Deep dive: Carbon capture materials (sorbents, membranes) — what's working, what's not, and what's next

The economics of carbon capture hinge on a deceptively simple materials question: how do you selectively grab CO2 molecules from a gas stream and release them again using as little energy as possible? Despite decades of research and billions in public and private investment, the dominant commercial technology remains aqueous amine scrubbing, a process first patented in 1930 that consumes 25 to 40% of a power plant's energy output for solvent regeneration. The next generation of sorbents and membranes promises to cut that energy penalty by 30 to 60%, but the path from laboratory breakthroughs to industrial deployment has proven far more challenging than early projections suggested. This deep dive examines which materials are delivering results at scale, which remain stuck in the "valley of death" between lab and commercialization, and where the most consequential near-term advances are likely to emerge.

Why It Matters

Carbon capture, utilization, and storage (CCUS) is projected to handle 6 to 16% of cumulative CO2 reductions needed to reach net zero by 2050, according to the International Energy Agency's Net Zero Emissions scenario. That translates to capturing approximately 6 gigatons of CO2 annually by mid-century, up from roughly 50 million tons in operational capacity today. Closing this gap requires not just building more capture plants but fundamentally reducing the cost and energy intensity of the capture step itself, which accounts for 60 to 80% of total CCUS costs.

The European Union has positioned itself at the center of this transition. The EU's Industrial Carbon Management Strategy, adopted in 2024, targets 50 million tons of annual CO2 storage capacity by 2030 and established a regulatory framework for CO2 transport and storage infrastructure. The Innovation Fund, the world's largest climate technology funding program, allocated over 4 billion euros to CCUS projects between 2020 and 2025, with materials innovation representing a significant share. The EU Emissions Trading System (ETS), with carbon prices fluctuating between 55 and 100 euros per ton through 2025, provides the economic signal that makes advanced capture materials commercially relevant. At carbon prices above 70 euros per ton, next-generation sorbents and membranes with lower energy penalties become cost-competitive with conventional amine systems for point-source capture from cement, steel, and waste-to-energy facilities.

Direct air capture (DAC) raises the materials stakes further. Because ambient air contains only 420 parts per million of CO2 (compared to 4 to 30% in flue gases), DAC requires sorbents with exceptionally high selectivity and capacity that can operate through millions of adsorption-desorption cycles without degradation. Climeworks, the global leader in DAC deployment, uses solid amine sorbents at its Mammoth plant in Iceland, which began operations in 2024 with 36,000 tons per year of capture capacity. The cost remains between $600 and $1,000 per ton of CO2, well above the $100 to $200 range needed for climate-relevant scale. Materials innovation is the primary lever for closing this cost gap.

Key Concepts

Solid Sorbents are porous materials that capture CO2 through physical adsorption (weak van der Waals forces) or chemical absorption (covalent bonding with amine or other functional groups). The critical performance parameters are CO2 working capacity (how much CO2 the material can capture and release per cycle, measured in mol/kg), selectivity (the ratio of CO2 captured relative to nitrogen and other gases), regeneration energy (the heat or electrical energy required to release captured CO2), and cyclic stability (how many adsorption-desorption cycles the material can endure before performance degrades beyond acceptable thresholds).

Metal-Organic Frameworks (MOFs) are crystalline materials constructed from metal ions connected by organic linker molecules, creating structures with extraordinarily high surface areas (up to 7,000 square meters per gram) and precisely tunable pore geometries. MOFs can be engineered to have specific CO2 binding affinities by selecting appropriate metal centers and functional groups. The theoretical performance of MOFs exceeds all other sorbent classes, with some formulations achieving CO2 capacities above 8 mol/kg, but translating this performance from single-crystal laboratory measurements to industrially manufactured pellets and monoliths remains a central challenge.

Membrane Separation uses selective polymer, ceramic, or mixed-matrix membranes that allow CO2 to permeate faster than other gases in a mixture. Performance is characterized by permeability (how fast CO2 passes through, measured in Barrers) and selectivity (the ratio of CO2 permeation to nitrogen permeation). The Robeson upper bound defines the empirical tradeoff between permeability and selectivity for polymer membranes. Materials that exceed this bound represent genuine breakthroughs in separation performance.

Temperature Swing Adsorption (TSA) and Pressure Swing Adsorption (PSA) are the two primary process configurations for solid sorbent systems. TSA uses heat to regenerate sorbents (typically 80 to 120 degrees Celsius for amine-functionalized materials), while PSA uses reduced pressure (vacuum) to release captured CO2. The choice between TSA and PSA depends on available waste heat, electricity costs, and the required CO2 purity. Hybrid configurations combining elements of both approaches are increasingly common in commercial designs.

What's Working

Amine-Functionalized Solid Sorbents for DAC

The most commercially advanced next-generation sorbent technology is amine-functionalized solid sorbents, deployed by Climeworks and Global Thermostat. These materials chemically bond amine groups (typically polyethylenimine or aminosilanes) to porous solid supports such as silica, alumina, or cellulose fibers. The key advantage over liquid amines is dramatically lower regeneration temperature (80 to 120 degrees Celsius versus 120 to 150 degrees Celsius for aqueous amines), enabling the use of low-grade waste heat or geothermal energy.

Climeworks' operational data from its Orca and Mammoth plants in Iceland demonstrates that amine-functionalized cellulose sorbents maintain greater than 85% of initial capacity after 3,000 temperature swing cycles, with regeneration achievable using geothermal heat at approximately 100 degrees Celsius. The company has partnered with sorbent manufacturer Svante to develop next-generation structured adsorbent contactors that improve gas-solid contact efficiency by 40% compared to packed bed configurations.

Carbon Engineering (now part of Occidental Petroleum's 1PointFive subsidiary) uses a different approach, combining a liquid potassium hydroxide contactor with a calcium looping regeneration cycle. While not strictly a sorbent play, the process achieves CO2 capture costs projected at $300 to $450 per ton at the Stratos DAC hub in Texas, which broke ground in 2024 with a target capacity of 500,000 tons per year.

Polymer Membranes for Post-Combustion Capture

Membrane technology has achieved commercial readiness for specific post-combustion applications, particularly at smaller emission sources where the capital intensity of amine scrubbing plants is prohibitive. Membrane Technology and Research (MTR), based in California, has deployed its Polaris membrane system at multiple natural gas processing and power generation facilities. The Polaris membrane, a thin-film composite with a CO2-selective polyether layer, achieves CO2/N2 selectivity of 50 and permeability exceeding 1,000 GPU (gas permeation units), placing it near the Robeson upper bound for polymer membranes.

MTR's National Carbon Capture Center testing in Alabama demonstrated 90% CO2 capture from coal flue gas at a cost of approximately $45 per ton, competitive with first-generation amine systems but with significantly lower capital expenditure and water consumption. The modular nature of membrane systems allows incremental capacity additions, reducing financial risk compared to large-scale absorption columns that require full-size construction from day one.

Air Liquide has scaled membrane-based CO2 separation for biogas upgrading, deploying over 200 installations across Europe that separate CO2 from methane in landfill gas and anaerobic digester streams. While biogas applications involve higher CO2 concentrations (35 to 45%) than power plant flue gas, they demonstrate membrane reliability over 5 to 10 years of continuous operation with minimal maintenance requirements.

Alkali Metal Carbonates for Medium-Temperature Capture

Sorbents based on sodium and potassium carbonates have emerged as cost-effective options for capture from industrial sources operating at 40 to 80 degrees Celsius. SRI International developed a fluidized bed process using sodium carbonate that captures CO2 at costs estimated at $35 to $50 per ton from cement and steel flue gases, with regeneration at 120 to 200 degrees Celsius. The raw material cost is essentially negligible, as sodium carbonate (soda ash) is an abundant industrial commodity priced at approximately $200 per ton.

Svante, a Canadian company backed by over $300 million in funding from investors including Chevron, Suncor, and the Canada Infrastructure Bank, commercializes structured adsorbent contactors using proprietary solid sorbent formulations for cement and hydrogen production facilities. Their technology achieves capture rates of 90 to 95% with energy penalties 30% lower than conventional amine systems, and they have secured contracts for commercial-scale deployment at LafargeHolcim cement plants in Canada and Europe.

What's Not Working

MOF Scale-Up Remains Elusive

Despite over 100,000 MOF structures reported in the Cambridge Structural Database and extraordinary laboratory performance metrics, commercial deployment of MOFs for carbon capture remains limited. The fundamental barriers are manufacturing cost and stability. Laboratory MOF synthesis typically uses expensive organic solvents, high-purity metal precursors, and multi-step crystallization processes that produce grams of material at costs of $50 to $500 per kilogram. Industrial carbon capture requires thousands of tons of sorbent at costs below $10 to $20 per kilogram.

BASF's large-scale production of Basolite MOFs (the first commercial MOF product line) has demonstrated that manufacturing costs can decrease to $30 to $75 per kilogram at multi-ton scale, but this remains far above cost targets for carbon capture applications. Furthermore, many high-performing MOFs degrade in the presence of water vapor, sulfur dioxide, and nitrogen oxides found in real flue gases. MOF-808 and UiO-66 families show improved hydrothermal stability, but their CO2 capacities (1.5 to 3.0 mol/kg under realistic conditions) are only modestly superior to amine-functionalized silicas that cost a fraction of the price.

NuMat Technologies, perhaps the most prominent MOF commercialization company, pivoted away from carbon capture toward gas storage and toxic gas monitoring applications where MOFs' unique properties command premium pricing. This strategic shift reflects a realistic assessment that MOFs are unlikely to compete on cost for bulk CO2 separation in the near to medium term.

Electrochemical Capture Faces Efficiency Hurdles

Electrochemical approaches to CO2 capture, which use electrical potential rather than heat to drive sorbent regeneration, have attracted significant attention for their potential to integrate with renewable electricity. Companies including Verdox (MIT spinout) and Carbon Capture Inc. have developed electrochemically mediated systems using quinone-based electrodes or pH swing processes. The theoretical advantage is the elimination of thermal regeneration losses, potentially achieving second-law efficiencies two to three times higher than thermal processes.

In practice, electrochemical capture systems face challenges with electrode degradation, parasitic energy losses from side reactions, and the cost of specialized electrode materials. Verdox's polyanthraquinone electrodes demonstrated CO2 capture at laboratory scale with energy consumption of 40 to 60 kJ/mol CO2, competitive with thermal systems, but electrode lifetime remained below 10,000 cycles as of their most recent published results. Commercial viability likely requires electrode lifetimes exceeding 100,000 cycles, a tenfold improvement that has not yet been demonstrated.

Ceramic and Inorganic Membranes Cannot Compete on Cost

High-temperature ceramic membranes (based on perovskite, fluorite, or zeolite structures) offer exceptional CO2 selectivity and resistance to chemical degradation, making them theoretically ideal for integration with industrial processes at elevated temperatures. However, manufacturing costs for defect-free ceramic membranes remain $1,000 to $5,000 per square meter, compared to $20 to $100 per square meter for polymer membranes. The fragility of ceramic membranes also introduces reliability concerns in industrial environments with vibration, thermal cycling, and particulate loading.

What's Next

Mixed-Matrix Membranes Approaching Commercial Viability

Mixed-matrix membranes (MMMs) embed nanoscale fillers (zeolites, MOFs, or graphene oxide) within polymer matrices to combine the processability and low cost of polymers with the superior separation performance of inorganic materials. Recent advances by research groups at Georgia Institute of Technology, Imperial College London, and the Helmholtz-Zentrum Geesthacht have produced MMMs that exceed the Robeson upper bound by 50 to 100%, with CO2/N2 selectivities above 80 and permeabilities above 1,500 Barrers.

The manufacturing pathway for MMMs builds on established polymer membrane fabrication infrastructure, avoiding the scale-up challenges that plague pure MOF and ceramic approaches. MemPro, a Norwegian startup, announced in 2025 that it had produced pilot-scale MMM modules using MOF-polymer composites at costs projected to reach $50 to $150 per square meter at commercial volume. If validated at scale, MMMs could enable membrane-based capture for coal and gas power plants at costs 20 to 30% below polymer-only systems.

Humidity Swing Sorbents for Ultra-Low-Energy DAC

A fundamentally different approach to direct air capture uses ion-exchange resins that absorb CO2 when dry and release it when exposed to moisture. Originally proposed by Klaus Lackner at Arizona State University, humidity swing sorbents require no thermal or electrical energy input for regeneration, relying instead on the Gibbs free energy of water vapor sorption. The theoretical minimum energy consumption is 50 kJ/mol CO2, roughly one-third of thermal swing sorbents.

Carbon Collect (formerly Silicon Kingdom Holdings) has licensed Lackner's technology and deployed prototype "MechanicalTree" passive DAC units in Arizona. Each unit is designed to capture approximately one ton of CO2 per day using columns of ion-exchange resin discs that extend into ambient air, collapse into a sealed chamber for moisture-driven regeneration, and then re-extend. Scaling this approach depends on developing durable resin formulations capable of sustaining performance through tens of thousands of humidity cycles in real-world conditions including dust, UV exposure, and temperature extremes.

AI-Accelerated Materials Discovery

Computational materials science is compressing the traditional 10 to 20 year materials development timeline. Research teams at the University of Ottawa, Lawrence Berkeley National Laboratory, and DeepMind have used machine learning models to screen millions of hypothetical sorbent and membrane formulations, identifying candidates with optimal combinations of capacity, selectivity, stability, and synthesizability. Microsoft's partnership with Pacific Northwest National Laboratory demonstrated in 2024 that AI-guided screening could identify a novel solid-state electrolyte material in 80 days, from initial computational screening through experimental validation.

For carbon capture specifically, the U.S. Department of Energy's Carbon Capture Simulation for Industry Impact (CCSI2) program has developed validated process models that link molecular-level sorbent properties to system-level capture costs, enabling researchers to evaluate the economic potential of new materials before investing in synthesis and testing. This computational pipeline reduces the number of dead-end experimental programs and focuses laboratory resources on the most commercially promising candidates.

Action Checklist

• Evaluate your emission source characteristics (CO2 concentration, temperature, contaminants, flow rate) to determine which sorbent or membrane class is most appropriate
• Request pilot-scale performance data from technology providers, not just laboratory results, and verify claims through independent testing
• Assess available waste heat resources, as regeneration energy source availability strongly influences technology selection
• Model total system costs including sorbent or membrane replacement schedules, not just initial capital expenditure
• Monitor EU Innovation Fund award announcements and DOE ARPA-E programs for emerging technologies approaching commercial readiness
• Engage with technology developers at TRL 6 to 7 (pilot scale) to secure early-mover positions on next-generation systems
• Include sorbent and membrane degradation rates in financial projections, as replacement costs can dominate lifecycle economics
• Track regulatory developments including the EU Carbon Border Adjustment Mechanism and Section 45Q tax credit enhancements that affect capture project economics

FAQ

Q: What is the current cost range for carbon capture using next-generation sorbents versus conventional amine scrubbing? A: Conventional aqueous amine scrubbing costs $50 to $80 per ton of CO2 for point-source capture from power plants and $35 to $55 per ton from high-concentration industrial sources. Next-generation solid sorbents are achieving $35 to $60 per ton at pilot scale for point-source applications, with projected costs of $25 to $45 per ton at commercial scale. For direct air capture, current costs are $600 to $1,000 per ton with solid amine sorbents, with targets of $100 to $200 per ton by 2035 contingent on materials improvements.

Q: How long do solid sorbents and membranes last in real operating conditions? A: Amine-functionalized solid sorbents have demonstrated 3,000 to 5,000 temperature swing cycles in commercial DAC operations (Climeworks), equivalent to approximately 2 to 4 years of continuous use. Polymer membranes in biogas upgrading applications have operated for 7 to 10 years with periodic replacement of individual modules. The key degradation mechanisms are oxidative degradation (exposure to SOx and NOx), thermal aging, and mechanical attrition in fluidized bed systems.

Q: Which carbon capture material technology is closest to displacing conventional amine scrubbing at scale? A: For point-source industrial capture, structured adsorbent contactors using alkali metal carbonate or amine-functionalized sorbents (as commercialized by Svante) are closest to displacing conventional amines, with multiple commercial-scale projects under construction. For direct air capture, amine-functionalized cellulose sorbents (Climeworks) are the only technology with significant operational track record. Polymer membranes (MTR Polaris) are competitive for natural gas processing and smaller-scale flue gas applications but have not yet been deployed at the scale of major amine scrubbing installations.

Q: What role does the EU's regulatory framework play in accelerating materials innovation? A: The EU's combination of high carbon prices (ETS at 55 to 100 euros per ton), direct innovation funding (Innovation Fund), and mandated deployment targets (Industrial Carbon Management Strategy) creates the strongest commercial pull for advanced capture materials globally. The Carbon Border Adjustment Mechanism adds additional incentive by imposing carbon costs on imports from jurisdictions without equivalent pricing, encouraging non-EU producers to adopt capture technologies. Several EU-funded projects, including the ACCSESS and MOF4AIR consortia, specifically target materials development with clear commercialization pathways.

Q: Should organizations invest in carbon capture materials now or wait for next-generation technologies? A: For organizations with near-term compliance obligations (EU ETS, state-level regulations) or contractual carbon neutrality commitments, deploying current best-available technology is advisable. Waiting for theoretical future improvements risks regulatory penalties and reputational exposure. However, organizations should design capture systems with modular architectures that allow sorbent or membrane upgrades as improved materials become available, avoiding lock-in to first-generation materials for the full 20 to 30 year asset lifetime.

Sources

• International Energy Agency. (2025). CCUS in Clean Energy Transitions: Global Status and Outlook. Paris: IEA Publications.
• European Commission. (2024). Industrial Carbon Management Strategy: Communication and Impact Assessment. Brussels: European Commission.
• National Academies of Sciences, Engineering, and Medicine. (2025). A Research Strategy for Carbon Dioxide Removal and Reliable Sequestration. Washington, DC: The National Academies Press.
• Climeworks AG. (2025). Mammoth Plant: First Year of Operations Technical Performance Report. Zurich: Climeworks.
• Svante Inc. (2025). Commercial Deployment Update: Structured Adsorbent Technology for Industrial Decarbonization. Vancouver: Svante.
• Membrane Technology and Research. (2024). Polaris Membrane System: National Carbon Capture Center Testing Results Summary. Newark, CA: MTR.
• U.S. Department of Energy. (2025). Carbon Capture Research and Development: Technology Readiness Assessment. Washington, DC: DOE Office of Fossil Energy and Carbon Management.
• Nature Materials. (2025). "Mixed-matrix membranes for CO2 separation: progress beyond the Robeson upper bound." Nature Materials, 24(3), 312-325.