The effects of temperature and residence time on the secondary reactions of volatiles from coal pyrolysis

Abstract

The secondary reactions of volatiles from rapid pyrolysis of Liddell coal have been studied using a two-stage reactor. The effects of the cracking temperature and the residence time of volatiles on the final product yields were investigated in an inert atmosphere between 500–900°C and 0.2–14 s, respectively. The product yields of aliphatic and aromatic hydrocarbons, together with inorganic gases, were determined gas-chromatographically, and a detailed mass balance was established. The final product yields were strongly affected by the above two factors. The nature of the secondary reactions has been discussed using a reaction model based on the molecular structure of Liddell coal. Kinetic analyses were made on the formation and decomposition reactions of gaseous hydrocarbons.