3. Hydrogen Management

It is essentially the very low H/C atomic ratio that distinguishes coal from other fossil fuels (Table 10 ). Thus, gasoline and conventional oil contain between 1.5 and 2 hydrogen atoms per carbon atom, while lignite contains only 0.85, and anthracite 0.4, with bituminous and sub-bituminous coals falling in between. This hydrogen is introduced throughout the process chain, first in the liquefaction unit, then in the hydrotreatment unit, where the volume consumed depends almost directly on the gains in density and cetane required for the diesel cut via the hydrogenation of aromatics and hydrocracking of naphthenic rings. This consumed hydrogen heavily impacts the liquefaction plant’s yield when produced from coal (the only possible solution in the absence of a natural gas source), due to the low hydrogen yield inherent in the gasification...