Biochar Production on a Homeowner Level

What is Biochar? 

Biochar is a form of charcoal produced when various types of organic matter burn at high temperatures with little or no oxygen. This process, called pyrolysis, semi-permanently traps the carbon in organic matter in a solid form. During normal combustion, leaves, firewood, and dry grass burn until all that is left is ash. During this “normal” burning process, enormous amounts of carbon dioxide and nitrous oxide, both extremely potent greenhouse gasses, are released into the atmosphere. However, the controlled burning of organic matter can stop the combustion process at the opportune time to create biochar, which is mostly charcoal.

Biochar, then, can sequester carbon dioxide from the atmosphere, thus helping to combat global warming. As a stable form of carbon, this material can be crushed and added to soils to increase soil fertility and act as a carbon sink buried underground.

What Are The Benefits Of Biochar?

Scientists are still researching the potential benefits associated with biochar production. However, we know that as organic matter decomposes, it will inevitably release carbon dioxide into the atmosphere. And yes, that does mean that your backyard compost pile is also releasing CO2 into the air. Finding ways to stop this natural decomposition process, then, can help to reduce carbon emissions.

Project Drawdown looks at dozens of different strategies for sequestering carbon. It explains that, where biomass decomposes above ground and releases methane and carbon into the atmosphere, biochar can hold and bury the carbon from the biomass feedstock. This enables a much slower release of carbon into the atmosphere - the now stable material can be retained for centuries! Experts estimate that biochar could lead to billions of tons of CO2 being sequestered annually.

When applied to the soil, biochar acts as an amendment that enhances plant growth. Biochar is often “activated” with beneficial microorganisms and nutrients. Because it has a porous surface area, biochar essentially acts as a sponge to hold nutrients and water in the soil, making them more easily accessible by plants.

Further research has found that biochar can act as an alternative heating source in conventional wood stoves. It might even help to reduce methane emissions when fed in small amounts to cattle.

What Can Be Used To Make Biochar?

One of the most beneficial aspects of biochar is that it is possible to make it from virtually any leftover organic matter. In rural areas around the country, burning crop residues is a severe problem that negatively affects air quality and releases enormous greenhouse gasses into the atmosphere. Instead of burning leftover wheat straw, corn stalks, coffee pulp, and pruned orchard branches, turning that organic matter into biochar is a win-win solution. We can convert a problematic waste product into a carbon-sequestering and soil-improving material with a minimum amount of work.

On a household level, the fallen autumn leaves that hundreds of thousands of homeowners either burn or send to the landfill could also be an excellent source of biochar. Fallen tree branches, wood scraps, and virtually anything burnable is other potential sources for homemade biochar.

What Is the Difference between Charcoal and Biochar?

After explaining how biochar is made, many people might assume that it is the same thing as charcoal used for grilling out. Unfortunately, most charcoal sold commercially today is a mix of biomass (mostly wood) and other chemical components, including limestone and some chemical fire starter agents. Charcoal is generally produced from different types of hardwood trees, and the end product is large chunks of wood useful for cooking and grilling. 

On the other hand, biochar is entirely derived from biomass (not just trees) heated in a limited oxygen environment. Because biochar is an agricultural and soil amendment product, it is usually crushed or made into smaller-sized pellets. This powder or pellet material can then added to soil to improve its physical properties and water retention capabilities.

 Charcoal and biochar are made similarly. However, one of the sustainability drawbacks of charcoal is that large areas of standing forest are often cut down for charcoal production. On the other hand, biochar can be made from the byproducts of farms and other industries that rely on biomass. However, if you live near a campground, leftover charcoal is often a great (and free) source of biochar that you can use to improve your soil.