Capture Applications Research Articles

Object Detection and Multiple Objective Optimization Manipulation Planning for Underwater Autonomous Capture in Oceanic Natural Aquatic Farm

ABSTRACTUnderwater autonomous capture operations offer significant potential for reducing labor and health risks in sea organism industries. This study presents a comprehensive solution for cross‐domain underwater object detection and autonomous capture. A novel unsupervised domain adaptive learning method is proposed, integrating multiscale domain adaptive modules and attention mechanisms into a Faster Region‐Convolutional Neural Network framework. This approach enhances feature alignment across diverse aquatic domains without parameter tuning. Additionally, an efficient, parameterless constrained multiobjective optimization algorithm is introduced for underwater autonomous mobile capture, integrating parameterized trajectory planning with innovative features, such as adaptive mutation strategies and constraint violation tolerance. The proposed approaches are extensively validated through simulations, tank experiments, and real‐world oceanic trials in the Natural Aquatic Farm of Zhangzidao Island. Results demonstrate the system's robustness in complex underwater environments with varying currents, with experimental outcomes validating the accuracy and reliability of detection and capture capabilities. This research significantly advances autonomous underwater systems' capabilities in object detection and capture tasks, addressing complex challenges in realistic organism capture applications across diverse aquatic environments.

Theoretical structural study of van der Waals complexes between oxazole and atmospheric gases CO2 and N2 for capture applications.

Theoretical structural study of van der Waals complexes between oxazole and atmospheric gases CO2 and N2 for capture applications.

The Road Ahead for Metal-Organic Frameworks: Current Landscape, Challenges and Future Prospects.

This perspective highlights the transformative potential of Metal-Organic Frameworks (MOFs) in environmental and healthcare sectors. It discusses work that has advanced beyond technology readiness levels of >4 including applications in capture, storage, and conversion of gases to value added products. This work showcases efforts in the most salient applications of MOFs which have been performed at a great cadence, enabled by the federal government, large companies, and startups to commercialize these technologies despite facing significant challenges. This article also forecasts the role of nanoscale MOFs in healthcare, including strides toward personalized medicine, advocating for their use in custom-tailored drug delivery systems. Finally we underscore the potential acceleration in MOF research and development through the integration of machine learning and AI, positioning MOFs as versatile tools poised to address global sustainability and health challenges.

Efficiency of carbon dioxide capture with metal substitutions in the MIL-88A metal-organic framework.

Carbon dioxide capture is a vital approach for mitigating air pollution and global warming. In this context, metal-organic frameworks are promising candidates. Particularly, MIL-88A (M), where the metal nodes (M) are connected to fumarate linkers in its structure, has demonstrated significant potential for CO2 capture. However, to date, no studies have investigated the effects of metal substitutions in MIL-88A (M) on CO2 capture performance. Therefore, the present work aims to address this gap by examining metal substitutions with M = Al, Sc, Ti, V, and Ga. To quantitatively understand the CO2 capture capabilities of MIL-88A (M), we employed grand canonical Monte Carlo simulations to study both excess and total CO2 uptakes. Our findings indicated that MIL-88A with Al and Ga as metal nodes exhibited the best performance for CO2 capture. Furthermore, the adsorption energy of the CO2 molecule in MIL-88A (M), obtained through van der Waals-corrected density functional theory calculations, indicated the following order of preference for CO2 adsorption: Ti > V > Sc > Ga ≈ Al. The adsorption strength of the CO2 molecule in MIL-88A (Ga and Al) was the weakest among the considered metals. However, MIL-88A (Al) exhibited the largest specific surface area and hence offered the best excess and total gravimetric uptakes, while MIL-88A (Ga), together with MIL-88A (Al), had the largest pore volumes. Therefore, they exhibited the best excess and total volumetric uptakes. The electronic density of states revealed that the interaction between the 3σ g , 2π u , and 1π g peaks of the CO2 molecule and the O and C p x and p y orbitals of MIL-88A (M) was found to be significant for understanding the physical interaction between CO2 and MIL-88A (M). Thus, our findings provide valuable insights for the rational design of metal-organic frameworks for gas capture and storage applications.

Process-based screening of porous materials for vacuum swing adsorption based on 1D classical density functional theory and PC-SAFT.

Adsorption-based processes are showing substantial potential for carbon capture. Due to the vast space of potential solid adsorbents and their influence on the process performance, the choice of the material is not trivial but requires systematic approaches. In particular, the material choice should be based on the performance of the resulting process. In this work, we present a method for the process-based screening of porous materials for pressure and vacuum swing adsorption. The method is based on an equilibrium process model that incorporates one-dimensional classical density functional theory (1D-DFT) and the PC-SAFT equation of state. Thereby, the presented method can efficiently screen databases of potential adsorbents and identify the best-performing materials as well as the corresponding optimized process conditions for a specific carbon capture application. We apply our method to a point-source carbon capture application at a cement plant. The results show that the process model is crucial to evaluating the performance of adsorbents instead of relying solely on material heuristics. Furthermore, we enhance our approach through multi-objective optimization and demonstrate for materials with high performance that our method is able to capture the trade-offs between two process objectives, such as specific work and purity. The presented method thus provides an efficient screening tool for adsorbents to maximize process performance.

Structural Design of Covalent Organic Frameworks and Their Recent Advancements in Carbon Capture Applications: A Review

Structural Design of Covalent Organic Frameworks and Their Recent Advancements in Carbon Capture Applications: A Review

CO2 capture by new ternary nanocomposite LDH/bayerite/Ag2O in tetrametallic NiZnAgAl layered double hydroxides fabricated via in situ growth

AbstractBACKGROUNDCarbon dioxide exerts the most substantial environmental influence of all greenhouse gases. Therefore, creating novel materials that exhibit minimal energy requirements, robust CO2 capture efficiency, outstanding adsorption and selectivity, economic viability and rapid scalability for applications in industry is important. This study aimed to fabricate the new ternary nanocomposite LDH/bayerite/Ag2O in tetrametallic NiZnAgAl layered double hydroxide (LDH) using the hydrothermal method and to investigate its use for efficient CO2 capture.RESULTSThe results showed that tetrametallic NiZnAgAl LDH, bayerite and Ag2O had grown and formed in situ ternary composites in the solid. Various characterization techniques confirmed the presence of tetrametallic NiZnAgAl LDH, bayerite and Ag2O in the composites. The composites exhibit surface areas ranging from 153.34 to 255.02 m2 g−1, pore volumes ranging from 0.19 to 0.26 cm3 g−1 and pore diameters ranging from 4.06 to 4.93 nm. Each composite has a laminar arrangement of stacked flakes, and the surface of the composite is covered with silver oxide. Transmission electron microscopy images exhibit the nano‐hexagonal construction of the composites. The selected area electron diffraction profile exhibited congruence with the X‐ray diffraction data of LDH, bayerite and Ag2O. The composites have an average particle size that ranges from 22.79 to 41.84 nm. The ternary composite exhibits CO2 capture activity with adsorption capacities ranging from 5.88 to 8.29 mmol g−1. We observed that variations in the molar ratios of Ni, Zn and Ag affected the properties of the composites.CONCLUSIONOverall, the new ternary nanocomposites LDH/bayerite/Ag2O in tetrametallic NiZnAgAl LDH exhibit promising potential for CO2 capture applications. © 2024 Society of Chemical Industry (SCI).

Nitrogen-Rich Conjugated Macrocycles: Synthesis, Conductivity, and Application in Electrochemical CO2 Capture.

Here we report a series of nitrogen-rich conjugated macrocycles that mimic the structure and function of semiconducting 2D metal-organic and covalent organic frameworks while providing greater solution processability and surface tunability. Using a new tetraaminotriphenylene building block that is compatible with both coordination chemistry and dynamic covalent chemistry reactions, we have synthesized two distinct macrocyclic cores containing Ni-N and phenazine-based linkages, respectively. The fully conjugated macrocycle cores support strong interlayer stacking and accessible nanochannels. For the metal-organic macrocycles, good out-of-plane charge transport is preserved, with pressed pellet conductivities of 10-3 S/cm for the nickel variants. Finally, using electrochemically mediated CO2 capture as an example, we illustrate how colloidal phenazine-based organic macrocycles improve electrical contact and active site electrochemical accessibility relative to bulk covalent organic framework powders. Together, these results highlight how simple macrocycles can enable new synthetic directions as well as new applications by combining the properties of crystalline porous frameworks, the processability of nanomaterials, and the precision of molecular synthesis.

Functionalized Dual/Multiligand Metal-Organic Frameworks for Efficient CO2 Capture under Flue Gas Conditions.

Reducing carbon dioxide (CO2) emissions has become increasingly urgent for China, particularly in the industrial sector. Striking a balance between a high CO2 adsorption capacity and long-term stability under practical conditions is crucial for effectively capturing CO2 from flue gas. In this study, a series of functionalized MFM-136 adsorbents were synthesized in which -NO2 and -NH2 groups were grafted onto the kagome lattice of MFM-136. Modifications with -NH2 groups were found to be highly effective for CO2 adsorption, specifically, the CO2 adsorption capacity peaked at 4.35 mmol/g for NH2(0.6)-MFM-136, representing a 55% enhancement more than MFM-136. Concurrently, the CO2/N2 selectivity for NH2(0.6)-MFM-136 was increased 1.57 times. Verification of novel adsorption sites introduced by NH2-H2L4 was conducted by using in situ DRIFT analysis and DFT calculations. It turns out that NH2-H2L4 modification can effectively mitigate the chemical deposition from the impurity gases and significantly improve the adsorbent's hydrophobicity and its tolerance to impurity gases. Remarkably, the reduction in the CO2 absorption capacity for NH2(0.6)-MFM-136 was 34% less than that for MFM-136 after 24 h of exposure to simulated flue gas, making NH2(0.6)-MFM-136 a promising candidate for the potential application of stable and selective CO2 capture under industrial flue gas conditions.

Ether chain-modified Alkanolguanidine for CO2 capture and subsequent conversion

Capturing CO2 and converting it into valuable chemicals has attracted considerable attention in recent years. Herein, a kind of ether chain-modified alkanolguanidines (ECMAs) was designed and synthesized as a dual functional reagent for carbon dioxide capture and conversion. Due to the presence of basic sites and CO2-philic ether chains, these ECMAs demonstrated almost equimolar CO2 capture at room temperature and atmospheric pressure through the synergy of physical and chemical absorption. Even for diluted CO2 (15 % CO2), 0.7 mol CO2 per mole capture reagent can still be achieved, showing their potential application in post-combustion capture. The synthesized ECMAs can also serve as catalyst in the cycloaddition reaction of CO2 with various epoxides, affording 75–99 % yield of corresponding cyclic carbonates under 3 MPa CO2 with tetrabutylammonium iodide (TBAI) as co-catalyst. Moreover, these ECMAs can be applied to the integrated CO2 capture and conversion, in which the ECMAs can react with CO2, forming the alkyl carbonate zwitterion as active CO2 species in the capture step. And in the subsequent cycloaddition reaction with propylene oxide, 52 % yield of propylene carbonate was obtained.

Scalable MOF-based mixed matrix membranes with enhanced permeation processes facilitate the scale application of membrane-based carbon capture technologies

Mixed-matrix membranes (MMMs) leverage the processability of polymers and selectivity of Metal-Organic Frameworks (MOFs). However, they still suffer from poor interfacial compatibility and limited scalability in preparation. In certain polymers, MOFs can bridge the pores within the polymer membrane, enhancing the CO2 adsorption and solubility properties, thus selectively boosting the CO2 permeability. In this study, high-performance MMMs were prepared using scalable CALF-20 in combination with PIM-1. MMMs with a 5% doping level achieved CO2 permeability up to 8003 barrer with 25% improvement in CO2/N2 selectivity. This enhancement was attributed to well-designed MMMs, where MOFs matched the abundant non-interconnecting pores in the PIM-1 membrane. This study represents a significant advancement towards scaling up the preparation of high-performance MOF-based MMMs for carbon capture applications.

Biobased ionic liquid solutions for an efficient post-combustion CO2 capture system

This study explores the use of ionic liquids (ILs) as a novel and efficient alternative to conventional monoethanolamine (MEA) for CO2 capture. While MEA scrubbing is well-known for carbon sequestration, it faces limitations such as high energy consumption, toxicity, and rapid degradation. In contrast, ILs offer advantages such as non-volatility, stability, and reduced corrosiveness. We focus on a biodegradable IL comprising choline ([Cho]) and proline ([Pro]) amino acids to create an eco-friendly solution. Dimethyl sulfoxide (DMSO) is introduced as a diluent to mitigate viscosity issues during CO2 uptake. Our research measures the thermo-physical properties, including density and viscosity of [Cho][Pro] in DMSO at different concentrations. The addition of DMSO resulted in a viscosity reduction of >97 % at a temperature of 303 K for the three virgin solutions compared to the pure IL. In addition, the CO2 capture performance was evaluated using a system of absorption and desorption reactors. The results show that the 25 % wt [Cho][Pro] solution excels, achieving over 90 % CO2 absorption, 0.66 molCO2/molIL in the first cycle, and demonstrating high reusability and regeneration efficiency over multiple cycles. Comparisons indicate that the IL solution outperforms traditional aqueous MEA solutions. Longer term testing confirms the solution's stability and minimal degradation, achieving a regeneration efficiency of >55 % over 30 cycles, suggesting the potential of [Cho][Pro] for sustainable long-term CO2 capture applications.

Experimental VLE data for the AMP/PZ/H2O system under relevant water wash conditions for carbon capture applications

Experimental VLE data for the AMP/PZ/H2O system under relevant water wash conditions for carbon capture applications

Recycling PCBs for nanoparticles production with potential applications in cosmetics, cement manufacturing, and CO2 capture

Electronic waste (e-waste) is a global problem, and many countries have established laws and regulations to promote its proper disposal and recycling. E-waste contains a significant content of printed circuit boards (PCBs), composed of metals and other valuable metals that may become scarce in Earth’s crust – Copper (Cu), nickel (Ni), gold (Au), silver (Ag), palladium (Pd), and others. The main objective of this review is to explore the potential for producing nanoparticles (NPs) from the metals extracted through PCB recycling, with applications in the cosmetics, cement manufacturing, and carbon dioxide (CO2) capture industries. For this purpose, the recycling methods for PCBs e-waste, using physical processes (gravity, magnetic, electrostatic separation, and flotation), metallurgical processes (pyrometallurgy and hydrometallurgy), and purification techniques to obtain an enriched metal solution for the subsequent nanoparticle synthesis was performed. The production of NPs is a novel approach to obtain value-added products for industry. Therefore, recent research from pre-treatment of PCBs to NPs production is summarized, aligning with the circular economy principles and sustainable development goals. Towards this end, wasted PCBs can be transformed into valuable materials with innovative and potential applications in cosmetics, cement manufacturing, and carbon dioxide capture, contributing to a more sustainable future.

Mechanisms and Applications of Electrochemical CO2 Capture Utilizing Activated Carbon Supercapacitors

Fundamental understanding of high energy efficiency and selective CO2 adsorption mechanisms could lead to improvements in direct-air CO2 capture technology. Supercapacitive swing adsorption is a high energy efficiency electrochemical method to reversibly capture CO2 under an applied bias on activated carbon electrodes, but its mechanism remains unclear. Here, we examine the mechanisms behind supercapacitive swing adsorption using both planar gold electrodes to probe the electric double layer response and activated carbon electrodes in a flow cell configuration to probe the effect of porosity and confinement. The double layer capacitance of polycrystalline gold electrodes decreased in a CO2 saturated electrolyte as compared to argon. We attribute this phenomenon to the presence of CO2 and/or bicarbonate in the electric double layer under applied bias. To determine the effect of porosity and confinement on supercapacitive swing adsorption, we developed a flow cell with symmetrical activated carbon electrodes. Upon comparing various commercially available activated carbons, we found that high surface area was a leading factor for increased CO2 adsorption capacity. We further varied the CO2 flow rate, charge protocol, gas composition, and electrode composition to determine which factors led to optimum CO2 adsorption capacity and energy efficiency.

Bipolar Membrane Development and Applications: A Review

Bipolar membranes (BPMs) are a versatile technology with the ability to drive water dissociation and ion transport, making them valuable for applications in energy storage, carbon capture, and water treatment. BPMs consist of a cation exchange membrane, an anion exchange membrane, and a catalyst layer between the two. This composite membrane enables water dissociation where an applied electric field can drive H+ and OH- ions out of the BPM in opposite directions. The pH gradient developed by the BPM’s water dissociation and ion transport enables chemical reactions that would otherwise require extreme conditions. BPMs can be used to operate the anode and cathode at a different pH, providing ideal conditions for electrocatalysts. This makes them a promising technology for electrolysers and fuel cells. BPMs are also being researched for use in CO2 capture and electrolysis. Current industrial uses include desalination, pH adjustment in water treatment, acid-base synthesis, and a variety of other applications where a pH gradient is required.In this review poster we survey current research on BPMs, from materials development to fabrication techniques. We also discuss their current applications in industry and promising technologies utilising BPMs. We review the materials development for high performance BPMs, looking in particular at how catalysts and membranes are developed and can work together to efficiently transport ions and perform water dissociation. Different catalysts from literature are surveyed and compared by their water dissociation performance. The latest cation and anion exchange membranes with high ion conductivity, high permselectivity, and good stability are reviewed. Finally, we describe different methods of fabricating BPMs, including layer-by-layer assembly, solution casting, hot pressing, and electrospinning. We map out the current state of the art and discuss potential avenues for research, including the use of novel catalysts and membranes, and advanced fabrication techniques for improved efficiency.

Bridging the Gap: A Cost Comparison of Electrochemical and Thermochemical Carbon Capture Technologies

Replacing fossil fuels with renewable energy and removing carbon dioxide (CO2) via carbon capture, utilization, and storage (CCUS) are necessary steps to addressing the current climate crisis and achieving net-zero emissions by 2050.1 While renewable energy is predicted to contribute 62.5% of all net electricity generation in the United States by mid-century, it is also predicted that coal and natural gas plants will need to continue operating in the near-term to meet growing energy demands.2,3 This, coupled with the persistence of hard-to-decarbonize processes such as the manufacturing of steel, iron, cement, and other chemicals, requires point-source capture technologies to mitigate remaining CO2 emissions. State-of-the-art CO2 separation systems are typically based on low efficiency, temperature-swing cycles that exploit the natural affinity of alkanolamines for CO2 at ambient conditions. Recently, electrochemical capture systems have been proposed that may enable CO2 removal from flue gas streams at higher energetic efficiencies while also offering more modular and scalable designs.4 However, direct comparisons between the thermochemical and electrochemical approaches are scant, likely due to the nascency of the latter.In this presentation, we introduce a process cost model to investigate the conditions that allow 4-stage electrochemical systems (i.e., comprise of an electrochemical reactor, absorption column, and flash tank) to compete economically with an amine scrubbing system. To do this, we first develop an Aspen Plus® model to determine the material and energy flows in a baseline thermochemical system. Second, we develop an in-house model of the electrochemical system to probe the effects of varying molecular properties, operating conditions, reactor configuration, and scale on the overall performance. We then feed the outputs from each of these models to a levelized cost of capture model to directly compare the costs of the electrochemical system to those of the thermochemical baseline, given the same set of assumptions. Finally, we use these models and parameter sweeps to assess the likelihood that electrochemical systems can outperform thermochemical systems on a cost, energy, and indirect emissions basis. Ultimately, this work seeks to lay the foundation for quantitative comparisons between different technologies available for point-source capture applications while also offering a pathway to shift from generalized sensitivity studies towards investigating the viability of promising molecules and electrolytes. References International Energy Agency. International Energy Agency (IEA) World Energy Outlook 2022. International Energy Agency 524 (2022). Annual Energy Outlook 2023. (2023).International Energy Agency. Energy Technology Perspectives 2020 - Special Report on Carbon Capture Utilisation and Storage. Energy Technology Perspectives 2020 - Special Report on Carbon Capture Utilisation and Storage (2020).Renfrew, S. E., Starr, D. E. & Strasser, P. Electrochemical Approaches toward CO2 Capture and Concentration. ACS Catal 10, 13058–13074 (2020).

CO2 selectivity and adsorption performance of K2CO3-modified zeolite: a temperature-dependent study.

High-performing zeolite materials for carbon dioxide capture are promising for applications such as flue gas CO2 capture. Potassium carbonate-loaded zeolites can offer a plethora of benefits. In this work, for the first time, zeolite-Y impregnated with K2CO3 was studied as a gas adsorbent (CO2, CH4, and N2) and characterized using TGA (thermogravimetric analyzer), XRD, BET, FTIR, FETEM (Field-Emission Transmission Electron Microscope), and XPS. The effect of carbonate loading, temperature, and pressure was particularly targeted and assessed. Accordingly, for a variation in K2CO3 loading from 5 to 15 wt.%, the CO2 adsorption capacity reduced from 3.61 to 1.73mmolg-1 in the synthesized adsorbents. Among all the cases, KYZC10 exhibited very good cyclic adsorption-desorption performance and thermal stability. Further equilibrium modeling studies indicate that the stable and optimally K2CO3-loaded adsorbent (KYZC10) demonstrates effective adsorption isotherm behavior, making it suitable for different temperature variation processes in commercial carbon dioxide capture applications. The KYZC10 adsorbent's stable performance at varying temperatures contributes to its enhanced economic feasibility. This study also used the ideal adsorbed solution theory (IAST) to predict CO2 selectivity over other gases (CH4 and N2).

The Influence of Mg, Na, and Li Oxides on the CO2 Sorption Properties of Natural Zeolite

This study presents a comparative analysis of the CO2 sorption properties of natural zeolites sourced from the Tayzhuzgen (Tg) and Shankanay (Sh) deposits in Kazakhstan. The Tayzhuzgen zeolite was characterized by a Si/Al ratio of 5.6, suggesting partial dealumination, and demonstrated enhanced specific surface area following mechanical activation. Modification of the Tayzhuzgen zeolite with magnesium oxide significantly improved its CO2 sorption capacity, reaching 8.46 mmol CO2/g, attributed to the formation of the CaMg(Si2O6) phase and the resulting increase in basic active sites. TPD-CO2 analysis confirmed that MgO/Tg exhibited the highest basicity of the modified samples, further validating its potential for CO2 capture applications.

A polydopamine coated magnetic spiral switchable composite material for photothermal sterilization and dual-color fluorescence detection of food-borne pathogens

A multifunctional magnetic composite material (MSp@PDA) featuring with helical structure, superparamagnetism, photothermal properties, and fluorescence quenching capability was synthesized through sequential magnetization and in-situ polydopamine coating on the Spirulina surface, then applied for multi-scenario application of pathogens capture, sterilization, and sensitive detection. The pathogens capture and sterilization was investigated by loading bacterial broad-spectrum recognition molecule (MPBA) on MSp@PDA, the capture efficiencies of 91.6 % and 94.2 % were obtained for Escherichia coli and Staphylococcus aureus in 15 minutes, respectively, with complete photothermal sterilization achieved within 4 minutes. The fluorescence real-time detection of E. coli and S. aureus was realized by connecting dual-color fluorescent carbon dots to MSp@PDA through specific aptamers (dCD-apt-MSp@PDA), the corresponding detection limits were 2 and 3 cfu·mL−1, respectively, with linear ranges of 101∼107 cfu·mL−1. The spiked recovery rates of target bacteria in actual samples were 97.4∼101.1 % and 98.2∼101.4 % for E. coli and S. aureus, respectively. The constructed capture, sterilization, and fluorescence detection methods demonstrated promising application value for on-site monitoring of food-borne pathogens in complex matrices.