Green blast furnace - Focus biomass

Important results from the project

The possibilities and challenges when using biocoal at the blast furnace for reducing the fossil CO2-emissions there and for the production system were analysed. Biocoal, injected or top-charged, are can reduce the fossil CO2-emissions from the entire steelworks. Biocoals for injection should preferably be medium torrefied and consist of sawdust and long tree tops. For top charging charcoal with low volatile content are recommended. Biocoal should be milled separately in an injection plant with inert atmosphere. Material bins should be able to empty quickly in case of fire.

Expected long term effects

The project result is the basis for future development towards lower CO2 emissions at Swedish integrated steelworks. The results will be used for industrial trials in the Bio4BF project. More knowledge is needed to be able to carry out operational test that will be important for future implementation and increased bio-coal production. For trials, separate grinding of biocoal, inert atmosphere and co-injection with pulverised coal or BF dust is possible. Parts of the results have been presented and discussed at a workshop within the project and at two international conferences.

Approach and implementation

The project was carried out in close cooperation with SSAB in Luleå and Oxelösund, data from respective works and the equipments was the basis of the study. The availability of biomass for producing biocoal and the demands for use at the blast furnaces was analysed. The modelling was made in detail for biocoal products of interest for future use and the effect of biocoal properties was evaluated for effects on process and CO2-emissions. Part of the results was discussed in a workshop with representatives from steelworks, the forest industry and biocoal producers as well as researchers.