The control technology available to prevent exposure to harmful substances during coal conversion operations is evaluated for the TOSCOAL Coal Pyrolysis Process which is being developed at the Tosco Rocky Flats Research Center, located in Golden, Colorado. In this process, crushed dry coal is preheated in lift pipes. Hot flue gas from the ball heater supplies the heat. Preheated or partially deagglomerated coal is fed to a rotating pyrolysis drum, where it is contacted with hot ceramic balls and heated in a ball heater fired by clean process derived fuel gas or fuel oil. The coal in the pyrolysis drum is decomposed at about 900 degrees-F to produce coal char and hydrocarbon vapors. The char is separated by a trommel screen and withdrawn from the char hopper. The balls are elevated, reheated, and returned to the pyrolysis drum. Hydrocarbon vapors are cooled and condensed to recover light hydrocarbon gases and coal liquids. Potential hazards exist through possible exposure to noise, heat stress, high temperatures, flammable or explosive materials, respirable coal and char dust, coal tar pitch volatiles, and toxic gases such as carbon-monoxide (630080) and hydrogen- sulfide (7783064). The major way to eliminate, or at least minimize, possible exposure to these hazards is through the use of a closed system operation. The potential hazards associated with coal pulverizing, slurry preparation, hydrogenation, and solid from liquid separation do not apply as they are not used in the TOSCOAL process.
Division of Physical Sciences and Engineering, NIOSH, Robert A. Taft Laboratories, Cincinnati, Ohio, CT-119-29a, 9 pages, 4 references