In the previous report, the authors analysed economically mineable coal resource by way of scrutinizing production and railway transportation cost with respect to horizontal and vertical annual progress, and annual removal of coal mining front line in NSW State, Australia, and concluded that the front line removal of coal mining could be extinct only in 13 years or one twenty fifth of duration in terms of demonstrated coal resources released by the State Government.
The authors therefore studied subsequently the pragmatic economic evaluation method envisaging that numerous numbers of studies covering World's potential coal fields are essential to detect actually available coal tonnages produced and supplied to the coal consuming countries particularly to Japan.
Basic analysis has been carried out in this report to compare established but complicated methodology (IRR) with newly developing conventional but ambiguous in its theoretical back ground (SC).
As the results of theoretical comparison of these methods, it was found that the SC method is suitable to study the economic potential of the World's major coal fields because
i) In principle, theoretical back ground of SC is the same as established IRR method.
ii) Data can be utilized, for the SC calculation is comparably easy to collect from the coal fields.

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Coal -derived liquid obtained from 150ton/day NEDOL pilot plant was upgraded over a presulfided Ni-W/Al₂O₃ catalyst under a hydrogen pressure of 12MPa. The original coal liquid and three upgraded oils were separated into several compound groups and analyzed by GC -FID/NPD, GCMS and FIMS in order to identify the molecular species in the feedstock and upgraded oils.
The coal liquid was composed of paraffins (17%), naphthenes (20%), oleffins (4%), monoaromatics (17%), polyaromatics (17%) and polar components (25%). After the upgrading over Ni-W/Al₂O₃, polyaromatics decreased to 0.7-4.7% and polar components were reduced below 0.1%, which resulted in the large increase of naphthenes and naphthenobenzenes. Basic nitrogen compounds (N: 4, 200ppm) in the coal liquid were piridines, anilines, quinolines and benzoquinolines and their hydrogenated derivatives, and nonbasic nitrogen compounds (N: 1, 400ppm) were alkylnitriles, pyrroles, indoles and carbazoles. Sterically hindered nitrogen compounds like 2, 4, 6-trimethylpyridines and 2, 6-anilines tended to remain in upgraded oils. Saturated cyclic nitrogen compounds of which molecular weights were expressed as 165+14n and 205+14n (n=0, 1, 2 …) were found to be least reactive for the denitrogenation, although their detail structure was not identified. Polyaromatic compounds which remained in upgraded oils were biphenyls and dibenzofurans due to their less reactivity and dihydrophenalene and pyrene at their hydrogenation equiribrium.

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