MODIFICATION OF A FLUIDIZED-BED COAL-GASIFICATION PROCESS TO IMPROVE CARBON CONVERSION

A spouted fluidised-bed coal-gasification process has been developed by the British Coal Corporation for the manufacture of a fuel gas of low calorific value (4.0 MJ m-3 gross) for use in industrial applications. During the initial development work the carbon-conversion efficiency of the process was restricted to 65%. The process has now been modified successfully by the substitution of bauxite for the original char bed. When the gasifier bed is operated in this way, a bed with a low carbon content is maintained; this has led to significantly reduced elutriation rates, which have allowed carbon conversion efficiencies of the order of 85% to be achieved.