Ignition characteristics of chars made in the G R & D coal-gasification and coal-to-liquids processes

Abstract

Chars are obtained as by-products in the coal-gasification and coal-to-liquids processes currently in the pilot-plant stage at Garrett Research & Development Company, Inc. Ignition tests have been carried out on these chars using an ignitability test, i.e. dispersing the chars in oxygen and igniting the mixture in a hot tube. DTA—TGA determinations have also been used to study the static reactions of the chars in air. Both types of char, under roughly simulated pulverized-fuel-firing conditions probably with a significantly lower heating rate, ignited readily at temperatures equal to or lower than those required to ignite the parent coals. Partial oxidation of the char raised the ignition temperature. The heats of combustion of the chars are slightly higher than those of the parent coals and approach that of petroleum coke; the sulphur content per unit of heating value is slightly lower. They are porous materials with a particle-size distribution suitable for use as pulverized fuel. Enough volatile matter remains to give a bright flame after ignition.