Key take aways:

Biocarbon (charcoal, bio-char, bio-coal) for industrial application such as metallurgy industry is definitely an open topic with large potential for exploration.

RESOURCES

• • There are examples of good practices from Brasil e.g. RIMA, Grupo Maringa, demonstrating that use of biocarbon for metallurgical processes is feasible. These approaches are however not based on virgin forest but dedicated plantations (eucalyptus) and charcoal producing plants that are integral parts of these plants operations to provide sustainable reductant.
• • In Europe the key challenge remains the primary source of material to produce biocarbon: sustainable management of forest resources, cultivation of appropriate plant species, certified wood production or search for other materials like alternative renewable waste material.
• • Briquettes may be an alternative to biocarbon but there are challenges (properties, the need to make them tailor needed for specific process, mechanical properties and chemical composition – binder, price).
• • A product that combines the features of biocarbon and the classic reductant, which is currently coke, can be bio-coke. Bio-coke is a hybrid reductant produced with the use of additives of biomass origin (charcoal, raw biomass etc.) and coking coal. The challenge is to obtain the largest possible share of the renewable component while maintaining the appropriate properties of the final product.
• • Also, the use of wood chips for the production of charcoal is interesting in terms of potential volumes of resources.

Key issues:

• • Using biocarbon is one of the most useful alternatives for the near future decreasing the emission factor of ferroalloys production.
• • Use waste as input material may require higher production costs making this option less cost effective / increase the biocarbon costs
• • The use of appropriate biomass waste creates opportunities for cheaper raw material, a slightly bigger problem is the design of the installation (rotary reactor, screw reactor, etc.), the source of heat for the process (preferably burning pyrolysis gas; in countries where electricity is cheap, it can be electricity)
• • Source and stability of supply of such waste material (which material, how to ensure its supply in significant accounts?)
• • Recognition of the key properties that the final product should have - depending on the specific process in which it will be used
• • Technical constraints of installations used currently for biocarbon production that are designed for wood processing
• • Stability of parameters of the produced end material
• • No sufficient practical experience/feedback from industry if this is an option to consider

TECHNOLOGY IMPLICATIONS

• • Metallurgical processes like Mn ferroalloys or Si alloys production require reductant NOT fuel. That makes the physical and chemical parameters of input material different from bicarbon used for other purposes.
• • An issue is the adaptation of the existing production process to the use of charcoal
• • The physical form and the composition of the reductant used for metallurgical processes matters a lot : if briquettes are to be used they need to demonstrate appropriate mechanical properties (the issue of fines, thermal stability) and chemical properties – the key role plays the binder as it must not affect the operation of the furnace and the resulting emissions, ash content and its chemical compositionis also an issue.
• • Depending on the application Mn alloys or ferrosilicons the parameters of the biocarbon based reductant such as reactivity or porosity relevant for in the processes are different therefore reductants with different properties are needed.
• • The proper size of the briquettes and their mechanical properties (to avoid excess dusting and ensure proper permeability of furnace batch) are crucial. The granulation of the material in the briquet may be also a challenge
• • The partial use of charcoal in ferroalloys production is possible and has advantages for high-quality alloys, especially for low Fe-content alloys (FeSi, Si-metal, CaSi probably), but shows several disadvantages: creating more fines during feeding; large volatility of moisture; more attention to stocking and transportation. Also, production side need more experience for brickets using
• • More experience in charcoal briquette use is preferable because historically using all types of briquettes shows low mechanical properties and have a compounds to make clogging gas filtration systems.

ECONOMIC IMPLICATIONS

• • Nowadays biggest brake for expanding of use of biocarbon is the price at the same time ratio of “fixed carbon/price” has a difference of more than 1.5X compared to the best coal on market.
• • Cost of the briquettes is an important factor determining their potential of use in metallurgical processes. For example in ferrosilicon industry 75% of the costs is energy consumption. Potentially making a briquetttes is more expensive than coke or unprocessed charcoal.

NEED to CONTINUE THE DIALOGUE

• • Both industry and biocarbon and coke producers have limited experience in use of biocarbon for metallurgical processes. There may be some promising results from the test labs but they may require testing in real scale applications.
• • The dialogue on the actual needs of the industry is essential to provide a product meeting the needs. The question is if industry is ready for that dialogue?
• • PreMa and BioCoke4FAI are a platform to continue the dialogue.