Bio-oil Geological Storage

1.0 Introduction

This protocolProtocol (A document that describes how to quantitatively assess the net amount of CO₂ removed by a process. To Isometric, a Protocol is specific to a Project Proponent's process and comprised of Modules representing the Carbon Fluxes involved in the CDR process. A Protocol measures the full carbon impact of a process against the Baseline of it not occurring.) provides the requirements and procedures for the calculation of net CO₂e removal (The term used to represent the CO₂ taken out of the atmosphere as a result of a CDR process.) from the atmosphere via the conversion of biomass to bio-oil (A mixture of water, organic acids, aldehydes, ketones, sugars, phenols, and other organic compounds derived from the thermal breakdown of biomass. Thermal breakdown of biomass is achieved via thermochemical processes, such as pyrolysis, which heat biomass in low- or no-oxygen environments to high temperatures (~e.g. 350-650°C). Bio-oil is often also referred to as pyrolysis oil or bio-crude.) (and co-products) and injection of bio-oil into natural or engineered subsurface features or geologic formations which may include, but are not limited to, reservoirs, saline aquifers, caverns or mines, for long term sequestration of atmospheric CO₂. Bio-oil Carbon Capture & Sequestration is considered a subsector of Biomass Carbon Removal and Storage (BiCRS) (A range of processes that use biogenic material to remove carbon dioxide (CO₂) from the atmosphere and store that CO₂ underground or in long-lived products (LLNL BiCRS Roadmap, 2020).). This protocolProtocol applies to bio-oil sequestration technologies or projects, which typically consist of activities (An activity or process or group of activities or processes that alter the condition of a Baseline and leads to Removals or Reductions.) associated with three sub-processes - biomass growth, biomass conversion, and bio-oil injection and storage.

Bio-oil is a mixture of water, organic acids, aldehydes, ketones, sugars, phenols, and other organic compounds derived from the thermal breakdown of biomass¹. Thermal breakdown of biomass is achieved via thermochemical processes, such as pyrolysis, liquefaction, or gasification, which heat biomass in low- or no- oxygen environments to high temperature (approximately 350°-650°C). Bio-oil is often also referred to as pyrolysis oil or bio-crude.

Bio-oil can have co-products like biochar mixed into it ahead of injection underground. Within this Protocol, we use the words ‘bio-oil’, ‘bio-oil with biochar’ and ‘injectant’ interchangeably.

The protocolProtocol accounts for quantification of the gross amount of carbonCO₂ removed via injection of bio-oil into geologic formations, as well as the accounting for all Greenhousegreenhouse Gasgas (GHG) emissions associated with the process, including growth, collection, use, and alternate usecollection of the biomass feedstock (Raw material which is used for CO₂ Removal or GHG Reduction.), biomass conversion, biomass injection process, and all transportation and embodied emissions (Life cycle GHG emissions associated with production of materials, transportation, and construction or other processes for goods or buildings.) associated with the process, and emissions associated with leakage (The increase in GHG emissions outside the geographic or temporal boundary of a project that results from that project's activities.). The GHG AssessmentStatement (TheA processdocument bysubmitted whichalongside allClaimed emissionsRemovals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction process, including leakages, are accounted for.) is considered as a cradle-to-grave (​​Considering impacts at each stage of a product's life cycle, from the time natural resources are extracted from the ground and processed through each subsequent stage of manufacturing, transportation, product use, and ultimately, disposal.) analysis.

This protocolProtocol is developed to adhere to the requirements of ISO (A worldwide federation (NGO) of national standards bodies from more than 160 countries, one from each member country.) 14064-2: 2019 – Greenhouse Gases – Part 2: Specification with guidance at the project (An activity or process or group of activities or processes that alter the condition of a Baseline and leads to Removals or Reductions.) level for quantification, monitoring, and reporting of greenhouse gas (Those gaseous constituents of the atmosphere, both natural and anthropogenic (human-caused), that absorb and emit radiation at specific wavelengths within the spectrum of terrestrial radiation emitted by the Earth’s surface, by the atmosphere itself, and by clouds. This property causes the greenhouse effect, whereby heat is trapped in Earth’s atmosphere (CDR Primer, 2022).)emission reductions (Lowering future GHG releases from a specific entity.) or removal enhancements. The protocolProtocol ensures:

• consistent, accurate procedures are used to measure and monitor all aspects of the process required to enable accurate accounting of net CO₂e (The amount of CO₂ emissions that would cause the same integrated radiative forcing or temperature change, over a given time horizon, as an emitted amount of GHG or a mixture of GHGs. One common metric of CO₂e is the 100-year Global Warming Potential.) removals,
• consistent system boundaries and calculations are utilized to quantify net CO₂e removal for bio-oil injection projects,
• requirements are met to ensure the CO₂e removals are additional (An evaluation of the likelihood that an intervention—for example, a CDR Project—causes a climate benefit above and beyond what would have happened in a no-intervention Baseline scenario.)
• evidence is provided and verified by independent third parties to support all net CO₂e removal claims

2.0 Sources and Reference Standards & Methodologies

Specific Standards and protocols which are utilized as the foundation of this protocolProtocol and for which this protocolProtocol is intended to be fully compliant with are the following:

• Isometric Standard 1.0.0
• ISO 14064-2: 2019 – Greenhouse Gases – Part 2: Specification with guidance at the project level for quantification, monitoring, and reporting of greenhouse gas emission reductions or removal enhancements

Additional reference standards that inform the requirements and overall practices incorporated in this protocolProtocol include:

• ISO 14064-3: 2019 – Greenhouse Gases – Part 3: Specification with Guidance for the verification and validation of greenhouse gas statements
• ISO 14040: 2006 - Environmental Management - life cycle Assessment - Principles & Framework
• ISO 14044: 2006 - Environmental Management - life cycle Assessment - Requirements & Guidelines

Additional standards, methodologies, and protocols that were reviewed, referenced, or for which attempts to align with or leverage in development of this protocolProtocol include:

• Bio-oil Sequestration Prototype Protocol for Measurement, Reporting, & Verification. Carbon Direct / EcoEngineers, 2022.
• Carbon Capture & Sequestration Protocol under the Low Carbon Fuel Standard. California Air Resources Board (CARB). August, 2018.

3.0 Future Versions

This protocolProtocol was developed based on the current state of the art and current publicly available science regarding biomass conversion and bio-oil injection. Because bio-oil injection and storage in geologic formations is a novel Carboncarbon Dioxidedioxide Removalremoval (CDR) approach, with limited published literature, the protocolProtocol incorporates requirements that may be more stringent than some current relevant regulations for underground injection, or other protocols related to biomass utilization for CDR.

This approach, notably when specifying requirements for demonstrating bio-oil storage (Describes the addition of carbon dioxide removed from the atmosphere to a reservoir, which serves as its ultimate destination. This is also referred to as “sequestration”.)durability (The amount of time carbon removed from the atmosphere by an intervention – for example, a CDR project – is expected to reside in a given Reservoir, taking into account both physical risks and socioeconomic constructs (such as contracts) to protect the Reservoir in question.) or permanence, will likely be altered in future versions of the protocolProtocol as the stability of bio-oil in geologic formations becomes well demonstrated and documented, reversal (The escape of CO₂ to the atmosphere after it has been stored, and after a Certificate has been Issued. A Reversal is classified as avoidable if a Project Proponent has influence or control over it and it likely could have been averted through application of reasonable risk mitigation measures. Any other Reversals will be classified as unavoidable.) risks are proven to be limited or non-existent, and the overall body of knowledge and data regarding all processes, from feedstock supply, to conversion, and to permanent storage is significantly increased.

4.0 Applicability

This protocolProtocol applies to projects or processes which:

• utilize agricultural or forestry residues as eligible feedstocks in accordance with the framework set out in the Biomass Feedstock Accounting Module 1.1.02
• convert the biomass to bio-oil via pyrolysis or similar processes or utilize bio-oil produced by a third-party supplier
• inject the bio-oil into natural or engineered geologic formations for long duration storage purposes via an underground injection well

This protocolProtocol applies to projects and associated operations that meet all of the following project conditions:

• the project provides a net-negative CO₂e impact (net CO₂e removal) as calculated in the GHG Statement, in compliance with Section 7, on a cradle to grave GHG Assessment basis
• the biomass feedstock utilized is sustainably sourced²
• the project does no net harm to the environment and society
• the project is considered additional (An evaluation of the likelihood that an intervention—for example, a CDR Project—causes a climate benefit above and beyond what would have happened in a no-intervention Baseline scenario.), in accordance with the requirements of Section 6.54
• the project provides long duration storage (>1000 yr estimated) of carbon in geologic formations
• the geologic storage site is located in the US
• the geologic storage site is properly permitted and has a current relevant UIC well permit ³. The site must be operated in compliance with current permits including those issued by the US EPA or U.S. States for underground injection control wells and specifically identify bio-oil or an equivalent type of injectant, as acceptable injectants under the permit ⁴.

Projects that are explicitly NOT eligible include the following:

• Projects that utilize bio-oil as part of enhanced hydrocarbon recovery (EHR or EHR+) (Enhanced hydrocarbon recovery (EHR) is a tertiary hydrocarbon production technique or process where the physicochemical (physical and chemical) properties of the rock and/or the fluids are changed to enhance the recovery of hydrocarbon, typically by altering the chemical, biochemical, density, miscibility, interfacial tension (IFT)/surface tension (ST), viscosity and thermal properties to enable additional hydrocarbon production (SPE, 2023). EHR+ is the specific use of CO₂ injection for EHR where the CO₂ remains stored in the geologic formation permanently (IEA, 2015).)
• Projects that utilize biomass that doesn't meet the eligibility criteria detailed in Biomass Feedstock Accounting Module 1.1.0 module2.

5.0 Environmental and Social Safeguarding

The project must consider other environmental and social impacts and the projectProject proponentProponent (The organization that develops and/or has overall legal ownership or control of a Removal or Reduction Project.) must provide evidence that the project will do no net environmental or socioeconomic harm, complying with Section 3.7 of the Isometric Standard.

In addtionaddition to that outlined with the Isometric Standard, it must consider all aspects of the project from feedstock growth through injection and storage. At a minimum the projectProject proponentProponent must:

1. document activities conducted under the project which would require it to obtain environmental permits and provide a listing of all permits or construction approvals received or applied for and their current status and compliance history. This may include, but is not limited to, activities under the Resource Conservation & Recovery Act (RCRA), the U.S. EPA Underground Injection Control (UIC) program, the National Pollutant Discharge Elimination System (NPDES) program under the Clean Water Act (CWA), the Prevention of Significant Deterioration (PSD) program under the Clean Air Act (CAA), and other relevant environmental permits such as federal, state, county, or city permits for air, water or waste discharges;
2. document activities that would require the projectProject proponentProponent to obtain any drilling permits, access agreements, or any encroachment permits under county or city guidelines, or any federal, state, or local air, water, or restricted land use operating permits;
3. when agricultural residues are used, provide documentation of characterization of biomass in accordance with the Biomass Feedstock Accounting Module 1.1.0 Module2 to demonstrate impact on carbon and nutrient (nitrogen, phosphorus, potassium) removal;
4. provide documentation demonstrating whether the bio-oil is non-hazardous or hazardous, based on U.S. EPA RCRA requirements and testing completed by an accredited laboratory in accordance with U.S. EPA methods recommended in the Test Methods for Evaluating Solid Waste: Physical/Chemical Methods Compendium (SW-846)⁵ or equivalent, unless exempted by permit rule or standard. If the bio-oil is classified as hazardous:
   • evidence must be provided that all protocols for hazardous substance handling and management are being followed.
   • injection well permits must allow for hazardous waste injection and evidence that the permit conditions are being followed, must be provided.
   • containment within the targeted storage reservoir (A location where carbon is stored. This can be via physical barriers (such as geological formations) or through partitioning based on chemical or biological processes (such as mineralization or photosynthesis).) must be ensured and monitored, and all evidence provided;
5. demonstrate a risk assessment and mitigation plan for safeguarding working conditions, especially when it comes to safe handling and transportation of biomass feedstocks as well as workers operating the storage facility.

6.0 Relation to the Isometric Standard

The following topics are covered briefly in this protocolProtocol due to their inclusion in the Isometric Standard, which governs all Isometric protocolsProtocols. See in-text references to the Isometric Standard for further guidance.

6.1 Project Design Document

For each specific project to be evaluated under this protocolProtocol, the projectProject proponentProponent must document project characteristics in a Project Design Document (PDD) (The document that clearly outlines how a Project will generate rigorously quantifiable Additional high-quality Removals or Reductions.) as outlined in Section 3.2 of the Isometric Standard. The PDD will form the basis for project verification and evaluation in accordance with this protocolProtocol, and must include consideration of processes unique to bio-oil such as:

• location information for biomass production, biomass conversion, bio-oil injection, and geologic storage formation,
• conditions of biomass use prior to project initiation, and
• details on technologies, products, and services relevant to biomass conversion processes, including production rates and volumes.

6.2 Validation and Verification

Projects must be validated (A systematic and independent process for evaluating the reasonableness of the assumptions, limitations and methods that support a Project and assessing whether the Project conforms to the criteria set forth in the Isometric Standard and the Protocol by which the Project is governed. Validation must be completed by an Isometric approved third-party (VVB).) and project net CO₂e removals verified (A process for evaluating and confirming the net Removals and Reductions for a Project, using data and information collected from the Project and assessing conformity with the criteria set forth in the Isometric Standard and the Protocol by which it is governed. Verification must be completed by an Isometric approved third-party (VVB).) by an independent third party consistent with the requirements described in this Protocol as well as in Section 4 of the Isometric Standard.

The Validation and Verification Body (VVB) (Third-party auditing organizations that are experts in their sector and used to determine if a project conforms to the rules, regulations, and standards set out by a governing body. A VVB must be approved by Isometric prior to conducting validation and verification.) must consider following requisite components:

1. Validate that feedstock adheres to the requirements listed in the Biomass Feedstock Accounting Module 1.1.0 Module2.
2. Verify that storage sites adhere to the requirements listed in the relevant storage module.
3. Verify that the quantification approach and monitoring plan adheres to requirements of Section 7, including demonstration of required records.
4. Verify that the Environmental & Social Safeguards outlined in Section 5 are met.
5. Verify that the project is compliant with requirements outlined in the Isometric Standard.

6.2.1 Verification Materiality

The threshold for Materiality (An acceptable difference between reported Removals/emissions or Reductions/emissions and what an auditor determines is the actual Removal/emissions or Reduction/emissions.), considering the totality of all omissions, errors and mis-statements, is 5%, in accordance with Section 4.3 of the Isometric Standard.

Verifiers should also verify the documentation of uncertainty (A lack of knowledge of the exact amount of CO₂ removed by a particular process, Uncertainty may be quantified using probability distributions, confidence intervals, or variance estimates.) of the GHG Statement (A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction.) as required by Section 2.5.7 of the Isometric Standard. Qualitative materialityMateriality issues may also be identified and documented, such as⁵:

• control issues that erode the verifier’s confidence in the reported data;
• poorly managed documented information;
• difficulty in locating requested information;
• noncompliance with regulations indirectly related to GHG emissions, removals or storage

6.2.2 Site Visits

Project validation and verification must incorporate site visits to project facilities in accordance with the requirements of ISO 14064-3, 6.1.4.2, including, at a minimum, site visits during validation and initial verification to the biomass conversion site and the bio-oil injection site. Validators should, whenever possible, observe operation of the conversion and injection processes to ensure full documentation of process inputs and outputs through visual observation.

A site visit must occur at least once every 2 years at each location.

6.2.3 Verifier Qualifications & Requirements

Verifiers and validators must comply with the requirements defined in Section 4 of the Isometric Standard. In addition, teams shall maintain and demonstrate expertise associated with the specific technologies of interest, including biomass growth, biomass conversion, bio-oil production and geologic storage.

Competency must be demonstrated through the below relevant sectoral scope accreditations listed below, orbased throughon demonstrationIAF ofMD relevant14 experience,and in accordance with Isometric's VVB policy:

• Storage - Carbon Capture and Storage of CO₂ in Geological Formations

6.3 Ownership

CDR via bio-oil production and injection is often a result of a multi-step process (such as biomass growth, harvesting, transport, conversion, injection, and storage), with activities in each step managed and operated by a different operator, company, or owner. When there are multiple parties involved in the process (e.g., forestry owner or injection site operator), and to avoid double counting (Improperly allocating the same Removal or Reduction from a Project Proponent more than once to multiple Buyers.) of net CO₂e removals, a single Project Proponent must be specified as the sole owner of the Credits. Contracts must comply with all requirements defined in Section 3.1 of the Isometric Standard.

6.4 Additionality

The Project Proponent shall be able to demonstrate additionality through compliance with Section 2.5.3 of the Isometric Standard. The baseline (A set of data describing pre-intervention or control conditions to be used as a reference scenario for comparison.) scenario and counterfactual (An assessment of what would have happened in the absence of a particular intervention – i.e., assuming the Baseline scenario.) scenarios and baselines (A set of data describing pre-intervention or control conditions to be used as a reference scenario for comparison.) utilized to assess additionality must be project-specific, and are described inSection the7.2 Biomassof Feedstockthis Accounting 1.1.0 moduleProtocol.

Additionality determinations should be reviewed and completed every two years, at a minimum, or whenever project operating conditions change significantly, such as the following:

• regulatory requirements or other legal obligations for project implementation change or new requirements are implemented
• project financials indicate carbon finance (Resources provided to projects that are generating, or are expected to generate, greenhouse gas (GHG) Emission Reductions or Removals.) is no longer required, potentially due to, for example
  • increased tipping fees for waste feedstocks
  • sale of co-products that make the business viable without carbon finance
  • reduced rates for capital access

Any review and change in the determination of additionality shall not affect the availability of carbon finance and carbon credits (A publicly visible uniquely identifiable Credit Certificate Issued by a Registry that gives the owner of the Credit the right to account for one net metric tonne of Verified CO₂e Removal or Reduction. In the case of this Standard, the net tonne of CO₂e Removal or Reduction comes from a Project Validated against a Certified Protocol.) for the current or past creditingCrediting periodsPeriods (The period of time over which a Project Design Document is valid, and over which Removals or Reductions may be Verified, resulting in Issued Credits.), but, if the review indicates the project has become non-additional, this shall make the project ineligible for future credits⁶.

6.5 Uncertainty

The uncertainty in the overall estimate of the net CO₂e removal as a result of the project must be accounted for. The total net CO₂e removed, CO2e([math: CO_2e_{Removal, n}]) for a specific batch ([math: n]) must be conservatively (Purposefully erring on the side of caution under conditions of Uncertainty by choosing input parameter values that will result in a lower net CO₂ Removal or GHG Reduction than if using the median input values. This is done to increase the likelihood that a given Removal or Reduction calculation is an underestimation rather than an overestimation.) determined based on the relevant requirements outlined in Section 2.5.7 of the Isometric Standard.

6.5.1 Reporting of uncertainty

Projects must report a list of all input variables used in the net CO₂e removal calculation and their uncertainties, including:

• emission factors (An estimate of the emissions intensity per unit of an activity.) utilized, as published in public and other databases used
• values of measured parameters from process instrumentation, such as truck weights from weigh scales, flow rates from flow meters, electricity usage from utility power meters, and other similar equipment
• laboratory analyses, including analysis of carbon content of injected bio-oil

The uncertainty information should at least include the minimum and maximum values of aeach variable that goes into the net CO₂e removal calculation. More detailed uncertainty information should be provided if available, as outlined in Section 2.5.7 of the Isometric Standard.

In addition, a sensitivity analysis (An analysis of how much different components in a Model contribute to the overall Uncertainty.) that demonstrates the impact of each input parameter’s uncertainty on the final net CO₂e uncertainty must be provided. Details of the sensitivity analysis method must be provided such that a third party can reproduce the results. Input variables may be omitted from an uncertantyuncertainty analysis if they contribute to a < 1% change in the net CO₂e removal. For all other parameters, information about uncertainty must be specified.

6.6 Data sharing

In accordance with the Isometric Standard, all evidence and data related to the underlying quantification of net CO₂e removal will be available to the public through Isometric's platform (A community resource where Project Proponents publish and visualize their early processes, Removal and Reduction data and Protocols – enabling the scientific community to share feedback and advice.). That includes:

• Project Design Document
• GHG Statement (A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction.)
• Measurements taken and supporting documentation, such as calibration certificates
• Emission factors used
• Scientific literature used

The projectProject proponentProponent can request certain information to be restricted (only available to authorized buyersBuyers (An entity that purchases Removals or Reductions, often with the purpose of Retiring Credits to make a Removal or Reduction claim.), the Registry (A database that holds information on Verified Removals and Reductions, and reviewed EACs, based on Protocols. Registries Issue Certificates, and track their ownership and Retirement.) and VVB) where it is subject to confidentiality. This includes emissions factors from licensed databases. However, thatall does not apply to anyother numerical data produced or used as part of the quantification of net CO₂e removal will be made available.

7.0 Quantification of net CO₂e removal

7.1 System Boundary & GHG Emissions Scope

The scope of this protocolProtocol includes GHG sources, sinks (Any process, activity, or mechanism that removes a greenhouse gas, a precursor to a greenhouse gas, or an aerosol from the atmosphere.), and reservoirs (SSRs) associated with a bio-oil injection CDR project. A cradle-to-grave GHG Statement must be prepared encompassing the GHG emissions relating to SSRs controlled by and related to the project, including the following activities:

• Biomass production (growth and harvesting)
  • Replacement emissions (Any emissions that occur to compensate for biomass that was previously serving another purpose and is now being used for carbon removal or GHG reduction. For example, if agricultural waste was previously left on a field to decompose - fertilizer production to replace those nutrients need to be accounted for.)
  • Direct and indirect land use changes, if applicable
  • Counterfactual storage
• Biomass transport
• Biomass conversion (bio-oil production)
• Bio-oil transport to processing sites and injection site
• Bio-oil injection
  • SequestrationMonitoring (including carbon content monitoring, reversals monitoring
• Embodied emissions associated with each process above, suchlab as for manufacture processing and shipping of conversion process equipment.surveys)

It should be noted that the physical and system boundaries for the bio-oil injection and storage site should include the following subprocess:

• Delivery of bio-oil to injection site (injection facility gate)
• Injection facility (including any surface processing or preparation of bio-oil and injectants, injection system, and balance of plant or auxiliary systems)
• Monitoring wells and any above ground monitoring systems or devices
• The limits of the geologic storage reservoir (vertical and lateral)
• Embodied emissions associated with each activity and process, such as for manufacture and shipping of process equipment and for consumables used

Emissions for processes within the system boundary shall include all GHG SSRs from the construction or manufacturing of each physical site and associated equipment, closure and disposal of each site and associated equipment, and operation of each process (biomass production, biomass conversion, bio-oil injection), to include embodied emissions of equipment and consumables in the process. Any emissions required to source the feedstock must be accounted for. These include feedstock collection/harvest, preparation, and transportation. The Project Proponent is responsible for identifying all sourcesGHG of emissionsSSRs directly or indirectly related to project activities.

Any emissions from sub-processes or process changes that would not have taken place without the involvement of the CDR process, such as subsequent transportation and refining, must be fully considered in the system boundary. This allows for accurate consideration of additional, incremental emissions induced by the CDR process.

Note that this protocol does not require inclusion of emissions resulting from ancillaryAncillary activities not directly related to project operations, (such as supplementary research and development activities, and corporate administrative activities) andthat anyare associated facilitieswith a project but are not directly or indirectly related to the issuance of Credits can be excluded from the system boundary. 

In addition, biomass conversion pyrolysis processes will typically produce co-products of biochar and ash, withand potentialpotentially other products. This protocol does not account for the production and use of those co-products and assigns allAll emissions associated with the entire system where bio-oil and co-products are produced must be allocated to the bio-oilCDR that is injected as a conservative estimateprocess.  When biochar is mixed into the bio-oil ahead of the injection, anyemissions emittingassociated with all activities or materials related to thatbiochar processproduction must be accounted for in totality.

Carbon fluxes (The amountsystem ofboundary carbonfor exchangedGHG betweenaccounting twomust orinclude moreall ReservoirsSSRs overcontrolled a period of time.)by and associatedrelated GHG emissions (positive and negative (Occur when a Sink – created or enhanced by human activity – removes greenhouse gasses from the atmosphere (CDR Primer, 2022).)) fromto the project may derive from, including but are not limited to, the following sourcesSSRs in Table 1:.

Table 1. Scope of activities and GHG SSRs to be included by the removal project

The Project Proponent must consider all GHGs associated with SSRs, in alignment with the United States Environmental Protection Agency’s definition of GHGs.All GHGs must be quantified and converted to CO2eCO₂e in the GHG Statement using the 100-yr Global Warming Potential (GWP) for the GHG of interest, based on the most recent volume of the IPCC Assessment Report (currently the Sixth Assessment Report).

7.2 Baseline

The projectbaseline proponentscenario shallfor usebio-oil projects assumes the frameworkactivities providedassociated in Section 2.5.2 ofwith the Isometric Standard as well as in this protocol to establish their GHG baseline. Development of a GHG baseline allows consistent comparison of abio-oil project activities’do effectsnot totake place and any existinginfrastructure oris alternativenot projects,built.

The activities,counterfactual oris technologiesthe thatCO₂ would be consideredstored in the absencebiomass of a proposed project.

7.2.1 Biomass Feedstock Accounting

The GHG baseline must be developed for the specific project and consider specific alternative uses of biomassfeedstock that would have occurredremained durably stored in the biomass in the absence of the project. TheThis GHGis baselineknown mustas alsoineligible considerbiomass, given that the baselineCO₂ relativestored would have remained stored in the biomass in the absence of the CDR project and is therefore not eligible to eachcount feedstocktowards used,Crediting. ifThe Biomass Feedstock Accounting Module 1.2 sets out requirements for establishing ineligible biomass as part of the projectCounterfactual utilizesStorage multipleEligibility feedstockcriteria. typesThe Biomass Feedstock Accounting Module 1.2 includes details for quantification of [math: CO_2e_{Counterfactual}].

7.3 Net CDR (Activities that remove carbon dioxide (CO₂) from the atmosphere and store it in products or geological, terrestrial, and oceanic Reservoirs. CDR includes the enhancement of biological or geochemical sinks and direct air capture (DAC) and storage, but excludes natural CO₂ uptake not directly caused by human intervention.) Calculation

7.3.1 Calculation Approach

The biomass pyrolysis process can be modeled as operating on a batch basis, consisting of a ‘Production Batch’, [math: p], which typically consists of utilizing a single type of biomass feedstock, often of a single source of origin, converting the biomass to bio-oil via pyrolysis, and storing and transporting that bio-oil to an injection site. The unique characteristics of the biomass used, its baseline or counterfactual, the bio-oil conversion process, the produced bio-oil characteristics, transportation distances, and storage site characteristics will be consistent for each Production Batch.

An ‘Injection Batch’, [math: n], is a single injection activity where a quantity of bio-oil is injected into an approved underground storage site. The Injection Batch may consist of a portion of a Production Batch, a full single Production Batch, or a blend of multiple Production Batches, which is injected for durable storage.

The approach for emissions calculations here is based on Injection- Batches and the specific calculation of net CO₂e removal for each Injection Batch. The following sections outline the process for calculating the net CO₂e removed for each specific Injection Batch batch of biomass processed and associated bio-oil injection, defined as a Removal.

WhenThe Reporting Period for a bio-oil project represents an interval of time over which removals are calculated and reported for verification. When total net CO₂e removalremovals must be calculated for anya specifiedReporting reportingPeriod, periodfor example during submission of Claimed Removals in a GHG statement, it is calculated as the sum of the net CO2e removal of all Injection Batchesremovals during the reportingReporting periodPeriod:

[math: CO_2e_{Removal,\ RP} =\sum_{1}^{n}\ CO_2e_{Removal,\ n}]

(Equation 1)

Where

• [math: CO_2e_{Removal,\ RP}]= the total net GHGCO₂e removal, as total net greenhouse gas emissions for reporting period [math: RP], in tonnes of CO₂e
• [math: CO_2e_{Removal,\ n}] = the total net GHGCO₂e emissionsremoval for Injection Batch [math: n], in tonnes of CO2e, occurring in reporting period [math: RP], in tonnes of CO₂e, see Section 7.4, Equation 2

TotalNote: emissionsReversals reductionsoccur mayafter beCredits adjustedhave been issued so are not included in futurethis yearsequation. for a reporting period, [math: RP], due to reversals (see Storage Modules inSee Section 8) that may occur over the duration5.6 of the long-termIsometric storageStandard periodfor further information.

7.4 Calculation of CO₂e_{Removal, n}

Net CO₂e removal for a process utilizing biomass conversion to bio-oil and bio-oil injection into geologic formationproject can be calculated as follows. Note that the calculation is completed for a discrete batch, [math: n], of bio-oil that is injected (‘Injection Batch’). The final net CO₂e quantification must be conservatively determined, giving high confidence that at least the estimated amount of carbonCO₂e was removed.

[math: CO_2e_{Removal,\ n} = CO_2e_{Stored,\ n}\ –\ CO_2e_{Counterfactual,\ n}\ - \\ CO_2e_{LCA\ Emissions,\ n}]

(Equation 2)

Where

• [math: CO_2e_{Stored,\ n}]= the total net CO₂e removalremoved from the atmosphere and durably stored as biogenic carbon for batch [math: n], in tonnes of CO₂e, see Section 7.4.1
• [math: CO_2e_{Counterfactual,\ n}]= the total counterfactual GHGCO₂ emissionsremoved from the atmosphere and durably stored as biogenic carbon in the absence of the project, for batch [math: n], in tonnes of CO₂e, see Section 7.4.2
• [math: CO_2e_{LCA\ Emissions,\ n}]= the total GHG emissions for a batch [math: n], in tonnes of CO₂e, see Section 7.4.3

7.4.1 Calculation of CO₂e_{Stored, n}

[math: CO_2e_{Stored}] represents the amount of carbon as CO₂e contained(stored inas theorganic injectantcarbon, C) that is injected and stored in the geologic or engineered storage formation. This is the gross amount stored for each batch injection and does not account for spillage nor reversals of storage from the storage formation.

The total amount of carbon dioxide equivalentCO₂ contained in the injectant thatcan is injected into a geologic formation is considered the gross amount of CO2e stored, or [math: CO_2e_{Stored}],be calculated as: follows.

Where all bio-oil production batches are blended prior to injection:

[math: CO_2e_{Stored,\ n} = \frac{C_{Bio-oil,\ n}\cdot m_{Inj,\ n}}{C_{CO_{2}}}]

(Equation 3)

Where bio-oil production batches are not blended prior to injection:

[math: CO_2e_{Stored,\ n} = \sum_{p=1}^{k} \bigg(\frac{C_{Bio-oil,\ p}\cdot m_{Inj,\ p}}{C_{CO_{2}}} \bigg)]

(Equation 4)

Where:

• [math: n] = Injection batch
• [math: p] = Production batch
• [math: k] = number of Production batches, [math: p], blended in the Injection batch, [math: n]
• [math: CO_2e_{Stored,\ n}]= the total CO₂e removed for batch [math: n], in tonnes of CO₂e
• [math: C_{Bio -oil,\ n (p)}] = the concentration as weight percent (%wt) of carbonC in the bio-oil injectant injected for Injection Batch [math: n] OR for each production batch [math: p] included in Injection Batch [math: n]
• [math: m_{Inj,\ n (p)}]= the total mass of injectant emplaced via injection (tonne) for Injection Batch [math: n] OR for each production batch [math: p] included in Injection Batch [math: n]
• [math: C_{CO_{2}}] = the content of C in CO₂, equivalent(as toa 12/44mass = 0.27percent)

7.4.1.1 Measurements - CO₂e_{Stored, n}

Calculation of [math: CO_2e_{Stored}] requires two primary measurements:

• [math: C_{Bio -oil}] (- %wt of C in the bio-oil injectant) and
• [math: m_{Inj}] (- total mass of injectant).

7.4.1.1.1 Bio-oil Carbon Content Measurement

TheIn valueorder ofto determine [math: C_{Bio -oil}], the %wt of C in the bio-oil injectant for either a blended bio-oil in Injection Batch [math: n], or for individual Production Batches [math: p], is determined via the analysis of samples of bio-oil injectant for total carbonC content.

The Acceptablefollowing test methodsmethod should be used where possible, and must be used for totalbio-oils carbonor contentblends includewith vapor pressures higher than 3 psi⁷:

• NREL Laboratory Analysis Procedure for Determination of Carbon, Hydrogen, and Nitrogen in Bio-oils⁷⁸ should be used where possible, and must be used for bio-oils or blends with vapor pressures higher than 3 psi⁸⁷

Where this is not possible, other acceptable test methods include:

• ASTM D5291: Standard Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants
• ASTM D5373: Standard Test Methods for Determination of Carbon, Hydrogen and Nitrogen in Analysis Samples of Coal and Carbon in Analysis Samples of Coal and Coke
• Alternative methods or analytical equipment which determine total carbon content may be utilized if justified and documented to be equivalent to ASTM D5291.

A minimum of one sample per Injection Batch (for blended injections) or one per Production Batch (for non-blended injections) of bio-oil must be collected and analyzed. Samples shall be from a well mixed and representative aliquot of the bio-oil as injected, insuring that solids are blended in the sample and representative of the amount in the injectant.

Analysis must be completed by a qualified laboratory, as evidenced by accreditation to ISO 17025 or equivalent standards (Standard physical constants as well as standard values set forth by bodies such as the National Institute of Standards and Technology (NIST) or others.) for laboratory quality management for the specific test method (ASTM D5291).

Laboratories shall complete standard quality assurance procedures on a schedule in accordance with their quality management plans and accreditation requirements to include:

• analysis of blanks
• analysis of duplicates
• instrumentation calibrations and analysis of calibration standards

This protocolProtocol provides two alternative methods for how often carbonC content must be measured and quantified. The first method (A) involves measuring every batch, the second method (B) involves only sampling some batches, and conservatively estimating the carbonC content of unsampled batches.

Method A: Measure every Batch

UsingThe this method, the carbonC content of every Injection Batch must be ascertained through direct measurement, either by:

1. Sampling the Injection Batch (which may be blended, or non-blended)
2. Sampling all constituent Production Batches which comprise the Injection Batch, and calculating the carbonC content of the Injection Batch through a linear weighted combination of the carbonC contents of these Production Batches, as given in Equation 3.
   • Note that in the case of an unblended Injection Batch, the Injection Batch originates from only a single Production Batch, by definition, and no calculation is required

For the acceptable minimum number of samples to take per sampled Batch, see Minimum number of samples per Batch below. If multiple samples are taken per Batch, the average carbonC content of these samples must be used.

Method B: Sampling a Production Process

For a given Production Process of a feedstock, samples must be taken directly for at least 30 Production Batches, to ensure there is enough data to estimate carbonC content for future Production Batches with appropriate statistical significance. Until this threshold is reached, Method A must be used.

Subsequently, samples must be taken at least every 10 Production Batches.

For the acceptable minimum number of samples to take per Batch, see Minimum number of samples per Batch below.

For batches which are not sampled, carbonC content must be conservatively estimated, as follows:

[math: C_{Bio-oil} = \mu_{CC} - \sigma_{\overline{CC}}]

(Equation 5)

[math: \sigma_{\overline{CC}} = \frac{\sigma_{CC}}{\sqrt{n_{samples}}}]

(Equation 6)

where:

• [math: \sigma_{\overline{CC}}] is the standard error of the mean of carbonC content, across all eligible samples for this Production Process
• [math: \sigma_{CC}] is the standard deviation of carbonC content, across all eligible samples for this Production Process
• [math: n_{samples}] is the number of eligible samples for this Production Process
• [math: \mu_{CC}] is the mean carbonC content of all eligible samples for this Production Process

Eligible samples are those taken in the previous 6 months before a specific Production Batch was produced. Older samples may not be used.

Additionally, batches must be subject to random sampling, to alleviate the risk of any given batch containing a substance with a substantially different carbonC content.

A random sampling approach must be agreed and documented in the Project Design Document, whereby Isometric will contact the Project Proponent on randomly selected days, at an agreed cadence, which must be no less frequent than once per month, on average. Once contacted, the Project Proponent must sample the carbonC content of the subsequent batches processed.

If the Project Proponent is unable to carry this random sampling out on 3 occasions within a 6 month period, or within a 6 month period more than 3 measurements are below 3 SD from the mean, this will trigger a Project review by Isometric.

If there is a significant change to a Production Process for a feedstock, which is likely to alter the average carbonC content of the feedstock, or if significant deviations in carbon content are detected, the feedstock should be considered as a new Production Process. This means that sampling must be restarted, with all prior samples no longer able to be used for estimating carbonC content.

Minimum number of samples per Batch

For all measurements taken, samples must be from a well mixed and representative aliquot of the injectant. To account for the possibility of variation within a single Production Batch (for example within a large container of the injectant), either of the following approaches must be adopted:

1. A minimum of 3 samples must be taken for each measured Production Batch.
2. Justification and evidence must be provided to demonstrate that the “within batch” variation is likely to be minimal. For example, this could be justified due to the physical details of the Production Process used, or alternatively by providing data examining the “within batch” carbonC content variation.

Process for handling carbonC content measurement outliers

For a given Production Process, an Outlier is defined as any individual sample which lies more than 3 standard deviations, [math: \sigma_{CC}], above or below the mean. To minimize the potential overall impact of outlier measurements, all carbonC content measurement outliers must be handled via the applying the technique of "winsorization”, as follows.

For a given measurement, [math: m], the winsorized measurement [math: m_w] is defined as follows:

• For a measurement [math: m] where [math: m > \mu + 3\sigma_{CC}], [math: m_w = \mu + 3\sigma_{CC}]
• For a measurement [math: m] where [math: m < \mu - 3\sigma_{CC}], [math: m_w = \mu - 3\sigma_{CC}]

The winsorized measurement, [math: m_w], must be used for the determination of carbon content.

This winsorization process must only be applied once a minimum number of 30 measurements have been taken, to ensure statistical significance.

The Project Proponent must monitor occurrences of outliers, and investigate if significantly more than the statistically expected number occurs, as it may be indicative of a systematic issue. This may be checked at verification, at the discretion of the verifying VVB.

7.4.1.1.2 Measurement of Mass of Bio-oil Injected

The mass of injectant, [math: m_{Inj}], is measured via determination of weight of delivered bio-oil to the injection site using a calibrated scale. The total mass injected may be determined by the difference in bio-oil delivery truck weight measured upon arrival at the injection facility and at departure, after offloading of bio-oil, either into storage or directly to injection.

Any truck scale used must have a current certification (The Isometric process which involves expert review and Public Consultation in order to arrive at an approved version of a Protocol, against which Projects will be Validated and Removals or Reductions will be Verified.) in accordance with applicable local, state, or federal regulations for legal-for-trade weights and measures. Testing and calibration of scales must utilize certified weights in accordance with local, state, or other regulations, calibration weights must meet NIST Handbook 44 specifications⁹, and scale testing and calibration must be performed by a state certified entity.

The total mass injected may also be determined by other methods, such as use of a calibrated flow meter and density measurement, or use of calibrated on site weigh scales for smaller containers, where such methods are viable and justified. Note that, due to typical viscosity of bio-oil, the use of flow meters is not often viable and can result in poor data quality.

7.4.1.2 Required Records & Documentation - CO₂e_{Stored, n}

The projectProject proponentProponent must maintain the following records as evidence of gross CO₂e storedremoval in injected bio-oil:

• weigh scale tickets for each delivery of bio-oil (arrival and departure weights) or other equivalent records
• analytical results for each ASTM D5291 analysis for carbonC content of bio-oil from each batch as required
• Documentation of any spills during injection operations and estimates of quantity released

Records of all C analyses and injection masses (e.g. weigh scale tickets) must be maintained by the injection facility and provided for verification purposes for a period of five years.

7.4.1.3 Other Considerations - CO₂e_{Stored, n}

Although limited and of small quantity, injection processes should be monitored to ensure that any process upsets or equipment failures and resulting spills of bio-oil are monitored, documented, quantified, and accounted for in the lifeGHG cycleStatement analysis(A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction.) of the project batch. For each batch, where a process upset results in loss of bio-oil, that amount must be deducted from the delivered amount of bio-oil based on delivery weigh tickets. Such amounts must be allocated directly to the specific injection batch of bio-oil.

7.4.2 Calculation of CO₂e_{Counterfactual, n}

The calculation of [math: CO_2e_{Counterfactual,\ n}], equivalent to [math: CO_2e_{Feedstock}], is determined by the requirements of the Biomass Feedstock Accounting Module.

7.4.3 Calculation of CO₂e_{GHG Emissions, n}

[math: CO_2e_{GHG\ Emissions,\ n}] is the total quantity of GHG emissions from operations and allocated embodied emissions for a batch [math: n]. This can be calculated as:

[math: CO_{2}e_{GHG Emissions,\ n} = CO_{2}e_{Energy,\ n} + CO_{2}e_{Transportation,\ n} \\ + CO_{2}e_{Embodied,\ n} +  CO_2e_CO_{Monitoring2}e_{Misc.,\ n} \\ + CO_{2}e_{Misc. ProjectLeakage, n}]

(Equation 7)

Where

• [math: CO_2e_{GHG\ Emissions,\ n}]= the total GHG emissions for a batch [math: n], in tonnes of CO₂e
• [math: CO_2e_{Energy,\ n}]= the total GHG emissions associated with energy consumption for a batch [math: n], in tonnes of CO₂e, see Section 7.4.3.12
• [math: CO_2e_{Transportation,\ n}]= the total GHG emissions associated with transportation of products for a batch [math: n], in tonnes of CO₂e, see Section 7.4.3.23
• [math: CO_2e_{Embodied,\ n}]= the total embodied GHG emissions allocated to a batch [math: n], in tonnes of CO₂e, see Section 7.4.3.34
• [math: CO_2e_{Monitoring,\ n}]= the total GHG emissions associated with storage monitoring allocated to a batch [math: n], in tonnes of CO2e, see the relevant Storage Modules in Section 8 for calculation details
• [math: CO_2e_{Misc.\ Projects,\ n}]= the total miscellaneous GHG emissions for a batch [math: n], that cannot be categorized by [math: CO_2e_{Energy,\ n}], [math: CO_2e_{Transportation,\ n}], [math: CO_2e_{Embodied,\ n}] or [math: CO_2e_{MonitoringEmbodied,\ n}], in tonnes of CO₂e, see Section 7.4.3.5
• [math: CO_2e_{Leakage,\ n}]= the total GHG emissions associated with the project’s impact on activities that fall outside of the system boundary of a project, allocated to batch [math: n], in tonnes of CO₂e, see Section 7.4.3.6

Note: Reversals occur after Credits have been issued so are not included in this equation. See Section 5.6 of the Isometric Standard for further information. Risk of reversal information is provided within the relevant Storage Module.

7.4.3.1 Emissions allocation

Emissions that occur relating to a batch, [math: n], must be included in the reporting of emissions associated with that batch and may not be allocated across multiple batches. Allocation across multiple batches must be agreed with Isometric on a case by case basis.

Embodied emissions which relate to multiple batches may be allocated in line with the allocation rules set out in the Embodied Emissions Accounting Module.

When the Project Proponent is planning to cease operations within a given storage site, the monitoring emissions required for post-closure monitoring must be calculated and allocated to the remaining removals taking place at the storage site. If that is not possible, the Project Proponent should allocate those emissions to other projects and/or storage sites they conduct removal operations at, in agreement with Isometric. If for any reason emissions are not appropriately allocated, the Reversal process will be triggered in accordance with Isometric Standard, to account for any remaining monitoring emissions.

In instances where monitoring activities are shared between entities, for example if multiple companies inject bio-oil into the same storage infrastructure, the emissions associated with these activities must be allocated proportionally between the entities.

7.4.3.2 Calculation of CO₂e_{Energy, n}

EmissionsGHG emissions associated with energy[math: CO_2e_{Energy, n}] should include all emissions associated with electricity usage, through electricity or fuel combustion. 

Examples of electricity usage may include, but are not limited to:

• processing equipment, motors, drives, and instrumentation
• facility operationoperations
• pyrolysis system start up
• injection operations
• monitoring equipment operation, including analyzers, instrumentation, on-site laboratories specifically for monitoring activities
• sampling pumps, sampling systems, or other similar monitoring activities
• off site analytical laboratory operation and sample analysis
• electricity for building operation & management for monitoring facility buildings

Examples of fuel consumption may include, but are not limited to:

• pyrolysis system start up
• pyrolysis reactor heating
• emission control (e.g. propane for flare co-firing or pilot)
• handling equipment, such as fork trucks or loaders
• sampling system operation, such as any pumps or heating systems
• monitoring system installation, operation or closure

The Energy Use Accounting Module provides guidance on how energy-related emissions must be calculated so that they can be subtracted in the net CO₂e removal calculation. It sets out the calculation approach to be followed for intensive facilities and non-intensive facilities and acceptable emissions factors.

7.4.3.2 Calculation of CO2eTransportation, n

Emissions related to transportation of products as part of a batch [math: n]’s process.

7.4.3.3 Calculation of CO₂e_{Transportation, n}

GHG emissions associated with [math: CO_2e_{Transportation, n}] should include all emissions associated with transportation of products as part of a batch [math: n]’s process, including the following:

• transportation of biomass feedstock to processing site
• transportation of bio-oil from processing site to injection site
• transportation of samples for lab analysis

7.4.3.4 Calculation of CO₂e_{Embodied, n}

ExamplesThe Project Proponent must identify all equipment and consumables used in the biomass conversion and storage process, identify appropriate cradle to grave emission factors, and allocate the emissions to removals appropriately in line with the Embodied Emissions Accounting Module.

GHG emissions associated with [math: CO_2e_{Embodied, n}] should include all emissions associated with the procurement and use of materials, consumables and equipment, that must be considered as part of the embodied emission calculation includeincluding but are not limited to:

• non-feedstock conversion process inputs or consumables:
  • catalysts
  • water
  • thermal oils used for heat transfer
  • coolants used for bio-oil quench
  • gasses such as nitrogen used for process or instrumentation purges
  • injection additives (i.e. biocide, salt, etc.)
  • gases, reagents or other materials used for operation of monitoring equipment and on-site analyzers
• equipment:
  • pyrolyzer reactor
  • feedstock conveyors, augers, feed bins, and related equipment
  • bio-oil quench or condenser units, including any heat transfer equipment, such as glycol chillers and pumps
  • ash and char collection systems and quench or cooling systems
  • tailgas emissions control systems, such as flares or oxidizers
  • preparation or mixing equipment
  • pumps, piping, and related equipment
  • storage tanks
  • injection well materials
  • all support structures, facilities, and infrastructure, including steel platforms, framing, supports, concrete footings and building structures
  • monitoring wells and all associated materials (steel casing, concrete, etc.)
  • on-line analyzers, measurement equipment, or other such devices
  • buildings and associated equipment utilized for monitoring purposes (e.g. on-site laboratories)

7.4.3.45 Calculation of CO₂e_{Misc. Project, n}

Miscellaneous GHG emissions forassociated a batchwith [math: CO_2e_{Misc., n}], should include all emissions associated with the project that cannot be categorized by [math: CO_2e_{Energy,\ n}], [math: CO_2e_{Transport,\ n}], or [math: CO_2e_{Embodied\ n}]. The Project Proponent is responsible for identifying all sources of emissions directly or indirectly related to project activities and must report any outside of the SSR categories identified as miscellaneous emissions.

Examples include, but are not limited to:

• waste processing associated with all aspects of the project's processes
• staff travel associated with the project
• Direct emissions (Emissions that are produced by a specific CDR process and are directly controllable.) of tailgas as part of a pyrolysis process, [math: CO_2e_{Tailgas,\ n}]. Further detail is provided in the section below.

Calculation of CO₂e_{Tailgas, n}

Direct emissions from a pyrolysis process may occur when pyrolysis gasses are emitted to the atmosphere, are combusted within the process or pyrolyzer to provide thermal energy for the process, or are combusted or oxidized in an emissions control process such as a flare or thermal oxidizer.

Emissions are calculated as follows:

[math: CO_2e_{Tailgas,\ p}\ =\\ m_{Tailgas} \cdot C_{Tailgas,\ CH_4}\ \cdot GWP_{CH_4}\ \cdot  t_p]

(Equation 8)

Where:

• [math: m_{Tailgas}] = the mass flow rate of tail gas (kg/hr)
• [math: C_{Tailgas,\ CH_4}] = the concentration of CH₄ in the tail gas (wt%)
• [math: GWP_{CH_4}] = global warming potential (A measure of how much energy the emissions of 1 tonne of a GHG will absorb over a given period of time, relative to the emissions of 1 ton of CO₂.) of methane, GWP100 using IPCC Sixth Assessment Report (or most recently released IPCC report, whichever is latest)
• [math: t_p] = duration of the conversion process operation (hr) for Production Batch [math: p]

Measurement - CO₂e_{Tailgas, n}

Quantification of [math: CO_2e_{Tailgas}] requires two primary measurements, the measurement of tail gas flow and the analysis of gas for CH₄ content. CO₂ content is not included as part of the [math: CO_2e_{Tailgas}] emissions as the Biomass Accounting Module requires that only biomass which would have decayed within 15 years is used. Therefore the immediate emissions of CO₂ due to pyrolysis are not discounted against the totalnet CO₂e removal due to the similarity of time horizons between these emissions and the counterfactual storage.

Tail gas flow rate, [math: m_{Tailgas}] can be determined by various acceptable methods, including:

• use of calibrated flow meters to provide continuous volumetric or mass flow measurement. Any flow meter must be calibrated for the composition and density of tail gas¹⁰, or use appropriate conversion factors;
• use of flow data and curves from tail gas emissions testing and pressure drop measurement (i.e. pitot tubes) in the tail gas stream. Such testing data should be produced by a qualified emissions testing company, accredited to the Stack Testing Accreditation Council for ASTM D7036, ISO 17025, or approved by state regulatory authority to perform compliance emissions testing. Testing should be completed for each type of biomass feedstock utilized unless analytical testing (ASTM D5291 ultimate analysis or proximate analysis for moisture, volatiles, fixed carbon and ash) can demonstrate that the feedstocks are similar (within 10% for each component)
• calculation of tailgas amount by a carbon material balance. Material balance calculation will require measurement of biomass weight fed to pyrolyzer and biomass carbonC content, bio-oil product mass and bio-oil carbon content, and ash/char mass with ash/char carbonC content for a given pyrolysis batch using calibrated weigh scales or other calibrated measurement equipment. CarbonC content analyses should be performed using ASTM D5291 or equivalent ultimate analysis procedure.

The concentration of CH₄ in the tail gas must be measured directly via one of the following methods:

• on-line analyzer measurement of CH₄ concentration, such as on-line gas chromatography, non-dispersive infrared (NDIR) detector, or similar. Analyzers must be calibrated regularly using NIST-traceable certified gas standards with concentrations of CH₄ within +/- 30% of expected average tailgas concentration;
• use of concentration data from tail gas emissions testing. Such testing data should be produced by a qualified emissions testing company, accredited to the Stack Testing Accreditation Council for ASTM D7036, ISO 17025, or approved by state regulatory authority to perform compliance emissions testing. Emissions data should only be used when pyrolysis operating conditions are similar to the conditions under which testing was completed, and for which the biomass feedstock processed during testing is sufficiently similar (within 10% for each component, as outlined earlier).

Required Records & Documentation - CO₂e_{Tailgas, n}

The projectProject proponentProponent must maintain the following records as evidence supporting calculation of emissions from the biomass conversion process:

• Results of any emissions tests used to determine emission rates of GHGs ( CH₄) in tail gas or flow measurements of gas flow from pyrolysis process or associated emission control devices, including signed report from accredited emissions testing entity
• flow rate data from flow meters (including pitot tubes) for each period of interest (batch), including flow meter data recorded in data acquisition systems, manual operation logs, or other records indicating date, time, and flow rate, as well as meter identification number or ID

7.4.3.6 Calculation of CO₂e_{Leakage, n}

[math: CO_2e_{Leakage,\ n}] includes emissions associated with a project's impact on activities outside the system boundary of the project. This includes instances where the Project causes an increase in GHG emissions by diverting material from other uses or incentivizing increased production activity.

It is the Project Proponent's responsibility to identify potential sources of leakage emissions. For a bio-oil project, replacement emissions (Any emissions that occur to compensate for biomass that was previously serving another purpose and is now being used for carbon removal or GHG reduction. For example, if agricultural waste was previously left on a field to decompose - fertilizer production to replace those nutrients need to be accounted for.) must be considered as a minimum. calculations required for replacement emissions associated with market leakage are set out in the Biomass Feedstock Accounting Module.

In line with the Eligibility Criteria set out in the Biomass Feedstock Accounting Module, projects which would lead to ecological leakage associated with land use change are not eligible under this Protocol.

8.0 Bio-oil Storage

This Protocol provides two options for durable storage of bio-oil. The Project Proponent can choose from available options when submitting their Project for verification.

9.0 Acknowledgements

Isometric would like to thank following contributors to this Protocol and relevant modulesModules:

• Tim Hansen (350 Solutions); Bio-oil Geological Storage Protocol and Energy Use Accounting, Transportation Emissions Accounting and Embodied Emissions Accounting Modules.
• Kevin Fingerman, Ph.D. (Cal Poly Humboldt); Biomass Feedstock Accounting Module.
• Chris Holdsworth, Ph.D. (University of Edinburgh); Bio-oil Storage in Permeable Reservoirs Module.
• Catherine Spurin, Ph.D. (Stanford University); Bio-oil Storage in Permeable Reservoirs Module.
• Wilson Ricks (Princeton University); Energy Use Accounting Module.
• Grant Faber (Carbon Based Consulting); Transportation Emissions Accounting Module.

Isometric would like to thank following reviewers of this Protocol and relevant modules:

• Sarah Saltzer, Ph.D. (Stanford University); Bio-oil Storage in Permeable Reservoirs Module.
• Grant Faber (Carbon Based Consulting); Energy Use Accounting & Embodied Emissions Accounting Modules.

10.0 Definitions and Acronyms

A document that describes how to quantitatively assess the net amount of CO₂ removed by a process. To Isometric, a Protocol is specific to a Project Proponent's process and comprised of Modules representing the Carbon Fluxes involved in the CDR process. A Protocol measures the full carbon impact of a process against the Baseline of it not occurring.

The term used to represent the CO₂ taken out of the atmosphere as a result of a CDR process.

A mixture of water, organic acids, aldehydes, ketones, sugars, phenols, and other organic compounds derived from the thermal breakdown of biomass. Thermal breakdown of biomass is achieved via thermochemical processes, such as pyrolysis, which heat biomass in low- or no-oxygen environments to high temperatures (~e.g. 350-650°C). Bio-oil is often also referred to as pyrolysis oil or bio-crude.

A range of processes that use biogenic material to remove carbon dioxide (CO₂) from the atmosphere and store that CO₂ underground or in long-lived products (LLNL BiCRS Roadmap, 2020).

An activity or process or group of activities or processes that alter the condition of a Baseline and leads to Removals or Reductions.

Raw material which is used for CO₂ Removal or GHG Reduction.

Life cycle GHG emissions associated with production of materials, transportation, and construction or other processes for goods or buildings.

The processincrease byin which allGHG emissions outside the geographic or temporal boundary of a project that results from that project's activities.

A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction process, including leakages, are accounted for.

​​Considering impacts at each stage of a product's life cycle, from the time natural resources are extracted from the ground and processed through each subsequent stage of manufacturing, transportation, product use, and ultimately, disposal.

A worldwide federation (NGO) of national standards bodies from more than 160 countries, one from each member country.

An activity or process or group of activities or processes that alter the condition of a Baseline and leads to Removals or Reductions.

Those gaseous constituents of the atmosphere, both natural and anthropogenic (human-caused), that absorb and emit radiation at specific wavelengths within the spectrum of terrestrial radiation emitted by the Earth’s surface, by the atmosphere itself, and by clouds. This property causes the greenhouse effect, whereby heat is trapped in Earth’s atmosphere (CDR Primer, 2022).

Lowering future GHG releases from a specific entity.

The amount of CO₂ emissions that would cause the same integrated radiative forcing or temperature change, over a given time horizon, as an emitted amount of GHG or a mixture of GHGs. One common metric of CO₂e is the 100-year Global Warming Potential.

An evaluation of the likelihood that an intervention—for example, a CDR Project—causes a climate benefit above and beyond what would have happened in a no-intervention Baseline scenario.

Describes the addition of carbon dioxide removed from the atmosphere to a reservoir, which serves as its ultimate destination. This is also referred to as “sequestration”.

The amount of time carbon removed from the atmosphere by an intervention – for example, a CDR project – is expected to reside in a given Reservoir, taking into account both physical risks and socioeconomic constructs (such as contracts) to protect the Reservoir in question.

The escape of CO₂ to the atmosphere after it has been stored, and after a Certificate has been Issued. A Reversal is classified as avoidable if a Project Proponent has influence or control over it and it likely could have been averted through application of reasonable risk mitigation measures. Any other Reversals will be classified as unavoidable.

Enhanced hydrocarbon recovery (EHR) is a tertiary hydrocarbon production technique or process where the physicochemical (physical and chemical) properties of the rock and/or the fluids are changed to enhance the recovery of hydrocarbon, typically by altering the chemical, biochemical, density, miscibility, interfacial tension (IFT)/surface tension (ST), viscosity and thermal properties to enable additional hydrocarbon production (SPE, 2023). EHR+ is the specific use of CO₂ injection for EHR where the CO₂ remains stored in the geologic formation permanently (IEA, 2015).

The organization that develops and/or has overall legal ownership or control of a Removal or Reduction Project.

A location where carbon is stored. This can be via physical barriers (such as geological formations) or through partitioning based on chemical or biological processes (such as mineralization or photosynthesis).

The document that clearly outlines how a Project will generate rigorously quantifiable Additional high-quality Removals or Reductions.

A systematic and independent process for evaluating the reasonableness of the assumptions, limitations and methods that support a Project and assessing whether the Project conforms to the criteria set forth in the Isometric Standard and the Protocol by which the Project is governed. Validation must be completed by an Isometric approved third-party (VVB).

A process for evaluating and confirming the net Removals and Reductions for a Project, using data and information collected from the Project and assessing conformity with the criteria set forth in the Isometric Standard and the Protocol by which it is governed. Verification must be completed by an Isometric approved third-party (VVB).

Third-party auditing organizations that are experts in their sector and used to determine if a project conforms to the rules, regulations, and standards set out by a governing body. A VVB must be approved by Isometric prior to conducting validation and verification.

An acceptable difference between reported Removals/emissions or Reductions/emissions and what an auditor determines is the actual Removal/emissions or Reduction/emissions.

A lack of knowledge of the exact amount of CO₂ removed by a particular process, Uncertainty may be quantified using probability distributions, confidence intervals, or variance estimates.

A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction.

Improperly allocating the same Removal or Reduction from a Project Proponent more than once to multiple Buyers.

A set of data describing pre-intervention or control conditions to be used as a reference scenario for comparison.

An assessment of what would have happened in the absence of a particular intervention – i.e., assuming the Baseline scenario.

A set of data describing pre-intervention or control conditions to be used as a reference scenario for comparison.

Resources provided to projects that are generating, or are expected to generate, greenhouse gas (GHG) Emission Reductions or Removals.

A publicly visible uniquely identifiable Credit Certificate Issued by a Registry that gives the owner of the Credit the right to account for one net metric tonne of Verified CO₂e Removal or Reduction. In the case of this Standard, the net tonne of CO₂e Removal or Reduction comes from a Project Validated against a Certified Protocol.

The period of time over which a Project Design Document is valid, and over which Removals or Reductions may be Verified, resulting in Issued Credits.

Purposefully erring on the side of caution under conditions of Uncertainty by choosing input parameter values that will result in a lower net CO₂ Removal or GHG Reduction than if using the median input values. This is done to increase the likelihood that a given Removal or Reduction calculation is an underestimation rather than an overestimation.

An estimate of the emissions intensity per unit of an activity.

An analysis of how much different components in a Model contribute to the overall Uncertainty.

A community resource where Project Proponents publish and visualize their early processes, Removal and Reduction data and Protocols – enabling the scientific community to share feedback and advice.

An entity that purchases Removals or Reductions, often with the purpose of Retiring Credits to make a Removal or Reduction claim.

A database that holds information on Verified Removals and Reductions, and reviewed EACs, based on Protocols. Registries Issue Certificates, and track their ownership and Retirement.

Any process, activity, or mechanism that removes a greenhouse gas, a precursor to a greenhouse gas, or an aerosol from the atmosphere.

Any emissions that occur to compensate for biomass that was previously serving another purpose and is now being used for carbon removal or GHG reduction. For example, if agricultural waste was previously left on a field to decompose - fertilizer production to replace those nutrients need to be accounted for.

The amount of carbon exchanged between two or more Reservoirs over a period of time.

Occur when a Sink – created or enhanced by human activity – removes greenhouse gasses from the atmosphere (CDR Primer, 2022).

Activities that remove carbon dioxide (CO₂) from the atmosphere and store it in products or geological, terrestrial, and oceanic Reservoirs. CDR includes the enhancement of biological or geochemical sinks and direct air capture (DAC) and storage, but excludes natural CO₂ uptake not directly caused by human intervention.

Standard physical constants as well as standard values set forth by bodies such as the National Institute of Standards and Technology (NIST) or others.

The Isometric process which involves expert review and Public Consultation in order to arrive at an approved version of a Protocol, against which Projects will be Validated and Removals or Reductions will be Verified.

Emissions that are produced by a specific CDR process and are directly controllable.

A measure of how much energy the emissions of 1 tonne of a GHG will absorb over a given period of time, relative to the emissions of 1 ton of CO₂.

Any emissions that occur to compensate for biomass that was previously serving another purpose and is now being used for carbon removal or GHG reduction. For example, if agricultural waste was previously left on a field to decompose - fertilizer production to replace those nutrients need to be accounted for.

11.0 Appendix 1: Monitoring Plan Requirements

This appendix details how the Project Proponent must monitor, document and report all metrics identified within this Protocol. Following this guidance will ensure the Project Proponent measures and confirms carbon removeddioxide removal and long-term storage compliance, and will enable quantification of the emissions removal resulting from the Project activity during the Project Crediting Period, prior to each Verification.

This methodology utilizes a comprehensive monitoring and documentation framework that captures the GHG impact in each stage of a Project. Monitoring and detailed accounting practices must be conducted throughout to ensure the continuous integrity of the carbon removals and crediting.

The Project Proponent must develop and apply a monitoring plan according to ISO 14064-2 principles of transparency and accuracy that allows the quantification and proof of GHG emissions removals.

11.1 Modular requirements

The Modules associated with this Protocol have their own set of required parameters that need to be monitored. Please refer to the following Sections of the Modules to see a complete list of all requirements:

• Biomass Feedstock Accounting Module 1.2
• Biomass or Bio-oil Storage in Salt Caverns Module 1.0
• Bio-oil Storage in Permeable Reservoirs Module 1.0

11.2 Net CDR Calculation Requirements

These parameters must be monitored for the purpose of Carbon Emissions Calculation and Embodied Carbon Emissions Calculation.

12.0 Relevant Works

ASTM D5291-21 Standard Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants. (2021, November). https://www.astm.org/standards/d5291

ASTM International. (2018). ASTM D7036: Standard Practice for Competence of Air Emission Testing Bodies. https://www.astm.org/d7036-16.html

California Air Resources Board. (2018, August 13). Carbon Capture and Sequestration Protocol under the Low Carbon Fuel Standard. https://ww2.arb.ca.gov/sites/default/files/2020-03/CCS_Protocol_Under_LCFS_8-13-18_ada.pdf

Carbon Direct & EcoEngineers. (2022). Bio-oil Sequestration Prototype Protocol for Measurement, Reporting, & Verification. https://d13en5kcqwfledinsights.cloudfrontcarbon-direct.netcom/fileshubfs/Bio-oil-proto-protocol.pdf

Charm Industrial. (2023). FAQ | Fastest growing carbon removal technology. Charm Industrial. Retrieved June 14, 2023, from https://charmindustrial.com/faq

International Energy Agency. (n.d.). Insights Series 2015 - Storing CO2 through Enhanced Oil Recovery – Analysis. IEA. Retrieved June 14, 2023, from https://www.iea.org/reports/storing-co2-through-enhanced-oil-recovery

International Organization for Standardization. (2006). ISO 14040:2006 Environmental management — Life cycle assessment — Principles and framework. https://www.iso.org/standard/37456.html

International Organization for Standardization. (2006). ISO 14044:2006 Environmental management — Life cycle assessment — Requirements and guidelines. https://www.iso.org/standard/38498.html

International Organization for Standardization. (2008). Evaluation of measurement data — Guide to the expression of uncertainty in measurement (ISO JGCM GUM). https://www.iso.org/sites/JCGM/GUM/JCGM100/C045315e-html/C045315e.html?csnumber=50461

International Organization for Standardization. (2011). ISO 14066:2011 Greenhouse gases — Competence requirements for greenhouse gas validation teams and verification teams. https://www.iso.org/standard/43277.html

International Organization for Standardization. (2017). ISO/IEC 17025:2017 General requirements for the competence of testing and calibration laboratories. https://www.iso.org/standard/66912.html

International Organization for Standardization. (2019). ISO 14064-2:2019. Greenhouse Gases - Part 2: Specification With Guidance At The Project Level For Quantification, Monitoring And Reporting Of Greenhouse Gas Emission s Or Removal Enhancements. ISO. https://www.iso.org/standard/66454.html

International Organization for Standardization. (2019). ISO 14064-3:2019. Greenhouse gases — Part 3: Specification with guidance for the verification and validation of greenhouse gas statements. ISO. https://www.iso.org/standard/66455.html

International Organization for Standardization. (2022). ISO 9300:2022 Measurement of gas flow by means of critical flow nozzles. https://www.iso.org/standard/77401.html

Isometric. (n.d.). Isometric — Glossary: Defining the terms that appear regularly in our work. Isometric. https://isometric.com/glossary

Matthews, J.B.R. (Ed.). (2018). IPCC, 2018: Annex I: Glossary [Matthews, J.B.R. (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of... Cambridge University Press. https://doi.org/10.1017/9781009157940.008

Methodology for assessing the quality of carbon credits, Version 3.0. (2022, May). https://carboncreditquality.org/methodology.html

National Renewable Energy Laboratory. (2016). Quantification of Semi-Volatile Oxygenated Components of Pyrolysis Bio-Oil by Gas Chromatography/Mass Spectrometry (GC/MS) Laboratory Analytical Procedure (LAP). https://www.nrel.gov/docs/fy16osti/65889.pdf

National Renewable Energy Laboratory. (2021, October 7). Determination of Carbon, Hydrogen, Nitrogen, and Oxygen in Bio-Oils Laboratory Analytical Procedure (LAP). https://www.nrel.gov/docs/fy22osti/80967.pdf

National Renewable Energy Laboratory. (2022). Corrosivity Screening of Pyrolysis BioOils by Short-Term Alloy Exposures Laboratory Analytical Procedure (LAP). https://www.nrel.gov/docs/fy22osti/82631.pdf

National Renewable Energy Laboratory. (2022). Elemental Analysis of Bio-Oils by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) Laboratory Analytical Procedure (LAP). https://www.nrel.gov/docs/fy22osti/82586.pdf

NIST. (2023). Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices - 2023 Edition. NIST. https://www.nist.gov/pml/owm/publications/nist-handbooks/handbook-44-current-edition

Sandalow, D., Aines, R., Friedman, J., McCormick, C., & Sanchez, D. (2020, October 2). Biomass Carbon Removal and Storage (BiRCS) Roadmap. https://www.osti.gov/servlets/purl/1763937

Schmidt, H., Anca-Couce, A., Hagemann, N., Werner, C., Gerten, D., Lucht, W., & Kammann, C. (20118, August 17). Pyrogenic carbon capture and storage. GCB Bioenergy, 11(4), 573-591. https://onlinelibrary.wiley.com/doi/full/10.1111/gcbb.12553

Society of Petroleum Engineers. (2020, April 13). Enhanced oil recovery (EOR) - PetroWiki. PetroWiki. Retrieved June 14, 2023, from https://petrowiki.spe.org/Enhanced_oil_recovery_(EOR)

Stas, M., Auersvald, M., Kejla, L., Vrtiska, D., Kroufek, J., & Kubicka, D. (2020, May). Quantitative analysis of pyrolysis bio-oils: A review. TrAC Trends in Analytical Chemistry, 126. https://www.sciencedirect.com/science/article/abs/pii/S0165993620300868

U.S. Environmental Protection Agency. (2014). Test Methods for Evaluating Solid Waste: Physical/Chemical Methods Compendium (SW-846). https://www.epa.gov/hw-sw846/sw-846-compendium

U.S. Environmental Protection Agency. (2023, April 18). Understanding Global Warming Potentials | US EPA. Environmental Protection Agency. Retrieved June 14, 2023, from https://www.epa.gov/ghgemissions/understanding-global-warming-potentials