PSOC coals

Not a PSOC coal. Supplied courtesy of Prof. L. Anderson, University of Utah. 

Figure 2. Typical scattering curves for the coal samples. Curves 1-4 were obtained for PSOC coals 095 (O), 022 0> 127 (+), and 081 (Ah respectively. The lines were determined by least-squares fits of Ref. 8.

We wish to point out the outer part of the scattering curve for PSOC Coal 135, which is a medium-volatile bituminous coal, is quite similar to the corresponding curves for the anthracites. The fact that the outer portion of the scattering curves from both a medium-volatile bituminous coal and also from anthracites have the same form can be quite naturally explained if the scattering at these angles is the result of superposition of the three structures mentioned above. 

There are pronounced shoulders on the scattering curves for PSOC Coals 105, 022, and 188, while there are no shoulders on the curves for Coals 197 and 138. The shoulders in the scattering curves from Coals 185 and 181 are less evident, and a shoulder can be seen for Coal 212 only after careful inspection. These results suggest that there will be well-defined shoulders in the scattering curves only when the specific surface of the transition pores is at least ten times as great as that of the macropores. 

The PSOC coals were especially convenient samples for our x-ray studies, because in the data bank, there is a considerable amount of information about these coals obtained by techniques other than x-ray scattering. Without these other results we would not have been able to make such a detailed interpretation of the scattering data. Moreover, since we had studied PSOC coals, we could compare our porosity studies with the work of others, such as that of Gan, Nandi, and Walker—. On the other Jujiui, as the other small-angle x-ray scattering studies of coals— — which we are aware of did not investigate PSOC coals, we could not make a quantitative comparison of our scattering results with those previously published. 

We would like to express our sincere gratitude and appreciation to S. R. Koirtyohann for assistance with the preparation of the ash samples by low-temperature ashing, to Robert G. Jenkins for measuring the specific surfaces of PSOC Coal 105, and to S. S. Pollack, D. W. Houseknecht, B. E. Cutter, Robert G. Jenkins, and Phillip L. Walker, Jr. for advice and assistance during parts of the investigation. Sponsored by the U.S. Department of Energy. 

Although we were able to obtain satisfactory fits of (3) with n 1 for all of the low-rank PSOC coals discussed below, the scattering data for Beulah lignite obtained with the Bonse-Hart and Beeman systems extended over such a wide Interval of scattering angles that we found that n had to be Increased to 2 in order to obtain a good fit for this curve. 

Corrected scattering curves for PSOC coals 93 and 248 are shown... 

As can be seen from the curve for PSOC coal 93 in Figure 2, the scattering data from lignites can also be fitted quite well with Equation (3) The quality of the fits of the two equations is nearly the same The fact that both equations can be employed in the fits is a result, we believe, of the fact that both Equations (3) and (6) correspond in this case to similar pore-dimension distributions ... 

As can be seen from Table 3, when the exponent 7-y > 3, the constant D is negative for the scattering curves for the PSOC coals. There is no reason (20) that these values cannot be... 

Original coals PSOC NO. Ultimate analysis (d. a.f. ) Proximate analysis Characteristics Conv. (50... 

Furthermore, in P.H. Given s data, the lignite sample, PSOC 87 coal is very reactive though its inert content is higher, and deviates considerably from the general tendency. This seems to indicate that this coal was chemically treated. 

Coals covering a range of rank downwards from low-volatile bituminous were examined in solvent-free catalytic hydrogenation over the temperature range 300-400°C and for reaction times up to 60 min. The work discussed here specifically Involved four coals which were obtained form the Penn State Coal Sample Bank. These were a subbituminous coal PSOC-1403, and three hvAb bituminous coals, PSOC-1168, PSOC-1266 and PSOC-1510. 

Figure 1. Relationship of H2 consumption and 0/A ratio for hvAb coal, PSOC-1266 (solvent-free hydrogenation 400°C 1% wt sulfided Mo 7MPa H2 cold).

Figure 2. Variation in atomic H/C ratio versus chloroform-soluble yields from subbituminous (PSOC-1403) and bituminous (PSOC-1266) coals (solvent-free hydrogenation 300-400°C 5-180 min 1% wt sulfided Mo 7 MPa H2 cold) (data from refs 7 and 8).

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. ... 

Figure 6. Relations among fluorescence intensity, chloroform-solubles yield and Gieseler placticity for hydrogenated coal (PSOC-1510 solvent-free hydrogenation, 400 C 5-60 min 1% wt sulfided Mo 7 MPa H2 cold.

Figure 7. Comparison of fluorescence spectra of two components in chloroform-solubles fraction with oil and asphaltene fractions of hydrogenated coal (PSOC-1266 solvent-free hydrogenation 400 C 60 min 5% wt sulfided Mo 7 MPa H2 cold).

Fi re 2. Comparison of FT-IR Spectra for Residue and Parent Coal for PSOC-1401 Wyodak Subbitiuninous Coal. 

The coals used were PSOC 1098 Illinois 6 and Beulah-Zap North Dakota lignite from the Argonne coal bank. The analytical data of these coals are shown in Table I. The ratio of catalyst to coal was approximately 0.6 mmoles of metal per gram of coal. The organometallic catalysts were molybdenum(II) acetate dimer, Mo2(OAc)4, obtained from Strem, molybdenum(II) allyl dimer Mo2(OAc)4, was prepared by die method of Cotton and Pipal (25). The NiMo supported catalyst was prepared by addition of bis(l,5-cyclooctadiene) Ni(0) (Strem) to sulfided Mo on alumina (. Cp2Mo2( l-SH)2(p.-S)2, referred to as MoS2(OM), was prepared by modification of method of Dubois et al. (26), and Cp2Mo2Co2( i3-S)2(li4-S)(CO)4, CoMo(OM) was prepared by the method of Curtis et al. (27). Pentacarbonyl iron was obtained from Aldrich,... 

Figure 4. Distribution of coal macerals in PSOC-106 as a function of H/C ratio.

TabLe II. Range of H/C and Ring Index Values of Coal Macerals in PSOC-106... 

The coals designated as PSOC-2 and PSOC-858 were obtained from the Coal Data Bank at the Pennsylvania State University. 

Table I. Elemental Analysis and Maceral Composition of Coal PSOC-2 and PSOC-858 Separated by Density Gradient Centrifugation Techniques...

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