MRV Stack
What is measured
| Domain | Typical measurements | Lab vs field |
|---|---|---|
| Feedstock | Waste/residue status, sustainability, counterfactual fate, transport, cultivation emissions | Documentary + activity data |
| Pyrolysis | Temperature, residence time, O₂ exclusion, mass balance, energy use, flue-gas CH₄/N₂O/CO | Continuous sensors and/or periodic stack tests |
| Biochar characterization | C_org, H/C_org, O/C_org, ash, moisture, metals, PAHs, PCDD/F, PCBs; optional Ro, HyPy | Accredited lab (ISO 17025) |
| Application / storage | Dry mass delivered & applied; GPS; incorporation; matrix mix ratios; custody | Field / logistics evidence |
| Permanence | Modeled F_durable / GPC–SPC from lab properties ± soil T | Lab proxies + models |
Why not field SOC stock change? Distinguishing biochar-C from native SOC at scale is difficult; standards credit characterized biochar applied to an eligible sink, discounted by permanence models—not measured ΔSOC.
Typical high-integrity characterization package
- Proximate/ultimate: moisture, ash, VM, C/H/N/O/S
- C_org (total C − inorganic C)
- Molar H/C_org and O/C_org
- Contaminants: Pb, Cd, Cu, Ni, Hg, Zn, Cr, As; PAHs; dioxins/furans; PCBs
- Agronomic: pH, EC/salts, liming, nutrients
- Advanced (program-dependent): Ro, BC_HyPy, Rock-Eval
Methods often cited: ASTM D5373 / D1762 / D4373; ISO 16948, 18134, 10390, 17025; ISO 7404-5 for Ro.
Common issuance pattern
- Produce & characterize batch
- Deduct LCA emissions (CSI: retire offsets from emission portfolio)
- Prove eligible end use with custody trail
- Apply permanence factor → issue credits ex post
- Maintain records (often ≥5 years); monitor reversal risks
Primary links
- IPCC 2019 App. 4 · estimates soil C stock change from biochar
- models soil GHG from biochar (DOI)
- Verra VM0044 v1.2
- Puro Biochar permanence
- Isometric Biochar v1.3
- CSI Global Biochar C-Sink 3.3