Biochar

News: The CO2 removal technologies such as biochar are expected to play a crucial role as the Indian carbon market set to be launched in 2026.

About Biochar

• Biochar is a type of charcoal rich in carbon and is produced from agricultural residue and organic municipal solid waste (also called biomass).
• Purpose: The main purpose for the creation of biochar is for carbon sequestration.
• Formation: It is made by burning the biomass in a controlled process called pyrolysis.
  • During pyrolysis, organic materials are burned in a container with very little oxygen.
  • As the materials burn, they release little to no contaminating fumes.
  • During the pyrolysis process, the organic material is converted into biochar, a stable form of carbon that can’t easily escape into the atmosphere.
  • The energy or heat created during pyrolysis can be captured and used as a form of clean energy.
• Physical characteristics: It is black, highly porous, lightweight, fine-grained and has a large surface area.
• Chemical features: Approximately 70 percent of its composition is carbon.
• The remaining percentage consists of nitrogen, hydrogen and oxygen among other elements.
• Applications of biochar as a carbon sink
  • In Agriculture: Biochar can hold carbon in the soil for 100-1,000 years due to its strong and stable characteristics, making it an effective long-term carbon sink.
    • Applying biochar can improve water retention, particularly in semi-dry and nutrient-depleted soils.
    • It can abate nitrous oxide emissions by 30-50% (a greenhouse gas with 273-times the warming potential of CO2).
  • Soil retention: Biochar can also enhance soil organic carbon, helping restore degraded soils.
    • This process is modeled after a 2,000-year-old practice in the Amazonian basin, where indigenous people created areas of rich, fertile soils called terra preta (meaning “dark earth”).
  • In carbon capture applications: The modified biochar can adsorb CO2 from industrial exhaust gases.
  • In the construction sector: It can be explored as a low-carbon alternative to building materials.
    • Adding 2-5% of biochar to concrete can improve mechanical strength, increase heat resistance by 20%, and capture 115 kg of CO2 per cubic meter, making building materials a stable carbon sink.
  • In wastewater treatment: It offers a low-cost and effective option to reduce pollution.
    • India generates more than 70 billion lt. of wastewater every day, of which 72% is left untreated. A kilogram of biochar, along with other substances, can treat 200-500 lt. of wastewater, implying a biochar demand potential of 2.5-6.3 million tones.