Design and Validation of a Laboratory-Scale System for Investigating Coking Byproducts

The byproducts of metallurgical coke production play a significant role in the economic well-being of integrated steel mills. In this context, this study aimed to design, construct and validate a laboratory-scale system to investigate the yields of the three main coking products: coke, coal tar and coke oven gas (COG). Laboratory yields of coke, coal tar and COG, as well as the COG composition, were validated against industrial values obtained with the same coking blend. The apparatus, comprising a coking retort and a cracking column, was designed based on systems described in the literature. The coking process was carried out at 1000 °C with a heating rate of 3 °C/min. The optimal cracking temperature and residence time for reproducing industrial conditions were determined to be 800 °C and 30 min, respectively. Under these conditions, laboratory coke yields differed by 1.6% from industrial yields, while coal tar yields were equivalent. Average volumetric yields of COG were 341 Nm³/t, compared to 315 Nm³/t industrially. Methane and hydrogen concentrations, the two major gases in the COG, differed by less than 5%. The developed methodology demonstrates high repeatability and mass balance consistency (product recovery) ranging from 99.7 to 100.2%. These results confirm the system's capability to replicate industrial conditions and provide a foundation for future studies on the impact of coals and additives on the yields and quality of coking products.