The Energy Systems Group of Rockwell International is investigating the application of its flash hydropyrolysis (FHP) technology to the hydroretorting of Eastern oil shale. This technology features the use of Rockwell's short-residence-time, entrained-flow reactor, derived from aerospace rocket injector technology, for quickly reacting pulverized carbonaceous solids with a hot, hydrogen-rich pyrolysis gas. Shale particle heat-up rates are extremely rapid (~50,000supO F/s), and devolatilization of the kerogen occurs in milliseconds.