Charcoal in silicon production

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Charcoal is regarded as CO2 neutral. Using charcoal instead of fossil coal in the production of silicon and ferrosilicon could reduce Elkem’s CO2 emissions significantly. This is a key part of Elkem’s sustainable production strategy.

Silicon is produced using quartzite rock. Silicon is formed in a chemical process under high temperatures in a smelting furnace filled with quartz and carbonaceous materials. The process in the furnace causes the oxygen in the quartz to bind with the carbon. Quartz that is free of oxygen is silicon. The carbon that binds with oxygen becomes CO2. That is why producing silicon always produces CO2.

Using charcoal

Today Elkem primarily uses fossil coal as the carbonaceous material in our silicon and ferrosilicon production. Fossil coal has many advantages: Elkem requires extremely large quantities of carbonaceous materials of many different qualities and the global fossil coal market can meet its needs. As well as being easy available, fossil coal is a financially attractive alternative. However, it is the main source of Elkem’s current CO2 emissions.

Elkem already uses some charcoal in the smelting process and has for many years researched the quality-related, technical and practical aspects of replacing fossil coal with charcoal. Charcoal has advantages as an ingredient in the smelting process, but also disadvantages, because it contains trace elements that diminish the quality of some of Elkem’s products.


The main challenge today is that there is no functioning market that can supply the quantity of charcoal Elkem needs in its production process. Elkem has investigated the possibility of buying charcoal from production plants in equatorial countries where biomass grows rapidly that could provide a basis for industrial-scale charcoal production. Elkem requires charcoal of a defined quality in large quantities for its production, and buying a little from here and a little from there from small producers is not a practical alternative. Our experience from these projects shows that the risk of becoming directly or indirectly involved in deforestation, human rights violations, and corruption is very high.

Sustainable charcoal

Elkem has to establish very strict controls for charcoal suppliers to avoid becoming complicit in such violations. Elkem has adopted a specification of requirements for sustainable charcoal, which all suppliers must satisfy, as  a basis for the further work on these issues. The requirements stipulate that the timber must come from a sustainable source, that the working conditions in the production process must be acceptable and comply with human rights, and that there will be zero tolerance of corruption and breaches of the law.

Norwegian timber

Charcoal produced using Norwegian timber as the raw material does not carry the same degree of risk with respect to sustainability, corruption, and human rights. The challenges here are availability, volume and price. Nor is there currently a production plant for charcoal in Norway and, given the current situation, estimates show that charcoal based on Norwegian timber would be many times more expensive than fossil coal. This would raise production costs and could result in Elkem’s products being priced out of the market. Such a situation would be bad for the climate because most of Elkem’s competitors in the global market use fossil coal in both their silicon production and their energy production.

Elkem wants to increase the proportion of charcoal in its production processes. We are actively seeking business opportunities that makes it possible to increase the use of charcoal that are ethically and financially sustainable.

A collaboration has been established with the industry, the Norwegian Ferroalloy Producers Research Association (FFF), and the Norwegian authorities to both analyse opportunities and find sustainable solutions.

Elkem is also working on technologies and research that in the future may make Norwegian timber attractive. The ultimate goal is for Elkem to become carbon neutral in the production of both silicon and ferrosilicon.