Direct Air Capture Research Articles

Solubility-Driven Ligand Design of Zn(II) Complexes for Enhanced CO2 Capture in Methanol.

Diacetyl-2-(4-methyl-3-thiosemicarbazonato)-3-(2-hydrazinatopyridine)(methanol) zinc(II) (ZnL10(MeOH)) and related structures use metal-ligand cooperativity to capture atmospheric CO2 under ambient conditions. However, the low solubility in protic solvents limits their practical use in direct air capture systems. This study reports the synthesis, characterization, and CO2 binding affinity of a series of new alkylthiocarbamato-hydrizinato(pyridine) ZnLn(MeOH) complexes (n = 1-9) and assesses the solubility and CO2 binding affinity of each complex. Replacement of the thiosemicarbazonato functional group with alkylthiocarbamato groups leads to increased Lewis acidity and CO2 binding affinity relative to ZnL10(MeOH). Additionally, the solubility of the complexes increased as a function of the alkylthiocarbamato group. In comparison to the structurally related thiosemicarbazonato complex, ZnL11(MeOH), the solubility of the ZnL1(MeOH) to ZnL9(MeOH) complexes was more than 100 times higher, accompanied by excellent binding affinities. The CO2 equilibrium binding constant (K1) showed an increase from 33,600 ± 1700 for ZnL1(MeOH) to 69,000 ± 7900 for ZnL8(MeOH) with the addition of the backbone phenyl group. Overall, the study revealed that the total amount of CO2 captured per unit volume is influenced by both the CO2 binding constant (K1) and the solubility of the complex, with the solubility being the dominant factor.

A Dataset for Investigations of Amine-Impregnated Solid Adsorbent for Direct Air Capture

Amine-impregnated solid adsorbents are widely explored for point source capture and direct air capture (DAC) to address climate change. Existing literature serves as a valuable source for the investigation of amine-functionalized solid adsorbents. This study selected 52 articles from bibliographic platforms using GPT-assisted data source screening. A total of 1,336 data points were manually collected. Each data point is characterized by 28 features including the CO2 capture performance of various adsorbents from diluted to concentrated sources, resulting in 29,857 records. The methodology addresses inconsistencies in units and terminologies in the published articles and demonstrates database reliability, regularity and integrity through statistical analysis. The diverse types of amines and mesoporous solids in the database offer innovation potential for future research. In addition, two machine learning models were trained to promote dataset reuse by scientists from lab-based research and cheminformatics. This study provides opportunities to explore the use of machine learning on small databases and encourages data sharing and uniform reporting among DAC communities.

Techno-economic and life cycle assessment of power-to-formic acid production using direct air capture and green hydrogen

Techno-economic and life cycle assessment of power-to-formic acid production using direct air capture and green hydrogen

A comprehensive review of life cycle assessments of direct air capture and carbon dioxide storage

A comprehensive review of life cycle assessments of direct air capture and carbon dioxide storage

Changing biomass into carbon-negative through dual-step approach: CO2-assisted pyrolysis and biochar-based CO2 adsorption.

Changing biomass into carbon-negative through dual-step approach: CO2-assisted pyrolysis and biochar-based CO2 adsorption.

Integration of direct air capture with Allam cycle: Innovative pathway in negative emission technologies

Integration of direct air capture with Allam cycle: Innovative pathway in negative emission technologies

Impact of direct air capture process flexibility and response to ambient conditions in net-zero transition of the power grid

Impact of direct air capture process flexibility and response to ambient conditions in net-zero transition of the power grid

High capacity and robust moisture-swing CO2 adsorption for direct air capture by functionalized cellulose aerogels

High capacity and robust moisture-swing CO2 adsorption for direct air capture by functionalized cellulose aerogels

Carton Capture and Storage Technologies:-Advancements, and Challenges In Combating Climate Change

ABSTRACT Carbon Capture and Storage Technologies play as key role in reducing Carbon Dioxide (CO2) from air help to fight against climate change. This technology captures Carbon released from industrial processes and power generation then by transporting it and storing it securely underground prevents the release of carbon into the atmosphere. Recent advancements such as Direct Air Capture (DAC), Bioenergy with carbon Capture and storage CBECCS) and improved carbon mineralization techniques have significantly enhanced. By bringing together renewable energy and developing cost-effective sorbent strengthened its potential. However, regardless of this CCS faces challenges like large scale implementation, high cost and energy requirement and risk of CO₂ leakage. Also, there is a need of better infrastructure to transport and Store CO2 safely. This paper discusses both the advancements and challenges in CCS technology and how it can contribute to a more sustainable future if the existing barriers are addressed.

Investigation of Moisture Swing Adsorbents for Direct Air Capture by Dynamic Breakthrough Studies

Investigation of Moisture Swing Adsorbents for Direct Air Capture by Dynamic Breakthrough Studies

Isolated and Paired Metal Sites in Zeolites Using Solid‐State Ion Exchange

AbstractIsolated and paired extraframework transition metal cations in zeolites are emerging as top candidates for numerous applications, including, but not limited to, selective methane oxidation to methanol, selective catalytic reduction of nitrogen oxides, propane dehydrogenation, propylene epoxidation, and direct air capture of carbon dioxide. Importantly, these well‐defined heterogeneous catalysts offer parallels with molecular and metalloenzyme catalytic active sites. Aqueous‐phase ion exchange (APIE) is the most common synthesis technique to obtain these catalysts. Solid‐state ion exchange (SSIE) is an often overlooked technique that offers synthetic advantages compared to APIE. Thus, recent advances in solid‐state synthesis strategies merit contemporary contextualization. In this minireview, we describe the basic principles, methods, mechanisms, challenges, and advances in solid‐state ion exchange in the context of well‐defined transition metal cation active sites located in extraframework positions of the zeolite.

Amine-Functionalized Defective MOFs for Direct Air Capture by Postsynthetic Modification.

Amine-functionalized defective metal-organic frameworks (DM) showed promise for direct air capture (DAC) of CO2 under ambient conditions. In this work, chromium-based DM was functionalized via a two-step postsynthetic modification with ethylenediamine (EDA), tris(2-aminoethyl)amine (TAEA), and polyethylene-polyamines (PEPA). Characterization by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM) confirmed successful synthesis and structural integrity. Among the samples, 1:1-PEPA-DM exhibited the best performance, with a CO2 adsorption capacity of 1.26 mmol/g, a regeneration energy of 75.1 kJ/mol, and only 26.62% capacity loss after 12 cycles in ambient air. In contrast, 1:1-TAEA-DM showed a high regeneration energy (158.61 kJ/mol) and a 95.17% capacity loss. Physically impregnating PEPA resulted in a lower capacity (0.94 mmol/g) and a loss of 76.32% after 12 cycles. These results highlight covalent PEPA grafting as a promising strategy for developing durable DAC sorbents.

Catalytic Membrane Vacuum Regeneration: Enhancing Energy Efficiency and Renewable Compatibility in Direct Air Capture.

Liquid-based CO2 direct air capture (DAC) is a pivotal technology for mitigating climate change. Energy-intensive CO2 desorption, high regeneration temperatures, and solvent degradation are key challenges. Here, low-temperature catalytic membrane vacuum regeneration (C-MVR) as a promising approach for sustainable and energy-efficient DAC is developed and evaluated. Noncatalytic experiments are conducted using three commercial membrane modules and four green amino acid salts under varying conditions (e.g., temperatures and flowrates). Based on CO2 transfer rates, ultra-thin dense composite membranes and aqueous potassium taurinate (TauK) are the most promising for MVR in DAC applications. For C-MVR trials, commercial ion-exchange resin improves CO2 desorption fluxes by up to 64.4% and reduces thermal energy requirements by up to 39.1%. TauK demonstrates the highest CO2 flux and lowest thermal energy consumption. Parametric analysis of catalyst performance for varying temperatures, catalyst amount, and solvent concentrations is also performed. To minimize any potential precipitation in TauK, potassium carbonate (K2CO3) is added, showing minimal impact on CO2 desorption kinetics and catalyst improvement. The findings of this study highlight the practical applicability of C-MVR using green amino acid salts as a sustainable approach to boost CO2 desorption rate and reduce thermal energy input.

Harnessing Collective Magnetic Forces for Enhanced Modulation of Oxygen Diffusion in CO2/O2 Separation toward Direct Air Capture.

Membrane-based direct air capture (m-DAC) has recently been introduced as a simple, scalable, and environmentally friendly method to capture CO2 from the atmosphere. The captured CO2 is considered to be a carbon source for chemical reduction to other value-added chemicals. However, the chemical reduction of CO2 is disrupted by any O2 in the captured gas. Therefore, membranes with high CO2/O2 selectivity are essential for the m-DAC process. In this work, we design magnetic mixed matrix membranes (MMMs) with magnetic nanoparticle (MNP) fillers in polymer matrices, which exhibit room-temperature trapping of gaseous O2 within the membrane to achieve high CO2/O2 selectivities. We found that the CO2/O2 selectivity increased with both the MNP content and the externally applied magnetic field strength, signifying the magnetic interaction of paramagnetic O2 with MNP, while the permeation of CO2 remained unaffected. The experimental results were supported by our mathematical model. Overall, the magnetic PolyActive-MMMs containing 40 wt % MNPs achieved the highest CO2/O2 selectivity of 35 under a magnetic field of 800 mT, corresponding to a selectivity enhancement of 60% over pure PolyActive membranes. Our findings demonstrate the potential of using magnetic fields to control gas transport for applications that require the separation of O2 from other gases.

Assessing climate change impact of blue ammonia via carbon capture and utilization in life cycle modelling.

Assessing climate change impact of blue ammonia via carbon capture and utilization in life cycle modelling.

Connecting Material Characteristics with System Properties for Membrane-Based Direct Air Capture (m-DAC) Using Process Operability and Inverse Design Approaches.

This paper presents a process modeling approach for a two-staged membrane-based direct air capture (m-DAC) process, considering material characteristics, membrane separation, and system properties. m-DAC is a negative emissions technology for capturing dilute CO2 from air. Its continuous and modular nature could reduce economic challenges compared to sorption-based processes, which require costly regeneration. Facilitated transport membranes, with specialized CO2 carriers, offer higher performance than traditional sorption-diffusion membranes. Their key properties-the CO2 apparent diffusion coefficient () and equilibrium constant (K eq)-determine membrane separation properties such as CO2 permeance and CO2/N2 selectivity. This work maps these inputs to feasible output spaces such as for CO2 recovery, purity, and capture cost. Additionally, inverse design is used to determine the required membrane properties for target system outcomes. Overall, this study provides a framework for membrane researchers to design cost-effective, scalable m-DAC solutions.

Optimizing the Synthesis of CO2-Responsive Polymers: A Kinetic Model Approach for Scaling Up.

The kinetic model is a crucial tool for optimizing polymer synthesis protocols and facilitating the scaled-up production processes of the CO2-responsive polymer poly(N-[3-(dimethylamino)propyl]-acrylamide)-b-poly(methyl methacrylate)(PDMAPAm-b-PMMA), which is supposed to be implemented in direct air capture (DAC) technology. This study presents a simulation of the kinetic model developed for the Reversible Addition-Fragmentation Chain-Transfer (RAFT) polymerization of N-[3-(dimethylamino)propyl]-acrylamide (DMAPAm), alongside an investigation into the kinetics of this polymerization using the simulation as an analytical tool, as well as the application of the simulation for the upscaling of RAFT polymerization. Ultimately, the kinetic model was validated through two kinetic experiments, confirming its reliability. It was subsequently employed to optimize the synthesis recipe and to predict the properties of PDMAPAm homopolymers, thereby supporting the upscaling of PDMAPAm-b-PMMA diblock copolymer synthesis. In the end, the preliminary results of the CO2-responsiveness of the diblock copolymer were determined with a simple experiment.

Closing the Carbon Cycle in Plasma‐Based CO2 Splitting – A Techno‐Economic Perspective

AbstractThis techno‐economic analysis examines the impact of CO₂ capture energy and capital costs on plasma‐based power‐to‐liquid (PtL) systems, identifying strategies to minimize the net production costs (NPC) for synthetic fuels. Three future development scenarios were defined. One, focusing on high efficiencies, reaches NPC of 2.9 EUR L−1 of marine diesel. The approach of prioritizing high CO2 conversion results in costs of 3.7 EUR L−1. A more balanced approach between efficiency and conversion achieves an NPC of 2.6 EUR L−1. Further NPC reductions are possible by sourcing lower‐cost renewable electricity, reducing the NPC further to a minimum of 1.6 EUR L−1. These findings underscore that direct air capture (DAC) cost‐efficiency and process integration improvements are essential for scalable, economically viable CO₂ utilization in PtL processes.

Sorbent Regeneration via Radiofrequency-Assisted Dielectric Heating for Direct Air Capture of CO2

Sorbent Regeneration via Radiofrequency-Assisted Dielectric Heating for Direct Air Capture of CO₂

Isolated and Paired Metal Sites in Zeolites Using Solid-State Ion Exchange.

Isolated and paired extraframework transition metal cations in zeolites are emerging as top candidates for numerous applications, including, but not limited to, selective methane oxidation to methanol, selective catalytic reduction of nitrogen oxides, propane dehydrogenation, propylene epoxidation, and direct air capture of carbon dioxide. Importantly, these well-defined heterogeneous catalysts offer parallels with molecular and metalloenzyme catalytic active sites. Aqueous-phase ion exchange (APIE) is the most common synthesis technique to obtain these catalysts. Solid-state ion exchange (SSIE) is an often overlooked technique that offers synthetic advantages compared to APIE. Thus, recent advances in solid-state synthesis strategies merit contemporary contextualization. In this minireview, we describe the basic principles, methods, mechanisms, challenges, and advances insolid-state ion exchange in the context ofwell-defined transition metal cationactive sites located in extraframework positions of the zeolite.