Abstract:
With the extensive utilization of low-sulfur, high-quality coke-making coal resources, the efficient and resource utilization of high-sulfur coal has become increasingly urgent, and the removal of sulfur is the key to addressing this issue. The inherent properties of coal, particularly its coalification degree and the existed forms and distribution of sulfur, directly impact the migration behavior of sulfur during coal conversion processes
. Based on this, the existed forms of sulfur in coal and the methods for its removal were reviewed, including the thermal transformation behavior of sulfur during coal pyrolysis, as well as the application of high-sulfur coal in the blending process for coke-making. The results indicate that the sulfur content in coal and its existed forms are closely related to the sedimentary environment during the coal formation. Different forms of sulfur decompose within distinct temperature ranges, leading to notable differences in their transformation behaviors during pyrolysis. Therefore, it is necessary to accurately identify the content and forms of sulfur in coal by combining existing or adopting new characterization methods. The use of machine learning combined with advanced algorithms to uncover patterns in statistical data represents a novel direction in the research of sulfur removal during coal pyrolysis. By adjusting the composition of blended coal, the hydrogen-rich radicals generated from the cracking of high-volatile coal can serve as in-situ hydrogen donors, combining with sulfur-containing radicals to allow the generated sulfur-containing gases to escape with the volatiles. Simultaneously, regulating the mineral composition (especially alkaline compounds) in high-volatile coal can reduce its sulfur-fixing effect, thereby producing low-sulfur, high-quality coke. This is an effective approach for the application of high-sulfur coal in coal-blending and coke-making. Additionally, investigating the mechanism of mass transfer effects on sulfur regulation during coal carbonization is crucial for inhibiting the surface reactions between sulfur-containing components and coke, achieving clean conversion of high-sulfur coking coal, and its utilization in coal-blending and coke-making.