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The Science of CoolTerra™ Biochar

Learn about the science behind biochar and biochar enhancement

A buzz has been building around biochar… but what exactly is biochar and how is it made? What are its applied benefits and what is its potential for impacting climate change?

Biochar is the residual solid material left over after pyrolysis under oxygen deficient processing conditions at temperatures usually ranging between 300 and 900 C. Biochars typically contain 70-80% fixed carbon and the residue consists of inorganic minerals (or ash), semi-volatile heavy organic compounds and low levels of water. The higher the carbon content, the longer a biochar will remain structurally and chemically unchanged in the soil.

Cool Planet starts with its proprietary pyrolysis process, which strips valuable hydrocarbons from the original biomass and converts them into different bio-fuels. Depending on the particular processing conditions, most of the bio stocks retain their original cellular and plant morphologies after pyrolysis and the resulting biochars preserve these structural features.

SEM images of biochar made from different bio stock

Figure 1: SEM images of biochars made from different bio stock: Pine (top) and Coconut shells (bottom)

The most important feature of all biochars is their relatively high surface area that results from complex networks of pores of different diameter. In turn these pores provide a wide range of secondary beneficial properties such as high water retention-, ion exchange- and sorption capacities. The pores enable the use of biochar in different practical applications – from agriculture to soil mitigation to water and air purification.

Cool Planet has developed a proprietary technology for biochar processing so that our biochar’s chemical, physical, and biological properties can be customarily matched to the specific requirements of a wide variety of applications. One area of focus is the development of Cool Planet biochars for agricultural applications as a soil amendment.

The benefits of the Cool Planet’s biochar become clear from the images below.

images of biochar showing fungal and bacterial growth in the pores of inoculated biochar after one week

Figure 2: Intense fungal (pink) and bacterial growth in the pores of the biochar.

Once mixed with the soil, the processed biochar stimulates vigorous micro- and macro-root growth both into the pores and through the biochar particles by providing nutrients and beneficial microorganisms to the plants, Figure 3. This in turn provides faster plant growth rates and higher yields, Figure 4. Lettuce field trials in a randomized bock design have demonstrated a statistically significant 60% increase in root biomass with 40% nitrogen reduction.

Development of extensive micro lettuce root systems onto and through biochar particles
Development of extensive macro lettuce root systems onto and through biochar particles

Figure 3: Development of extensive micro (top) and macro (bottom) lettuce root systems onto and through treated biochar particles

Showing difference in lettuce plants root systems and biomass sizes with and without Cool Terra(tm) biochar

Figure 4: Difference in root systems and yields of lettuce plants grown with and without (control) Cool Planet processed biochar

Biochar and Climate Change

In addition to its functional benefits, biochar has inherent value as a means of carbon sequestration. The biomass feedstock itself has a zero-carbon dioxide emission life cycle: first, the living plant absorbs CO2 from the atmosphere to support its function. When the plant dies, the carbon which the plant stored in its structure is decomposed by microbes and released back into the atmosphere as CO2. What was absorbed is released, resulting in zero-net CO2 emissions.

In contrast, the biochar production process takes the plant biomass that absorbed CO2 during its lifetime and concentrates its carbon into biochar. Biochar decomposes more slowly than the plant would have otherwise by orders of magnitude. This in effect stores the carbon dioxide absorbed by the plant into the soil and removes it from the atmosphere.

Development of extensive macro lettuce root systems onto and through biochar particles

Biochar has a multitude of benefits, be it improved agricultural productivity, improved livestock health, or a reduction in atmospheric greenhouse gases. The Cool Planet Biochar Team is dedicated to making this technology an economic reality.

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