Groups keyboard shortcuts have been updated
Dismiss
See shortcuts

Evaluating the two-pool decay model for biochar carbon permanence

26 views
Skip to first unread message

Geoengineering News

unread,
Jan 10, 2025, 6:17:00 PMJan 10
to CarbonDiox...@googlegroups.com
https://link.springer.com/article/10.1007/s42773-024-00408-0

Authors
Hamed Sanei, Henrik Ingermann Petersen, David Chiaramonti & Ondrej Masek 

08 January 2025

Abstract
Accurate estimation of biochar carbon permanence is essential for assessing its effectiveness as a carbon dioxide removal (CDR) strategy. The widely adopted framework, based on the two-pool carbon exponential decay model, forms the basis of policy guidelines and national CDR accounting. However, our re-analysis of the meta-data used in this model reveals significant deficiencies in its parameterization, leading to two critical issues. First, the current parameterization assigns a disproportionally low percentage of the labile carbon fraction (C1) relative to the recalcitrant fraction (C2), effectively reducing the model to a single-pool approach. Due to the limited duration of incubation experiments, the decay constant of the labile fraction is incorrectly applied to the entire biochar mass, resulting in a considerable overestimation of the biochar decay rate. Second, our analysis reveals a lack of causal correlation between the assigned proportions of C1 and C2 and key carbonization parameters such as production temperature and hydrogen-to-carbon (H/C) ratios, suggesting that the model does not accurately represent the underlying chemistry. This misalignment contradicts the established relationship between increased biochar stability and a higher degree of carbonization. Consequently, the the parameterization of current model may not adequately reflect the carbon sequestration potential of biochar. While a multi-pool decay model is suitable for predicting the permanence of biochar, the primary issue with the current model lies in its parameterization rather than its structure. To address these limitations, we recommend that future research prioritize the development of a revised multi-pool decay model with improved parameterization, supported by empirical decomposition data from a variety of experimental methods, including incubation studies, accelerated aging experiments, and comprehensive physicochemical characterization. This refined approach will improve the accuracy of biochar permanence estimations, strengthening its role in global carbon management strategies.

Highlights
Reassessment of biochar decay model reveals key parameterization deficiencies.

Current model substantially overestimates biochar decay rates.

Model misaligns with the chemistry underlying the decay behavior of biochar.

New decay models for biochar permanence need improved parametrization.

Enhanced model aims to strengthen biochar's role in carbon management strategies.

Source: SpringerLink

Greg Rau

unread,
Jan 14, 2025, 11:40:22 PMJan 14
to andrew....@gmail.com, CarbonDiox...@googlegroups.com
--
You received this message because you are subscribed to the Google Groups "Carbon Dioxide Removal" group.
To unsubscribe from this group and stop receiving emails from it, send an email to CarbonDioxideRem...@googlegroups.com.
To view this discussion visit https://groups.google.com/d/msgid/CarbonDioxideRemoval/CAHJsh9-Ej5GJh4QEXQtm_1iXfqheqp9febk-DonkBmjy8Nm8KA%40mail.gmail.com.
Reply all
Reply to author
Forward
0 new messages