Test study on the coal pyrolysis process has been carried out by using thermogravimetric analyser. The influence of different terminated temperature and particle size of the coal sample upon conversion rate of volatile nirrogen and coke nitrogen in bituminous coal or hard coal has been investigated. It is found from the results that the more nitrogen retention existing in the chars when pyrolysis of deeply carbonized coal; on the contrary

the nitrogen is more easily to separate out along with volatile

forming gaseous nitrogen contained products; high temperature is helpful for nitrogen to be separated out from the chars

and the particle size of coal has obvious effect for volatile nitrogen to separate out. The more finely pulverized coal has more higher conversion rate of volatile nitrogen.