Ring-number distribution

Table XII. Ring Number Distributions for Coal Liquids Produced from Illinois No. 6 and Wyodak Coal Using Different Processing Conditions, Weight Percent Total Coal Liquid Basis...

In further studies it was also found that the aromatic fraction of these bitumens as obtained from silica gel chromatography also contained naphthenic sulfides (5) with molecular weight and ring number distribution similar to those of the sulfoxides. Relative abundances versus carbon number as obtained from the field ionization mass spectrum for each ring number series are shown in Figure 4. It is clear from these and... 

Table II. Ring-Number Distributions for Saturate Concentrates Derived from Five Coal Liquids and a Hydrotreated Shale Oil...

Ring Number Distributions for Clay-Gel Aromatic Fractions... 

Figure 8.20. Cumulative number distribution of fragments from four expanding ring experiments (10 fragments each) and comparison with one-dimensional theoretical distribution based on Poisson statistics.

At the conclusion of the calculation, a fragment size distribution as well as fragment number is provided. A cumulative number distribution is shown in Fig. 8.22 and compared with aluminum ring data acquired at = lO s (Grady and Benson, 1983). With the assumed fracture site nucleation law, the calculated distribution appears to agree reasonably well with the data. The calculation better predicts the tails of the distribution which have trends which deviate from strict exponential behavior as was noted in the previous section. 

Coal Liquids and Shale Oil. Some properties of five coal liquids and a hydrotreated shale oil are given in Table I, including sulfur, nitrogen, acid and base contents, and distributions by boiling range. Ring-number... 

The ring-number tabulations in Tables II, III, IV, and V are satisfactory for a simplified summary of composition and comparison. The typical Co-Mo or Ni-Mo catalyst commonly used for upgrading will saturate many of the multiple aromatic rings, depending upon severity and activity, but frequently not the last ring of a condensed-ring polyaromatic. Thus, the total number of rings is a measure of the complexity of the hydrocarbon structure. As noted earlier, more detailed data on the distribution of hydrocarbon types in these liquids are available when needed. 

Z(Oz) series. It is not obvious how this result, which is opposite to that observed for the aromatic neutral fractions, is reconciled with a separation of acids based upon their physical properties, such as solubilities, in pentane and benzene. Similar to the result attained for the aromatic hydrocarbons, the carbon-number distributions for the acid fractions are characterized by the occurrence of maxima early in the distributions of weight percents in the various specific-Z series. However, for corresponding compound types (i.e., the same basic ring structure) the range in carbon number is significantly shorter for the acids than for the aromatic hydrocarbons. 

Hydrogenation of aromatic petroleum fractions is an example of reversible reactions. Wilson et al. s experiments " show how various aromatic ring-number fiactions approach equilibrium. Also, Ihe distribution of equilibrium constants within each ring-number fiaction is not wide. The hydrogenation of coal extract in a CSTR shows an overall order of unity. " There are a few theoretical studies of the reaction mixture represented by c k, t) O c k, Xo examine the mixture s near-equilibriiun... 

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