Open research questions in Carbon Dioxide Capture Technologies

What the literature leaves open

• The high cost of DAC-U systems. The need for a comprehensive strategy to achieve carbon neutrality. The potential impact of the DAC-U system on the energy grid and other infrastructure.

  Scalable carbon solutions: life cycle insights and public willingness to adopt direct air capture and utilization systems · 2026 · DOI

• Future studies should investigate the potential impact of the DAC-U system on the energy grid and other infrastructure. Further research is needed to understand the factors that influence adoption of the DAC-U system and to develop strategies to promote uptake.

  Scalable carbon solutions: life cycle insights and public willingness to adopt direct air capture and utilization systems · 2026 · DOI

• High energy consumption of chemical absorption. Limited capture efficiency of current technologies. Material stability of integrated capture-conversion technology.

  A Comparison of Carbon Dioxide Capture and Conversion Technologies · 2026 · DOI

• The complexity of MOF structures, which makes it difficult to evaluate their CO2 capture performance. The need for accurate simulations of molecular diffusion dynamics. The limited understanding of the relationships between MOF structure and CO2 capture performance.

  Molecular diffusion enhanced performance evaluation of metal-organic frameworks for CO2 capture · 2026 · DOI

• The complexity of modeling implicit solvation effects. The need to consider co-solvation effects in the design of CO2 capture technologies.

  Implicit solvent effects on the binding interactions of amines with CO2 · 2026 · DOI

• Conclusion Biochar has gained recognition as a remarkably promising material for CO2 adsorption, owing to its environmentally friendly properties, cost-effective production, and adaptable physicochemical attributes. This review highlights that engineered biochar is not merely a simple carbon skeleton but serves as a highly tailorable physicochemical framework. Through heteroatom doping (N, S, P, B) and activation processes (encompassing both physical and chemical activation), it enables the synergistic optimization of surface chemistry and microporous structure. On the one hand, ultramicropores/micropores provide pore-filling and molecular sieving effects, which largely determine capacity and selectivity at low temperature and low partial pressure. On the other hand, introducing specific functional groups-particularly pyridinic and pyrrolic nitrogen-effectively bridges the gap between physical adsorption capacity and chemical selectivity. These groups modulate adsorption strength and gas selectivity through Lewis acid–base interactions, hydrogen bonding, and van der Waals forces. Consequently, this enables highly efficient CO2 capture even under low partial pressures. However, bridging the chasm between laboratory breakthroughs and industrial deployment requires a pragmatic confrontation of current limitations. While modifications enhance performance, they often incur higher energy consumption and production costs. However, the transition to industrial viability faces several hurdles. Key challenges include uncertainties in techno-economic feasibility and potential performance degradation over long-term cycles. Furthermore, the lack of standardized protocols for characterizing biochar heterogeneity remains a critical barrier. 7.2 Overarching perspectives To advance biochar-based adsorbents toward industrial CO2 capture, future research should move beyond maximizing single-gas uptake and increasingly address manufacturability, regenerability, and process integration. Key directions include: Li et al. Carbon Research (2026) 5:26 Page 27 of 32 (1) Condition-oriented structure-chemistry codesign: optimizing the balance among ultramicroporosity, N-functionalities, selectivity, and regenerability for targeted scenarios (post-combustion capture, gas upgrading, or DAC). (2) A closed loop between mechanism and identification: combining operando/quasi-operando characterization with theoretical calculations to quantitatively link pore filling, hydrogen bonding, van der Waals forces, and Lewis acid–base interactions to adsorption thermodynamics and kinetics; strengthening reproducible identification of N-species using cross-validated techniques such as XPS and FTIR to mitigate uncertainties from peak overlap.

  Recent advances in the development of engineered biochar for CO2 adsorption: Research on heteroatom-doped biochar · 2026 · DOI

• Biotechnological innovations are increasingly recognized as critical components of low-carbon strategies, particularly within carbon cap- ture, storage, and utilization (CCUS) systems. This review has demon- strated that CCUS technologies exhibit heterogeneous maturity levels, with conventional capture and geological storage approaches reaching near-commercial deployment, while emerging utilization pathways. Across these technologies, life cycle assessment (LCA) and techno- economic analyses consistently highlight that energy demand, process integration, and carbon intensity of inputs are decisive factors in deter- mining overall environmental performance and cost-effectiveness. The analysis further shows that biotechnological approaches offer distinct advantages for carbon mitigation, including operation under mild conditions, high selectivity, and the ability to convert CO2 into value-added products such as biofuels, bioplastics, and biochemicals. When integrated with thermochemical and catalytic systems, such as hybrid biochar–metal–organic framework (MOF) materials, these technologies can enhance capture efficiency, improve product selectiv- ity, and enable more flexible carbon utilization pathways. In parallel, advances in thermochemical biomass conversion and carbon utiliza- tion routes underscore the importance of optimizing mass transfer, energy efficiency, and reaction kinetics to maximize yields and mini- mize environmental impacts. From a policy perspective, the review highlights a transition from fragmented climate strategies toward more coordinated frameworks supporting bio-based carbon mitigation, including international ini- tiatives and regional CCUS policies. However, persistent challenges remain, particularly regarding regulatory clarity, risk management, and the integration of biotechnological solutions into existing climate and energy systems. The incorporation of robust carbon accounting, certification schemes, and carbon market mechanisms emerges as a key enabler for translating technological performance into economic value and incentivizing large-scale deployment.

  Biotechnological innovations in the realm of carbon capture, storage and utilization · 2026 · DOI

• The study identifies a research gap in the development of membraneless electrochemical carbon capture techniques. There is a need for further research to reach industrially relevant current densities and lifetimes.

  Membraneless and Electrochemical Carbon Capture: Disrupting Traditional Amine-Based Systems for Industrial De-carbonization: A Review · 2026 · DOI

• The lack of sustainable and low-cost CO2 capture technologies. The need for efficient and recyclable CO2 adsorbents.

  Sustainable CO2 capture using acid activated alkaline sludge from photovoltaic industry: longevity and recyclability study · 2026 · DOI

• Further experimental validation of the model is needed to confirm its accuracy. Investigation of the effect of other operating conditions, such as temperature and pressure, on oxygen permeation and combustion. Development of more advanced models that account for all possible factors affecting oxygen separation and combustion.

  Mathematical Modelling and Computational Simulation of Oxy-Combustion Carbon Capture Using Ion-Transport Membranes · 2026 · DOI

• There is a lack of experimental data for oxyfuel combustion, particularly for annular reactor configurations. There is a need for more efficient and novel technologies for carbon capture and reduction of greenhouse gas emissions.

  Mathematical Modelling and Computational Simulation of Oxy-Combustion Carbon Capture Using Ion-Transport Membranes · 2026 · DOI

• Future research should focus on improving the efficiency and cost-effectiveness of DAC systems. Future studies should evaluate the use of DAC systems in different greenhouse crop production systems. Future research should investigate the potential for DAC systems to reduce greenhouse-gas emissions in other industries.

  Decarbonizing desert greenhouse crop production with direct air capture–based CO2 enrichment · 2026 · DOI

• The current method of CO2 enrichment via trucked liquid-CO2 is emissions-intensive and costly. There is a need for alternative methods of CO2 enrichment that can reduce greenhouse-gas emissions. The study identifies a gap in the literature on the use of DAC systems for CO2 enrichment in high-tech greenhouses.

  Decarbonizing desert greenhouse crop production with direct air capture–based CO2 enrichment · 2026 · DOI

• Material stability remains a challenge for integrated capture-conversion technology. Thermal catalytic conversion is highly dependent on green hydrogen supply and is constrained by thermodynamic equilibrium. Bioconversion has a slow process and a large land footprint.

  A Comparison of Carbon Dioxide Capture and Conversion Technologies · 2026 · DOI

• Further studies can investigate the technical and economic feasibility of CCS implementation in other regions. Research can focus on developing more efficient and cost-effective CCS technologies.

  Analysis of CCS implementation in Indonesia’s coal fired power plants, economic optimization, and potential impact on Java-Bali grid for future decarbonization · 2026 · DOI

• There is a need to evaluate the impact of retrofitting carbon capture and storage (CCS) technology on coal fired power plants (CFPP) in Indonesia. There is a lack of studies on the economic viability of CCS implementation and its potential impact on the Java-Bali grid for future decarbonization.

  Analysis of CCS implementation in Indonesia’s coal fired power plants, economic optimization, and potential impact on Java-Bali grid for future decarbonization · 2026 · DOI

• The optimization of the agricultural waste supply chain remains a complex challenge. The development of efficient carbon capture technologies is necessary to combat climate change.

  A comprehensive review of agricultural waste-derived activated carbon for carbon dioxide (CO2) capture using PRISMA methodology · 2026 · DOI

• Low capture efficiency, high energy consumption, equipment degradation, and high costs are limitations of CO2 capture technologies. The use of some technologies is limited due to high loss of energy and expense. The paper identifies research gaps in CO2 capture and conversion.

  Review of CO₂ Capture Technologies from Flue Gases and their Conversion Pathways to Value-Added Products · 2026 · DOI

• The paper identifies research gaps in CO2 capture and conversion. The study highlights the need for more effective and sustainable CO2 capture technologies. The results suggest that combining technologies and researching novel chemicals can improve effectiveness and operational viability.

  Review of CO₂ Capture Technologies from Flue Gases and their Conversion Pathways to Value-Added Products · 2026 · DOI

• The development of novel catalysts for CO2 conversion that exhibit stable behavior at high temperatures and in the presence of typical poisoning elements remains a challenge. The understanding of the number and distribution of oxygen vacancies, particularly their potential modification by doping with transition metal single atoms, is crucial for enhancing catalyst design and optimising structure-reactivity relationships.

  Single Ce atom-assisted oxygen vacancies as active and stable sites for CO2 conversion · 2026 · DOI

• The study is limited to simulations and does not include experimental validation. The study only considers a subset of MOF structures and does not evaluate all possible MOF candidates.

  Molecular diffusion enhanced performance evaluation of metal-organic frameworks for CO2 capture · 2026 · DOI

• Despite extensive equilibrium adsorption studies, the dynamic behavior of activated carbons under fixed-bed operating conditions relevant to post-combustion CO2/N2 remains insufficiently understood, particularly for renewable materials.

  Influence of Ultramicroporosity and Surface Chemistry on Dynamic CO2 Capture in Activated Carbons · 2026

• Amine-based electric swing adsorption (ESA) offers a promising low-energy, steam-free pathway, but its efficiency is fundamentally limited by an inherent 2:1 amine-to-CO 2 stoichiometric penalty.

  Proton trap engineered electric swing adsorption for scalable and cost-effective direct air capture · 2026 · DOI

• The capture stage accounts for over 70% of the total investment and operating costs of CCUS. Current mainstream capture technologies have limitations.

  Diethylamine Hydrochloride-Based Deep Eutectic Solvents for CO2 Capture: Experimental Characterization and soft-SAFT Thermodynamic Modeling · 2026 · DOI

• The need for a comprehensive analysis of implicit solvation effects on the binding interactions of amines with CO2. The lack of understanding of the role of co-solvation in CO2 capture by amine-based solvents.

  Implicit solvent effects on the binding interactions of amines with CO2 · 2026 · DOI

Most-cited papers in Carbon Dioxide Capture Technologies

• Review of carbon capture absorbents for CO₂ utilization · Greenhouse Gases Science and Technology · 2022 · 228 citations
• Carbon capture, utilization, and storage (CCUS) technologies: Evaluating the effectiveness of advanced CCUS solutions for reducing CO2 emissions · Results in Surfaces and Interfaces · 2024 · 184 citations
• An overview of technologies for capturing, storing, and utilizing carbon dioxide: Technology readiness, large-scale demonstration, and cost · Chemical Engineering Journal · 2024 · 177 citations
• Integration of carbon emission reduction policies and technologies: Research progress on carbon capture, utilization and storage technologies · Separation and Purification Technology · 2024 · 174 citations
• A review of CO₂ adsorbents performance for different carbon capture technology processes conditions · Greenhouse Gases Science and Technology · 2021 · 163 citations
• Capturing carbon dioxide from air with charged-sorbents · Nature · 2024 · 160 citations
• Review on post-combustion CO2 capture by amine blended solvents and aqueous ammonia · Chemical Engineering Journal · 2024 · 156 citations
• Harnessing the power of functionalized biochar: progress, challenges, and future perspectives in energy, water treatment, and environmental sustainability · Biochar · 2024 · 150 citations
• Feasible deployment of carbon capture and storage and the requirements of climate targets · Nature Climate Change · 2024 · 140 citations
• Considering technology characteristics to project future costs of direct air capture · Joule · 2024 · 139 citations

Most recent work

• Recent advances in the development of engineered biochar for CO2 adsorption: Research on heteroatom-doped biochar · Carbon Research · 2026
• Demonstration of an electrochemical mobile CO₂ capture and utilization system: Design and implementation at industrial sites · Journal of environmental chemical engineering · 2026
• A Low-Temperature Regenerative Porous Amine–Epoxy Polymer for Direct Air Capture · Industrial & Engineering Chemistry Research · 2026
• Cost‑effective offshore carbon capture, utilization and storage deployment and transport network optimization in southern China · Communications Earth & Environment · 2026
• Synergistic urea nitrogen doping engineering and potassium oxalate activation for N-doped ultramicroporous carbon toward efficient CO2 adsorption · Biomass and Bioenergy · 2026
• Integrating Catalytic Regeneration with Nonaqueous Absorbents for Low-Temperature CO ₂ Capture · ACS Sustainable Chemistry & Engineering · 2026
• Redox-decoupled electrolysis for direct air capture of CO2 · Nature Chemical Engineering · 2026
• Spatially programmed amine–hydrophobic dual domains in MIL-101(Cr) toward humidity-tolerant CO2 capture · Chemical Engineering Journal · 2026
• Zeolite 13X for Post-Combustion CO 2 Capture: Adsorption Mechanisms, Process Performance, and Practical Challenges · 2026
• Molecular Dynamics Simulation on CO2/SO2/H2S Gas Absorption by Amine-Based Deep Eutectic Solvents · Journal of Solution Chemistry · 2026

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