Dry Ice Research Articles

Analysis of Density Distribution in a Cylindrical Specimen under Compaction Using the Example of Dry Ice.

When dealing with processes involving the compaction of bulk materials, very often the quality of the product is determined based on density measurements. Methods used in the industry do not produce compacted materials with high degrees of homogeneity. As a result, the quality of the resulting product, interpreted as its density, varies over the cross-section of the product. In this article, the authors present the results of a numerical study involving the analysis of the density distribution of compacted dry ice during the reciprocating process. The Drucker-Prager/cap model was used in this study, which allowed the change in mechanical properties of the compacted material to be taken into account during the simulation of the process. The diameter, height and density of the cylindrical specimens used in the numerical tests were taken as the variable parameters. Thus, as a result of the testing, the authors could formulate conclusions relating to their impact on the homogeneity of the material.

Enhancing Eastern Equine Encephalitis Virus Surveillance in New Jersey: Optimized Collection of Culiseta melanura.

Eastern equine encephalitis virus (EEEV) causes the most clinically severe neuroinvasive arboviral disease in the United States. The virus is endemic in eastern and Gulf Coast states and the Great Lakes region, causing cases annually. To detect EEEV circulation in its enzootic cycle before the virus infects humans and other mammals, mosquito control agencies in New Jersey have conducted mosquito surveillance using a series of permanent wooden resting box sites since 1975. We conducted 2 field studies, 1 evaluating resting traps and 1 evaluating efficacy of CO2 lures, to optimize collection of Culiseta melanura, the primary enzootic vector of EEEV. Resulting mosquito samples were subjected to molecular analysis to determine EEEV infection rates. Corrugated plastic boxes trapped more bloodfed Cs. melanura than other resting trap types (resting boxes, Centers for Disease Control and Prevention [CDC] resting traps, or fiber pots) and were similar to resting boxes in total number of female Cs. melanura caught. Further, non-baited CDC light traps were more successful in trapping host-seeking Cs. melanura than those baited with dry ice, a CO2 lure. The EEEV RNA was identified in Cs. melanura, Aedes vexans, Anopheles quadrimaculatus, and Uranotaenia sapphirina. Our findings indicate that corrugated plastic boxes and non-CO2 baited traps could improve detection of Cs. melanura. Mosquito control agencies are encouraged to periodically assess their surveillance strategy for EEEV.

Load Carrying Capacity of Case-Carburized Gears with Different Cryogenic Treatments

Abstract Gearboxes of modern drivetrains, e.g., in wind turbines, can be exposed temporarily to low ambient temperatures during their manufacturing or during operation. During manufacturing or assembly, for example, very low temperatures sometimes occur during joining processes due to the cryogenic treatment of the components. In these cases, the temperature depends on the cooling medium used (typically dry ice or liquid nitrogen). Furthermore, depending on the application, gearboxes may be exposed to low ambient temperatures up to -60 °C when used in cold regions. The low temperatures can have an impact on the component properties and thus on the gear load carrying capacity. Therefore, the knowledge of these influences is very important regarding the design and dimensioning of gearboxes. In this publication, further investigations on the load carrying capacity of cryogenic treated gears are presented based on previous research work. The focus is on results on the tooth root and pitting load carrying capacity. The load carrying capacity is analyzed in the context of changes in the component properties as a result of different low temperature treatments, and the dominant influencing factors are identified.

MRO overview: Sixteen years in Mars orbit

Launched on August 12, 2005, the Mars Reconnaissance Orbiter (MRO) entered Mars orbit on March 10, 2006. Following a period of aerobraking, MRO completed its entry into its primary science orbit in September 2006, initiating a program of systematic observations of Mars that still continues. Five providers, including the Italian Space Agency, provided 6 instruments for flight, observing the surface, atmosphere, and subsurface of Mars with greater spatial resolution and systematic coverage than ever before. Two investigations utilized the spacecraft accelerometers and tracking of the orbiter via the Deep Space Network to study upper atmosphere densities and the gravity field of the planet. The data acquired by MRO have revealed a dynamic planet whose change from an ancient wetter climate to the drier climate of today was a complex transition and not a simple “drying out”. Furthermore, that climate continues to change even today. The diversity of the early habitable environments, the ice ages recorded in the polar cap layering and subsurface ice deposits, the repeating patterns of dust storms, and the revelation of new features at the limit of resolution are all part of the scientific return from MRO during nearly a decade of Mars years. The story of that mission, of the evolution of its capabilities, and its contributions to our current understanding of Mars are the subject of nearly two dozen papers in the Icarus special issue, MRO: Sixteen Years at Mars. Three papers describe in more detail the evolution of instrument operations and data products over the mission; several papers describe new analysis techniques for the radar, including construction of 3-dimensional views, and for the atmospheric sounder, enabling better retrievals in a dusty lower atmosphere. Other papers report on recent research including, but not limited to, dune movement, the roles of water and carbon dioxide ice in surface change, and attempts to understand the formation and fading of the enigmatic recurring slope lineae. This paper describes general aspects of the MRO spacecraft, payload, and mission as context for the special issue papers; it also summarizes scientific results and mission support events on a mission phase by mission phase basis to give a time history of discovery and effort.

A new approach based on a concurrent cooling method during GTAW and DC-LSND welding to mitigate residual stresses in Al 6061-T6

Welding often induces residual stresses and undesired distortion in components. The negative impacts of these detrimental residual stresses have prompted researchers to explore methods for preventing or mitigating these stresses. Altering the temperature history can influence residual stress, and employing cold or heating techniques during welding has the potential to reduce harmful residual stress. In this study, the dynamically controlled low-stress no-distortion (DC-LSND) method with TIG welding was utilized to reduce the residual stresses in Al alloy 6061-T6. The methodology was simulated using Abaqus software, and the simulation results were validated with experimental data. The Al alloy served as the base metal, alloy (ER-4043) as the filler, and dry ice as the coolant. In the finite element analysis, the longitudinal residual stress at the center of the weld line in TIG welding was calculated to be 77 MPa. In the DC-LSND welding method, this value approached zero. Experimental measurements revealed residual stresses in the center of the welding line to be 183 MPa in conventional welding and 130 MPa in DC-LSND welding. According to the DC-LSND results, a 100% reduction in residual stresses was achieved in the finite element method. In the experimental test, a reduction of approximately 30% in residual stress was observed. The method developed in this research is recommended for application in welding metals and alloys where phase changes do not occur.

Development of a Sampling and Storage Protocol of Extracellular Vesicles (EVs)-Establishment of the First EV Biobank for Polytraumatized Patients.

In the last few years, several studies have emphasized the existence of injury-specific EV "barcodes" that could have significant importance for the precise diagnosis of different organ injuries in polytrauma patients. To expand the research potential of the NTF (network trauma research) biobank of polytraumatized patients, the NTF research group decided to further establish a biobank for EVs. However, until now, the protocols for the isolation, characterization, and storage of EVs for biobank purposes have not been conceptualized. Plasma and serum samples from healthy volunteers (n = 10) were used. Three EV isolation methods of high relevance for the work with patients' samples (ultracentrifugation, size exclusion chromatography, and immune magnetic bead-based isolation) were compared. EVs were quantified using nanoparticle tracking analysis, EV proteins, and miRNAs. The effects of different isolation solutions; the long storage of samples (up to 3 years); and the sensibility of EVs to serial freezing-thawing cycles and different storage conditions (RT, 4/-20/-80 °C, dry ice) were evaluated. The SEC isolation method was considered the most suitable for EV biobanking. We did not find any difference in the quantity of EVs between serum and plasma-EVs. The importance of particle-free PBS as an isolation solution was confirmed. Plasma that has been frozen for a long time can also be used as a source of EVs. Serial freezing-thawing cycles were found to affect the mean size of EVs but not their amount. The storage of EV samples for 5 days on dry ice significantly reduced the EV protein concentration.

Anionic Effect on Electrical Transport Properties of Solid Co2+/3+ Redox Mediators.

In a solid-state dye-sensitized solar cell, a fast-ion conducting (σ25°C > 10-4 S cm-1) solid redox mediator (SRM; electrolyte) helps in fast dye regeneration and back-electron transfer inhibition. In this work, we synthesized solid Co2+/3+ redox mediators using a [(1 - x)succinonitrile: x poly(ethylene oxide)] matrix, LiX, Co(tris-2,2'-bipyridine)3(bis(trifluoromethyl) sulfonylimide)2, and Co(tris-2,2'-bipyridine)3(bis(trifluoromethyl) sulfonylimide)3 via the solution-cast method, and the results were compared with those of their acetonitrile-based liquid counterparts. The notation x is a weight fraction (=0, 0.5, and 1), and X represents an anion. The anion was either bis(trifluoromethyl) sulfonylimide [TFSI-; ionic size, 0.79 nm] or trifluoromethanesulfonate [Triflate-; ionic size, 0.44 nm]. The delocalized electrons and a low value of lattice energy for the anions made the lithium salts highly dissociable in the matrix. The electrolytes exhibited σ25°C ≈ 2.1 × 10-3 (1.5 × 10-3), 7.2 × 10-4 (3.1 × 10-4), and 9.7 × 10-7 (6.3 × 10-7) S cm-1 for x = 0, 0.5, and 1, respectively, with X = TFSI- (Triflate-) ions. The log σ-T-1 plot portrayed a linear curve for x = 0 and 1, and a downward curve for x = 0.5. The electrical transport study showed σ(TFSI-) > σ(Triflate-), with lower activation energy for TFSI- ions. The anionic effect increased from x = 0 to 1. This effect was explained using conventional techniques, such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), UV-visible spectroscopy (UV-vis), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA).

Method for Determining the Coefficient of Friction Variation Pattern as a Function of Density at Low Temperatures Using the Example of Dry Ice-Steel Contact.

The developments in manufacturing technologies are expected to reduce energy input without compromising product quality. Regarding the material densification process, numerical simulation methods are applied to achieve this goal. In this case, relevant material models are built using functions that describe the variation in mechanical parameters of the material in question due to its deformation. The literature review conducted for this research has revealed a shortage of experimental research methods allowing a determination of the coefficient of friction at low temperatures, approximately 200 K. This article proposes a method for determining the friction coefficient of dry ice sliding against steel. The experimental results were analysed to obtain several functions describing the variation in the coefficient of friction. These functions were then compared using goodness-of-fit indexes. Finally, two functions with similar goodness-of-fit values were chosen. The findings of this research project will complement the already available information and may be used in various research and implementation projects related to the development or improvement of currently used crystallised carbon dioxide conversion processes.

Scalable Jet‐Based Fabrication of PEI‐Hydrogel Particles for CO2 Capture

The capture, regeneration, and conversion of CO2 from ambient air and flue gas streams are critical aspects of mitigating global warming. Solid sorbents for CO2 absorption are very promising as they have high mass transfer areas without energy input and reduce emissions and minimize corrosion as compared to liquid sorbents. However, precisely tunable solid CO2 sorbents are difficult to produce. Here, we demonstrate the high‐throughput production of hydrogel‐based CO2‐absorbing particles via liquid jetting. By wrapping a liquid jet consisting of an aqueous solution of cross‐linkable branched polyethylenimine (PEI) with a layer of suspension containing hydrophobic silica nanoparticles, monodisperse droplets with a silica nanoparticle coating layer was formed in the air. A stable Pickering emulsion containing PEI droplets was obtained after these ejected droplets were collected in a heated oil bath. The droplets turn into mm‐sized particles after thermal curing in the bath. The diameter, PEI content, and silica content of the particles were systematically varied, and their CO2 absorption was measured as a function of time. Steam regeneration of the particles enabled cyclic testing, revealing a CO2 absorption capacity of 6.5 ± 0.5 mol kg−1 solid PEI in pure CO2 environments and 0.7 ± 0.3 mol kg−1 solid PEI for direct air capture. Several thousands of particles were produced per second at a rate of around 0.5 kg per hour, with a single nozzle. This process can be further scaled by parallelization. The complete toolbox for the design, fabrication, testing, and regeneration of functional hydrogel particles provides a powerful route toward novel solid sorbents for regenerative CO2 capture.

Produce low-CO2 silica fume hybrid high-strength concrete using dry ice (solid CO2) as a CO2-utilized admixture

Concerns about high-strength concrete (HSC) have increasingly grown in tandem with the building industry's rapid development. However, the high CO2 emissions, high hydration heat, and high autogenous shrinkage of HSCs considered key issues that limit their wide application. In this study, various proportions of dry ice (solid CO2) were added to concrete to optimize HSC. The test results indicated that adding solid CO2 decreased the hydration heat and autogenous shrinkage and increased the mechanical properties and surface electrical resistivity of HSC. This is primarily attributed to the physical and chemical effects of solid CO2 in HSC curing. At 28 d of curing, the sample containing 3 wt% solid CO2 exhibited the most significant optimization effect. This is attributed to the fact that, at lower solid CO2 content (3%), the production of carbonation products compensates for the loss of strength caused by the reduction of hydration products. In addition, the addition of solid CO2 caused a decrease in the initial temperature, which delayed the hydration reaction and reduced the autogenous shrinkage. Adding solid CO2 led to an increase in acidity and promoted the formation of AFt, further reducing the autogenous shrinkage. And the more solid CO2 added, the greater the reduction in CO2 emissions for the mixture. Therefore, adding solid CO2 can play a role in optimizing the performance and promoting the sustainability of HSC and can contribute to the objectives of low CO2 emissions, low hydration heat, and low autogenous shrinkage of HSC.

Evaluation of Dry Ice for Short-Term Storage and Transportation of Frozen Boar Semen.

To address the safety problems posed by the transportation of boar semen using LN, this study was conducted on the short-term storage of frozen boar semen in dry ice (-79 °C). Boar semen frozen in LN was transferred to dry ice, kept for 1 day, 3 days, 5 days, 7 days, or 8 days, and then moved back to LN. The quality of frozen semen stored in LN or dry ice was determined to evaluate the feasibility of short-distance transportation with dry ice. The results showed that 60 °C for 8 s was the best condition for thawing frozen semen stored in dry ice. No significant differences in spermatozoa motility, plasma membrane integrity, or acrosome integrity were observed in semen after short-term storage in dry ice compared to LN (p > 0.05). There were no significant changes in antioxidant properties between storage groups either (p > 0.05). In conclusion, dry ice could be used as a cold source for the short-term transportation of frozen boar semen for at least 7 days, without affecting sperm motility, morphological integrity, or antioxidant indices.

Energy optimization of a non-aqueous solvent CO2 absorption system with pressure swing regeneration

This study focuses on optimizing the energy requirement in the post-combustion CO2 capture system using pressure swing regeneration through a model-based design (MBD). The simulation results highlight the significant impact of CO2 recovery, inlet gas and liquid flow rate, and CO2 concentration in the flue gas on the overall energy demand of the system. Moreover, an investigation into the de-sublimation chamber was undertaken, revealing a relationship between dry ice formation and the heat transfer between the LNG stream and CO2 in the heat exchanger. The parametric analysis study reveals that the sensible heat of the lean solvent is significantly influenced by the CO2 concentration in the liquid, consequently affecting the overall system energy. According to the results, the utilization of cold energy from LNG could save 80 % of the total energy requirement. The optimization results found the best working condition, which consumes energy of 0.190 GJ/ton CO2, 31 % lower than the basic scenario.

Experimental Study of Heat Transfer Characteristics of Pulsed Dry Ice Sublimation Spray Cooling with High Thermal Load

Experimental Study of Heat Transfer Characteristics of Pulsed Dry Ice Sublimation Spray Cooling with High Thermal Load

A non-invasive capacitive sensor to investigate the Leidenfrost phenomenon: a proof of concept study

A volatile sessile liquid droplet or a sublimating solid manifests levitation on its own vapor when placed on a sufficiently heated surface, illustrating the Leidenfrost phenomenon. In this study, we introduce a non-invasive capacitance method for investigating this phenomenon, offering a potentially simpler alternative to existing optical techniques. The designed sensor features in-plane miniaturized electrodes forming a double-comb structure, also known as an interdigitated capacitor. Initially, the sensor’s capacitance is characterized for various distances between the sensor and a dielectric material. The influence of the sensor substrate material and the spacing between the electrodes on the sensor’s capacitance is also investigated. To demonstrate the feasibility of the method, a sublimating dry ice pellet is placed on the capacitive sensor, and its performance is evaluated. We present results for the dimensionless vapor layer thickness and the pellet’s lifetime at different substrate temperatures, derived from the capacitance output. The results are compared with Optical Coherence Tomography (OCT) data, serving as a benchmark. While the temporal evolution of the sensor’s output, variation in the dimensionless vapor layer thickness, and the lifetime of the dry ice pellet align with expected results from OCT, notable quantitative deviations are observed. These deviations are attributed to practical experimental limitations rather than shortcoming in the sensor’s working principle. Although this necessitates further investigation, the methodology presented in this paper can potentially serve as an alternative for the detection and measurement of Leidenfrost vapor layers.

PSII-9 Whole genome sequences of two nitrate-reducing strains of Selenomonas ruminantium isolated from the rumen

Abstract Selenomonas ruminantium is a functionally diverse, non-fibrolytic member of the rumen microbial community with two subspecies: lactilytica and ruminantium. Some strains of S. ruminantium can reduce nitrate and nitrite, which may be associated with ruminal fiber degradation and, thus, greater forage diets. Most work done with S. ruminantium has been culture-based, with less genomic and functional data. Here, we performed whole genome sequencing with an Oxford Nanopore GridION on two isolated, nitrate-reducing strains of S. ruminantium to provide complete genomic data and determine the nitrogen usage functional capacities of these novel strains. The two isolated strains, 223 and 231, were shipped on dry ice to the University of Wisconsin-Madison, where they were grown, pelleted, and observed under a microscope to determine purity. The samples were processed with a 3 min bead-beating step before extraction with the Zymo Quick-DNA High Molecular Weight MagBead Kit. Subsequently, the extracted samples underwent a quality assessment step before moving into library preparation for Oxford Nanopore sequencing. The two libraries were then loaded onto two R9.4.1 flow cells per library and were sequenced on an Oxford Nanopore GridION for 72 h. The data were extracted from the GridION, and the combined passed reads from each of the two flow cells per library were assembled with Canu and Flye, long-read de novo genome assemblers designed for noisy, single-molecule sequences. The assembled genomes were compared with a reference S. ruminantium genome with Quast, a quality assessment tool that evaluates assembly accuracy. Finally, the assembled genomes with the highest accuracy were analyzed with prodigal to generate protein-coding gene predictions and then with BLAST to assign functional predictions. For each strain, a different assembly was used. The Canu assembly of strain 223 had greater accuracy rates at 3205.23 mismatches per 100 kbp, while the Flye assembly of strain 231 had 2494.40 mismatches per 100 kbp. The two strains had similar genome sizes: 3,098,553 base pairs for strain 223 and 3,138,614 base pairs for strain 231. Strain 223 had less GC content than strain 231 of 51.02%, while strain 231 had a GC content of 52.80%, which were both less than the 50.68% GC content of the reference genome. These genomes provide a resource for understanding nitrate reduction in the rumen and work to build a better database for analyzing the rumen microbiome.

Numerical investigation of jet impingement on flat/concave cooling of CO2 with different phase states under high heat flux

The thermal load and high temperature brought by the increase in power of electronic devices or the increase in speed of supersonic aircraft limit the respective development. In this paper, a numerical model of CO2 jet impingement cooling of a constant heat flux plate/concave surface in different phase states was established. Secondly, the non-equilibrium phase transition and the real-thermophysical properties of CO2 was considered. The effects of different wall heat flux (0.7 MW/m2 ∼ 6.5 MW/m2) and initial phase states on the impact cooling performance of CO2 jet were studied.It is found that for SCO2 jet impingement, when the inlet temperature is lower than the pseudo-critical temperature, the heat transfer coefficient increases with the increase of inlet pressure, and the maximum increase is 24.7 %. For near-critical liquid CO2 (LCO2) jet impingement, low latent heat prevents temperature overshoot in the heat flux range studied. With the increase of the proportion of dry ice in the inlet, the heat transfer coefficient also increases. When q > 3 MW/m2, the heat transfer coefficient of dry ice jet impact is 2.5 ∼ 3 times and 1 ∼ 1.4 times of that of SCO2 and near-critical LCO2 jet impingement for the flat plate model, respectively. For concave surface with high heat flux, near-critical LCO2 jet impingement cooling effect is relatively good. In addition, concave surface will aggravate the uneven cooling surface temperature.The results can provide more references for the CO2 jet impingement technology in the design of stagnation cooling system of supersonic aircraft and thermal management of high-power electronic devices.

A protocol for accurately calibrating thermocouples at cryogenic temperatures

To study the quenching characteristics of materials in a cryogenic liquid bath transient temperature measurements of high accuracy are necessary. Thermocouple is an ideal tool for this application because of its low self-heat capacity. However, they require calibration before usage that require multiple fixed-point temperatures. The common fixed-point temperatures are the water-ice melting temperature, the dry ice sublimation temperature, and the boiling temperature of liquid nitrogen. It is important to note that there are uncertainties associated with dry ice sublimation and liquid nitrogen boiling temperature inherent to the heat and mass transport phenomenon at their phase-changing interface or inside the bulk medium. The dry ice temperature is influenced by the mass transport phenomenon occurring at the interface between the dry ice and the ambient surrounding it. In a typical lab environment, dry ice temperature is significantly lower than the commonly quoted sublimation temperature of -78.5 °C at 1.013 bar. In the case of liquid nitrogen stored in a cryostat, temperature gradients develop in the liquid bath. This paper describes a protocol for calibrating thermocouples by accurately defining and using fixed-point temperatures of dry ice in a saturated environment and a liquid nitrogen slush.

Systems design and techno-economic analysis of a novel cryogenic carbon capture process integrated with an air separation unit for autothermal reforming blue hydrogen production system

In the transition of the global energy paradigm toward decarbonization, hydrogen is expected to play a crucial role as an energy vector. To enhance the sustainability of hydrogen as an energy source, it is important to reduce costs and carbon emissions in the hydrogen production. Among various hydrogen production technologies, the autothermal reforming (ATR)-based blue hydrogen production method can stand out as a promising option in terms of both economic and environmental considerations. However, there are several bottlenecks: (i) ATR requires an air separation unit that increases the cost burden, and (ii) conventional amine-based carbon capture method consumes a significant amount of energy. To address these bottlenecks, this study proposes a novel cryogenic carbon capture process for ATR-based blue hydrogen production. In the proposed process, air separation unit are utilized not only for oxygen production but also for carbon capture. The compressed air from the air separation unit provides cooling energy to the mixture gas, leading to solidification and separation of carbon dioxide. Despite imposing an additional burden on the air separation unit, it significantly reduces the energy and cost associated with carbon capture. Consequently, there exists a trade-off relationship between the increased load on the air separation unit and the decreased load in carbon capture. This trade-off was evaluated by comparing it with the conventional absorption-based carbon capture process in terms of energy and economic aspects. The proposed process exhibits a 36.4% reduction in total energy consumption, with a particularly approximately 49.5% decrease in the energy consumed for carbon capture (0.278 kW h/kg-CO2). The economic performance indicates an 11% decrease in the levelized cost of hydrogen (1.62$/kg-H2), and a 45.3% decrease in CO2 avoidance cost (40.1$/kg-CO2). The captured solid CO2 can offer advantages during storage and transportation. Furthermore, the potential utilization of cooling energy of solid CO2 from an end-user perspective is expected to contribute to the establishment of a new industrial value chain.

A Novel Low-Temperature Extrusion Method for the Fused Filament Fabrication of Fluoroelastomer Compounds.

In this work, an additive manufacturing process for extruding fully compounded thermosetting elastomers based on fluorine-containing polymer compositions is reported. Additive manufacturing printers are designed with a dry ice container to precool filaments made from curable fluoroelastomer (FKM) and perfluoroelastomer (FFKM) compounds. A support tube guides the stiffened filament towards the printer nozzle. This support tube extends near the inlet to a printer nozzle. This approach allows low-modulus, uncured rubber filaments to be printed without buckling, a phenomenon common when 3D printing low-modulus elastomers via the fused deposition modeling (FDM) process. Modeling studies using thermal analyses data from a Dynamic Mechanical Analyzer (DMA) and a Differential Scanning Calorimeter (DSC) are used to calculate the Young's modulus and buckling force, which helps us to select the appropriate applied pressure and the nozzle size for printing. Using this additive manufacturing (AM) method, the successful printing of FKM and FFKM compounds is demonstrated. This process can be used for the future manufacturing of seals or other parts from fluorine-containing polymers.

A general Energy-Efficient strategy for optimizing CO2 Capture: Designing and harnessing the rapid adsorption kinetics of Amine-Impregnated adsorbents

This study aims to optimize the performance of amine-impregnated CO2 adsorbents for both direct air capture (DAC) and point source CO2 capture (PSC) applications. The main objective of this study is to investigate the relationship between the weight fraction of amine loading and the efficiency of CO2 uptake on the designated support, aiming to find a straightforward method to design effective amine support materials. To this end, a composite material denoted as PEI/CNT@ZIF-8 has been developed. This composite is comprised of polyethylenimine (PEI), multi-walled carbon nanotubes (CNTs), and zeolitic imidazolate frameworks (ZIF-8). CNTs offer several advantages for enhancing CO2 uptake, including rearranging the ZIF-8 particles to facilitate PEI loading, creating strong electrostatic interaction for amine anchoring, and establishing CO2 diffusion channels to improve CO2 capture kinetics. In DAC scenarios, with a CO2 concentration of 400 ppm balanced with N2, the 25.0 wt% PEI/CNT(1)@ZIF-8(5) demonstrates superior CO2 uptake, achieving 4.08 mmol g−1 within a one-hour interval by harnessing the rapid kinetic region and exhibiting a low desorption energy of 55.8 kJ mol−1 for releasing CO2. In PSC scenarios, with a CO2 concentration of 15 vol% under both dry and wet conditions, the 37.5 wt% PEI/CNT(1)@ZIF-8(5) exhibits excellent CO2 uptake of 2.21 and 2.58 mmol g−1, respectively, at 50 ℃. The findings suggest that adjusting the balance between CO2 uptake and adsorption kinetics by considering the amine weight fraction can optimize the performance of solid amine CO2 adsorbents across diverse operational conditions. Furthermore, rather than relying on a single support material, this study reveals the potential of combining CNTs with materials such as SiO2 nanoparticles, Al2O3, or metal–organic frameworks (MOFs) to enhance CO2 capture performance. This approach holds promise as an effective and straightforward strategy.