Linby coal

Primary Conversions and Influence of Mobile Phase Yields for the various H-donor and non-donor solvent extractions of Linby coal at 400% are summarised in Table III the conversions for the THF-extracted coal include the extracted material. Surprisingly, pre-extraction with THF significantly increases primary conversions in the polynuclear aromatic compounds (PACs) investigated. These findings appear to be contrary to those of other liquefaction (16) and pyrolysis (17) studies where prior removal of chloroform-extractable material significantly reduced conversions. However, Rincon and Cruz (18) have reported recently that pre-swelling coals in THF increases conversions for both anthracene oil and tetralin. The fact that Point of Ayr (87% dmmf C) coal yielded over 80% pyridine-solubles in pyrene (C.E. Snape, unpublished data) without pre-extraction is consistent with the earlier results of Qarke et al (19) for anthracene oil extraction where UK coals... 

Conversions to pyridine-solubles for non-THF-extracted Linby coal were much greater with naphthalene than with phenanthrene and pyrene (Table m, pre-soaking at 250% has little effect on conversions) and, even after THF extraction, naphthalene conversions are comparable to those of pyrene. 

Although Neavel obtained high yields of pyridine-solubles with naphthalene at short contact times for some US bituminous coals (201. conversions were much lower after longer extraction times. This trend is not evident for Linby coal... 

Figure 1. Conversion of THF-extracted Linby coal with naphthalene at 400 C. Pyridine-solubles and THF-solubles.

Figure 4. Conversion of THF-extracted Linby coal with tetralin at 400 "C. Pyradine-solubles, normal aPyradine-solubles, after presoak at 250 " C THF-solubles, normal and QTHF-solubles, after presoak at 250 " C.

Figure 2 shows the effect of cracking temperature at 2 s vapor residence time on the yields of BTX, benzene, and ethylene from Linby coal (A), coal extract (B), and anthracene oil (C). 

The yields of BTX and ethylene are low, less than 3.5% BTX and 1.5% ethylene the highest yields were from Linby coal. Although the BTX yields are greater than the 1% from conventional, high temperature coal carbonization ( 2), they are only a fraction of those obtainable from petroleum feedstocks. ( 4)... 

Figure 2. Effect of cracking temperature on yields from unhydrogenated coal-derived materials top, Linby coal middle, anthracene oil extract of Linby coal bottom, anthracene oil carbonizer temperature, 873 K vapor residence time, 2 s ...

Feedstock Linby coal A Anthracene Oil Extract of Linby coal B Anthracene oil C Partially hydrogenated anthracene oil Cl... 

Feedstocks - The vapors from the carbonization of a bituminous, low-rank coal, an anthracene oil, and a coal extract in anthracene oil were diluted with nitrogen and cracked their product yields were compared with those from the cracking of a partially hydrogenated anthracene oil and coal extracts hydrogenated to various extents. The coal was Linby (National Coal... 

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