Explainer: CO2 utilization pathways (mineralization, fuels, chemicals) — what it is, why it matters, and how to evaluate options

Carbon capture often dominates climate conversations, but capturing CO2 is only half the equation. The other half, what you actually do with captured carbon, is where the economics, scalability, and long-term climate impact are determined. CO2 utilization, also known as carbon capture and utilization (CCU), refers to the conversion of captured carbon dioxide into commercially valuable products including building materials, synthetic fuels, chemicals, and polymers. Global CCU capacity reached approximately 230 million tonnes of CO2 per year by 2025, but the vast majority of that volume flows into enhanced oil recovery rather than permanent storage or displacement of fossil-derived products. The emerging pathways in mineralization, e-fuels, and chemicals represent the next frontier, and sustainability professionals evaluating these options face a complex landscape of competing claims, varying levels of technological readiness, and divergent climate benefits.

Why It Matters

The scale of the CO2 utilization opportunity is enormous. The International Energy Agency estimates that CCU pathways could absorb 5-10 gigatonnes of CO2 annually by 2050 if technologies mature and deployment accelerates. That represents roughly 10-20% of current global emissions. However, not all utilization pathways deliver equivalent climate benefits. The distinction between temporary and permanent carbon storage is critical: converting CO2 into synthetic fuels re-releases the carbon when the fuel is combusted, while mineralizing CO2 into building materials locks carbon away for centuries or millennia.

The regulatory landscape in the European Union has shaped the CCU market more aggressively than anywhere else. The EU Innovation Fund, backed by revenues from the Emissions Trading System (ETS), allocated over EUR 3.6 billion between 2020 and 2025 for low-carbon technology demonstration, with CCU projects receiving a significant share. The EU's Carbon Removal Certification Framework (CRCF), proposed in 2022 and adopted in 2024, establishes definitions and quality criteria for carbon removals that directly affect how CCU products are counted toward climate targets. ReFuelEU Aviation, effective from 2025, mandates that 1.2% of aviation fuel must be synthetic (e-kerosene) by 2030, rising to 35% by 2050, creating guaranteed demand for CO2-derived fuels.

At the same time, the EU Taxonomy for Sustainable Activities classifies CCU activities based on net lifecycle emissions, requiring that CCU products demonstrate greenhouse gas reductions of at least 70% compared to fossil alternatives over their lifecycle. This threshold excludes many early-stage CCU pathways from "green" financing unless they can demonstrate rigorous lifecycle performance. The Inflation Reduction Act in the United States offers complementary incentives through the 45Q tax credit, which provides $60 per tonne for CO2 used in qualifying products and $180 per tonne for direct air capture with permanent storage.

For sustainability professionals, the practical question is not whether CO2 utilization will play a role in decarbonization, it will, but rather which pathways deliver genuine, verifiable climate benefits and which risk becoming greenwashing vehicles that delay more effective action.

Key Concepts

Carbon Mineralization is the process of reacting CO2 with alkaline minerals (primarily calcium and magnesium silicates) to form stable carbonate minerals such as calcium carbonate (CaCO3) or magnesium carbonate (MgCO3). This mimics a natural weathering process that occurs over geological timescales but accelerates it to hours or days through engineered reactors, elevated temperatures, or catalytic processes. The resulting carbonates are thermodynamically stable and store carbon permanently for thousands of years. Applications include CO2-cured concrete, aggregates, and supplementary cementitious materials. CarbonCure Technologies injects CO2 into fresh concrete during mixing, where it mineralizes into calcium carbonate nanoparticles that become permanently embedded in the concrete matrix, simultaneously reducing cement content requirements by 5-8% and improving compressive strength.

Electrofuels (E-Fuels) are synthetic hydrocarbons produced by combining captured CO2 with green hydrogen (produced via water electrolysis powered by renewable energy). The primary conversion pathway involves the reverse water-gas shift reaction (converting CO2 and H2 to carbon monoxide and water) followed by Fischer-Tropsch synthesis (converting CO and H2 into liquid hydrocarbons). E-fuels can produce synthetic diesel, gasoline, kerosene, and methanol that are chemically identical to their fossil counterparts and compatible with existing engines, pipelines, and refueling infrastructure. The critical limitation is energy efficiency: producing one unit of e-fuel energy requires approximately 5-7 units of renewable electricity, making e-fuels the most expensive decarbonization pathway per tonne of CO2 abated.

CO2-Derived Chemicals encompass a range of industrial chemicals synthesized using CO2 as a carbon feedstock, replacing fossil-derived inputs. The most commercially advanced pathways include methanol synthesis (CO2 + H2 over copper-zinc-alumina catalysts), urea production (already the largest industrial user of CO2 at roughly 130 million tonnes per year), polyols and polycarbonates (used in polyurethane foams and coatings), and formic acid. Emerging pathways include electrochemical CO2 reduction to ethylene, carbon monoxide, and ethanol using novel catalysts. The chemical pathway's climate benefit depends entirely on whether the end product stores carbon durably or releases it within a short cycle.

Life Cycle Assessment (LCA) for CCU is the analytical framework used to determine whether a CCU pathway delivers net climate benefits. A rigorous CCU LCA must account for: the energy source and carbon intensity of the capture process; transportation of CO2 to the utilization facility; the energy inputs and emissions of the conversion process; the carbon storage duration in the product; and the fossil product displaced by the CCU product. The ISO 14040/14044 standards and the European Commission's 2023 guidelines on LCA for CCU provide the methodological framework. Studies from the Global CO2 Initiative at the University of Michigan show that CCU pathways using fossil energy for capture or conversion can have lifecycle emissions exceeding those of conventional products, underscoring the importance of renewable energy integration.

Technology Readiness Level (TRL) provides a standardized scale from 1 (basic research) to 9 (commercial deployment) that helps professionals assess how close a CCU pathway is to market. As of 2025, CO2-cured concrete and CO2-to-urea are at TRL 8-9. Methanol from CO2 is at TRL 7-8. E-kerosene and synthetic diesel are at TRL 6-7, with first commercial plants under construction. Electrochemical CO2 reduction to ethylene is at TRL 4-5. Understanding TRL is essential for evaluating procurement timelines, cost trajectories, and investment risk.

CCU Pathway Comparison

Pathway	TRL (2025)	Cost (EUR/tonne CO2 utilized)	Carbon Storage Duration	EU Market Demand Signal
CO2-Cured Concrete	8-9	30-80	Permanent (>1,000 years)	EU Taxonomy eligible
Mineralized Aggregates	7-8	50-120	Permanent (>1,000 years)	EU Taxonomy eligible
Methanol from CO2	7-8	200-400	Temporary (months)	Fuel blending mandates
E-Kerosene (SAF)	6-7	800-2,000	Temporary (hours)	ReFuelEU Aviation mandate
CO2 to Polyols/Polycarbonates	7-8	150-350	Medium (years to decades)	Growing polymer demand
Electrochemical CO2 to Ethylene	4-5	500-1,500	Variable	Early R&D stage
CO2 to Formic Acid	6-7	300-600	Temporary (months)	Niche industrial demand

How to Evaluate Options: A Decision Framework

Step 1: Define the Climate Objective

The first and most important question is whether the goal is permanent carbon removal, fossil product displacement, or both. Mineralization pathways offer permanent storage with high confidence. E-fuels displace fossil fuels but do not remove carbon from the atmosphere on a net basis. Chemical pathways fall somewhere between, depending on product lifetime and the fossil product displaced. Organizations with science-based targets aligned to 1.5C pathways should prioritize permanent storage and high-displacement pathways, while organizations focused on compliance with fuel mandates may prioritize e-fuels regardless of lower climate efficiency.

Step 2: Assess Energy Requirements and Source

Every CCU pathway requires energy, and the carbon intensity of that energy determines whether the pathway delivers net climate benefits. E-fuel production requires 5-7 MWh of renewable electricity per tonne of fuel produced. If that electricity comes from grid power with a carbon intensity above 100 gCO2/kWh, the e-fuel may have lifecycle emissions comparable to or higher than conventional fossil fuels. Mineralization pathways require significantly less energy (0.5-2 GJ per tonne of CO2) and are less sensitive to grid carbon intensity. Professionals should require suppliers to disclose the energy source, consumption, and resulting lifecycle emissions for any CCU product under evaluation.

Step 3: Verify with Rigorous LCA

Demand full lifecycle assessments aligned with ISO 14040/14044 and, for EU applications, the European Commission's 2023 CCU LCA guidelines. Credible LCAs must include system boundary definitions, functional unit specifications, allocation procedures, sensitivity analyses, and third-party review. Be skeptical of claims based on "cradle-to-gate" analyses that exclude use-phase emissions or end-of-life carbon release. The Global CO2 Initiative's LCA toolkit provides a standardized framework for comparing pathways on a consistent basis.

Step 4: Evaluate Cost Trajectories and Policy Support

Current costs vary by an order of magnitude across pathways. Learning rates and policy support will determine which pathways achieve cost parity with fossil alternatives. Mineralization benefits from low energy requirements and the ability to generate revenue through building material sales. E-fuels face the steepest cost curves but benefit from guaranteed demand through mandates like ReFuelEU Aviation. Chemical pathways have diverse economics depending on the target molecule and market conditions.

Real-World Examples

CarbonCure Technologies (Canada)

CarbonCure has deployed its CO2 mineralization technology in over 700 concrete plants across North America and Asia. The system injects recycled CO2 into ready-mix concrete during batching, where it reacts with calcium ions to form calcium carbonate nanoparticles permanently embedded in the hardened concrete. Each cubic meter of concrete sequesters 10-25 kg of CO2. The technology reduces cement content by 5-8% while maintaining or improving compressive strength, creating a dual economic and environmental benefit. By 2025, CarbonCure reported cumulative CO2 savings exceeding 350,000 tonnes. Amazon, Microsoft, and the US General Services Administration have specified CarbonCure concrete for major construction projects.

Norsk e-Fuel (Norway)

Norsk e-Fuel is constructing Europe's first commercial-scale e-fuel plant in Mosjoen, Norway, with initial production capacity of 12.5 million liters of synthetic aviation fuel per year, scaling to 100 million liters by 2029. The facility combines direct air capture (supplied by Climeworks), electrolysis powered by Norwegian hydroelectric power, and Fischer-Tropsch synthesis to produce e-kerosene meeting ASTM D7566 aviation fuel standards. The plant's access to cheap, abundant renewable electricity (approximately EUR 30-40/MWh) is critical to its economics. Even so, production costs are projected at EUR 2-3 per liter, roughly 4-6 times the current price of fossil jet fuel. The project is supported by the EU Innovation Fund and advance purchase agreements from Lufthansa and KLM.

Covestro CO2-Based Polyols (Germany)

Chemical giant Covestro has commercialized the production of polyols using CO2 as a feedstock, replacing up to 20% of the fossil-derived raw materials in polyurethane foams. The technology, branded as cardyon, uses a zinc-cobalt catalyst to incorporate CO2 into the polymer backbone during polyol production. Covestro's Dormagen facility in Germany produces several thousand tonnes of CO2-based polyols annually, used in mattress foams, automotive interiors, and sports flooring. Lifecycle analysis shows a 15-20% reduction in the carbon footprint compared to conventional polyols. While the CO2 storage duration is limited to the product's service life (typically 10-30 years for foam applications), the displacement of petrochemical feedstock provides an additional and immediate emissions benefit.

Action Checklist

• Map your organization's potential CO2 utilization touchpoints across procurement, operations, and product development
• Require full lifecycle assessments (ISO 14040/14044) from any CCU product supplier, covering capture through end-of-life
• Distinguish between permanent storage (mineralization), medium-term storage (chemicals), and temporary displacement (fuels) when evaluating claims
• Assess the energy source and carbon intensity behind any CCU product before procurement
• Monitor EU regulatory developments including the Carbon Removal Certification Framework and ReFuelEU Aviation for compliance deadlines
• Evaluate CO2-cured concrete and mineralized aggregates for near-term procurement in construction projects
• Engage with industry initiatives such as the Global CO2 Initiative and the Carbon Utilization Research Council for benchmarking data
• Include CCU pathway assessment in corporate net-zero transition plans, specifying which pathways count toward removal targets versus avoidance targets

FAQ

Q: What is the difference between CCU and CCS? A: Carbon capture and storage (CCS) captures CO2 and injects it into geological formations (depleted oil and gas reservoirs, saline aquifers) for permanent storage. Carbon capture and utilization (CCU) captures CO2 and converts it into products with commercial value. The climate outcomes differ significantly: CCS provides permanent storage with high confidence, while CCU's climate benefit depends on the product's carbon storage duration and the fossil product it displaces. Some analysts use the combined term CCUS to encompass both approaches.

Q: Do e-fuels actually reduce emissions? A: It depends entirely on the energy source. E-fuels produced using 100% renewable electricity and CO2 from direct air capture can achieve lifecycle emission reductions of 80-95% compared to fossil fuels. However, e-fuels produced using grid electricity in regions with carbon-intensive grids can have lifecycle emissions equal to or exceeding fossil fuels. The energy penalty is substantial: producing one liter of e-kerosene requires roughly 25-30 kWh of renewable electricity, meaning e-fuels should be reserved for sectors without viable electrification alternatives, primarily long-haul aviation and maritime shipping.

Q: How mature is CO2 mineralization in construction? A: CO2-cured concrete is commercially deployed at scale (TRL 8-9) with CarbonCure operating in over 700 concrete plants. Mineralized aggregates from companies like Blue Planet and Carbon8 are at TRL 7-8. CO2-injected concrete typically costs 0-5% more than conventional concrete and can deliver compressive strength improvements. The technology is procurement-ready for most commercial construction projects today, with the primary barrier being specification awareness among architects and structural engineers rather than technical or economic limitations.

Q: Which CCU pathway offers the best climate return on investment? A: Mineralization pathways offer the best combination of permanent storage, low energy requirements, and near-term economic viability. Per EUR invested, CO2-cured concrete delivers more permanent CO2 storage than any other commercially available CCU pathway. E-fuels offer the weakest climate return per EUR due to high energy requirements and temporary carbon storage, but they serve a critical role in decarbonizing sectors that cannot electrify. Chemical pathways occupy a middle ground, with economics and climate benefits varying widely by target molecule.

Q: How should CCU fit into a corporate net-zero strategy? A: CCU should be treated as one component of a broader decarbonization portfolio, not as a substitute for direct emissions reductions. The Science Based Targets initiative's net-zero standard limits the role of carbon removals (including CCU with permanent storage) to neutralizing residual emissions after achieving at least 90% reduction through direct action. Organizations should first maximize energy efficiency and electrification, then deploy CCU for hard-to-abate emissions and as a means of generating revenue from unavoidable CO2 streams.

Sources

• International Energy Agency. (2024). Energy Technology Perspectives 2024: Carbon Capture, Utilisation and Storage. Paris: IEA Publications.
• European Commission. (2023). Commission Recommendation on the Use of Life Cycle Assessment for CCU Products. Brussels: Official Journal of the European Union.
• Global CO2 Initiative, University of Michigan. (2025). CO2 Utilization Roadmap: Pathways, Economics, and Climate Impact Assessment. Ann Arbor: University of Michigan.
• CarbonCure Technologies. (2025). 2025 Impact Report: CO2 Mineralization in Ready-Mix Concrete. Halifax: CarbonCure Technologies.
• Transport & Environment. (2024). E-Fuels: Where Do They Make Sense? An Assessment of Lifecycle Emissions and Costs. Brussels: Transport & Environment.
• Hepburn, C., Adlen, E., Beddington, J., et al. (2019). "The technological and economic prospects for CO2 utilization and removal." Nature, 575, 87-97.
• European Parliament and Council. (2024). Regulation on an EU Certification Framework for Carbon Removals (CRCF). Brussels: Official Journal of the European Union.