Decreasing the carbon footprint with biochar
Case story

Decreasing the carbon footprint with biochar

At Höganäs, we explore different ways of decreasing our carbon footprint, to be able to reach the very ambitious goal of net-zero in 2037. Replacing fossil coal with biochar in the sponge iron process is one way of reaching that goal.

The iron and steel industry, where metal powders are included, is among the largest industries in the world and a large emitter of carbon dioxide. The industry contributes to around 20 percent of global industrial sector energy consumption, and a fair amount of that energy consists of fossil-based fuels. To make the necessary transition, the industry needs to find an effective, environmentally friendly, and sustainable substitute instead of coke and coal. And biochar could be one of the possible solutions.

“Replacing fossil coal with renewables is more complicated than it may sound,” says Ryan Robinson, Process Development Engineer at Höganäs. “Our fossil coal-based process has been developed during more than 100 years and even smaller changes can have major consequences for both the process and product quality.”

Höganäs currently uses fossil coal as a reducing agent to convert iron ore into sponge iron. However, the company has successfully conducted various small-scale tests involving biochar made from biomass. In 2022, the project went from small-scale tests to full-scale tests. The project is supported by both the Swedish Energy Agency and Luleå University of Technology.

“When the small-scale tests, both in the laboratory and in production, showed no effect on the quality of Höganäs’ sponge iron, we continued planning full-scale tests with up to 20 percent biochar.

It is expected to reduce Höganäs’ fossil carbon dioxide emissions in Sweden by more than 10 percent,” says Elin Hernebrant, Development Engineer at Höganäs.

 Unfortunately, there was a setback in the project in the summer of 2022 due to a fire.

“If all goes to plan, we will resume these full-scale tests later in 2023 and it will verify if this proportion of biochar can be used permanently in our production to reduce emissions while maintaining high-quality sponge iron,” says Elin Hernebrant.



Biochar instead of fossil coke

  • Biochar could be used in the two main processes at Höganäs for metal powder production: the sponge iron process and the atomisation process.
  • If the full-scale tests are successful, Höganäs will be able to use 20 percent biochar in the processes.
  • This is expected to reduce Höganäs’ carbon dioxide emissions with more than 10 percent approximately 27,000 tonnes per year.
  • The project is supported by the Swedish Energy Agency and a collaboration with Luleå University of Technology.