To comprehensively understand the properties of the products in coke making technology to better design a coke reactor

the rapid pyrolysis characteristics of Jinjie bituminous coal were studied in atmosphere of normal pressure nitrogen

by means of drop-tube furnace

at pyrolysis temperatures ranging from 800 ℃ to 1 100 ℃ and with the residence time of 3～5 seconds. It focuses on the distribution and properties of different pyrolysis products including semi-coke

tar and pyrolysis gases. The results show that

the pyrolysis temperature and residence time affect the distribution and properties of the pyrolysis products greatly. It is better to maintain the pyrolysis temperature over 1 000 ℃ to reduce tar yield and ensure the safety of storage of semi-coke. At the same time

the yield of the pyrolysis gases and the proportion of H_2 are also in a large value. However

the adsorption performance of the semi-coke prepared at high temperatures is poor. The tar is mainly composed of aromatic hydrocarbons and their derivatives

which has small content of matters with extremely high boiling points. Therefore

it is better to keep the temperature of tubes around 400 ℃ to limit the probability of slagging effectively.