ACI · Technical Note · TN-013

CO-Route, Biogas and Water Restoration in SGFA Architecture

CO₂ thermochemical conversion · biogas · water restoration · SGFA circular economy · reduced forest harvest pressure

Version 1.0 Date May 2026 Domain D-2 · D-4 · D-5 (Bio) Basis WP-019 · SM-010 · TN-011 · TN-012 Status Published
Abstract

TN-011 and TN-012 established CCU and biosynthesis as flexibility sinks in SGFA retrofit nodes. This note extends the framework to a four-sector circular economy: the CO-route (CO₂ + biogenic carbon + electricity → CO + activated carbon), biogas production from aquatic and agricultural biomass, and the restoration of eutrophied waterbodies as a biomass source. The combination creates a node that simultaneously addresses energy resilience, water quality, food security, and reduced forest harvest pressure — not as separate policy objectives but as a single integrated investment. The CO-route (VTT-originated thermochemical process, 1 MW pilot Finland 2026–2027) is economically viable without policy incentives due to activated carbon by-product revenue. Finland's biogas sector has 39 projects pending (1,769 GWh, €800M, 3% of agricultural potential versus Denmark's 70%), indicating structural underinvestment that SGFA node logic directly addresses.

§ 01

§ 01 — CO-Route: Thermochemical Conversion as Industrial Retrofit

High-temperature thermochemical conversion offers an alternative CCU pathway to the hydrogen electrolysis route (TN-011). The core process:

CO₂ + biogenic carbon + renewable electricity → CO (carbon monoxide) + activated carbon

CO is a valuable industrial intermediate usable directly as industrial fuel, feedable into Fischer-Tropsch synthesis for e-fuels, or processable into methanol. Activated carbon is a sellable by-product with growing markets in water and gas purification. The process offers an unusual economic property among CCU technologies: activated carbon revenue can make it viable without policy incentives or elevated carbon prices, most CCU routes requiring either a high CO₂ price or very cheap electricity.

Process parameters

ParameterValueSource / basis
First industrial pilots (Finland)1 MW scale, 2026–2027VTT Bioruukki / thermochemical infrastructure
Primary target sectorsLime, cement, steel, pulp industryCombined emissions exceed aviation + shipping combined
Activated carbon price~€1,000–2,000/tMarket range, water/gas purification
Electricity intensity~50–60 kWh/MWh CO producedThermochemical (vs ~300 kWh/MWh for electrolysis route)
Biogenic carbon feedstockWood chips, bio-char, woody residuesDomestically available and affordable in Finland

Comparison with hydrogen route (TN-011)

TN-011 showed that 80–90% of CCU product costs come from hydrogen. The CO-route avoids this entirely: biogenic carbon replaces the electrolysis step. The CO-route is less electricity-intensive and immediately economically viable; the hydrogen route remains relevant for nodes with large electrolysis capacity targeting e-fuel production at scale. In SGFA nodes near pulp mills or sawmills with abundant biogenic carbon, the CO-route provides the more accessible entry point.

§ 02

Biogas: Structural Underinvestment and Pending Capacity

Finland's biogas sector illustrates the same coordination failure SM-010 identifies in energy investment generally: the technology is mature, the potential is large, but the institutional instruments are misaligned.

Biogas consumption reached 2.3 TWh in 2025 (up from 1.3 TWh in 2024). Imports from Denmark, France, and the Netherlands totalled 1.3 TWh — countries with established production scale. Finland currently utilises approximately 3% of its agricultural feedstock potential for biogas; Denmark utilises approximately 70%. Thirty-nine projects are pending for 2026–2030 with combined capacity of 1,769 GWh, investment value approximately €800M, and projected employment of 1,700. Domestic liquefied biomethane capacity of 0.5 TWh is scheduled for 2026–2027.

The primary obstacle is investment environment predictability: 23 of the 39 pending projects have unresolved timelines. Industry actors consistently identify a long-term distribution obligation (jakeluvelvoite) as the critical instrument for unlocking private investment. This is precisely the kind of demand-side signal that HVK strategic reserve designation would provide.

Reference case: Säkylä (Auris Energia)

A €50M biogas plant in Säkylä would process 230,000 t/a of local industrial (Apetit) and agricultural residues, producing 130 GWh of upgraded biogas. By-product recycled fertiliser returns to regional agriculture. The project is investigating biogas supply to P2X Solutions' green hydrogen plant — exactly the SGFA node integration logic WP-019 describes for Varkaus and Lappeenranta.

§ 03

Waterbody Restoration as Biomass Source

Eutrophied lakes and coastal areas in Finland represent a dual opportunity: ecological restoration produces biomass that can be processed into biogas, activated carbon, and recycled fertiliser, while simultaneously improving water quality and reducing nutrient load to the Baltic Sea.

The technical chain is straightforward. Aquatic biomass (water hyacinth, reed, harmful algae) harvested from eutrophied waterbodies can be fed to a biogas plant producing biogas and digestate (nutrient-rich fertiliser). A portion can be processed through thermochemical CO-route to produce CO and activated carbon. The activated carbon can then be applied to the same waterbody for phosphorus removal and micropollutant treatment, closing a restoration loop.

Scientific basis

Algal biomass-derived activated carbon removes approximately 90% of phosphorus from water within 30 minutes in documented studies. VTT has researched domestic biomass activated carbon for micropollutant removal from wastewater. Activated carbon produced from aquatic biomass is suitable for algal toxin and odour compound removal. These are not theoretical properties — they are documented performance characteristics of the specific material class that the CO-route would produce from waterbody biomass feedstock.

§ 04

Forest Harvest Pressure Reduction

Biogas and activated carbon production from aquatic and agricultural biomass reduces forest harvest pressure through several mechanisms. Forest industry residues (bark, sawdust, sludge) used as biogas and activated carbon feedstock represent existing waste streams that do not compete with higher-value timber uses. Biogas replacing natural gas in energy production reduces general demand for forest-based fuels (wood chips, pellets). Domestic activated carbon production from biogenic feedstocks reduces dependence on fossil-based imported activated carbon, which is currently the primary industrial substitute.

The combined effect is not a direct substitution of forest harvesting — it is a reduction in the marginal pressure that drives conversion of forest biomass to energy and industrial carbon uses. Each tonne of activated carbon produced from aquatic biomass is a tonne not sourced from forest pathways.

§ 05

Four-Sector Circular Economy Node

Combining the SGFA retrofit framework with CO-route thermochemical conversion, biogas, and waterbody restoration produces a node that addresses four sectors simultaneously from shared physical infrastructure:

ComponentInputsOutputs
CHP plantBiogas, CO, possibly wood fuelDistrict heat, electricity, FCR-D reserve
Biogas plantAquatic biomass, agricultural residues, forest industry wasteBiogas, recycled fertiliser
CO-route moduleCO₂ (industrial), biogenic carbon, electricityCO, activated carbon
Fischer-Tropsch (optional)CO + H₂ (from electrolysis)e-fuels (e-diesel, e-kerosene, methanol)
Solar Foods (optional, TN-012)CO₂, H₂, electricityProtein (Solein)
Waterbody restorationActivated carbon (from node)Phosphorus removal, improved water quality

Revenue streams

Electricity and heat sales (CHP). FCR-D capacity payments (~€30,600/MW/year). Biogas sales or internal use. Activated carbon sales (~€1,000–2,000/t). CO sales to industry or e-fuels production. Recycled fertiliser sales. Protein sales if Solar Foods included. Public service compensation for waterbody restoration (potential new financing mechanism under environmental law).

This revenue structure is qualitatively more resilient than any single-product node: it withstands energy price shocks (multiple products), demand shocks (different sector cycles are uncorrelated), and raw material disruptions (all feedstocks are domestic or regional).

§ 06

Coordination Gap — Expanding Actor Map

SM-010 identified TEM, Fingrid, and municipalities as the actors whose coordination failure blocks SGFA investment. TN-012 added MMM (food security). TN-013 adds further actors whose mandates the waterbody restoration and biogas components require:

The Ministry of the Environment (YM) holds mandate over waterbody restoration and environmental permits for aquatic biomass harvesting and processing. Regional State Administrative Agencies (AVI) issue permits for waterbody biomass harvesting operations. Municipalities and cooperatives manage local waterbodies and have existing infrastructure for monitoring and maintenance. Industrial actors supply CO₂ and purchase CO and activated carbon outputs.

The pattern is consistent across all ACI sector analyses: no single actor owns the compound investment. The institutional response — SGFA Holding Oy with cross-sectoral mandate — is the same answer TN-012 arrived at independently.

Finland CCU Cluster

Solar Foods (protein from CO₂ + H₂), CO-route (CO + activated carbon from CO₂ + biogenic carbon), and VTT (research, pilot infrastructure, catalyst development) constitute a world-leading integrated CCU cluster. No comparable cluster combining protein biosynthesis, CO-route chemistry, and industrial retrofit expertise in a single national innovation ecosystem has been documented elsewhere. The coordination instruments to deploy this cluster at scale are the missing element — not the technology.

§ 07

Recommendations

Verify CO-route parameters with VTT thermochemical research group (Bioruukki). Document parameters for SGFA node integration at Varkaus or Oulu. Assess fit with Stora Enso CO₂ stream and existing CHP infrastructure.

Pilot (2026–2028). Fund an integrated SGFA node pilot incorporating CHP, biogas plant, CO-route module, and activated carbon application to regional waterbody restoration. Funding: TEM + YM + EU Innovation Fund, JTF, LIFE programme. Target sites: Varkaus (Stora Enso), Lappeenranta (Solar Foods + PVO), or Säkylä (Auris Energia model).

HVK extension. Include activated carbon (crisis water purification) and biogas in HVK strategic reserve designation. Basis: domestic production, self-sufficiency, crisis resilience — identical to existing HVK criteria for other strategic commodities.

Cross-ministry working group. TEM + MMM + YM joint preparation of regulatory framework enabling waterbody biomass harvesting and processing as part of SGFA node investment. Include coordination mechanism design (SGFA Holding Oy) and financing instruments (SM-010 §4).

International version. Translate TN-013 core sections for EU Commission (Climate Resilience Framework), UNIDO, and potential Asian partners. Lime and cement industry emissions exceed aviation plus shipping combined globally — the CO-route's primary market extends well beyond Finland.

Core Finding

The CO-route (economically viable without policy incentives), biogas production from aquatic and agricultural biomass (structurally underinvested at 3% of potential), and waterbody restoration as a biomass source create a four-sector circular economy node from shared SGFA infrastructure. The technology readiness is high across all components. The coordination gap is identical to that documented in TN-011, TN-012, SM-007, and SM-010: no single actor owns the compound investment, and the institutional instrument (SGFA Holding Oy) that would enable it does not yet exist.

Series: TN-011 — CCU as Flexibility Sink · TN-012 — Biosynthesis in SGFA · WP-019 — SGFA Retrofit Pathways · SM-010 — Financing Instruments · SM-007 — The Convergence Finding
Lisäviite — Ruokopankki

Ruokopankki (KiertoaSuomesta.fi, 2026): Digitaalinen kohtaamispaikka ruo'on tuottajille, kerääjille ja hyödyntäjille. Kaakkois-Suomen AMK / RuokoLog-hanke. Järviruoko biomassaksi: maanparannus, kuivikkeet, bioenergia, rakentaminen. Koordinaatiokerros joka kytkee tarjonnan, kysynnän ja logistiikan — täsmälleen SGFA-arkkitehtuurin paikallistason biomassakoordinaattori. kiertoasuomesta.fi