1
Biomass is made of carbon, oxygen, and hydrogen between the water and structural components of which it’s comprised. When the biomass is heated, it first releases moisture together with initial volatile organic compounds (VOC’s). When the moisture is driven off, gasses like methane become dominant and flammable, enabling a clean and efficient pyrolysis process.
2
In the second stage, VOC’s are driven off and ash starts to form. At Carboneers, we carefully manage this phase by introducing fresh biomass. This new biomass provides fresh energy for the fire while preserving the layers from losing their carbon to VOC’s and turning to ash. The remaining carbon reorganizes into rings which make Biochar a highly stable material.
Well-established, peer-reviewed research indicates that biochar with an H/C ratio below 0.4 consists of two fractions with different permanence[1]. Approximately 25% by weight is expected to decompose within the first 350 years, while the remaining 75% has a very high permanence of at least 1,000 years, and likely even longer.
Based on our current and consistently low H/C ratios and well-reviewed research, we can assume that at least 75% of our biochar remains stable for over 1,000 years. Carboneers only brings to market the 75% fraction of biochar produced that is estimated to have a permanence over 1,000 years, reinforcing our commitment to high quality, durable carbon removals.
Research increasingly shows that biochar is more durable than previously thought when the right parameters are met. Carboneers has demonstrated that the H/C ratio of our biochar is consistently below 0.4. Our latest tests show H/C ratios of 0.35 for corn cobs, 0.29 for cocoa pods, 0.32 for corn stalks, 0.22 for cotton stalks, 0.26 for fruit tree trimmings, 0.24 for rice straw, 0.28 for soybean stalks, and 0.06 for sorghum stalks.
[1] Schmidt HP, Abiven S, Hageman N, Meyer zu Drewer J: Permanence of soil applied biochar.
An executive summary for Global Biochar Carbon
Sink certification, the Biochar Journal 2022, Arbaz, Switzerland
www.biochar-journal.org/en/ct/109, pp 69-74
[2] Sanei, H., Rudra, A., Przyswitt, Z. M. M., Kousted, S., Sindlev, M. B., Zheng, X., Nielsen, S. B., & Petersen, H. I. (2024). Assessing biochar's permanence: An inertinite benchmark. International Journal of Coal Geology, 281, 104409.
https://doi.org/10.1016/j.coal.2023.104409
[3] Chiaramonti, D., Lotti, G., Vaccari, F. P., & Sanei, H. (2024). Assessment of long-lived Carbon permanence in agricultural soil: Unearthing 15 years-old biochar from long-term field experiment in vineyard. Biomass and Bioenergy, 191, 107484.
https://doi.org/10.1016/j.biombioe.2024.107484