Thermal hydrogenolysis of polyaromatic hydrocarbons and activated carbon at elevated temperatures and pressures

Vaporised polyaromatic hydrocarbons (indene, naphthalene, biphenyl, phenant hrene, anthracene) admixed with benzene, have been processed in flow reacto rs at 1-35 bar H-2 at temperatures between 500 and 990 degreesC. Smooth gas ification to methane on a 4-20 s timescale occurs, nearing completion at th e higher T and P values. Relative rates at 977 degreesC (benzene/naphthalen e/anthracene ca, 0.1:1:2.5) are interpreted on the basis of the mechanism a dvanced earlier for benzene: (reversible) addition of H-. and opening of ta rget aromatic rings. Activated carbon reacts analogously, but on a per C ba sis its rate is about 500 times smaller than that of naphthalene. Resistanc e to ring-opening hydrogenolysis in highly condensed entities and limited a ccessibility for H-2/H-. together account for this difference.