Fact sheet biochar concrete

Key Facts A1-3

  • CO₂- emissions: 131.6 kg/m³

  • Specific weight: 2350 kg/m³

  • Fire protection class: A1 according to EN 13501-1; DIN 4102

  • Thermal conductivity: 0.138 - 0.155 W/m.ºK

The only significant way to get a C-sink in concrete at the moment is biochar. There are a number of start-ups in this area. We have achieved industrial scaling through our own research & development together with CarStorCon. You can now use biochar concrete in any construction project and receive CO2 certificates for your use. Worldwide.

    • CO₂- Capturing biogenic: 3.19 kg CO₂/kg biochar = CO₂ - reduction of greenhouse gases through photosynthesis

    • 100% from biogenic residues - organic materials from waste e.g. green waste, municipal waste

    • Biomass to biochar: Green waste is thermally decomposed/gasified in a controlled manner
      with a lack of O₂ and used for energy (pyrolysis at approx. 700 °C)

    • contains approx. 87 % organic carbon and has a
      surface area of 400 m²/g

    • Replaces aggregates with negative environmental impact - Life cycle assessment improvement

    • More environmentally friendly than normal concrete

    • more difficult flammability - strongly covalent C-C
      bonds delay oxygen transport

    • low thermal conductivity- high porosity
      interrupts thermal bridges

    • low (bulk) density - lighter concrete

    • increased flexural strength - mechanical interlocking
      of the biochar with the cement matrix

  • #biogen:

    • CO₂- Capturing: 3.19 kg CO₂/kg plant carbon

    • CO₂- emissions Production: 0.2 kg CO₂/kg vegetable carbon

    • If plant carbon is installed, the absorbed CO₂ remains stored for long periods.

    • Biochar embodies optimal resource utilization

    • Food/wood waste means waste of resources used for production (land, water, energy, inputs)

    • Cradle-to-Cradle: concrete with biochar is recyclable, or can be crushed and returned to production

    • Approx. 100 CHF /m3 more expensive than conventional concrete

    • Additional costs can be partially offset by CO2 certificates

    • If the dosage is "wrong", the concrete quality decreases, which in turn has to be compensated for with more cement.

      Conclusion: CO2 net emissions from 230 to around 130kg/m3 is a milestone. However, "climate concrete" is a fallacy as much more cement is used to achieve parity.