US cleantech manufacturer ONYM is due to commission its first commercial-size biochar plant later this year, supplying steelmaker ArcelorMittal with 15,000 t/yr of biochar, about 36,000 t/yr of dry pyrolysis oil and 10,000 t/yr of wood vinegar for its steel mill in Quebec, Canada, the firm's executive vice-president Mustapha Ouyed told Argus. The project follows the successful trial of an ONYM demonstration plant in La Tuque, Quebec, which produced 1,700 t/yr of biochar, 4,300 t/yr of dry pyrolysis oil and 1,300 t/yr of wood vinegar in 2016-19.
1. What stage is the project with ArcelorMittal currently at and when do you expect to start commissioning biochar production at the plant?
Following the collaboration agreement signed with ArcelorMittal Long Products Canada, ONYM is currently producing metallurgy-grade biochar to support qualification testing.
The tests will validate biochar performance for potential use in low-carbon steel production.
These trials will also support the development of ONYM's first large-scale commercial facility dedicated to serving heavy industry needs.
2. What type and volumes of biomass will it use? And where will you source the raw material?
The upcoming commercial facility will process approximately 80,000 t/yr of dry woody biomass.
Feedstock will primarily come from forest industry residues, but ONYM is also committed to maximising the use of urban wood waste — such as tree trimming, pruning residues and clean post-industrial wood — replicating the short supply chain and circular economy approach already in place at our Montreal pilot site.
3. How much CO₂ emissions reduction will result from the use of biochar at the industrial client's site? And will you earn carbon removal credits from biochar sales?
Based on current scenarios:
• If our anhydrous pyrolytic oil replaces natural gas combustion and biochar replaces metallurgical coal, the potential GHG reduction could reach around 70,000 t/yr of CO₂ equivalent.
• If heavy fuel oil is displaced instead, the reduction could exceed 90,000 t/yr of CO₂ equivalent.
When sold to facilities regulated under Quebec's Cap-and-Trade System (SPEDE), our products generate surplus emission allowances for the buyers.
The carbon value is embedded in our product pricing while remaining competitive against the total cost of using fossil alternatives such as natural gas or metallurgical coal.
4. How do you price biochar?
We position our biochar at a price point that is competitive with the total cost of metallurgical coal usage, while integrating the embedded carbon reduction value.
Our pricing remains lower than most comparable market offerings observed to date, supporting industrial decarbonisation at scale.
5. What technology are you using to produce biochar?
ONYM's proprietary technology is based on an auger-type pyrolysis reactor operating at near-atmospheric pressure, using carbon steel balls as the heat transfer medium instead of traditional sand.
This design results in lower capital and operating expenditures compared with conventional pyrolysis technologies.
Unlike many systems that focus on a single output, ONYM's platform enables the simultaneous and efficient production of biochar, pyrolytic oil, renewable gases and wood vinegar, maximising biomass valorisation across multiple markets.
6. What was the outcome of your showcase plant? And what was the biochar production capacity of the project?
Our Montreal showcase plant successfully achieved its design capacity of 1.2 t/hr of dry biomass processed. With full continuous operations, the plant's potential reaches approximately 2,000 t/yr of biochar.
Operations validated product quality, reactor stability, and the ability to meet the stringent performance standards required by industrial sectors.
7. How many other projects are you planning, what capacity are they and when will they start operating?
ONYM has secured a robust pipeline of projects across North America and internationally, with target processing capacities ranging from 80,000 t/yr to 120,000 t/yr of dry biomass per facility.
Several of these projects are scheduled to materialise over the next two to three years, aiming to supply decarbonisation solutions to multiple heavy industries.
8. To which industries and geographies do you plan to supply biochar?
Our focus is on heavy industry applications — including steel, cement, and metallurgy — where carbon-neutral materials can displace fossil carbon sources directly.
We are also targeting the carbon credit market and emerging opportunities in sustainable agriculture.
Our geographic reach prioritises Canada, the US and selective entry into European markets aligned with strong decarbonisation policies.
9. What key challenges and opportunities does ONYM see in the coming years?
To accelerate decarbonisation, the availability of high-quality, carbon-negative bioenergies must scale rapidly.
At ONYM, we believe it is time to move beyond pilots and prototypes — and build the infrastructure necessary to industrialise circular bioenergy production at scale.
We invite industries, governments and biomass suppliers to collaborate with us to expand the volume, reach and climate impact of these essential solutions.
