Fuel Gas Demonstration Plant Program: Small-Scale Industrial Project. Demonstration plant design manual, Phase I

The plant will utilize fixed bed, stirred, two stage gasifiers. The lower stage will be a standard gasifier configuration. The upper stage will be an undivided distillation section containing a slowly rotating stirrer which will move vertically through the bed. The bottom of the gasifier will contain a standard dry grate and will have lock hoppers to discharge the ash. This type of gasifier provides high coal utilization. It also distills the tars and oils from the coal in the upper zone at minimum temperatures, thereby providing minimum viscosity liquid fuels which can be used for the induration of iron ore pellets. The very hot bottom gases leaving the combustion zone, after passing through a cyclone to remove coal and ash dust can be used to generate steam. This steam is in addition to the steam generated in the water jacket of the lower zone which is used in the steam air blast to the bottom of the gasifier retort