Buying Bio-Coal and Met-Coal Biochar for the Steel Industry

Bio-coal and met-coal biochar are trade names for a high-carbon biochar engineered to replace fossil metallurgical coal, coke and anthracite in steel and iron production. Unlike agricultural grade material, met-coal biochar is bought on fixed carbon, volatiles, ash chemistry and sizing - the same spec sheet a mill would apply to conventional coke.

For steel buyers the business case is unusually clean: replacing fossil coal saves carbon, and under the EU Emissions Trading System (EU ETS) and the Carbon Border Adjustment Mechanism (CBAM), that saved carbon has a direct euro value per tonne of steel. This is the one category where carbon framing is not marketing - it is the economics.

Where bio-coal and met-coal biochar are used in steelmaking

Steel is not one process. Bio-coal can substitute fossil carbon at several different points, each with its own specification, each with its own economics. A buyer should know which stage they are sourcing for before anything else.

• Sintering. Fine coke breeze (0-5 mm) is burned in the sinter strand to agglomerate iron ore fines into sinter feed. Bio-coal breeze can replace 20-50% of coke breeze without major process change. This is the easiest entry point because sinter plants already handle fine, variable carbon sources.
• Blast furnace coke substitution. Metallurgical coke is the structural carbon column in a blast furnace. Biochar itself cannot replace coke mechanically (it lacks compressive strength), but bio-coal can be blended into coal blends before coking at 5-15%, producing a hybrid coke with lower fossil content. Higher replacement rates are an active R&D area.
• Pulverised coal injection (PCI). Modern blast furnaces inject 150-220 kg of pulverised coal per tonne of hot metal through tuyeres. Bio-coal PCI replaces fossil PCI coal at substitution rates of 10-40% in production and up to 100% in pilot trials. PCI is the single largest near-term lever for biochar in integrated steel.
• DRI (direct reduced iron) and EAF (electric arc furnace) recarburisers. EAF shops add granular carbon to foam the slag and to carburise the steel. Bio-coal granulate (1-5 mm or 3-8 mm) can replace fossil anthracite and petroleum coke recarburiser. Specification here is tight: low ash, low sulphur, low nitrogen, predictable sizing.
• Foundry and ferroalloy. Cupola foundries, ferromanganese, ferrosilicon and silicon metal furnaces all consume metallurgical carbon. Bio-coal can enter the blend where fixed carbon and ash chemistry match the process.
• Non-steel adjacent uses. Cement kilns, lime kilns and carbon black plants are not steel but share the same buyer profile and lookalike spec, so producers often sell into both pools.

If you are new to biochar in steel

The easiest first purchase is sinter breeze or PCI-grade bio-coal at a 10-20% substitution rate. These routes do not require changes to the coke plant or to the blast furnace lining; they only require material handling discipline. Start there, then decide whether to trial coke-blend injection.

Examples across geographies

• Sweden and Finland. SSAB and its peers have been running HYBRIT and green-steel pilots for years. Bio-coal enters as PCI substitute and as a coke-blend component. Nordic producers use domestic forest residue as feedstock; the market is small, tightly integrated, and premium-priced.
• Germany and Benelux. Thyssenkrupp, ArcelorMittal (Bremen, Duisburg, Gent) and Tata Steel IJmuiden source bio-coal for PCI trials and for sinter. EU ETS and CBAM make the economics work even at a substantial premium over fossil PCI coal.
• Austria (voestalpine), Italy, Spain. EAF-heavy portfolios use bio-coal recarburiser. Here the value is as much about avoiding imported anthracite volatility as about carbon accounting.
• North America. US integrated mills (Cleveland-Cliffs, US Steel) and EAF operators (Nucor, Steel Dynamics) are early buyers of bio-coal granulate recarburiser. Without a federal carbon price, the business case rests on customer specifications (automotive green-steel premiums, Inflation Reduction Act incentives).
• Brazil. Brazil has the world's largest biochar-in-steel programme, with millions of tonnes of charcoal used in mini blast furnaces by pig-iron producers. Feedstock is eucalyptus plantation wood. The product is closer to traditional charcoal than to certified EBC bio-coal, but the operating experience is decades old.
• India, Japan, South Korea. Integrated steel giants (Tata Steel, JFE, POSCO, Nippon Steel) are running pilot injections and coke blends. Imports from Southeast Asia and Australia complement domestic production.
• Global South producers. Vietnam, Indonesia, Malaysia and parts of Africa are emerging suppliers of high-carbon bio-coal for export, typically from residue feedstock such as coconut shell, rice husk or palm kernel shell.

Lab test parameters - what metallurgists actually check

Met-coal biochar is bought against a proximate analysis, an ultimate analysis, an ash chemistry, and sizing - in that order. Below is the practical procurement table.

Parameter	Why it matters	Target or look for	Red flag or avoid	Priority
Fixed carbon (% dry)	The active reductant	85 to 95%	Below 80%	Critical
Volatile matter (% dry)	Too high lowers energy density and raises PCI flame	4 to 12% (PCI); below 8% (recarburiser)	Above 15%	Critical
Ash (% dry)	Dilutes carbon, loads slag, costs flux	Below 6% (premium), below 10% (acceptable)	Above 12%	Critical
Sulphur (% dry)	Goes into the steel; poisons product	Below 0.10%	Above 0.20%	Critical
Phosphorus (% dry)	Embrittles steel, hard to remove later	Below 0.03%	Above 0.08%	Critical
Nitrogen (% dry)	Affects NOx and steel nitrogen content	Below 0.5%	Above 1.0%	Important
Ash fusion temperature (deformation)	Slag-forming behaviour in furnace	Above 1300 C	Below 1200 C	Important
Hardgrove Grindability Index (HGI)	Pulverising cost for PCI	45 to 65	Below 30	Important (PCI only)
Caking / Gieseler fluidity	Only for coke-blend	Matching the base coal blend	Non-caking if used as coke component	Critical (coke blend only)
Particle size distribution	Must match the process	0-5 mm sinter; <75 um PCI; 1-5 or 3-8 mm recarburiser	Wide tails, excess fines or oversize	Critical
Moisture (% wet)	Energy loss, conveyor sticking	Below 10%	Above 15%	Important
Calorific value (gross, MJ/kg)	Energy contribution to the process	30 to 34 MJ/kg	Below 28 MJ/kg	Important
Heavy metals (Zn, Pb, Cd, As, Cu)	Accumulate in dust and in slag	Below fossil coal baseline	Any metal significantly above coal baseline	Important
PAH16 and dioxin profile	Environmental compliance, permit risk	Below site permit limits	Exceeds EBC-BasicMaterials or local permit	Important

If you are new to biochar in steel

Do not let a supplier sell you on fixed carbon alone. Ash, sulphur and phosphorus decide whether a bio-coal is usable; particle sizing decides whether you can even feed it. On a first purchase, require a full proximate plus ultimate analysis and a particle size distribution on every lot, not just the qualification sample.

Certifications and standards

The two biochar certification schemes worth asking about are the European Biochar Certificate (EBC) and the World Biochar Certificate (WBC), both issued by Carbon Standards International (CSI) in Switzerland. EBC has seven class-specific grades (from strictest to most permissive: EBC-FeedPlus, EBC-Feed, EBC-AgroOrganic, EBC-Agro, EBC-Urban, EBC-ConsumerMaterials, EBC-BasicMaterials). WBC is a simpler international three-grade scheme (WBC-Premium, WBC-Agro, WBC-Material) used mainly by producers outside Europe. For metallurgical bio-coal the relevant grade is the lowest tier of each - EBC-BasicMaterials in Europe, WBC-Material internationally - which cover PAH, heavy metals, feedstock traceability and production-process transparency.

• EBC-BasicMaterials (or WBC-Material for non-EU producers). The European Biochar Certificate grade covering industrial bio-carbon product such as metallurgical bio-coal. Covers PAH, heavy metals, feedstock traceability and CO2 balance methodology.
• ISO 17225-8. International solid biofuel specification for thermally treated and densified biomass (including bio-coal). Often referenced in tender documents.
• ISO 14067 / PAS 2050 lifecycle assessments. Product carbon footprints prepared to ISO standard are increasingly mandatory for tier-1 OEM customers of the steel mill.
• CBAM-ready documentation. The EU CBAM requires monthly reporting of embedded emissions from 2026 onwards. A bio-coal supplier that ships to EU mills must provide auditable LCA data compatible with the CBAM default-values system.
• REACH. Industrial bio-coal usually falls under REACH as a substance. Ensure the supplier either holds a registration, benefits from a charcoal exemption, or has a documented position with the European Chemicals Agency.
• Feedstock traceability. Buyers under EU Deforestation Regulation (EUDR) and similar regimes need geocoded feedstock sourcing. Ask for it.

Shipping - bulk logistics for metallurgical product

Volumes are larger than for agricultural biochar. A mid-size trial is 500-2000 tonnes; a commercial offtake is 20,000-200,000 tonnes per year. Handling formats change accordingly.

• Bulk vessel (handysize or supramax). Used for transoceanic export of 10,000-50,000 tonne parcels. Requires a CIQ self-heating test report (Class 4.2 exemption or declaration) and a Material Safety Data Sheet acceptable to the P&I club.
• Containerised bulk (20ft sea containers with liners). Default for 50-1000 tonne parcels. Typically 18-22 tonnes per container for dense densified bio-coal, 10-14 tonnes for loose granulate. Liner bags prevent dust and moisture ingress.
• FIBC big bags in containers. Standard for PCI pilot volumes and for recarburiser shipments where traceability matters. 500-1000 kg bags, four loops, UV-treated PP, liner optional.
• Densified and pelleted formats. Some suppliers pelletise or briquette to improve handling, reduce dust and lift bulk density from 280-400 kg/m3 (loose) to 550-700 kg/m3 (pellets). Densification adds cost but often pays back in freight and dust-control savings.

Points to negotiate explicitly:

• Moisture at load port. Below 10% wet basis is the technical ideal: higher moisture means lost calorific value and freight paid on water. Before you fix a target in the contract, check with your shipping line and with the supplier whether the carrier, the port authority or the hazmat classification imposes a mandated minimum moisture level for self-heating or dust-explosion reasons - some carriers will not load finely pulverised carbon below a floor (often 5 to 8%) without a Class 4.2 declaration. Agree a range that clears both the metallurgical spec and the shipping rules.
• Self-heating classification. Finely pulverised or freshly produced bio-coal can be UN 3088, Class 4.2. Require the supplier to present either an N.4 self-heating test exemption or a hazmat declaration with appropriate packaging and stowage.
• Dust management. Request a maximum fraction below 125 um and ask whether the product is sprayed, densified or bagged with dust-suppressant liners.
• Explosion risk. For pulverised PCI grade, bio-coal has a higher volatile content than anthracite and can behave differently in pulverising mills. Require a dust explosibility (Kst, Pmax) data sheet.
• Ship-hold monitoring. For parcel shipments, insist on temperature monitoring on the ship-hold and a cooling plan.

Import and customs clearance

• HS codes. Bio-coal typically clears under HS 4402.90 (wood charcoal, not agglomerated, other than coconut shell), HS 4402.10 (coconut shell charcoal), or HS 3802.90 depending on activation and destination. Ask the supplier which code has worked for previous EU or US shipments.
• CBAM reporting (EU). From 2026 onwards, EU importers pay for the embedded emissions of steel product. If your mill substitutes bio-coal for fossil carbon, the CBAM certificate burden falls per tonne of steel produced, not per tonne of bio-coal, but the accounting must be airtight. Expect to request a supplier-specific LCA report.
• Anti-dumping and safeguard duties. Some jurisdictions treat imported carbon products the same as coal and apply duties. Check with your customs broker.
• Feedstock legality. EU Deforestation Regulation (EUDR) applies to wood-based feedstock from mid-2025. Supplier must provide geolocation and legality evidence.
• Document stack. Commercial invoice, packing list, bill of lading, certificate of origin, SDS/MSDS, N.4 self-heating test exemption or classification note, proximate and ultimate CoA per lot, ash chemistry, LCA / CBAM-ready emissions report, EBC or ISO certification where applicable.

Economics - where the euros come from

This is the one use case where the carbon math is the business case. A tonne of bio-coal replacing fossil PCI coal or coke in the blast furnace typically avoids between 2.5 and 3.2 tonnes of CO2 per tonne of carbon substituted, depending on the carbon ratio of the coal being displaced.

Put into today's prices:

• EU ETS allowance price (EUA). Trading roughly in the USD 65-110 per tonne CO2 band in recent years. A steel mill that replaces one tonne of fossil PCI coal with one tonne of bio-coal avoids about USD 215-325 per tonne in ETS cost alone (at 3 t CO2 avoided x USD 85 per tonne).
• CBAM embedded emissions cost (EU imports). For non-EU mills exporting to the EU, the same math translates into CBAM certificates. From 2026 the price is effectively the EUA.
• Offtake premiums from green-steel customers. Automotive (BMW, Volvo, Mercedes-Benz), white goods and wind-tower OEMs are signing multi-year offtake contracts at USD 110-325 per tonne of steel premium. The mill pays that back up the supply chain to the bio-coal supplier.
• Stable input pricing. Seaborne coking coal has traded between roughly USD 100 and USD 600 per tonne in the past decade. Bio-coal contract pricing typically sits in a narrower band, often with indexation rather than spot exposure, which finance desks value even before the CO2 savings.

A realistic price range for industrial-grade bio-coal delivered CIF North Europe sits at USD 430 to 975 per tonne depending on fixed carbon, volatiles, ash, sizing and certification. PCI grade is typically at the lower end; premium recarburiser or coke-blend grades at the upper end. Compare to fossil PCI coal at USD 160-325 per tonne FOB Newcastle or Richards Bay, and the bio-coal premium is roughly USD 160-540 per tonne. Against avoided ETS/CBAM cost of USD 215-325 per tonne substituted, that premium is covered and a green-steel offtake premium turns it net positive.

If you are new to biochar in steel

The business case is a four-line model, not a spreadsheet: bio-coal price minus fossil coal price, minus avoided ETS/CBAM, minus green-steel offtake premium, plus any national incentive. Build it once, test it at realistic EUA prices of USD 55, 85 and 130, and the answer is usually the same - bio-coal pays back, and it does so faster the higher the carbon price goes.

Questions to ask a supplier on a first call

1. What is the fixed carbon, volatiles, ash, sulphur, phosphorus and nitrogen on the product you would be shipping?
2. What particle size distribution can you deliver, and how tight is the tolerance batch to batch?
3. What feedstock do you use, and can you provide EUDR-compliant geolocation?
4. Do you have EBC-BasicMaterials (or WBC-Material) or ISO 17225-8 certification, and can you share a recent third-party audit?
5. What is your UN 3088 / Class 4.2 classification position and do you have an N.4 exemption on file?
6. What is your current production capacity, your expected capacity next year, and what is your maximum contractable volume?
7. Can you provide a supplier-specific LCA compatible with CBAM reporting?
8. What formats do you deliver in (bulk, containerised, big bag, densified, pelleted) and at what typical moisture?
9. Which steel or ferroalloy customers have you delivered to previously, and can you provide a reference?
10. What are your typical commercial terms - CIF, FOB, EXW, indexation, minimum volume, lead time?

Next steps

BiocharLink connects EU, North American and Asian steel mills, ferroalloy producers and foundries with screened bio-coal suppliers from Europe, the Americas, Africa and Asia. Start a buyer questionnaire and we will match you to producers with the sizing, tonnage and certification your process needs.

Our team includes seasoned biochar application experts with metallurgical and sintering, blast furnace, PCI, EAF and foundry experience. If you would like to discuss specification, CBAM reporting or process integration before committing to a purchase, reach out via our contact form and we will come back to you.

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