Subbituminous coal, solvent effects

Table III shows that hydrogenated and unhydrogenated SRC recycle solvents were equally effective for the conversion of a western subbituminous coal at low reaction severity. At higher severity but at times shorter than 10 minutes, significantly higher conversions were achieved only with the hydrogenated solvents which could donate more hydrogen.

SOLVENT EFFECTS ON SHORT TIME CONVERSION OF BELLE AYR SUBBITUMINOUS COAL (800°F, 3 min., 1500 psi H2)... 

In the higher-rank bituminous coals, a- and fS-naphthol are both effective solvents, but for subbituminous coal, (S-naphthol may produce even less extract than phenanthrene, but a-naphthol may extract as much is 83% w/w of the coal. Ring compounds, such as phenanthrene, appear to be superior for extracting bituminous coals of medium rank. 

A comparison of the effect of the two solvents on the composition of SRCs from Wyodak subbituminous coal is shown in Figure 8. Compared to the hydrogen-enriched solvent, use of the hydrogen-depleted solvent results in a SRC with higher sulfur and oxygen contents and lower carbon and hydrogen contents. 

The Effect of Solvent Compositions on the Liquefaction Behavior of Western Subbituminous Coal... 

In this study subbituminous coals were liquefied and desulfurized effectively by hydrotreating with synthesis gas at moderate operating conditions In the presence of steam and anthracene oil used as a solvent. The data were compared when the same coals were liquefied with pure hydrogen under similar experimental conditions. Pyrltlc and organic sulfur present In these coals appear to be responsible for the formation of catalytic active form of Iron sulfide that functions as an effective hydrotreating catalyst (14). The presence of... 

---