An experimental apparatus was set up for batch simulation of coal pyrolysis with solid heat carrier in a fixed bed. Quartz sand as heat carrier preheated to about 700-800 degreesC was mixed with Datong bituminous coal by an agitator. The thermal history of the coal particle has been followed by a K-type thermocouple. The effects of particle size, pyrolysis time and temperature on the gas yield during pyrolysis of coal with solid heat carrier were examined for different conditions. The experimental results showed that a dominant percentage of the gas product is produced during the first 1-3 min, although gas evolution would last for as long as 10 min. The total gas yield, insensitive to particle size of the heat carrier, depends on carrier temperature and coal particle size under rested conditions. The contact heat transfer of cold and hot particles was analyzed. (C) 2001 Elsevier Science B.V. All rights reserved.