Bio-oil Geological
Storage
TTS v1.0 - Annex H
Bio-oil Geological Storage converts sustainably sourced biomass into a viscous, carbon-rich liquid through fast pyrolysis, then injects that bio-oil into deep geological formations for long-term storage. Unlike gaseous CO₂ injection, bio-oil is a stable liquid at ambient conditions with far lower buoyancy and mobility - reducing the risk of upward migration and offering a simpler, lower-cost storage engineering profile than supercritical CO₂ injection, while achieving the same underlying goal: durably removing atmospheric carbon captured by growing biomass.
Submit Bio-oil Storage Project View TTS v1.0 Annex H →How this pathway works
Fast pyrolysis rapidly heats biomass (agricultural residue, forestry residue, or dedicated energy crops meeting the Teravent Sustainable Biomass Criteria) in the absence of oxygen, typically at 450–550°C for under two seconds, decomposing it into three products: bio-char (a solid), bio-oil (a viscous, oxygenated liquid rich in carbon), and a non-condensable syngas often used to power the pyrolysis process itself. Bio-oil is the largest fraction by mass and carries roughly half the original biomass's carbon content in liquid form.
Under the Teravent Technology-Based Carbon Standard (TTS v1.0) Annex H, this pathway injects the bio-oil fraction into deep geological formations - more than 500 metres below surface - for long-term storage, earning Teravent Technology Credits of the Removal type (TTC-R) for verified net tonnes of biogenic carbon durably stored, net of full lifecycle project emissions. Bio-oil's chemical stability and viscosity at storage-site pressure and temperature conditions substantially reduce the buoyant migration risk associated with supercritical CO₂, though its long-term chemical stability over multi-century timescales is less extensively studied than mineral or gaseous storage, placing this pathway at Class II–III depending on demonstrated monitoring confidence.
Two methodology variants are approved under Annex H, differentiated by the storage formation depth and monitoring regime, which together determine whether a project achieves Class II (monitored, 100–1,000 years) or Class III (deep, unmonitored-equivalent confidence, >1,000 years) durability.
TTS v1.0 - Annex H
This pathway is governed exclusively by the Teravent Technology-Based Carbon Standard (TTS v1.0). No external registry, standard, or methodology is referenced or incorporated. All requirements - additionality, quantification, durability, safeguards, and credit issuance - are defined within TTS v1.0 and Annex H, with reference to Annex G storage integrity principles for the deepest, best-characterised sites.
Two approved methodology variants
TTS v1.0 Annex H approves two methodology types for Bio-oil Geological Storage, differentiated by injection depth and the resulting monitoring and durability classification. Both require feedstock to meet the Teravent Sustainable Biomass Criteria before any capture or storage credit can be considered.
Where bio-oil is injected into a formation meeting the same site characterisation standard as Annex G geologic CO₂ storage - confirmed caprock integrity, adequate injection depth, and a monitoring regime equivalent to gaseous CO₂ storage sites - the project can achieve Class III durability. This methodology is most often deployed at repurposed depleted hydrocarbon reservoirs or dedicated saline formations, leveraging existing site characterisation data where available.
- Bio-oil injection volume and density at wellhead, converted to mass carbon injected at ±2% accuracy
- Bio-oil carbon content assay per production batch, via elemental analysis
- Formation pressure and caprock integrity monitoring, consistent with Annex G protocols
- Feedstock chain-of-custody documentation confirming Sustainable Biomass Criteria compliance
- Periodic core or fluid sampling to confirm bio-oil chemical stability under formation conditions
Where full Annex G-equivalent deep site characterisation is not available or the injection formation sits above the 800 m Class III threshold, projects may still register under a monitored storage regime - accepting Class II durability (100–1,000 years) in exchange for a lower site characterisation bar, provided an ongoing monitoring commitment tracks bio-oil location and chemical stability over time. This methodology is well suited to smaller-scale, regional pyrolysis facilities without access to extensively characterised deep formations.
- Bio-oil injection volume and density at wellhead, converted to mass carbon injected at ±2% accuracy
- Bio-oil carbon content assay per production batch
- Periodic monitoring well sampling to confirm bio-oil has not migrated beyond the injection zone
- Groundwater quality monitoring at overlying aquifers per DNSH provisions, given shallower injection depth
- Feedstock chain-of-custody documentation confirming Sustainable Biomass Criteria compliance
Which emission sources must be counted
TTS v1.0 Module 3 requires a full lifecycle GHG emissions inventory within the project boundary, deducted from the gross bio-oil carbon injected to arrive at the Net TTC figure.
Measurement, reporting
& verification
Teravent's Science Advisory Board assesses each pathway against four MRV dimensions. Bio-oil injection quantification is very high confidence given straightforward volumetric and compositional metering, but long-term storage monitoring confidence is comparatively lower than gaseous or mineral storage, reflecting the pathway's earlier stage of commercial deployment.
Bio-oil quantity is measured via volumetric and density metering at the injection wellhead, accurate to ±2% mass, with carbon content independently assayed per production batch through elemental (CHNS) analysis. Because bio-oil chemical stability under multi-century subsurface conditions is less extensively studied than mineral carbonation or gaseous CO₂ trapping, this pathway requires ongoing periodic monitoring well sampling to confirm the injected bio-oil has not degraded, migrated, or reacted unexpectedly with formation fluids - the monitoring frequency and duration required scale inversely with the depth and site characterisation quality achieved (BOG-M01 versus BOG-M02).
Demonstrating additionality
TTS v1.0 Module 2 requires all projects to pass a three-test additionality framework, with a Technology Readiness Level (TRL) screen applied ahead of the common practice test. Bio-oil geological storage at commercial scale remains an early-stage technology, so most projects qualify for the streamlined TRL-based screen.
Leakage types & deductions
TTS v1.0 Module 3 defines three leakage types applicable across all engineered pathways. Bio-oil Geological Storage shares the ILUC and residue-diversion leakage exposure of BECCS, plus an energy-source leakage consideration for the pyrolysis and injection process.
Buffer pool & reversal risk
Annex H durability class depends on injection depth and site characterisation quality. BOG-M01 achieves Class III where deep, well-characterised containment is confirmed; BOG-M02 defaults to Class II given shallower injection and a reliance on ongoing monitoring rather than deep structural containment alone.
| Methodology | Durability Class | Buffer Pool Rate | Primary Reversal Risks |
|---|---|---|---|
| BOG-M01 Deep Formation | Class III | 2–8% | Caprock breach; wellbore integrity failure; long-term bio-oil chemical stability under formation conditions |
| BOG-M02 Monitored Shallow | Class II | 7–20% | Shallower injection depth increases migration risk; monitoring lapse; groundwater intrusion |
Key registration criteria
Projects must meet all of the following minimum requirements to qualify for registration under TTS Annex H. Additional methodology-specific requirements are detailed in the Annex H methodology tables for each BOG-M code.
Sustainable Development
Goal alignment
All Teravent registered Bio-oil Geological Storage projects must complete an SDG impact assessment at registration and at each verification period. Three SDGs are systematically tracked for this pathway. Projects may apply for co-benefit quality labels where independently verified indicators are met.
Deployment scope: Regions with established agricultural or forestry residue supply chains and access to characterised sedimentary basins or depleted hydrocarbon reservoirs - currently most active in North America and Northern Europe.
Ready to register your
bio-oil storage project?
Submit a Project Concept Note under TTS v1.0 Annex H to begin your registration. Confirm your feedstock meets the Teravent Sustainable Biomass Criteria, select the BOG-M code matching your injection depth and monitoring regime, and appoint an accredited VVB to validate your PDD.