CRCF Isometric Biochar Requirements

This Module is developed for issuing Credits under the EU Carbon Removal and Carbon Farming (CRCF) framework established by EU Regulation 2024/3012.

The CRCF Biochar Protocol v1.0 contains the core requirements for Biochar according to the CRCF Delegated Act Annex methodologies. This supplementary Module contains the relevant additional Isometric requirements from our Biochar Protocol. Any Isometric requirements entirely satisfied by the CRCF Delegated Act Annex methodologies are omitted. Those partially satisfied have been reformulated to build on the framework from the CRCF methodologies.

Additional reference standards and methodologies that inform the requirements of this Module include:

• The Isometric Biochar Production and Storage Protocol v1.2
• European Biochar Certificate (EBC) Guidelines for a Sustainable Production of Biochar v10.3
• World Biochar Certificate (WBC) v1.1

Biochar produced must not be deployed into any of the following end-uses:

• Biochar deployed into animal feed is not eligible. Biochar incorporated into the digestive tract of livestock is exposed to biological and chemical conditions under which the durability of stored carbon cannot be reliably demonstrated, and the eventual fate of the carbon (excretion, decomposition, methanogenesis) introduces durability and reversal risks that fall outside the current scope of this Module.
• Biochar deployed as an additive to anaerobic digestion processes is not eligible. The conditions within anaerobic digesters and the downstream fate of the digestate introduce durability uncertainties that are not consistent with the Isometric Standard's requirements for long-duration storage.
• Biochar deployed into oil wells, whether as a drilling additive, completion material, or for any other purpose associated with hydrocarbon extraction, is not eligible. Such deployment is incompatible with the additionality and environmental safeguarding principles set out in the Isometric Standard.

Activities depositing biochar into the built environment must not credit storage using the 200-year persistence model presented in Woolf et al. (2021).

The atomic ratio of hydrogen to organic carbon (H/C_org) in the biochar must be measured for every Production Batch and must be below 0.5. Production Batches with H/C ≥ 0.5 are not eligible for CRCF crediting and must be excluded from the Activity.
A higher H/C ratio is associated with a lower degree of aromatic condensation and reduced chemical stability of the biochar (see the Isometric Biochar Protocol). The 0.5 threshold reflects the upper bound at which biochar can be considered to have undergone sufficient pyrolytic conversion to support long-duration carbon storage.

For each Production Batch, the Activity must measure and report the properties listed in Table 1. Measurement methods must be cross-referenced to the relevant standard in Table 1, or to an equivalent method agreed with Isometric in advance.

Table 1. Required biochar properties for CRCF certification

This Section details the sampling requirements for biochar Activities.

The CRCF Delegated Act Annex permits Certification Schemes to set additional requirements on the definition of a Production Batch, to limit the permissible variation of the biochar within a batch, and to set a maximum allowable batch size.

A Production Batch must be defined as a period of less than one month, even where the Production Process is consistent across a longer interval. Once a maximum Production Batch duration is defined for the Activity, it must be applied consistently across all sampling activities.

The Operator must justify their chosen Production Batch duration in the Activity Plan.

A Production Batch must consist of biochar produced from a consistent feedstock under consistent pyrolysis conditions. The Activity must define in the Activity Plan the acceptable operating ranges for the parameters detailed in Section 5.1.2.1 to 5.1.2.4. Any excursion outside these documented ranges during production must trigger termination of the current Production Batch and initiation of a new Production Batch.

Activities with continuous-flow pyrolysis equipment must document how batch boundaries are defined in operational practice (for example, by start/stop events, feedstock change events, or shift changes).

The Operator must specify in the Activity Plan the biomass feedstock species or blend permitted within a single Production Batch. Where a blend of feedstocks is used, the Operator must define the acceptable variation in blend ratio (mass-fraction tolerance) within a single batch. A change in feedstock species, or a deviation in blend ratio outside the documented tolerance, must trigger a batch break.

The Operator must specify in the Activity Plan the acceptable feedstock moisture content range (% w/w) within a single Production Batch. Feedstock entering pyrolysis with moisture content outside this range must either trigger a batch break, or be pre-treated (e.g. dried) to bring moisture content within the documented tolerance prior to pyrolysis.

The Operator must specify in the Activity Plan the acceptable pyrolysis peak temperature range (°C) within a single Production Batch. Continuous monitoring of pyrolysis temperature is required across the batch. A sustained excursion outside the documented range must trigger a batch break.

The Operator must specify in the Activity Plan the acceptable pyrolysis residence time range within a single Production Batch. A deviation outside this range, for example, due to changes in feed rate, equipment fault, or a change in operating mode, must trigger a batch break.

A Production Batch must not exceed 500 tonnes of biochar (dry-mass basis). Where the time limit, mass limit, or any of the consistency limits is reached first, the current Production Batch terminates and a new Production Batch must be initiated.

An Operator may propose to Isometric an alternative maximum Production Batch mass in advance of the Certification Audit, where the Activity's sampling design demonstrably preserves statistical representativeness at a higher mass threshold. Any alternative threshold must be agreed with Isometric in writing prior to its application, and documented in the Activity Plan.