Puro Project Cycle and MRV
Parent concept: Puro CORC200+
Method detail: Puro Biochar Methodology Edition 2025
Operator: Puro.earth Overview
Generic MRV framing: MRV Stack
This chapter walks the full path from listing a facility to retiring CORCs: audits, lab metrics, chain of custody, auditor allocation, public fees, and a practical US producer path with common pitfalls. Facts from the Puro deep-dive research (2026-09-14) and primary fee/V&V documents cited there.
End-to-end cycle (one page)
Initial Qualification
↓
Platform Agreement + KYC → MyPuro (€1,400/yr)
↓
Facility Registration
↓
Audit Package (± optional Preliminary Assessment / Future Facility)
↓
Facility Audit (Puro-allocated VVB) → Certified Facility
↓
Produce → Apply to eligible use → Monitor
↓
Output Report → Output Audit (≥ annually)
↓
CORC issuance → transfer / sale → Buyer retirement
Critical rule: Point of CORC creation = first durable eligible use (rule 2.3.1) — ex-post relative to application, not factory gate alone. Claiming credits before use proof is a top failure mode. Eligibility of uses: Puro Biochar Methodology Edition 2025 · ownership: Double Counting and Credit Ownership.
Certification journey (detailed)
Public journey from Fees / certify pages:
| Step | What happens | Notes |
|---|---|---|
| 1. Initial Qualification | Supplier interest / questionnaire | Screens fit for Puro engineered-CDR pathways |
| 2. Platform Agreement + KYC | Become MyPuro Account Holder | Annual Fee €1,400 / 12 months |
| 3. Facility Registration | Unique Production Facility ID in registry | Stationary vs Mobile definitions matter under Ed. 2025 |
| 4. Audit Package | Biomass evidence, LCA, Monitoring Plan, additionality questionnaire, permits, SDG/safeguards | Heaviest prep step for most producers |
| 5. Preliminary Assessment (optional) | Future Facility listing | 2022 PAs do not transfer to Edition 2025 |
| 6. Facility Audit | Third-party VVB; typically on-site first audit | Puro allocates VVB; Puro covers verification costs per public fees narrative |
| 7. Operations + Output Audits | Output Report → Output Audit → issuance | ≥ annually; more frequent by volume tiers |
| 8. Issuance → sale → retirement | CORCs to supplier account | Retirement fee €0.25/CORC unless offtake waiver |
Crediting period under Edition 2025: 10 years, renewable twice after new Facility Audit against latest rules. Capacity expansion of similar reactors possible without resetting period (rules 3.1.6–3.1.8).
Output frequency scales with volume (General Rules 4.4 table on fees page): from 1×/yr below ~10k CORCs up to 12×/yr above 60k (per deep-dive extraction of fees page).
Who the supplier is
- CO₂ Removal Supplier = biochar producer or contracted representative with sole CORC claim rights and end-to-end data access (rules 2.1.1–2.1.3)
- Must comply with methodology + Puro Standard General Rules + local law
- Double-claiming / intermediary diversion risks: Double Counting and Credit Ownership
MRV stack under Edition 2025
| Layer | Requirements |
|---|---|
| Biomass CoC | Declared sources + batch records; BSC category / traceability / sustainability; impurity & fossil-C monitoring |
| Process | Temperature/residence monitoring for Regime A (1-min); combustion uptime; CH₄/N₂O; waste & co-product fate |
| Lab | Accredited lab preference; elemental analysis standards (ISO 16948, ASTM D5373, etc.); moisture/bulk density methods listed in methodology §6.1 |
| Sampling frequency | Regime A: ≥2×/year/biochar type; Regime B: ≥4×/year; auditor may resample on site |
| End-use evidence | Proof of eligible use (geotag/application docs, sales contracts, intermediary agreements); cascading-use evidence where required; retail R3: particle size/moisture, labelling, last-intermediary contracts, country RDF |
| Digital MRV | MyPuro portal + registry tracking; third-party dMRV platforms (e.g., Carbonfuture) used by some suppliers in market practice — not a universal Puro mandate in the methodology text |
| Auditors | Puro-approved VVBs; Puro allocates auditor (geography, expertise, rotation, fees) |
| Records | Monitoring Plan; Output Report; retention per General Rules |
Generic vault framing of the same layers: MRV Stack · production science: Production · quality: Contaminants and Quality · permanence metrics: Properties · Permanence
Lab metrics and sampling regimes
What must be measured for quantification
| Analytic | Why |
|---|---|
| Dry mass (impurity-corrected) | Mass basis for (Q_{\mathrm{biochar}}) |
| (C_{\mathrm{org}} = C_{\mathrm{tot}} - C_{\mathrm{inorg}}) | Enters (C_{\mathrm{stored}}) |
| H → H/C_org | Enters persistence fraction PF; hard gate H/C_org < 0.70 |
| Contaminants / environmental quality | Table 3.2 → WBC class thresholds where local regulation absent |
| Ro / petrography | Optional complementary reporting; does not change CORC math yet |
Methods listed in methodology §6.1 include ISO 16948, ASTM D5373, DIN carbonate methods, etc. Auditor may request on-site resample.
Permanence equations and worked PF examples: Puro Biochar Methodology Edition 2025 · Puro CORC200+ · Permanence Science for Credits
Sampling frequency
| Regime | When | Minimum lab frequency (permanence + C) |
|---|---|---|
| A | Continuous uniform carbonization monitoring (1-min T & residence; ±10% stability) | ≥2× per year per biochar type |
| B | No continuous uniform proof | ≥4× per year per biochar type |
Pitfall: batches with H/C_org ≥ 0.70 fail the quantification gate; under-sampling Regime B facilities is a common audit risk.
Chain of custody and end-use evidence
Biomass
- Source list + batch records
- BSC category coding + sustainability evidence
- Impurity & fossil-C monitoring (plastics, paints, sludge fossil C)
- Stockpile CH₄ controls; biohazard treatment (≥500 °C × 3 min if relying on carbonization) — method detail in Puro Biochar Methodology Edition 2025
Product
- Batch IDs, weigh tickets, moisture
- Separation of ineligible / no-CORC streams (e.g., category P land-clearing may be processed but shall not issue CORCs)
Use / application
- Proof matching Table 3.2 (application records, contracts, geotags/GIS as applicable)
- Cascading-fate evidence where required (e.g., animal cascades AH*)
- Intermediary agreements preventing diversion / double claiming (Double Counting and Credit Ownership)
- Retail R3: last-intermediary contracts + country-level RDF + product particle size/moisture + labelling
US ag practice context (not a credit methodology): NRCS soil carbon amendment in US ag
Emissions MRV highlights
| Topic | Rule / practice |
|---|---|
| Combustion uptime | Systems ≥95% normal operating time; flameout procedures |
| Residual CH₄ / N₂O | Monitoring rules for carbonization |
| Stockpile CH₄ | Quantify unless negligible criteria met |
| Fossil C in plastics / paints / sewage sludge | Counted as project emissions (assumed fully re-emitted) |
| Full LCA | Operational + embodied; co-product allocation; cut-offs |
| Leakage | Identify, mitigate, quantify residual market/activity-shifting leakage |
| Fossil support fuel | Allowed for ignition/support if no fossil C enters biochar and LCA includes emissions; coal as process fuel not allowed |
Net equation reminder:
[ \mathrm{CORCs} = C_{\mathrm{stored}} - C_{\mathrm{baseline}} - C_{\mathrm{loss}} - E_{\mathrm{project}} - E_{\mathrm{leakage}} ]
Full quantification: Puro Biochar Methodology Edition 2025
Auditors (VVBs)
Source: Validation & Verification Requirements v1.3
| Rule | Detail |
|---|---|
| Approval | Must be Puro-approved (application + methodology training) |
| Allocation | Puro allocates VVB (geography, expertise, availability, rotation, fees) — suppliers do not freely shop from a public list |
| Contracting | Framework or per-audit contracting negotiated by Puro |
| Conflicts | Conflict-of-interest checks required |
| Cost narrative | Puro covers verification costs per public fees page narrative; suppliers pay annual + volume service fees |
This allocation model differs from many VCS-style shop-your-auditor practices — relevant when comparing Verra VM0044 in Puro vs Other Standards.
Public fee anchors
Source: puro.earth/certified-carbon-credits/fees
| Item | Amount |
|---|---|
| Annual account fee | €1,400 / 12 months |
| Service fee (volume) | Tiered €10.00 → €0.40 per CORC by trailing 12-mo volume |
| Low-volume audits (≤1,000 CORC) | €12,000 flat when audit booked |
| Biochar complexity premium | 0% |
| Retirement fee | €0.25 / CORC (waivable for qualifying multi-year offtakes reported in MyPuro spanning >1 calendar year) |
| Secondary trading fee | 0% |
| Pooling admin | €2,000 / facility / year if pooling |
| Issuance-time payment | 5% service-fee discount |
Market pricing / indexes (CORCCHAR, CORCX) and deal structures: Puro Pricing and CORC Indexes · Market Volumes and Pricing · Buyers and Offtakes
Honesty: Fees change — re-pull before investment decisions.
Practical path for a US biochar producer
Recommended sequence
- Confirm feedstock fit against BSC categories (avoid A, J; understand P = processable but no CORCs).
- Map end-use channel to Table 3.2 before promising buyers CORC volumes (farm contracts vs retail R3).
- Submit Initial Qualification → Platform Agreement + KYC → MyPuro.
- Register Production Facility (Stationary vs Mobile; host-country spatial extent for fleets).
- Build Audit Package early: biomass evidence, LCA (stockpile CH₄, impurities, sludge fossil C, transport), Monitoring Plan, additionality questionnaire (especially financial additionality), permits, SDG/safeguards.
- Optional Preliminary Assessment — remember 2022 PAs are obsolete for Edition 2025.
- Facility Audit (VVB allocated by Puro).
- Produce, apply, monitor → Output Audit → issuance → sell/retire.
- Budget annual €1,400 + volume service tiers + retirement €0.25 (or offtake waiver).
Edition 2025 transition checklist
| Situation | Action |
|---|---|
| New registration on/after 1 Nov 2025 | Must use Edition 2025 |
| Pre-launch registration, not yet audited | Prefer 2025; 2022 only if complete Audit Package by 15 Dec 2025 |
| Certified under 2022 | Finish current period; renew on latest edition; optional early upgrade at next Output Audit |
| Planning beyond 12 Jun 2030 | Edition 2022 terminated — design for 2025 now |
Common pitfalls (from deep dive)
- Weak waste/residue / BSC evidence; mixing ineligible feedstock (A, J) or issuing CORCs on category P
- Claiming CORCs before eligible end-use proof
- Retail / diffuse channels without R3 safeguards / RDF
- Underestimating LCA — stockpile CH₄, plastic impurities, sludge fossil C, transport
- Failing financial additionality when biochar product margins / waste-treatment savings already make the project viable without CORCs
- Mobile fleet spatial-extent / multi-state host-country issues
- Lab cadence shortfalls; H/C_org ≥ 0.70 batches
- Edition 2022→2025 transition — renewals must meet 2025; Preliminary Assessments don’t transfer
- Double counting across registries or intermediaries — Double Counting and Credit Ownership
- Assuming CCP credit labels from program eligibility alone — biochar methodology not yet CCP-Approved (Puro.earth Overview · Puro vs Other Standards)
Broader market/integrity risks: Risks and Controversies
When to choose Puro vs other standards (ops lens)
| Choose Puro when… | Choose Verra VM0044 when… | Choose Isometric when… | Choose CSI when… |
|---|---|---|---|
| Mature BCR buyer recognition + CORCCHAR price signal + Nasdaq registry ops; mobile/retrofit/charcoal-repurpose fit | Need CCP-labelled methodology today + VCS buyer familiarity; clearly new waste facility | Buyer demands 1000-year Ro path or maximal soil MRV stringency | Already hold EBC/WBC and want GPC/SPC + EU CRCF alignment path; artisan track |
Many large buyers are registry-agnostic on BCR but diligence MRV; dual pathways are uncommon for the same tonne (double-counting rules). Full comparison: Puro vs Other Standards · peer notes: Verra VM0044 · Isometric Biochar Protocol · CSI Global Biochar C-Sink
Primary citations
- Fees / supplier journey
- V&V Requirements v1.3
- Edition 2025 v2 PDF
- Transition plan PDF
- Retail v2 update
- Registry
Also: Key Sources
See also
Puro CORC200+ · Puro.earth Overview · Puro Biochar Methodology Edition 2025 · Puro Pricing and CORC Indexes · Puro vs Other Standards · MRV Stack · Double Counting and Credit Ownership · NRCS soil carbon amendment in US ag · Biochar as Durable CDR · Permanence Science for Credits · Permanence · Production · Properties · Contaminants and Quality · Buyers and Offtakes · Market Volumes and Pricing · Risks and Controversies · Verra VM0044 · Isometric Biochar Protocol · CSI Global Biochar C-Sink · Carbon Markets Hub · Key Sources