Additional polynuclear aromatics - production and uses

Product distribution data (Table V) obtained in the hydrocracking of coal, coal oil, anthracene and phenanthrene over a physically mixed NIS-H-zeolon catalyst indicated similarities and differences between the products of coal and coal oil on the one hand and anthracene and phenanthrene on the other hand. There were differences in the conversions which varied in the order coal> anthracene>phenanthrene coal oil. The yield of alkylbenzenes also varied in the order anthracene >phenanthrene>coal oil >coal under the conditions used. The alkylbenzenes and C -C hydrocarbon products from anthracene were similar to the products of phenanthrene. The most predominant component of alkylbenzenes was toluene and xylenes were produced in very small quantities. Methane was the most and butanes the least predominant components of the gaseous product. The products of coal and coal oil were also found to be similar. The most predominant components of alkylbenzenes and gaseous product were benzene and propane respectively. The data also indicated distinct differences between products of coal origin and pure aromatic hydrocarbons. The alkyl-benzene products of coal and coal oil contained more benzene and xylenes and less toluene, ethylbenzene and higher benzenes when compared to the products from anthracene and phenanthrene. The gaseous products of coal and coal oil contained more propane and butanes and less methane and ethane when compared to the products of anthracene and phenanthrene. The differences in the hydrocracked products were obviously due to the differences in the nature of reactants. Coal and coal oil contain hydroaromatic, naphthenic, heterocyclic and aliphatic structures, in addition to polynuclear aromatic structures. Hydrocracking under severe conditions yielded more BTX as shown in Table VI. The yields of BTX obtained from coal, coal oil, anthracene and phenanthrene were respectively 18.5, 25.5, 36.0, and 32.5 percent. Benzene was the most... 

Liquid products were characterised using GC-MS. A range of aromatic compounds were identified in which the concentrations of aJkybenzenes are greater than those of alkylindans and naphthalenes while polynuclear aromatic compounds (PACs) were only minor constituents. The prominent group of constituents eluting between n-pentadecane and n-hexadecane are mixtures of alkenes, alley (benzenes and naphthalenes. Phenanthrene addition had no significant effect on the overall liquid product distribution. 

The reagent alkali metal/naphthalene in tetrahydrofuran reacts with graphite, polynuclear aromatics, and various coals to form chemically reduced products. In the present paper, we emphasize the use of electron paramagnetic resonance data, in the form of g values, linewidths, radical densities, and saturation characteristics, to analyze the reduced coal products and to infer certain differences between the reduced coals and the anions of graphite and simple aromatic hydrocarbons. Additionally, because the interaction of coals with alkali metal/naph-thalene requires much time for completion, we have investigated internal decomposition pathways for the... 

Fillers are materials that modify rubber characteristics (e.g., hardness) and improve its physical characteristics (e.g., tensile strength), in addition to reducing costs. Rubber is sometimes compounded without the use of fillers the resultant product is called gum rubber. Typical fillers are calcined and hydrated clays, magnesium silicate (talc), magnesium oxide, and silicas. Carbon black, a common filler used to increase the heat resistance in industrial components such as tires, is not used as a filler in pharmaceutical components but it is used in smaller amounts as a black pigment. Polynuclear aromatic (PNA) hydrocarbons are a concern with carbon blacks but the grades used by manufacturers of pharmaceutical components contain very low concentrations. 

Presently the major step in the GTL conversion is considered to be the Fischer-Tropsch synthesis of hydrocarbons from synthesis gas (CO-I-H ). The classical processes produce waxes (solid hydrocarbons) that are further upgraded into the components of liquid fuels (gasoline, diesel). Diesel production by this technology seems to be the best solution. The synthetic diesel fuel has better characteristics compared to the fuel grades produced from oil (standard EN-590) the cetane number is 75 (versus 55 for the oil-derived diesel) the content of polynuclear aromatic compounds is 0.1 (versus 6%) the sulfur content is 0 ppm (versus 50 ppm). Such synthetic fuels can be used as additives to the oil-based diesel. GTL-diesel is used in Germany, Austria, and Sweden and the blends of the synthetic fuel and conventional diesel are used in France, Italy, and other countries. 

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