Isotopic investigation of the chemistry of coal hydroliquefaction

This paper presents the results of experiments which were conducted to investigate the respective roles of gas-phase and donor-solvent hydrogen in coal hydroliquefaction. Coal hydrogenation experiments were carried out with /sup 2/H/sub 2//tetralin-h/sub 12/ and /sup 1/H/sub 2//tetralin-d/sub 12/ mixtures and tetralin-d/sub 12/ under N/sub 2/ pressure to study the mechanisms that are in operation. The following conclusions have been drawn from these measurements: (1) the relative reactivities of the ..cap alpha..-aliphatic, ..beta..-aliphatic, and aromatic C-H bonds of tetralin at 425/sup 0/C for /sup 1/H-/sup 2/H isotopic exchange between tetralin and coal are: 75:16:9; (2) these ratios do not change significantly regardless of whether N/sub 2/ or /sup 1/H/sub 2/ cover gas or whether tetralin-d/sub 12///sup 1/H/sub 2/ or tetralin-h/sub 12///sup 2/H/sub 2/ reactant combinations are used.