Hydrocracking of hydrocarbons

On the other hand, it was proposed that acid catalyzed reactions such as skeletal isomerization of paraffin [2], hydrocracking of hydrocarbons [3] or methanol conversion to hydrocarbon [4] over metal supported acid catalysts were promoted by spillover hydrogen (proton) on the acid catalysts. Hydrogen spillover phenomenon from noble metal to other component at room temperature has been reported in many cases [5]. Recently Masai et al. [6] and Steinberg et al. [7] showed that the physical mixtures of protonated zeolite and R/AI2O3 showed high hydrocracking activities of paraffins and skeletal isomerization to some extent. 

Our main purpose for developing residual hydroconversion catalyst is the upgrading of petroleum residue, decomposition of asphaltenic components and hydrocracking of hydrocarbons to obtain useful middle distillates from petroleum residue. Through extensive studies on HDS catalysts, hydroconversion was determined to be entirely dependent on reaction temperature [2]. On the other hand, coking and metal deposition onto catalyst were reported to occur under such high temperatures as to decrease catalyst activity and shorten catalyst life [5,6,7,8]. 

At the H2 pressures normally inside the FT reactors, hydrocracking of hydrocarbons is thermodynamically favored but in practice it hardly occurs, if at all. 

Figure 5.27 Adsorption and hydrocracking of hydrocarbons on nickel surface [529], For rn>rA, gum cannot accumulate on the surface.

The second example deals with the hydroisomerization and hydrocracking of hydrocarbons on... 

Antimony trichloride is used as a catalyst or as a component of catalysts to effect polymerisation of hydrocarbons and to chlorinate olefins. It is also used in hydrocracking of coal (qv) and heavy hydrocarbons (qv), as an analytic reagent for chloral, aromatic hydrocarbons, and vitamin A, and in the microscopic identification of dmgs. Liquid SbCl is used as a nonaqueous solvent. 

Other catalytic hydrocarbon reactions indude decomposition of olefins over a powdered nickel catalyst [84], hydrogenation of alkenes, hydrocracking of cycloalk-enes, and water-gas shift reactions [64]. 

A species frequently maintains phase equilibrium while it is reacting in one phase. An example is hydrocracking of heavy hydrocarbons in petroleum refining, where H2 from the vapor dissolves into the liquid hydrocarbon phase, where it reacts with large hydrocarbons to crack them into smaller hydrocarbons that have sufficient vapor pressure to evaporate back into the vapor phase. As long as equilibrium of the species between phases is maintained, it is easy to calculate the concentrations in the hquid phase in which reaction occurs. 

Table II. Hydrocracking of Pure Hydrocarbons in the Presence df Nickel-Silica-...

Robert B. Anderson. Iron catalysts apparently do not isomerize hydrocarbons however, there is little experimental evidence besides the products of the Fischer-Tropsch synthesis. In hydrocracking of paraffins on nickel and cobalt catalysts the isomerization does not occur. 

A study is presented of the synthesis and properties of the novel synthetic zeolite omega. The synthesis variables and kinetics of formation are discussed, as well as the ion exchange, sorption, and thermal properties. By decomposition of imbibed tetra-methylammonium ions and exhaustive treatments of the zeolite with ammonium ions, a pure hydrogen form can be obtained which is a suitable substrate for the preparation of hydrocarbon conversion catalysts. Several catalysts were prepared and utilized to isomerize n-hexane, and to hydrocrack a heavy gas oil. 

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... 

Isocracking process a hydrocracking process for conversion of hydrocarbons which operates at relatively low temperatures and pressures in the presence of hydrogen and a catalyst to produce more valuable, lower-boiling products. 

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