Preface to the Special Issue on “Recent Progress of Cokemaking Technologies for Low-quality and Unused Carbon Resources”

Study

Recent years, a manufacturing of high-strength coke for stable low RAR blast furnace operation is required to reduce CO₂ emission. On the other hand, resource depletion of high-quality coal and iron ore continues. Thus it has become much more important to produce high quality burden using low grade resource. As for coal, in conjunction with the rising price of high-quality caking coals, it is difficult to obtain non or slightly caking coals. So utilization of carbon resources for cokemaking is an important issue.

If we pay more attention to overall carbon resources, there are biomass, subbituminous coal, lignite and the oil residue which are not used for coke production. Figure 1 shows the “Van Krevelen Diagram” which was proposed by Krevelen¹⁾. It is supposed that above-mentioned unused carbon resources will be converted to carbon resources which are suitable for cokemaking, in other words, an “Artificial Coalification” which is such as mechanical compression, dehydration, decarboxylation and demethanation, implements the formation of “reformed coal” and “binder”. As approaches for achievement of this purpose,

Fig. 1.

Development line from unused carbon resources to coking (caking) coal.

1) Understanding of chemical structure of the binder which develops and promotes the melting-adhesion action between low-quality carbon resources and high-quality caking coals, should be achieved. This results in the development of advanced blending technology of carbon resources.

2) Co-carbonization mechanism between unused carbon resources and caking coals should be clarified chemically. Also pre-treatment condition of low-quality carbon resources for cokemaking should be understood.

3) The composite material design technology should be developed with considering the different carbon resources as matrix elements of coke.

By promoting these fundamental researches, it is necessary to develop the cokemaking technologies for low-quality and unused carbon resources.

The division of High Temperature Process, the Board of Academic Society, ISIJ has continued specific fundamental research projects over 20 years. In those meetings, basic thermophysical properties of caking coals/cokes, coal carbonization control for coke production, thermoplasticity and adhesion of coals, high-strength, high-reactivity coke were studied. The knowledge from these meetings was applied to development of Super Coke Oven for Productivity and Environmental enhancement toward the 21st century (SCOPE21).

In order to implement a further development for cokemaking technology, the specific fundamental research project called “Cokemaking Technology for Low-quality and Unused Carbon Resources” was established in ISIJ and fundamental researches for the purpose of above-mentioned approaches were carried out for three years. The member for this research project was researchers from universities and national institute who were specialized in carbon resources such as coal or oil or chemical engineers and the middle and young researchers of Japanese iron- and cokemaking companies.

In order to summarize the activities of this research project, a special issue on “Recent Progress of Cokemaking Technologies for Low-quality and Unused Carbon Resources” was invited for publication. Wide range of researchers, which could be bases of a new technology/process or a process improvement and also a technical development on reforming of low-quality coal/biomass, development of binder to maintain coal plasticity and so on were welcome to contribute this issue. As a result, large number of papers had been submitted from worldwide researchers. This result symbolizes that many researchers have a significant interest and are carrying out the research to overcome a near-future problem with utilization of carbon resources.

We sincerely hope that this special issue will contribute to the new cokemaking technology development following SCOPE21.

Finally, on behalf of the editors of this special issue, I am grateful to all the authors and the reviewers for their contributions.

References

• 1)   D. W.  Van Krevelen: Coal Typology-Physics-Chemistry-Constitution, 3rd ed., Elsevier Sci. Pub., Amsterdam, (1993), 183.