H/C atomic ratio

Fig. 15. The H/C atomic ratio versus heat-treatment temperature for samples as indicated...

Fig. 22. The capacity of the one volt plateau measured during the second cycle of several series of samples versus the H/C atomic ratio in the samples. The solid line suggests that each lithium atom binds quasi-reversibly to one hydrogen atom.

Figures 5 and 6 show that there is a good correlation between the percentage conversion and the H/C atomic ratio of the coals for both experimental procedures.

There is also intercorrelation between the volatile matter and the H/C atomic ratio for the South African coals studied. 

Thus a good correlation between conversion yield and one of these properties obviously implies a similar correlation with the other property. The correlations between the volatile matter yield and the reactive maceral content and between the H/C atomic ratio and the reactive maceral content are not statistically significant. 

Figure 5. Percentage conversion against H/C atomic ratio (hot rod mode)...

It is well known that the characteristics of coal differ widely according to the age of the coal formation as well as to the location of coal, etc. And the reactivity during hydroliquefaction depends on the characteristics of coals. This relationship will he a guidance to select and develop coal mines. Many parameters to indicate the reactivity of coal have heen proposed (l, 2, 2). Among these parameters, carhon content, volatile matter content, value of H/C atomic ratio, reactive macerals content, etc. are reported to he relatively closely related parameters to coal reactivity. However, these relations are usually found only in limited reaction conditions. Therefore, attempts to find better parameters still continue. 

The relations between coal reactivity and several parameters are shown in Figs. 3 to 8. In these figures the reactivity of coal is measured by conversion. In the results, volatile carbon % is selected as a more closely related parameter than the common parameters, such as C%9 H, 0, H/C atomic ratio, volatile matter, etc. 

The effectiveness of these parameters is considered to depend heavily on the liquefaction conditions and the characteristics of the coal which is used. The better parameters can possibly be derived from both the amounts of the petrographic components %9 such as inerts ingredients %9 or reactive macerals % and their quality, such as H/C atomic ratio and so on. Consequently, it must be said that much further study is necessary to finally clarify the more comprehensive parameter. 

The spectroscopic evidence indicates that the catalyst concentration had very little effect on the "gross" hydrocarbon structure present and this is substantiated by the H/C atomic ratios of the oils which showed no significant change with catalyst concentration. 

Fuel The influence of fuel gas composition on the theoretical open circuit potential of SOFCs is illustrated in Figure 8-12, following the discussion by Sverdrup, et al. (8). The oxygen/carbon (0/C) atom ratio and hydrogen/carbon (H/C) atom ratio, which define the fuel composition, are plotted as a function of the theoretical open circuit potential at 1000°C. If hydrogen is absent from the fuel gas, H/C = 0. For pure CO, 0/C = 1 for pure CO2, 0/C = 2. The data in the figure... 

It is to be noted that the magnitude of the increase in each of the measured properties, between the initial and maximum values, was quite different for the subbituminous coal and the three bituminous coals. Examples of the increases from the initial value (determined for the chloroform-soluble extract from the parent coal) to the maximum are the 0/A ratio increased from 0.8 initial value to 8.0 maximum value for the subbituminous coal, PSOC-1403, and from 0.25 to 1.5 for the bituminous coal, PSOC-1266 the H/C atomic ratio increased from 1.46 to 1.60 for the subbituminous coal, PSOC-1403, and from 1.01 to 1.06 for the bituminous coal, PSOC-1266 (see Figure 2). 

For each coal, at the maximum in hydrogen content, or H/C atomic ratio, the aliphatic hydrogen content (determined by H NMR analysis) accounted for over 90% of the total hydrogen. The aliphatic hydrogen contents were 10.5% for the subbituminous coal,PSOC-1403, and 6.9% for the bituminous coal, PSOC-1266. The high aliphatic hydrogen content was associated with the presence of polymethylene chains. The early release of paraffinic material, as n-alkanes and as long chain substituents to aromatic structures, under conditions of mild pyrolysis has been observed in other research (13-15. ... 

Noth All values are percentages except for the H/C atomic ratios. aSee Table II for sample names. 

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