Low temperature chemical fragmentation of coal Available to Purchase

Trifluoroperoxyacetic acid chemically fragments coals at 25–80°. The reagent is so selective for oxidizing aromatic rings and is so inert towards benzylic hydrogen that isopropylbenzene, tetralin, indan, and dihydrophenanthrene have their benzene ring(s) totally destroyed without any evidence of oxidation at the benzylic hydrogen. The fragments contain more and different structural information relative to conventional oxidataions with Mn (7+), Cr (6+), HNO₃, and O₂. These latter selectively oxidize benzylic hydrogen. Produces from 27 selected coals show that 9,10‐dihydroanthracene and 9,10‐dihydrophenanthrene units are prominent features in most bituminous coals in accord with Given’s structure of coal. Their frequency accounts for the fact that no continuous fused ring structure or graphite exists. The only simple alkyl substituent is methyl. Liquefaction (solvent refining) sharply increases the amount of arylmethyl and aromatic structure and causes the appearance of unsubstituted phenyl groups. Nitric acid degradations have been reinvestigated and are developed into a premier method for analyzing the amounts and lengths of linear alkane chains in coals. Generally the amounts of such chains represent –2% of the carbon in coal, but in one Utah coal they account for about 42% of the carbons.