catalyzed by anhydrous aluminum chlotide and by other inorganic chlotides (17). The order of catalytic activity increases in the order... 

Cyclic Hydrocarbons. The cyclic hydrocarbon intermediates are derived principally from petroleum and natural gas, though small amounts are derived from coal. Most cycHc intermediates are used in the manufacture of more advanced synthetic organic chemicals and finished products such as dyes, medicinal chemicals, elastomers, pesticides, and plastics and resins. Table 6 details the production and sales of cycHc intermediates in 1991. Benzene (qv) is the largest volume aromatic compound used in the chemical industry. It is extracted from catalytic reformates in refineries, and is produced by the dealkylation of toluene (qv) (see also BTX Processing). 

Catalysis. As of mid-1995, zeoHte-based catalysts are employed in catalytic cracking, hydrocracking, isomerization of paraffins and substituted aromatics, disproportionation and alkylation of aromatics, dewaxing of distillate fuels and lube basestocks, and in a process for converting methanol to hydrocarbons (54). 

The y -phenylenediamiaes are easily obtained by dinitrating, followed by catalyticaHy hydrogenating, an aromatic hydrocarbon. Thus, the toluenediamiaes are manufactured by nitrating toluene with a mixture of sulfuric acid, nitric acid, and 23% water at 330°C which first produces a mixture (60 40) of the ortho and para mononitrotoluenes. Further nitration produces the 80 20 mixture of 2,4- and 2,6-dinitrotoluene. Catalytic hydrogenation produces the commercial mixture of diamiaes which, when converted to diisocyanates, are widely used ia the production of polyurethanes (see Amines, aromatic, DIAMINOTOLUENES) (22). 

The various reaction rate properties of the different solvents influence the design of a catalytic reactor. Eor example, for a specific catalyst bed design, an effluent stream containing a preponderance of monohydric alcohols, aromatic hydrocarbons, or propjiene requires a lower catalyst operating temperature than that required for solvents such as isophorone and short-chain acetates. 

Plants have now been installed by some manufacturers to produce ethylbenzene via catalytic reforming processes. The reforming process is one which converts aliphatic hydrocarbons into a mixture of aromatic hydrocarbons. This may be subsequently fractionated to give benzene, toluene and a xylene fraction from which ethylbenzene may be obtained. 

Mochida, I., Shimizu, K.., Korai, Y., Otsuka, H. and Fujiyama, S., Structure and carbonization properties of pitches produced catalytically from aromatic hydrocarbons with HF/BFj, Carbon, 1988, 26(6), 843 852. 

Many of the reactions of BF3 are of the Friedel-Crafts type though they are perhaps not strictly catalytic since BF3 is required in essentially equimolar quantities with the reactant. The mechanism is not always fully understood but it is generally agreed that in most cases ionic intermediates are produced by or promoted by the formation of a BX3 complex electrophilic attack of the substrate by the cation so produced completes the process. For example, in the Friedel-Crafts-type alkylation of aromatic hydrocarbons ... 

The distribution of the products obtained from this reaction depends upon the reaction temperature (Figure 5.1-4) and differs from those of other poly(ethene) recycling reactions in that aromatics and alkenes are not formed in significant concentrations. Another significant difference is that this ionic liquid reaction occurs at temperatures as low as 90 °C, whereas conventional catalytic reactions require much higher temperatures, typically 300-1000 °C [100]. A patent filed for the Secretary of State for Defence (UK) has reported a similar cracking reaction for lower molecular weight hydrocarbons in chloroaluminate(III) ionic liquids [101]. An... 

Flowever, information concerning the characteristics of these systems under the conditions of a continuous process is still very limited. From a practical point of view, the concept of ionic liquid multiphasic catalysis can be applicable only if the resultant catalytic lifetimes and the elution losses of catalytic components into the organic or extractant layer containing products are within commercially acceptable ranges. To illustrate these points, two examples of applications mn on continuous pilot operation are described (i) biphasic dimerization of olefins catalyzed by nickel complexes in chloroaluminates, and (ii) biphasic alkylation of aromatic hydrocarbons with olefins and light olefin alkylation with isobutane, catalyzed by acidic chloroaluminates. 

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