Apparatus and a process are described for compressing superheated steam into porous coal batches in chambers, and, after a time interval, expanding this steam out of the chambers, and repeating this steam cycle of compression followed by expansion. Thusly heated by the steam, volatile matter separates from the solid coke portion of the coal and separate volatile matter and coke products can be produced from coal or biomass fuels. These volatile matter liquids and tars can be used as fuel components in slurry fuels, for internal combustion engines used in our surface transportation industries. These solid coke products can be used as boiler fuel in steam electric plants. In this way our large domestic reserves of coal can be used as a fuel source, not only for electric power generation, but also for our surface transportation needs.