> For the complete documentation index, see [llms.txt](https://docs.rainbowstandard.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.rainbowstandard.io/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-storage/bio-oil-in-asphalt.md). # Bio-oil in asphalt
Module nameBio-oil in asphalt
Module categoryCarbon storage
Methodology nameBiomass carbon removal and storage (BiCRS)
Version1.0
Methodology IDRBW-BICRS-CS-BOIL
Release dateJuly 30th , 2026
StatusIn use
Glossary | **Crude bio-oil** | Bio-oil extracted from pyrolysis, that has not been treated | | ---------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | **Processed bio-oil** | Crude bio-oil that has been treated to remove volatile organic compounds. | | **Bio-bitumen** | Bio-based binder derived from non-petroleum sources such as bio-oils, lignin, or other organic materials. Used to replace fossil bitumen in asphalt production or as sealant. | | **Fossil bitumen** | Viscous, black hydrocarbon material refined from crude oil, widely used as a binder in asphalt pavements and as a sealant. | | **Asphalt** | Composite construction material consisting of mineral aggregates (gravel, sand, crushed stone) bound together with bitumen, used predominantly for road surfacing, airport runways, and parking lots. | | **Bio-bitumen recipe** |

A production specification for bio-bitumen, defined by

|
This is a **Carbon Storage Module** and covers the production of bio-oil and its use in asphalt. This module is part of the Rainbow BiCRS methodology, which allows Project Developers to choose the relevant modules for their project, and shall be used with the necessary accompanying modules. See more details on how modules are organized in the [BiCRS home page](/methodologies/biomass-carbon-removal-and-storage-bicrs.md#efpqng3v3ute).
How to use this module/pages/Jy6o8q5Q31d2U0OK7Yuo#efpqng3v3ute/files/0zYtLJBdzIemkx7iKe9C
BiCRS Methodology/pages/Jy6o8q5Q31d2U0OK7Yuo/files/4B3R2CjT9hA3bBYbzz1a
## Eligibility and scope ### Eligible technologies This module covers projects that * use waste and residual biomass as feedstock, according to the [Biomass feedstock](/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-capture/biomass-feedstock.md) module; and * meet all of the following bio-oil requirements:
Bio-oil production
Bio-oil processing
Bio-oil end use
  • Use bio-bitumen in the eligible permanent end use: asphalt.
Projects may be designed to prioritize biochar or bioenergy production, where bio-oil is the co-product of the pyrolysis. Such projects may still be eligible for removal Rainbow Carbon Credits under this module, if they meet all criteria outlined herein. This module allows for issuance of **removal RCCs on the basis of bio-oil end use/delivery**, i.e. incorporation as bio-bitumen into asphalt, not on the basis of bio-oil production. **Eligible end uses of bio-oil** under this methodology are limited to the production of bio-bitumen and its use in asphalt for road construction or paving of other areas (e.g. parking lots, airport runways, docks). This includes the use in any bitumen-containing asphalt layers (i.e surface, binder and base course). Any other use of the bio-oil (e.g. as fuel) or of the bio-bitumen (e.g. in roofing applications or for sealing and insulating purposes) is not eligible for removal RCCs. Use of bio-oil as biofuel may be issued avoidance RCCs by following the requirements in the [Energy co-products](/modules/energy-co-products.md) transformation module. The Project Developer and entity eligible for receiving carbon finance is the **operator of the bio-oil production site**. Pyrolysis and gasification equipment manufacturers or users of the bio-oil (e.g. bio-bitumen producers that do not produce the bio-oil, road construction companies) are not eligible Project Developers. ### Certification requirements Certification requirements for this module are defined in the [BiCRS methodology](/methodologies/biomass-carbon-removal-and-storage-bicrs.md#certification-requirements). These cover crediting period duration, monitoring period duration, site audits, and versioning and project compliance. ### Project scope One project is defined as: * the operation of one or more pyrolysis units, across one or more sites, * within a single country, * using similar types of pyrolysis units and technology, * operated at sites that are under the oversight or data access of a single Project Developer, regardless of whether the developer directly owns or manages each site. The project scope is cradle-to-grave and includes all processes that result from bio-oil production and use. This includes but is not limited to the following: all removals from bio-oil production, and all induced emissions related to biomass sourcing, leakage, upstream and downstream transport, embodied emissions from infrastructure and machinery, and onsite processing and energy use emissions from biomass conversion, bio-oil processing, and bio-bitumen production. Any processes that would have occurred regardless of the bio-oil production and usage activities may be excluded from the project scope. ### Baseline scope The baseline for **RCCs from bio-oil carbon removal shall** include any permanent carbon removal that would have occurred in the absence of the project. This includes but is not limited to permanent carbon storage from the alternate fate of the biomass feedstock used for pyrolysis. It shall be assumed by default that no biomass feedstock would have been used to produce bio-oil in the absence of the project (i.e. there is no share of the project activity in the baseline scenario). The baseline scenario **structure** remains valid for the entire crediting period but may be significantly revised earlier if: * The Project Developer notifies Rainbow of a substantial change in project operations or baseline conditions, and/or * The methodology is revised, affecting the baseline scenario. The **specific values** within the baseline scenario will be updated during each crediting period, using project data to accurately reflect the equivalent of the project’s operations. #### **Product substitution** Bio-oil derived bio-bitumen is used as a substitute for fossil bitumen. The baseline is fossil bitumen use in asphalt, and Project Developers shall prove that the project's bio-oil derived bio-bitumen is a valid and safe substitute for the baseline. Project Developers shall identify the **specific type of conventional bitumen** and its function that the project's bio-bitumen replaces (e.g. paving grade bitumen for surface course asphalt). They shall justify that the project's bio-bitumen **meets the same quality and performance criteria** as the conventional bitumen it replaces, considering relevant regulations or industry standards for bitumen in road constructions (e.g. [EN 12591:2009](#user-content-fn-1)[^1], [ASTM D946](#user-content-fn-2)[^2]). This shall also include compliance with hazard classification and pollutant levels for bitumen in road construction, as detailed in the [Environmental and social safeguards](#id-82n4j72vjt9v) section. If a national or international bio-bitumen standard exists and is applicable, it shall be cited in preference to petroleum-bitumen standards. Quality and performance criteria shall at least include, but are not limited to the following: * penetration * softening point * viscosity * flash point * solubility * long-term aging simulations Evidence shall be provided through representative test results from pilot testing, R\&D laboratories, or full-scale operations. Compliance with the applicable regulation or industry standard shall be assessed for a given [bio-bitumen recipe](#bio-bitumen-recipe). If the project's bio-bitumen does not meet the standard applicable to the conventional bitumen it replaces, it shall be treated as lower-performing than the conventional product. In that case, Project Developers shall justify why a specific quality or performance criteria is not met and describe the expected consequences. A gap in performance is assumed to cause emissions outside the project boundary (e.g. through a reduced product lifetime, requiring more frequent road renewal). A **leakage assessment** to quantify the associated emissions from the performance gap shall be carried out on a case-by-case basis. The leakage emissions shall be deducted from the project removals. ### Production batch A production batch is the [**processed bio-oil**](#user-content-fn-3)[^3] **produced under the same conditions** regarding * biomass feedstock mix, * pyrolysis temperature, * processing conditions of the crude bio-oil (i.e. removal of volatile organic compounds, see [Reversal risk assessment](#reversal-risk-assessment) section below). It is assumed that all bio-oil from the same production batch has similar characteristics (i.e. thermally stable fraction, organic carbon content). Pyrolysis temperature and biomass feedstock composition must not change by more than 20% to be considered part of the same Production Batch. {% hint style="info" %} For example, if the declared pyrolysis temperature is 600°C, temporary fluctuations between 480 °C and 720°C are acceptable. If a mixture of 50% tree clippings and 50% nut shells is pyrolyzed, the proportions can vary between 40% and 60% (±20% of the original 50%) {% endhint %} If bio-oil is produced as a co-product of biochar, and Project Developers want to issue removal RCCs for the biochar produced using the [Biochar application to soils module](/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-storage/biochar-application-to-soils.md), the production batches of bio-oil and biochar are linked: creating a new biochar batch automatically triggers a new bio-oil batch, and vice versa. This enables a clear allocation of project emissions between the two pathways (see [Co-product allocation](#co-product-allocation)). Measurements and reporting are performed at the **production batch level**. Verification and credit issuance may be done at the Project Developer's request for any number of production batches, on the cumulative production batches from that monitoring period. A production batch has a **maximum validity of 365 days**, after which bio-oil shall be considered part of a different production batch even if conditions are unchanged. In other words, the production batch ID number resets and a new production batch is created, and new monitoring requirements applied, after 365 days, regardless of if feedstock, pyrolysis conditions or processing steps change or not. ### Bio-bitumen recipe The [#product-substitution](#product-substitution "mention") and the [hazard comparability assessment](#hazard-comparability-assessment) shall be conducted for a given bio-bitumen recipe. It is defined as bio-bitumen produced: * under defined production conditions (i.e. mixing temperature and time), * using defined types and proportion of additive(s), * using bio-oil that was stored for a defined length of time between production of the bio-oil production batch and processing into bio-bitumen, * using bio-oil produced using a defined feedstock mix, and under defined pyrolysis and crude bio-oil processing conditions. A new recipe is created if either of the following applies: * the mixing temperature and time change by more than 20%, * different additives are used or the proportion of each changes by more than 20%, * the storage time of bio-oil before processing into bio-bitumen is different by more than 1 week, * the bio-oil used is produced from different feedstock or under different pyrolysis or crude bio-oil processing conditions. Using a new bio-oil batch generated after reaching the 365 day production batch validity does not by itself create a new recipe. See [Production batch](#id-2xck12gc2auz) for further details on the batch definition. {% hint style="info" %} For example, as illustrated in Figure 1 below * Recipes 1 and 2 are different from recipes 3 and 4 because they use different bio-oil production batches. Although coming from the same Feedstock mix A, recipe 1 and 2 use bio-oil processing via distillation #1, while recipe 3 and 4 use bio-oil processing via distillation #2. * Recipes 1 and 2 use the same bio-oil batch (i.e. feedstock mix A, processing via distillation #1), the same additives mix A, but differ in bio-oil storage time. It is 4 weeks for recipe 1 and 2 weeks for recipe 2. * Recipes 3 and 4 use the same bio-oil batch (i.e. feedstock mix A, processing via distillation #2), the same bio-oil storage time of 2 weeks, but use different additive mixes. Recipe 3 uses mix A, and recipe 4 uses mix B. * Recipe 5 is different to all other recipes, because it uses a different feedstock mix B, although using the same crude bio-oil processing (distillation #1), the same bio-oil storage time (2 weeks) and the same additives mix A as recipe 2. {% endhint %} Project Developers shall submit any number of bio-bitumen recipes, together with the [#product-substitution](#product-substitution "mention") and the [hazard comparability assessment](#hazard-comparability-assessment) at validation. New recipes and the corresponding assessments may be added at each verification.

Figure 1: System flow diagram showing the different steps in bio-oil to asphalt production: (1) Pyrolysis of biomass, (2) processing of crude bio-oil, (3) (optional) storage of bio-oil, (4) mixing of bio-oil and additives to produce bio-bitumen, and (5) use of bio-bitumen as binder in asphalt, where it is typically blended with conventional bitumen and mixed with aggregates. The diagram also shows the properties defining a bio-oil production batch, as well as those defining a bio-bitumen recipe.

## Principles & requirements The principles and requirements specific to this module are detailed in the sections below. Other principles and requirements shall be taken from the accompanying modules and methodologies:
BiCRS methodology
  • Additionality
  • No double counting
  • Environmental and social safeguards
/pages/Jy6o8q5Q31d2U0OK7Yuo/files/4B3R2CjT9hA3bBYbzz1a
Other modules
  • Co-benefits
  • No double counting
  • Environmental and social safeguards
  • Leakage
/pages/eQTO2zpdCEv368f4bRT6/files/CxuE4U5JkYE63biLhW6k
### Durability #### Durability threshold All projects certified under this module shall prove **durable carbon removals from bio-oil** **for at least 100 years**. #### Reversal risk assessment This module covers the production of bio-oil derived bio-bitumen and its use in asphalt. Asphalt is a composite paving material consisting of mineral aggregates like gravel, crushed stone, and sand, bound together by bitumen, a dark, viscous petroleum-derived binder. It is also referred to as asphalt concrete or blacktop. Asphalt, more precisely the bitumen in it, **ages continuously from the moment of production**, through mixing and laying, and throughout decades of road service through three main mechanisms: * distillative aging: The **low-boiling components of the bitumen evaporate,** mainly during mixing and laying, but also to a small extent at elevated temperatures in the use phase. * oxidative aging: Dominant long-term aging mechanism but also present during mixing and laying. Atmospheric oxygen reacts with hydrocarbons in the bitumen. The carbon in the bitumen is chemically transformed but remains stored. * structural aging: Slow structural change of bitumen during extended service life, also called physical hardening. Asphaltenes are formed and are no longer held in solution by the remaining maltenes. **Distillative aging** is the most relevant risk of non-permanence for carbon removals, as it results in the release of carbon-containing molecules. Hence, the major carbon reversal risks from bio-oil to bio-bitumen for asphalt are: 1. **Distillative aging of bio-bitumen**, where light organic compounds in the bio-oil used for bio-bitumen production vaporize during the production and use-phase of asphalt due to elevated temperatures, resulting in release of stored carbon. 2. **Failure to durably incorporate bio-oil into asphalt**, where bio-oil does not end up in a durable storage matrix (i.e. as bio-bitumen for asphalt production) and is instead lost or degraded due to inappropriate use (e.g. as fuel) or prolonged storage. This module establishes the following mandatory project design requirements to mitigate these risks, detailed in the following sections: * analysis of regional asphalt production and recycling practices, with a focus on maximum temperatures asphalt would be exposed to * using only the thermally stable fraction of bio-oil for crediting * proof of thermal stability of bio-oil * verification of bio-oil end use Upon meeting these requirements for each verification and credit issuance, the risk of reversal is considered **negligible** for bio-bitumen for asphalt mixes. There are no further project requirements to assess reversal risks or conduct post-crediting monitoring for reversals. All projects certified under this module shall contribute the default minimum 2% of their verified removal RCCs to the Rainbow Buffer Pool, as defined in the Rainbow Standard Rules. #### Analysis of asphalt practices During the production, use, and recycling of asphalt, bitumen is exposed to high temperatures, reaching a maximum of 190°C for hot-mix asphalt production. Some practices and technologies, however, risk exposing bitumen to even higher temperatures (e.g. through direct contact with a flame). Project Developers shall therefore conduct a market analysis of regional asphalt production and recycling practices, demonstrating that the maximum temperature to which bitumen is exposed does not exceed 190°C in the project's geography. #### Risk mitigation: Thermally stable fraction for crediting Not all biomass carbon converted to bio-oil during pyrolysis is expected to remain durably stored when used as bio-bitumen for asphalt. Only the **thermally stable, heavy fraction is considered durable and eligible for crediting**, since it will not vaporize under the production, use, and recycling conditions of asphalt, which are expected to reach a maximum temperature of 190°C for hot-mix asphalt. Project Developers shall demonstrate that **all volatile organic compounds (VOC) prone to vaporizing at temperatures up to 190° are removed from the crude bio-oil** before it is transformed into bio-bitumen. Out of an abundance of caution, the 190° threshold is assumed for all bio-oil, regardless of the specific production conditions of its first use as bio-bitumen in asphalt. Adding a safety margin for temperature fluctuations during asphalt mixing, compliance is demonstrated at 200°C rather than 190°C, via: * distillation at 200°C; or * alternative technologies that demonstrate that the remaining organic carbon in bio-oil is resistant to temperatures up to 200°C, evaluated on a case-by-case basis. The organic carbon content of the resulting thermally stable fraction of the bio-oil, hereafter referred to as **processed bio-oil** as opposed to crude bio-oil, shall be measured by elemental analysis and used in the [GHG quantification](#ghg-quantification) section to calculate the total carbon removals of the project. #### Risk mitigation: Proof of thermal stability of bio-oil To cross-validate the successful removal of VOC and to prove the **thermal stability of the processed bio-oil**, Project Developers shall conduct the following measurement: * **Thermogravimetric Analysis (TGA)** under inert gas (e.g. Nitrogen) atmosphere and up to a minimum temperature of 300°C. The **cumulative weight loss up to 200°C is assumed to be 100% carbon and deducted from the bio-oil carbon content**. Where cumulative weight loss up to 200°C exceeds 5%, the bio-oil batch is not eligible for crediting. Project Developers shall explain the source of any weight loss up to 200°C. {% hint style="info" %} **Example 1** After processing of the crude bio-oil to remove all VOCs up to a temperature of 200°C, the carbon content was measured to be 66% using elemental analysis. To verify the thermal stability of the resulting processed bio-oil, TGA is measured from room temperature up to 300°C. From room temperature to 200°C, only 1.2% of the sample mass is lost. From 200°C to 300°C, the sample mass drops by another 75%, indicating a significant weight loss due to combustion at elevated temperatures * This bio-oil batch is eligible. The cumulative weight loss up to 200°C is 1.2%. It is assumed to be 100% carbon and deducted from the bio-oil carbon content. The carbon content used to calculate the gross carbon removals is 66% - 1.2% = 64.8%. **Example 2** From room temperature to 200°C, 6% of the sample mass is lost. From 200°C to 300°C, the sample mass drops by another 75%, indicating a significant weight loss due to combustion at elevated temperatures. * This bio-oil batch is ineligible. The cumulative weight loss up to 200°C exceeds 5%. The bio-oil processing step is considered insufficient to guarantee the remaining carbon content is stable. {% endhint %} The elemental analysis and TGA measurements shall be conducted at **validation** and repeated for each bio-oil production batch (see the [Sampling and measurements](#sampling-and-measurements) section for details on the sampling requirements and measurement frequency per batch). #### Risk mitigation: Proof of bio-oil end use Project Developers shall prove that all processed bio-oil has been used in the intended durable storage application: **bio-bitumen as binder in laid** [**asphalt**](#user-content-fn-4)[^4]. This shall be done in **Bio-oil Use Verification Reports** that contain all of the following: * Tracking records of the purchase and/or delivery of the bio-bitumen to asphalt paving companies or bitumen production companies, amount of bio-bitumen, amount of bio-oil contained in the bio-bitumen and corresponding bio-oil batch ID. * Signed agreements with the buyer/user of the bio-bitumen, specifying that the bio-bitumen is solely used is asphalt production and not for any other, ineligible use (e.g. roofing, waterproofing, sealants, coatings). * GPS coordinates or street address of the paving/construction site where the bio-bitumen containing asphalt was laid, with according amounts of bio-bitumen. * The date the bio-bitumen containing asphalt was laid. * Company name and individual contact information for each buyer/user of bio-bitumen, for traceability and random checking by VVBs. Issuing removal RCCs only after verified incorporation into a permanent storage matrix mitigates the risk that bio-oil is burned, destroyed or used in other, non-permanent end-uses, and the carbon stored in the bio-oil is re-emitted. ### No double counting Project Developers shall sign the [Rainbow MRV & Registry Terms & Conditions](/other/terms-and-contracts/terms-and-conditions-for-registry-users.md), committing to follow the requirements outlined in the [Rainbow Standard Rules](/rainbow-standard-documents/rainbow-standard-rules/principles-and-requirements.md#double-counting), including not double using or double issuing carbon credits. Project Developers shall prove that they hold the sole ownership of the carbon removal in the asphalt, and that other parties involved in the supply chain (e.g. asphalt mixing company) do not. This includes ensuring that no other party claims the carbon removal through Environmental Product Declarations (EPDs), product-level marketing, or corporate greenhouse gas reporting. ### Co-benefits Projects should support at least two **quantifiable and verifiable** environmental or social co-benefits, aligned with the [UN Sustainable Development Goals](https://unstats.un.org/sdgs/indicators/Global-Indicator-Framework-after-2024-refinement-English.pdf) (SDGs) framework. Any co-benefits claimed by the Project Developer shall be **quantified, monitored, and audited** for each verification and credit issuance. Common co-benefits under this methodology are detailed in the table below. Project Developers may suggest and prove other co-benefits not mentioned here. SDG 13 on Climate Action by default is not considered a co-benefit here, since it is implicitly accounted for in the issuance of carbon credits. If the project delivers climate benefits that are not accounted for in the GHG reduction quantifications, then they may be considered as co-benefits. *Table 1 Common co-benefits that projects under this methodology may provide are detailed, including types of proof that can be used to justify each co-benefit.*
UN SDGExampleProof
SDG 9.4: Upgrade infrastructure to make them sustainableThe use of bio-bitumen in asphalt production replaces fossil bitumen, thereby avoiding/reducing GHG emissions from asphalt production.Verification of end use of bio-oil, GHG quantification of bio-bitumen production
SDG 12.2: Achieve the sustainable management and efficient use of natural resourcesThe use of bio-bitumen in asphalt production replaces fossil bitumen, thereby reducing the extraction of and the reliance on non-renewable resourcesVerification of end use of bio-oil
SDG 12.2: Achieve the sustainable management and efficient use of natural resourcesSustainable reuse of biomass, avoiding open field burning of biomass or landfilling.Type of feedstock used, verification of end use of bio-oil
### Environmental and social safeguards Project Developers shall prove that the **project does not contribute to substantial environmental and social harms.** Projects must follow all national, local, and European (if located in Europe) environmental regulations, including but not limited to those related to pyrolysis, gasification, waste feedstock management, and bitumen and asphalt performance and pollutant thresholds. #### Hazard comparability assessment Project Developers shall demonstrate that the bio-bitumen produced from the project's bio-oil is **not more hazardous** than the [conventional product it replaces.](#product-substitution) Compliance shall be assessed for a given [bio-bitumen recipe](#bio-bitumen-recipe) and compared against applicable regulatory classifications and thresholds for the equivalent conventional product. Where bio-bitumen does not meet the applicable requirements, the assessment may instead be applied to the final blended asphalt product. The detailed assessment process is outlined below. For the assessment, Project Developers shall: {% stepper %} {% step %} #### **Identify the counterfactual product** The conventional product being replaced shall be identified (e.g. paving grade bitumen, penetration grade bitumen, cutback bitumen, ...) and its applicable [regulatory classification or hazard profile](#user-content-fn-5)[^5] documented. {% endstep %} {% step %} #### **Assess the hazard classification of the bio-bitumen** The bio-bitumen shall be assessed against the same regulatory frameworks or standards applicable to conventional bitumen. If a national or international bio-bitumen standard exists and is applicable, it shall be cited in preference to petroleum-bitumen standards. The assessment shall at minimum cover PAH content and [bitumen fume emissions](#user-content-fn-6)[^6]. The sum of the [16 EPA PAHs](#user-content-fn-7)[^7] in the bio-bitumen shall not exceed 1000 ppm, or the threshold set by the applicable standard/regulation, whichever is lower. {% endstep %} {% step %} #### **If bio-bitumen does not meet the applicable requirements, apply the assessment to the final asphalt product** Project Developers shall provide an explanation of why the bio-bitumen does not satisfy the requirements on a standalone basis. They may then instead apply the hazard assessment to the final traceable blended asphalt product in which the bio-bitumen is blended with conventional bitumen. The final asphalt product shall be assessed against the same regulatory thresholds applicable to conventional asphalt.The sum of the [16 EPA PAHs](#user-content-fn-7)[^7] in the asphalt shall not exceed 50 ppm, or the threshold set by the applicable standard/regulation, whichever is lower. {% endstep %} {% endstepper %} Acceptable evidence includes: * Third-party certification of the final traceable product confirming that the product meets the applicable non-hazardous classification and/or that regulated parameters (e.g. PAH content, bitumen fume emission rate, leachate toxicity) are within permitted thresholds. * Safety Data Sheet (SDS) documents for the project's bio-bitumen as supplied to the asphalt plant, and the finished asphalt mix incorporating it, with an explicit comparison of hazard classifications (GHS/CLP categories) showing the final product is equal to or less hazardous than the conventional product. #### Environmental and social risk assessment Project Developers shall fill in the [Rainbow bio-oil in asphalt risk assessment](#risk-assessment-template), to evaluate the identified environmental and social risks of projects. The identified risks include: * Worker injury or illness due to exposure to hazardous substances in the bio-oil and/or bio-bitumen * Worker injury or illness due to exposure to hazardous fumes during bio-oil production and processing and during bio-bitumen production * Harm to human health and environment due to exposure to hazardous substances and fumes during use-phase of bio-oil * Leaching of hazardous substances in bio-oil and/or bio-bitumen due to improper storage The risk assessment also includes the identified risks from the [Biomass feedstock](/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-capture/biomass-feedstock.md#id-82n4j72vjt9v) module and the risks from the [Processing and energy use](/modules/processing-and-energy-use.md#environmental-and-social-safeguards) module, used in conjunction with this carbon storage module. Project Developers shall assign a likelihood and severity score of each risk, and provide an explanation of their choices. The VVB and Rainbow’s Certification team shall evaluate the assessment and may recommend changes to the assigned scores. Any identified material risk (defined as issues with a risk score of moderate or higher) shall be subject to a [Risk Mitigation Plan](/rainbow-standard-documents/rainbow-standard-rules/principles-and-requirements.md#environmental-and-social-risk-assessment), which outlines how Project Developers will mitigate, monitor, report, and if necessary, compensate for any environmental and/or social harms. Additional proof may be required for certain high risk environmental and social problems. The Project Developer, the Rainbow Certification Team, or the VVB may suggest additional risks to be considered for a specific project. {% hint style="info" %} Note that the **life-cycle GHG reduction calculations account for the climate change impacts of most environmental risks**. Nonetheless, Project Developers shall transparently describe any substantial and sensitive GHG emission risks in the risk evaluation template. {% endhint %} {% hint style="info" %} All risk assessments must also address the [Minimum environmental and social risks ](/rainbow-standard-documents/rainbow-standard-rules/principles-and-requirements.md#environmental-and-social-risk-assessment)defined in the Rainbow Standard Rules. {% endhint %} ### Monitoring Monitoring Plans for this module shall include, but are not limited to, tracking of the following information **for each Bio-oil Production Batch**: * Description of the pyrolysis conditions (temperature and residence time) and any variability in the process * Description of the crude bio-oil processing step to remove volatile organic compounds * Amount of processed bio-oil produced, in tonnes * Amount of processed bio-oil delivered, in tonnes: [Bio-oil Use Verification Reports](#id-5a8ye61po9ri) * Organic carbon content of the processed bio-oil * Cumulative weight loss up to 200°C of the processed bio-oil (TGA) * Bio-bitumen recipes used, and for each recipe * Compliance with [Product substitution](#product-substitution) requirements * Compliance with [Environmental and social safeguards: Hazard assessment](#id-82n4j72vjt9v) requirements Monitoring Plans for this module shall include, but are not limited to, tracking of the following information **for each monitoring period**: * Number of bio-production batches * Total amount of processed bio-oil per year, in tonnes * Total amount of processed bio-oil delivered per year, in tonnes * [Sampling records](#representative-sampling) * Co-benefits Monitoring Plans shall include the following information for each monitored parameter: * monitoring frequency * emission sources and sinks * data source * measurement methods/procedures, and their accuracy and calibration * quality assessment or quality control procedures * responsible party for collecting and archiving data ## GHG quantification The GHG quantification instructions from all other BiCRS modules used by the project must be used in conjunction with the present module in order to obtain full life-cycle GHG quantifications. The system boundary of this quantification section starts at the recovery of crude bio-oil from the pyrolysis reaction, and ends at the delivery of bio-bitumen to the site of asphalt mixing. **Quantification shall be done at a minimum for each bio-oil production batch**, but removal RCCs are issued on the basis of bio-oil delivery and application in an eligible end use. The following equation is used to determine the number of RCCs to issue per monitoring period, accounting for **a potential delay in bio-oil use after production**. See the [Functional unit](#kpxsamb8logm) section for more details.
Calculation: Bio-oil carbon removal RCCs $$\textbf{(Eq.1)}\ Net\ Removal = R\_{baseline, \ bio-oil}-R\_{project, \ bio-oil}-E\_{project, \ bio-oil }$$ * $$Net\ Removal$$ represents the project's net removals from one bio-oil production batch, in tonnes of CO$$\_2$$eq. Its sign is positive. * $$R\_{baseline, \ bio-oil}$$ represents any baseline GHG removals attributed to the bio-oil pathway, in tonnes of CO$$\_2$$eq. Its sign is negative. * $$R\_{project, \ bio-oil}$$ represents the project's gross GHG removals from one bio-oil production batch, in tonnes of CO$$\_2$$eq. Its sign is negative. * $$E\_{project, \ bio-oil}$$ represents the project's total induced GHG emissions attributed to the bio-oil pathway for one bio-oil production batch, in tonnes of CO$$\_2$$eq. Its sign is positive. $$\textbf{(Eq.2)}\ Removal\ RCCs= \frac{Net\ Removal}{A\_{bio\text {-} oil,\ produced}} \times A\_{bio\text {-} oil,\ delivered}$$ * $$Removal\ RCCs$$ represents the number of removal credits to be issued in the monitoring period. * $$Net\ Removal$$ is defined in Eq. 1. * $$A\_{bio\text {-} oil,\ produced}$$ represents the amount of processed **bio-oil produced** in the entire Production Batch, in tonnes. * $$A\_{bio\text {-} oil,\ delivered}$$ represents the amount of processed **bio-oil of the same production batch delivered to an eligible end use** in the monitoring period, in tonnes.
### Functional unit The functional unit shall be **1 tonne of processed bio-oil produced.** Input data shall be provided for all processes related to bio-oil production in the given Production Batch, and net project removals are first calculated for **all processes across the entire duration of the Production Batch**. This is normalized to net removals per functional unit by **dividing by the amount of processed bio-oil produced** in the Production Batch. The number of credits to issue in the given monitoring period is calculated by multiplying the amount of processed bio-oil applied in an eligible end use (i.e. bio-bitumen for asphalt production), by the net removals per tonne of processed bio-oil produced. This approach is detailed in Eq. 2 above. ### Data source The required **primary data** for GHG reduction calculations from projects are presented in Table 2. These data shall be provided either for each monitoring period or each production batch, as indicted in the table, and made publicly available. *Table 2 Summary of primary data needed from projects and their source for initial project certification and validation. All primary data sources listed here are required to be monitored and updated during verification (see Monitoring Plan section).*
ParameterUnitSource
Total amount of processed bio-oil produced in the monitoring periodTonnesInternal tracking documents
Total amount of processed bio-oil delivered as bio-bitumen to the asphalt producer in the monitoring periodTonnesBio-oil use verification record
Amount of processed bio-oil produced per production batchTonnesInternal tracking documents
Amount of processed bio-oil delivered per production batchTonnesBio-oil use verification record
Organic carbon content of processed bio-oil per production batchFractionLaboratory chemical analysis
Cumulative weight loss up to 200°C (TGA) of processed bio-oil per production batch FractionLaboratory chemical analysis
No other secondary data sources are used in this module. ### Co-product allocation If biochar is a co-product of bio-oil production, and Project Developers issue removal RCCs for both pyrolysis co-products, then **baseline removals and induced GHG emissions from shared processes shall be allocated between the two products**. This allocation is based on the proportion of gross carbon removals (in tonnes of CO2eq) from each product, following the rules outlined at the methodology level in the [BiCRS methodology document](/methodologies/biomass-carbon-removal-and-storage-bicrs.md). Allocated emissions sources shall at least include the following: * baseline removals from the biomass feedstock, calculated using the [Biomass feedstock ](/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-capture/biomass-feedstock.md)carbon capture module. * emissions from biomass supply (i.e. transport and processing), calculated using the [Processing and energy use](/modules/processing-and-energy-use.md) and the [Transportation](/modules/transportation.md) modules. * operational and embodied emissions form the pyrolysis of biomass, calculated using the [Processing and energy use](/modules/processing-and-energy-use.md) and the [Infrastructure and machinery](/modules/infrastructure-and-machinery.md) modules. All GHG emissions from processes **after the point of co-product generation** and that solely serve the bio-oil are attributed in full to the bio-oil production. This shall include at least the following: * crude bio-oil processing * bio-bitumen production * any transport, e.g. of bio-oil to bio-bitumen production facility, or of bio-bitumen to asphalt mixing company. If biochar is not treated as a co-product of bio-oil production, and no removal RCCs are issued for the biochar pathway, all baseline removals and project emissions are fully attributed to the bio-oil pathway.
Calculation: Allocation of emissions between co-products $$\textbf{(Eq.3)}\ R\_{baseline,\ bio\text{-}oil} = \frac{R\_{project,\ bio\text{-}oil}}{R\_{project,\ bio\text{-}oil}+R\_{project,\ biochar}} \times R\_{baseline}$$ * $$R\_{baseline, \ bio-oil}$$ is defined in Eq. 1. * $$R\_{project,\ bio-oil}$$ represents the project's gross removals from the bio-oil in asphalt module in one production batch, calculated according to Eq. 5, in tCO2eq. * $$R\_{project,\ biochar}$$ represents the project's gross removals from the biochar application to soils module in one production batch, calculated according to the GHG quantification section of the [Biochar application to soils module](/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-storage/biochar-application-to-soils.md#ghg-quantification), in tCO2eq. * $$R\_{baseline}$$ represents any baseline GHG removals in one production batch, representing permanent storage that would have occurred in the absence of the project, in tonnes of CO2eq. It is calculated according to the [Biomass feedstock carbon capture module](/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-capture/biomass-feedstock.md#calculations-baseline-scenario). $$\textbf{(Eq.4)}\ E\_{project, \ bio\text{-}oil} = (\frac{R\_{project,\ bio\text{-}oil}}{R\_{project,\ bio\text{-}oil}+R\_{project,\ biochar}}\times E\_{processes,\ shared }) + E\_{processes,\ bio\text{-}oil}$$ * $$E\_{project,\ bio\text{-}oil}$$ is defined in Eq. 1. * $$E\_{processes, \ shared}$$ represents the project's induced emissions from processes shared between biochar and bio-oil, in tCO2eq. This includes any operational and embodied emissions upstream from the physical separation of the two co-products. * $$E\_{processes, \ bio\text{-}oil}$$ represents the project's induced emissions from processes serving only the bio-oil pathway, in tCO2eq.
{% hint style="info" %} For example, a project's produces both biochar and bio-oil via pyrolysis. The biochar and the bio-oil can be used for carbon removal and be issued removal RCCs. The gross carbon removal from one Production Batch from bio-oil is 400 tCO2eq and from biochar is 600 tCO2eq. Baseline removals and shared processes are allocated using the factor $$\frac{R\_{project,\ bio\text{-}oil}}{R\_{project,\ bio\text{-}oil}+R\_{project,\ biochar}} = \frac{400}{400+600}=0.4$$ **Baseline removals** In the absence of the project, 10 tCO2eq would have remained stored in the soil due to biomass degradation. They are allocated to the co-products based on their total carbon storage capacity. * Bio-oil: 0.4 x 10 tCO2eq = 4 tCO2eq * Biochar: 0.6 x 10 tCO2eq = 6 tCO2eq **Shared process emissions** Emissions from biomass transport, biomass processing, methane emissions from pyrolysis and embodied emissions from infrastructure and machinery amount to 200 tCO2 eq and are allocated to the co-products accordingly: * Bio-oil: 0.4 x 200 tCO2eq = 80 tCO2eq * Biochar: 0.6 x 200 tCO2eq = 120 tCO2eq **Biochar-only emissions** Emissions of 30 tCO2 eq from biochar delivery and soil application occur after the co-products are split. The processes serve only the biochar production and are attributed in full to biochar. **Bio-oil-only emissions** Crude bio-oil processing, bio-bitumen production and delivery similarly occur after the split point of the co-products and serve only the bio-oil stream. Their full emissions of 20 tCO2 eq are attributed entirely to the bio-oil production. **Net removals** * Bio-oil production: (-4 baseline carbon storage - (-400 total carbon storage) - 80 shared project emissions - 20 bio-oil-only project emissions) tCO2 eq = 296 tCO2eq * Biochar production: (-6 baseline carbon storage - (-600 total carbon storage) - 120 shared project emissions - 30 biochar-only project emissions) tCO2 eq = 444 tCO2eq {% endhint %} ### Assumptions * Asphalt production and any subsequent asphalt recycling cycle happens at a maximum temperature of 190°C. This must be proven to be a reasonable assumption for each project-specific geography. * Distillation of the crude bio-oil at 200°C (or other similar, approved procedures) removes all volatile organic compounds from the crude bio-oil. * In the TGA measurement, the cumulative weight loss up to 200°C is 100% carbon. In reality it is a mixture of carbon, hydrogen, oxygen and traces of nitrogen and sulphur, but assuming it is all carbon is a conservative approach, assuming maximum carbon loss. * All bio-bitumen produced using the same recipe has the same characteristics regarding quality, performance and hazard profile. * All bio-oil from the same production batch has the same characteristics (i.e. organic carbon content, cumulative weight loss up to 200°C). * Once processed into bio-bitumen, the bio-oil does no longer degrade or significantly change in chemical composition or property. Processing of the crude bio-oil in a first step removes the unstable volatile fraction and leaves only the thermally stable fraction. The addition of additives in the bio-bitumen production step then further stabilizes this fraction. ### Baseline scenario The baseline shall include **any permanent carbon storage that would have occurred in the absence of the project**. It is assumed that there is no significant share of the project activity already occurring in business-as-usual. Therefore, the baseline for removal credits is zero and is omitted from calculations. The baseline shall be revised at least every 5 years. A more conservative baseline scope may be applied on a case-by-base basis. It must be representative and transparently justified. Note that baseline scenario carbon sequestration may be included for the project according to the requirements of the [biomass feedstock module](/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-capture/biomass-feedstock.md#ghg-quantification). ### Project scenario The total removals of this module are calculated for each production batch according to the following equation: $$\textbf{(Eq.5)}\ R\_{project, \ bio\text{-}oil}=(C\_{org}-W\_{loss}) \times A\_{bio\text {-} oil,\ produced}\times C\ to\ {CO}\_{2} \times -1$$ * $$R\_{project,\ bio\text{-}oil}$$ is defined in Eq. 1. * $$C\_{org}$$ represents the organic carbon content of the processed bio-oil, as a mass fraction. * $$W\_{loss}$$ represents the cumulative weight loss up to 200°C of the processed bio-oil, as a mass fraction. It is measured by TGA. * $$A\_{bio\text{-} oil,\ produced}$$ represents the amount of processed bio-oil produced, in tonnes. * $$C\ to\ {CO}\_{2}$$ is 44/12 = 3.67, and represents the molar masses of CO$$\_2$$ and C respectively, and is used to convert tonnes C to tonnes of CO$$\_2$$eq. * It is multiplied by -1 to obtain a negative sign. Removals are reported as a negative value. ### Uncertainty assessment An uncertainty assessment is presented below for all aspects of GHG quantification set **at the methodology level**. The findings from this assessment are then applied **at the project level**, where project-specific GHG quantification also undergoes an uncertainty assessment. The **overall project GHG quantification uncertainty** is determined by qualitatively combining both the methodology-level and project-specific uncertainties for each identified source of uncertainty. The uncertainty of the assumptions presented in the [Assumptions](#assumptions) section are assessed at the methodology level: * Asphalt is typically produced or recycled via the hot-mix (160–190°C), warm-mix (\~20°C below hot-mix), or cold-mix route (ambient temperature). The assumption carries medium to high uncertainty, as asphalt production mixes are country- or region-specific. However, assuming all asphalt is hot-mix asphalt (HMA) and that bio-bitumen is processed at 190°C throughout its entire life cycle represents the most conservative approach, as asphalt producers are expected to operate at lower temperatures wherever possible to reduce energy consumption. This assumption therefore carries **low uncertainty**. * Appropriate processing of the crude bio-oil (e.g. distillation at 200°C) removes all VOCs, leaving behind only the thermally stable fraction of the bio-oil. This assumption is inherently **high uncertainty**; however, the requirement for thermogravimetric analysis (TGA) to assess the validity of this assumption for each production batch reduces this to **moderate uncertainty**. * Any cumulative mass loss up to 200°C in TGA is assumed to be 100% carbon. In reality, bio-oil typically contains around 40-70% carbon by weight, the volatile fraction removed below 200°C is therefore not pure carbon. This assumption carries high inherent uncertainty. However, it also underestimates the carbon retained in the bio-bitumen and is therefore considered conservative from a carbon accounting perspective, resulting in **low uncertainty.** * The assumption that all bio-bitumen produced using the same recipe has the same characteristics regarding quality, performance and hazard profile has **low uncertainty**, as the definition of a bio-bitumen recipe is narrow and to account for any source of major variability. * All processed bio-oil within a production batch is assumed to have uniform characteristics. This assumption carries **moderate uncertainty**. * Once transformed into bio-bitumen, the bio-oil does not significantly change in chemical composition and properties. This assumptions carries **low uncertainty.** The uncertainty at the methodology level is estimated to be low. This translates to an **expected discount factor of at least** **3%** for projects under this methodology. ## Sampling and measurements The following indicators shall be measured for **each bio-oil sample** (see [Representative sampling](#representative-sampling) below) and the **mean** **average** of each indicator shall be reported **per production batch**: * **Organic carbon content** of processed bio-oil * determined by elemental analysis following the [ASTM D5291](#user-content-fn-8)[^8] standard test method or equivalent, if justified and documented. The measurement shall be done in replicates of three and the mean average of the measurement results shall be used. * **Cumulative weight loss** up to 200°C of processed bio-oil * determined by Thermogravimetric analysis (TGA) under an inert gas atmosphere, following ISO 11358-1:2014, ISO 19579:2006, ISO 21687:2007 or equivalent, if justified and documented. The measurement shall be done in replicates of three The measurement shall be done in replicates of three and the mean average of the measurement results shall be used. Measurements shall be performed by laboratories with at least one quality assurance accreditation, such as: * ISO/IEC 17025 * CEN/TS 17225-1 * ISO 10694 Unaccredited laboratories from academic settings shall be evaluated on a case by case basis by the VVB and the Rainbow Certification Team. #### Representative sampling Bio-oil composition is variable and changes over time due to its reactive nature. The following requirements ensure that samples are **representative of the bio-oil material that enters bio-bitumen production**, and that measurements are sufficiently frequent to capture this variability. * A bio-oil sample shall be taken and analyzed **once every 100 tonnes of processed bio-oil produced**, or once per production batch, whichever comes first, for the first 1,000 tonnes of production. * After 1,000 tonnes of processed bio-oil have been produced, the sampling frequency may be **reduced to once every 250 tonnes**, provided that measurement stability has been demonstrated. To demonstrate stability, Project Developers shall calculate the relative standard deviation (RSD) of the prior measurement dataset and demonstrate that the RSD does not exceed 10%. If this criterion is not met, the reduced frequency is not permitted. * Samples of bio-oil shall be taken and analyzed just before bio-bitumen production within a tolerance of ±1 week. The sample cannot be taken just before bio-bitumen production and analyzed later, because the elapsed time would allow the bio-oil to degrade, making the sample no longer representative. Nor can the sample be taken and analyzed significantly before bio-bitumen production, since the bio-oil going into production may itself have changed by the time it is used. * Samples shall be taken from a homogeneous portion of the bio-oil, ensuring that all phases and solids are fully blended prior to sampling.

Upon validation, Project Developers shall submit a Sampling Plan, that details

  • the procedure to ensure representative sampling

    • tools or equipment for taking samples,
    • homogenization techniques,
    • sample storage conditions

  • the anticipated number of measurements performed

    • per production batch, and
    • in the first monitoring period
  • the anticipated number of measurements until the reduced measurement frequency applies (> 1,000 tonnes of processed bio-oil produced and demonstrated measurement stability)

For each monitoring period, Project Developers shall submit a Sampling Record

documenting all sampling activities. This record shall include the following information:

  • Description of representative sampling method

  • Date and time of

    • processed bio-oil production
    • sampling
    • analysis of sample
    • bio-bitumen production with the sampled bio-oil (within 1 week)
  • Name or ID of the person(s) performing sampling
  • Number of samples taken per production batch
  • Processing or preparation steps of the laboratory before analysis, if any
  • Sample ID for traceability
  • Notes on anomalies, if any
## Risk assessment template This module uses the risk assessment template version 1.0 :point\_right: Download the template [here](https://docs.google.com/spreadsheets/d/1lRkrxT1KtSSpsNSHPdBnFCEK3yjRoxQBQ-tftxiDacs/edit?usp=sharing) {% embed url="" %} ## Version history | Description of the change | Justification | Date | Version changed | | ------------------------- | ------------- | --------------- | --------------- | | Release of methodology | -- | July 30th, 2026 | V1.0 | [^1]: EU standard: Bitumen and bituminous binders - Specifications for paving grade bitumens, [URL](https://webgate.ec.europa.eu/circabc-ewpp/d/d/workspace/SpacesStore/397bb835-6152-4bdc-8816-08b5838d675f/download) [^2]: US standard: Paving Grade Bitumen, [URL](https://bernetbitumen.com/bitumen-standards-and-grades/astm-bitumen-standards/) [^3]: as opposed to crude bio-oil. Bio-oil that has been processed to remove volatile organic compounds. [^4]: This includes all bitumen-containing asphalt layers (i.e surface, binder and base course). [^5]: Bitumen, for example: * EN 12591 (bitumen for road construction); * applicable SDS/GHS classification under CLP Regulation (EU) 1272/2008 or equivalent; * REACH substance registration where applicable. Asphalt, for example: * EN 13108 series (asphalt mix standards); * workplace exposure limit (WEL) / occupational exposure limit (OEL) for bitumen fume, typically expressed as inhalable fraction; * polycyclic aromatic hydrocarbon (PAH) content thresholds under relevant national road authority or environmental permitting requirements [^6]: Bitumen fume emissions are the volatile organic and inorganic compounds released when bitumen (also known as asphalt) is heated during road construction, roofing, waterproofing, and other industrial processes. [^7]: The 16 polycyclic aromatic hydrocarbons (PAHs) the US Environmental Protection Agency (EPA) designates as priority pollutants for monitoring due to their toxicity and prevalence: * Naphthalene * Acenaphthylene * Acenaphthene * Fluorene * Phenanthrene * Anthracene * Fluoranthene * Pyrene * Benzo\[a]anthracene * Chrysene * Benzo\[b]fluoranthene * Benzo\[k]fluoranthene * Benzo\[a]pyrene * Indeno\[1,2,3-cd]pyrene * Dibenzo\[a,h]anthracene * Benzo\[g,h,i]perylene [^8]: Standard Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants, [URL](https://store.astm.org/d5291-21.html) --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://docs.rainbowstandard.io/methodologies/biomass-carbon-removal-and-storage-bicrs/carbon-storage/bio-oil-in-asphalt.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.