All About Biochar

Chris Brinton For several years, our biology instructor, Mr. Chris Brinton, has been using biochar to introduce sustainability concepts to AGCS High School students. He encourages students to explore biochar in a hands-on way, employing principles drawn from chemistry, biology, physics, environmental engineering and mathematics. Mr. Brinton’s use of biochar as a teaching tool is not only innovative, it is faithful to our school’s ongoing commitment to project-based-learning. 

 

What is Biochar?

Biochar is charcoal that is specifically produced for application to soil to improve plant growth and health. Many sources of organic matter may be used to produce biochar, but will impact its properties. Biochar differs from the charcoal that is used for cooking because its components are specially formulated and optimally balanced for soil.   Biochar

Current interest in biochar has been inspired by the historical use of charcoal to amend “terra preta” and “terra mulata” soils in the Amazon Basin. These soils were high in
crop productivity in an otherwise unproductive soil type, and were the result of the use of charred materials by the area’s inhabitants. The study of these ancient soils has demonstrated the benefits and persistence of charred matter in soils for long spans of time.

What is Biochar made from?

Biochar is made from the pyrolysis (heating) of organic biomass. In simple terms, waste materials are heated in the absence of oxygen to break chemical bonds of volatile matter within the biomass. This process results in a carbonen-riched co-product (along with heat energy and syn-gas/bio-oils) called biochar. Biochar has been made from most organic wastes such as wood chips, crop residues and manures; emphasis is placed on using currently discarded organic waste.

How does it benefit soil?

Many benefits to soil characteristics have been demonstrated by the incorporation of biochar. Increases in water retention, microbial activity and plant yields have been documented, in addition to reductions in nutrient leaching and fertilizer inputs. These benefits are realized due to the porous nature of biochar, which allows for the adsorption of nutrients, water and other soil inhabitants. These benefits are potentially superior to those of other organic sources due to the longevity of biochar in the soil.

Are there any other benefits?

Biochar production retains carbon while producing energy and synthesis gas, harboring the potential to be carbon negative. The energy production potential and the stability of biochar in soil combine to have important implications for reducing atmospheric CO2 increases, and therefore the impact of climate change.

Biochar-Producing Stoves to Benefit Climate, Health, and Soil

To those who live in the developed world, it may come as a surprise to learn that more than two billion people still cook and heat their homes with primitive stoves or open fires, burning wood, straw, dung, or coal.

These inefficient technologies emit air pollution that can harm respiratory and cardiac health and exacerbate global warming. People struggle to gather enough biomass fuels to meet their needs. And in many cases, the demand for wood accelerates deforestation.

For nearly two decades a small group of researchers and development advocates has worked to improve household biomass energy technologies. Now concerns over global warming have added a new reason to accelerate the transition to cleaner biomass energy use in the developing world. New stove technologies can produce both heat for cooking and biochar for carbon sequestration and soil building. Limited testing indicates that these stoves are much more efficient and emit less pollution.

Potential Benefits of Biochar-Producing Stoves

Health 

Biochar-producing stoves are potentially much cleaner, with lower emissions of carbon monoxide, hydrocarbons, and fine particles. 

Climate

Biochar-producing stoves have lower greenhouse gas (carbon dioxide and methane) and black carbon emissions, create biochar that can be used to sequester carbon in soils, and reduce the use of fossil-fuel based fertilizers.

Deforestation

Biochar-producing stoves use less fuel, can use a wider variety of fuels, and can replace inefficient charcoal production technologies.

Soils

Biochar-producing stoves create biochar that sequesters carbon in soils, may in some cases reduce emissions of nitrous oxide (a powerful greenhouse gas) from soils, improves fertility, and increases productivity in degraded soils.

Income Generation: Biochar-producing stoves can accommodate many forms of agricultural residues — some without further treatment. Collecting this residue is another income generating opportunity not presently available for most other stoves since they cannot utilize that type of fuel.

Source: International Biochar Initiative Website  Biochar International