Coal hvAb

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 1. Electron micrograph of an ultrathin section of a dull attrital layer (durain) in a high volatile A bituminous (hvab) coal. V—vitrinitey E—exinite, M—granular micrinite. X 10,500...

Figure 6. Electron micrograph of a replica of granular micrinite in vitrain in hvab coal.

Figure 10. Electron micrograph of an ultrathin section of exinite in hvab coal. X 42,000...

This paper presents isotherms for the adsorption of methane, nitrogen, carbon dioxide, and water vapor on a Pocahontas No. 3 (lvb) and a Pittsburgh (hvab) coal. Rate data for the adsorption of methane on these coals will be described in a subsequent paper. 

Gates from the flash and laser irradiation of Pittsburgh seam (hvab) coal were investigated to determine the action of high temperatures on coal. Temperatures in excess of 1000°C. were reached with both types of irradiation. Craters about 300 microns in diameter were produced in the coal with millisecond pulses from the laser unit rated at 1.7 joules output. Gaseous products from the laser and flash irradiations showed 21% and 8% acetylene, respectively. Diacetylene, vinylacetylene, and other products to molecular weight 130 were indicated in the mass spectrum of the gas from the laser study. The results indicated that the distributions of products obtained from the flash and laser irradiations of coal were different from that produced in high temperature carbonization. 

Figure 2. Laser irradiation of Pittsburgh seam (hvab) coal, 84% carbon ...

Table I. Gaseous Products from laser and Flash Irradiations and High Temperature Carbonization of Pittsburgh Seam (hvab) Coal...

The conclusions that can be drawn from this study of the irradiation of hvab coal under extreme temperatures are ... 

Two recent studies have examined the NMR spectra of coal macerals and lithotypes respectively. Retcofsky and VanderHardt (12) reported the aromaticities of the vitrinite, exinite, micrinite, and fusinite from Hershaw hvAb coal using non-spinning cross-polarization techniques. The fa values of 0.85, 0.66, 0.85, and 0.93 -0.96 for these macerals demonstrate clear variations between the materials at a given rank. Gerstein et. al. (13) used carbon-13 CP/MAS proton combined rotation and multiple pulse spectroscopy (CRAMPS) to examine Iowa vitrain (Star coal) and a Virginia vitrain (Pocahontas 4 coal) with aromaticities of 0.71 and 0.86 respectively. 

Several of these extracts have been analyzed for iron and titanium via the X-ray fluorescence technique. The results for West Virginia (Ireland Mine) hvAb coal, one which has been found to deposit titanium on fixed bed catalysts, are presented in Table HL... 

Ireland Mine hvAb coal was used in the coal pyrolysis studies. The method of heat treatment was essentially that reported by Petrakis and Grandy (8), Ireland Mine coal was also the feed coal used to obtain most of the coal liquefaction products. The coal-derived liquids investigated were centrifuged liquid products (CLP) and their subfractions from selected runs in the Pittsburgh Energy Technology Center s 400-lb coal/day coal liquefaction process development unit (PDU) (9). 

Figure 2. The 9,5-GHz spectra of West Virginia (Ireland Mine) hvAb coal and its pyridine extract...

ESR g values for West Virginia (Ireland Mine) hvAb coal heat-treated at four different temperatures are shown graphically in Figure 9. The points connected by the dashed lines represent the results of measurements made on neat samples after heat treatment. The general shape of this curve has been established for other coals (8, 15). The point for the sample heat-treated at 450 C falls considerably below the free electron value similar results for other coals have been attributed to the formation of sigma radicals during heat treatment (8). Three experiments were conducted to show that this observed g value was an apparent and not a true value. 

Figure 9. ESRg values for heat-treated I reland Mine hvAb coal measurement...

For the investigation of composition of the gases evolved at different stages of the volatilization, pyrolyses have been carried out with interruptions of the discharge231 - For both lignite (67% C) and hvab coal (82% C) the concentration of H2 increased but that of CO and C02 decreased, in analogy to thermal decomposition... 

Fig. 8. Gas composition at various stages of micro-wave pyrolysis (solid curves) and thermal pyrolysis (broken curves) of hvab coal. (Redrawn from Fu, Y. C., Blau stein, B. D. Ind. Eng. Chem., Process Design Develop. 8, 257 (1969), by permission of the publishers, the American Chemical Society)...

Experiments similar to those described above have been reported for nearly the same conditions but with added N2232>. In addition to the usual H2 and CO, HCN, C2H2, small amounts of (CN)2 and CH4 were found in the products. By trapping at 77 K more than 42% of C in the hvab coal was converted to HCN and C2H2. Of course, small amounts of higher hydrocarbons were formed in the cold trap. 

Fig. 11. Variation in rates of H2, CO, C02, E CH4 and C2H (— C2H2 + C2H4) forma- > tion from hvab coal in argon discharge 2 with time. (Redrawn from Fu, Y. C., Blau-... 

The distinguishing characteristic of non-plasma and plasma methods of gasification is that the products are different the non-plasma conventional carbonization process yields gas and tar plasma processes yield gas and soot. Based on the representative data collated for hvab coal in Table 17 it is inferred that the gas from carbonization is richer in methane, the chief component of natural gas and the preferred product the gas from plasma is richer in acetylene. In most of the plasma methods collated in Table 17 the gas temperatures were 1300 K or more and any methane formed would readily decompose to yield acetylene. Clearly, in-so-far as the plasma formation of methane is concerned the temperature region of 700—1000 K needs to be investigated. Her 60 Hz discharges, with or without electrodes, in reactors heated to the desired temperature may be advantageous. 

Table 17. Comparison of gas composition for plasma and non-plasma methods of treating hvab coal...

Hvab coal Tar sand Oil shale Kerogen Gilsonite... 

Figure 3. Composition of gas from devolatilization of Pittsburgh hvAb coal...

Pittsburgh Seam hvab Coal Illinois No. 6 hvcb Coal N. Dakota Lignite... 

Hvab coal from U.S. Bureau of Mines experimental mine, Bruceton, Pa. Hvcb coal from Orient 3 mine, Freeman Coal Co., Waltonville, 111. Lignite from Baukol-Noonan mine, Burke Co., N. Dakota. 

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