Biochar
Understanding Biochar: A Solution for Climate and Soil
Biochar technology shows promise in mitigating climate change, improving soil quality, reducing waste, and producing energy as a byproduct. But what exactly is biochar, and what is it made of?
What is Biochar?
Biochar is a charcoal-like substance created by burning organic material from agricultural and forestry wastes, known as biomass, in a controlled process called pyrolysis. Unlike common charcoal, biochar is produced to reduce contamination and safely store carbon.
How is Biochar Made?
Biochar is made through pyrolysis, where organic materials like wood chips, leaf litter, or dead plants are burned in a low-oxygen environment. This process ensures that the materials release minimal contaminating fumes. The organic material is converted into biochar, a stable form of carbon that resists escaping into the atmosphere. Additionally, the heat generated during pyrolysis can be harnessed as a clean energy source. Biochar is more efficient at converting carbon into a stable form and is cleaner than other forms of charcoal.
Physical and Chemical Properties of Biochar
- Appearance: Black, highly porous, lightweight, and fine-grained.
- Composition: Approximately 70% carbon, with the remainder consisting of nitrogen, hydrogen, oxygen, and other elements. The chemical composition of biochar can vary depending on the feedstocks and pyrolysis methods used.
Benefits of Biochar
- Climate Change Mitigation: By converting organic material into stable carbon, biochar helps reduce the amount of carbon released into the atmosphere.
- Soil Improvement: Biochar enhances soil quality by improving its structure, water retention, and nutrient-holding capacity.
- Waste Reduction: The use of agricultural and forestry wastes for biochar production reduces waste.
- Energy Production: The pyrolysis process produces energy that can be captured and used as a clean energy source.
Sequestering Carbon in the Soil Using Biochar
Soils store three times more carbon than exists in the atmosphere. Plants absorb atmospheric carbon during photosynthesis, and when plant residues return to the soil, they contribute to soil carbon. Although much of this carbon eventually returns to the atmosphere as soil microbes decompose the plant biomass and release carbon dioxide, soil carbon stores can increase if the rate of carbon inputs exceeds the rate of microbial decomposition. Carbon sequestration refers to this process of storing carbon in soil organic matter, thereby removing carbon dioxide from the atmosphere.
What Type of Carbon is Biochar?
Biochar, as defined by the International Biochar Initiative, is “the solid material obtained from the thermochemical conversion of biomass in an oxygen-limited environment.” Biochar is a stable solid rich in pyrogenic carbon that can persist in the soil for thousands of years.
Biochar remains a significant topic of interest for increasing soil carbon stores and combating climate change. However, many questions remain about the specific conditions under which biochar can effectively contribute to soil carbon sequestration. Continued research is needed to draw definitive conclusions.
Our Vision for a Carbon Negative Future at Middle World Farms
At Middle World Farms, we are committed to producing biochar ourselves to sequester more carbon than we produce, achieving our ambitious goal of becoming not just carbon neutral, but carbon negative. By doing so, we aim to make a positive impact on the environment while generating millions of BTUs of energy. This energy can extend our growing seasons by heating our greenhouses and even be converted into electricity. Imagine a power station that sequesters carbon while producing power – this is our vision.
Our biochar production process is remarkably clean, producing no smoke. The key to our success lies in a steady supply of organic material, which we will source from agricultural waste, local tree surgeons, joinery workshops, and even food waste. We will never cut down trees for this purpose; instead, we will utilise materials that would otherwise go to waste and eventually release CO2 back into the atmosphere.
This is a massive project with a long journey ahead, but with your support, we believe we can turn this vision into reality. Together, we can create a sustainable future that benefits both our community and the planet.