Pyrolyzed Products of Coal Rapidly Heated on a Molten Slag

Abstract

Behavior of rapid pyrolysis of coal is of considerable importance in understanding an early stage of post combustion in an iron are smelting reduction converter.
Products by pyrolysis of various kinds of coal under conditions of high heating rate and high temperature on a molten slag have been studied quantitatively.
By analyzing the pyrolysis products such as gas, tar and residual char, data were obtained as a function of coal rank(eleven coals and one metallurgical coke), temperature(13501500°C), gas residence time(2.510 s), and coal diameter(0.87.0 mm) in the experiments using high frequency induction furnace.
Total coal volatiles released in these experiments increased by 10 to 20% compared to the proximate volatile matters. Carbon oxide gas(CO+CO₂) and hydrocarbon gas (CH₄-C₃H₆) yields increased with increasing [O] content and [H]/[C] atomic ratio in parent coal, respectively.
The effect of coal diameter and slag temperature on total volatiles did not become significant.
The ratio of [S] and [N] retained in residual char to total [S] and [N] contained in parent coal decreased with increasing volatile matter of coal. Normalization of the data, by taking the ratio of [S] and [N] released to total volatiles released, indicated that [S] and [N] in all coals examined were preferentially retained in volatiles and showed the maximum retention at around [C]_daf=85% coal.