Abstract: A method and apparatus for catalytic hydroconversion processing of less volatile carbonaceous material to volatile liquid products is disclosed. The process is carried out in a plug-flow reactor system using nanosize metallic catalyst particles dispersed in the reactant slurry with compressed hydrogen/hydrogen-sulfide at a temperature between about 275° C. and 525° C. at a pressure of between about 800 psi and 6000 psi and a residence time in the reactors between about 1 minute and 4 hours.