Phenanthrene Extraction of Bituminous Coal

Three bituminous coal samples were extracted at 350°C. with phenanthrene, labeled in one series with tritium, in another with C14. The extract yield was 80—90%. Results: converting coal to soluble products breaks C-H bonds; 10—15% of the hydrogen content of the coal exchanged with that of the phenanthrene during extraction; 3—8% chemically linked phenanthrene was found in the extracts; less than 1% hydrogen exchange took place between pure model compounds (anthracene, p-benzylphenol) and tritiated phenanthrene under similar experimental conditions. Thus, chemical reactions take place during phenanthrene extraction of bituminous coals. The role of phenanthrene in this process is probably an interaction with the free radicals which are formed in the thermal decomposition of coal.