CO2 Absorption Research Articles

Assessment of the Furniture Board Ecological Footprint: Case Study of a Woodworking Enterprise in the Carpathian Region of Ukraine

Understanding a product's ecological footprint has become incredibly important, as its assessment supports efforts to promote sustainable practices. However, there is limited knowledge about the specific environmental impacts of woodworking enterprises and their products. The purpose of the study is to evaluate the ecological footprint of a typical product from a woodworking enterprise in the Carpathian Economic Region of Ukraine. A middle-sized wood-processing enterprise was used as a case study. To achieve this objective, the study quantified the land area directly involved in producing 1 m3 of furniture board. Also, the concept of a "virtual area" of land, essential for CO2 absorption resulting from the transportation of raw materials for the production of 1 m³ of furniture board, was applied. Then the methodological approach to determine the "virtual area" of land necessary for the absorption of CO2 generated during the production of electricity which is spent on the operation of the main technological equipment and electricity consumption to produce 1 m3 of furniture panel is considered. The overall ecological footprint of producing 1 m3 of furniture board at the studied woodworking company is estimated as equivalent to 0.492 ha of forested area, from which only 3% of area is represented by direct land use - area used to produce wood for furniture board production.

Thermodynamic properties and CO2 absorption performance of the deep eutectic solvent (dipropylene glycol + 1, 2-propylenediamine) + H2O

This work selected dipropylene glycol (DPG) as the hydrogen bond donors to amalgamate with 1, 2-propylenediamine (1,2-PDA) as hydrogen bond acceptors, and introduced water into this system, adjusting the molar ratios of components to modulate the physicochemical properties of deep eutectic solvents. The discourse commences with the fundamental exploration of solution density and viscosity, delving into the microscopic principles of intermolecular interactions, and scrutinizing factors mitigating amine loss in the process of CO2 sequestration. Optimizing the performance of amine solutions by introducing alcohol substances and subsequently incorporating water to enhance their CO2 absorption capacity is undertaken. Based on the measured density and viscosity data of (DPG + 1,2-PDA) + H2O, fitting and molecular simulation calculations are performed to ascertain the most potent binding forms. Hydrogen nuclear magnetic resonance, Raman, and Fluorescence spectral analyses were also carried out to demonstrate the presence of intermolecular hydrogen bonding in the form of –OH···N(H2)- between DPG and 1,2-PDA. Ultimately, the solution undergoes CO2 absorption capacity determination to assess its absorptive efficacy.

Improving physical properties, microstructure and actual carbon sequestration of steel slag based autoclaved aerated concrete by accelerated carbonation

This study presents an autoclaved aerated concrete (AAC) with steel slag (SS) as carbonate-able binder. The traditional autoclaving process was augmented with a carbonation stage to improve the physical properties, microstructure and actual carbon sequestration of steel slag based autoclaved aerated concrete (SS-AAC). The macroscopic and microscopic test results showed that the carbonation process stimulated the reactivity of SS to generate gel products, allowing the additional formation of tobermorite during the autoclaving process. Under the synergistic positive effect of the densification-induced micro-pore refinement caused by calcium carbonate precipitation and the excellent gas permeability of AAC, the intervention of carbonation process resulted in SS-AAC with higher compressive strength, more homogeneous carbonation, and more outstanding actual CO2 absorption efficiency. The research provides a potential method for preparing high-volume solid waste AAC with large-scale CO2 utilization to encourage the concrete sector to adopt a sustainable stance.

Integrated CO2 capture and mineralization approach based on KOH and cement-based wastes

To extend current Carbon Capture, Utilization, and Storage (CCUS) strategies and explore a circular carbon economy, an integrated CO2 capture and mineralization approach was developed in this work. KOH was used as CO2 absorption agent to simulate post-combustion carbon capture from flue gas, and then cement-based wastes were used as CO2 mineralization feedstock to convert the sequestered carbonate/bicarbonate ions in the solvent to carbonate minerals and thereby recover and regenerate KOH. The features of the integrated CO2 capture and mineralization process were characterized through ICP-OES analysis, TGA, SEM, quantitative XRD analysis, and particle size analysis. In this study, the carbon capture from the simulated flue gas with CO2 concentration of 10 % using 2.0 M KOH was examined, and the real CO2 capture capacity of 2.0 M KOH was determined at around 1.5 M. After CO2 capture, ground mortar wastes were added into the CO2-loaded KOH solvent, which enables CO2 mineralization and thereby decarbonizes the CO2 liquid absorbent. In CO2 mineralization process, the carbonation characteristics of mortar waste at different pH levels were analysed in-depth. The optimum pH interval for the CO2 mineralization of mortar waste was between 10 and 11, and correspondingly, the highest CO2 sequestration capacity was measured at around 164 g CO2/kg. Apart from CO2 capture and mineral sequestration, another two valuable by-products – silica gels and carbonated mortar waste were also collected and analysed. To increase the applicability of the integrated CO2 capture and mineralization process on a commercial scale, future research was also identified and discussed.

Revealing the potential of cyclic amine morpholine (MOR) for CO2 capture through a comprehensive evaluation framework and rapid screening experiments

The present study comprehensively evaluates the CO2 capture performance of morpholine (MOR) at concentrations of 2 M, 5 M, and 7 M, comparing its effectiveness against conventional amines, monoethanolamine (MEA) and 2-(methylamino)ethanol (MAE). The assessment criteria include CO2 absorption rate, desorption rate, cyclic capacity, regeneration energy consumption, and relative economic cost. Utilizing 13C Nuclear Magnetic Resonance (NMR) technology, we analyzed the variations in ion concentration of the amine solvents under different CO2 loadings to reveal the reaction mechanisms of MOR with CO2. Our results demonstrate that MOR outperforms MEA and MAE in CO2 capture performance, particularly excelling in desorption efficiency. At a concentration of 7 M, MOR exhibited a 357.86% increase in average desorption rate and a 46% larger cyclic capacity compared to MEA. Additionally, MOR showed a 33.33% reduction in regeneration energy consumption and a 7.89% decrease in relative economic cost. The comprehensive evaluation method developed in this study indicates that MOR, with its high thermal stability and low corrosivity, maintains excellent CO2 capture performance at high amine concentrations, suggesting it as a promising absorbent for industrial applications. The findings contribute to the optimization of amine-based CO2 capture technologies and provide a robust framework for the selection and assessment of amine solvents, paving the way for more sustainable and cost-effective carbon capture solutions.

Performance of a novel CO2 absorption and reverse electrodialysis system with different amine solutions for simultaneous energy and bicarbonate recovery

In this study, the performance of a novel integrated carbon dioxide (CO2) capture and reverse electrodialysis (RED) system was evaluated. The optimal operating conditions and carbon dioxide absorption and desorption mechanisms were identified. The proposed system utilizes a RED device to recover energy from the desorption step of the CO2 capture process, which is known to have high energy requirements in conventional processes. It has the potential as a hybrid process capable of recovering absorbent, energy, and bicarbonate through RED. To verify the performance of the system, CO2 loading, power density, and absorbent regeneration were evaluated using primary (monoethanolamine, MEA), secondary (diethanolamine, DEA), and tertiary (N-methyldiethanolamine, MDEA) amines. In the case of primary and secondary amines, carbamates, intermediate products, are formed and pass through the ion exchange membrane of RED, thereby achieving high power density. However, they are re-substituted with amines after passing through the ion exchange membrane (IEM), leading to the loss of absorbent. Conversely, in the case of tertiary amines, no intermediate products were formed, and excellent absorbent regeneration performance of more than 99.9% was demonstrated through multi-stage RED. Through this, the feasibility of future applications of this technology was confirmed.

Constructing Gradient Orbital Coupling to Induce Reactive Metal-Support Interaction in Pt-Carbide Electrocatalysts for Efficient Methanol Oxidation.

Reactive metal-support interaction (RMSI) is an emerging way to regulate the catalytic performance for supported metal catalysts. However, the induction of RMSI by the thermal reduction is often accompanied by the encapsulation effect on metals, which limits the mechanism research and applications of RMSI. In this work, a gradient orbital coupling construction strategy was successfully developed to induce RMSI in Pt-carbide system without a reductant, leading to the formation of L12-PtxM-MCy (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W) intermetallic electrocatalysts. Density functional theory (DFT) calculations suggest that the gradient coupling of the d(M)-2p(C)-5d(Pt) orbital would induce the electron transfer from M to C covalent bonds to Pt NPs, which facilitates the formation of C vacancy (Cv) and the subsequent M migration (occurrence of RMSI). Moreover, the good correlation between the formation energy of Cv and the onset temperature of RMSI in Pt-MCx systems proves the key role of nonmetallic atomic vacancy formation for inducing RMSI. The developed L12-Pt3Ti-TiC catalyst exhibits excellent acidic methanol oxidation reaction activity, with mass activity of 2.36 A mgPt-1 in half-cell and a peak power density of 187.9 mW mgPt-1 in a direct methanol fuel cell, which is one of the best catalysts ever reported. DFT calculations reveal that L12-Pt3Ti-TiC favorably weakens *CO absorption compared to Pt-TiC due to the change of the absorption site from Pt to Ti, which accounts for the enhanced MOR performance.

Study on CO2 absorption by EmimCl-MEA deep eutectic solvent in microchannel

Carbon dioxide (CO2) is widely acknowledged as the primary contributor to the greenhouse effect. Microchannel reactors can be used for enhancing chemical processes, solving the problems of limited gas-liquid mass transfer, and have significant advantages in CO2 capture. In this study, the deep eutectic solvent (DES) prepared by mixing ionic liquid (1-ethyl-3-methylimidazolium chloride, EmimCl) and Ethanolamine (MEA) in a molar ratio of 1:1 was selected for CO2 capture in a microchannel. The structure and physical properties of the DES were investigated, and the effects of gas and liquid flow rates, water content, and CO2 concentration on the CO2 absorption properties were analyzed. The increase of the water content not only significantly reduces the viscosity of DES, but also improves the CO2 absorption performance. In addition, the CO2 absorption mechanism of this DES has been obtained by the NMR spectrum, showing that the absorption process is a rapid chemical absorption process between CO2 and MEA. The Cl- of EmimCl could stabilize the protonated amine and prevent it from further reacting with MEACO2-, furthermore increasing the CO2 absorption rate.

Activation-free preparation of porous carbon fiber derived from phenolic resin for CO2 absorption

BackgroundIt is not uncommon to study the preparation of porous carbon materials for CO2 adsorption, but it is still a challenge to simultaneously achieve the good mechanical strength, porous structure, and efficient adsorption performance of porous carbon fibers. MethodsPorous carbon fibers with desirable morphology and selective CO2 adsorption were prepared using an activation-free method. The fibers were prepared through melt spinning of phenolic resin modified with polyvinyl butyral (PVB) and urea, followed by curing treatment, and then the pore structures were adjusted by controlling the carbonization temperature. Significant findingsThe porous carbon fibers prepared by carbonization at 900 °C not only had excellent CO2 adsorption (3.48 mmol/g) but also possessed desirable tensile strength (132 MPa). Those carbonized at 700 °C showcased CO2/N2 selectivity of 57 (Ideal adsorption solution theory (IAST), CO2: N2 =15:85), and tensile strength of 148 MPa, much higher than most fibers using other methods. The study revealed that the adsorption of CO2 was mainly performed by nitrogen-containing groups and physical function through pores ranging from 0.3 nm to 0.8 nm, and the micropores between 0.3 nm and 0.6 nm were conducive to the selective adsorption of CO2/N2.

Robotic Pediatric Urologic Surgery-Clinical Anesthetic Considerations: A Comprehensive Review.

Minimally invasive robotic approaches have become standard in many institutions over the last decade for various pediatric urological procedures. The anesthetic considerations for common laparoscopic and robotic-assisted surgeries are similar since both require the insufflation of CO2 to adequately visualize the operative area. However, few studies exist regarding anesthesia for robotic procedures in children. We hypothesized that pediatric patients undergoing robotic urologic surgeries would require specific anesthetic strategies, especially given the inherently longer durations of these procedures. This study aimed to evaluate anesthetic considerations, current robotic procedures, optimal patient positioning, and port placement for robotic-assisted surgery in pediatric patients. A comprehensive literature review of all published manuscripts from PubMed, EMBASE database, and Google Scholar was performed, focusing on robotic procedures involving pediatric patients, anesthesia for pediatric urology patients, and related topics from 1996 to 2023. Forty published manuscripts were identified and reviewed in depth. In pediatric cases, insufflation pressures and volumes are lower due to the laxity of the abdominal wall. However, the increase in intra-abdominal pressure and absorption of CO2 may result in disproportionate changes in cardiopulmonary function. Specific patient positioning for robotic approaches may further compound these physiological changes. Correct patient positioning is essential to facilitate surgery optimally and safely. Understanding the physiological changes that can occur during a pediatric patient's robotic urologic surgery allows for safer anesthesia management.

Physicochemical properties and CO2 absorption performance of poly(ethylene glycol) 300 + hydroxyethyl ethylenediamine mixed solution

Density (ρ) and viscosity (η) data of the polyethylene glycol 300 (PEG300) and hydroxyethyl ethylenediamine (AEEA) mixed solution were measured at P = 1005 hPa and T = (298.15–318.15) K. Following these data, Jouyban-Acree model exhibited superior correlation to density in the mixed system compared to nonlinear least square method, while the McAllister four-body equation yielded a better fitting for kinematic viscosity than other models. Utilizing ρ and η data, the Redlich-Kister equation was employed for the systematic computation and analysis of excess molar volume (VmE), excess activation Gibbs free energy (ΔG*E), partial molar volumes (V1¯ and V2¯), and viscosity deviation (Δη) in the PEG300 (1) + AEEA (2) mixed solution. These excess properties indicated the advantageous nature of intermolecular binding in the PEG300 (1) + AEEA (2) mixed solution, further substantiated on the basis of various spectroscopic characterizations. Finally, under conditions of CO2 flow rate at 150 mL/min, absorption experiments were conducted for 4 h in the PEG300 (1) + AEEA (2) mixed solution, pure AEEA, and pure PEG300, which indicated that the mixed solution exhibited the highest CO2 absorption capacity of 0.95 mol CO2/mol AEEA, demonstrating superior absorption performance compared to the two pure substances.

Performance of a new water lean absorbent composed of EHA and DEGDEE in CO2 capture and regeneration

Previous work has shown that non-aqueous absorbent composed of dimethyl sulfoxide (DMSO) and 2-ethylhexylan-1-amine (EHA) is superior to commercial monoethanolamine (MEA) in both absorption of CO2 and desorption. However, the price of DMSO is too high, which leads to the high cost of reagents. It is worthwhile to choose a cheap solvent instead of DMSO, which can also achieve satisfactory absorption and desorption performance. Around this goal, we selected diethylene glycol diethyl ether (DEGDEE) to form a non-aqueous absorbent with EHA and investigated the absorption and desorption performance. The desorption efficiency of 70 wt% EHA +30 wt% DEGDEE was 99 % at 373 K. The desorption efficiency was 89.4 %, and the desorption energy consumption was only 45.1 % of MEA when the water content was 10 wt%. DEGDEE can achieve similar or even better performance than DMSO, while the cost of DEGDEE (12000–31000 RMB/ton, technical grade purity 99 %) is lower than DMSO (40000–48000 RMB/ton, technical grade purity 99 %). In addition, it also has a good recycling capacity. These advantages will certainly endow this newly developed absorbent with great application prospects in the field of CO2 capture.

Enhanced CO2 absorption in amine-based carbon capture aided by coconut shell-derived nitrogen-doped biochar

The sluggish CO2 absorption kinetics and constrained CO2 absorption capacity diminish the practicality of using amine-based absorption for CO2 capture, impeding progress toward carbon neutrality goals. This study aims to develop a catalytic CO2 absorption process to promote CO2 absorption by introducing a solid base catalyst, namely, coconut shell-derived nitrogen-doped biochar (NBC), into an amine-based solution. The coconut shells were modified with urea and activated with KOH to prepare an NBC catalyst with improved basic characteristics. The findings showed that compared to non-catalytic absorption, the NBC catalyst increased the CO2 absorption amount, CO2 absorption rate, and absorption efficiency of the monoethanolamine (MEA) solution by 16.9 %, 43.4 %, and 13.1 %, respectively. The basic sites on the NBC surface provided extra electrons to motivate the formation of MEACOO- and HCO3-. NBC’s large surface area and porous structure also advanced the gas–liquid mass transfer, accelerating the CO2 absorption rate. Furthermore, the NBC exhibited excellent cyclic stability and facilitated the subsequent CO2 desorption process. This work develops a promising and practical approach to significantly improve the amine-based absorption and reuse of waste biomass resources for efficient CO2 capture.

Carbazole-fused coumarin bis oxime esters (CCOBOEs) as efficient photoinitiators of polymerization for 3D printing with 405 nm LED

In this research, the innovative design and successful synthesis of two visible light photoinitiators, namely CCOBOE0 and CCOBOE1, have been confirmed through nuclear magnetic resonance (NMR) and mass spectrometry (MS). Both compounds exhibit strong absorption properties at 385, 405 and 450 nm, and FT-IR analyses have substantiated the ability of CCOBOE1 to initiate the polymerization of a trifunctional acrylate monomer (TMPTA) under these three light sources. The optimal conditions for maximizing the photoinitiation potential of CCOBOE1 were determined to be at a concentration of 2 × 10−5 mol.g−1 and under 405 nm LED irradiation. Photolysis experiments, theoretical calculations, detection of CO2 absorption peaks, and ESR experiments have all confirmed the generation of methyl radicals by CCOBOE1. Utilizing the identified optimal conditions, a “XYZ” pattern with a thickness of 963 μm and a 3D-object were successfully obtained via direct laser write (DLW) and digital light processing (DLP) 3D-printing upon irradiation at 405 nm. Additionally, differential scanning calorimetry (DSC) analyses demonstrated the promising performance of CCOBOE1 in initiating the thermal polymerization of acrylate monomers. In summary, the difunctional CCOBOE1 showed outstanding performance in both photo-initiation and thermal initiation of acrylate monomers. It provides a novel direction for the development of novel OXEs with dual activation modes.

Experimental study of hollow fiber membrane contactor process using aqueous amino acid salt-based absorbents for efficient CO2 capture

Gas–liquid membrane contactors are a promising alternative to packed columns that suffer from channeling, bubble formation, and flooding problems. In this study, potassium serinate + piperazine (PSZ) and potassium alaninate + piperazine (PAZ), which are amino acid salts with good CO2 absorption performances and high surface tensions, are investigated to determine the effects of the operating parameters on the CO2 removal efficiency, CO2 absorption flux, CO2 loading, and overall mass-transfer coefficient in the membrane contactor process. The experimental results demonstrate that the 2.5 M PSZ and 2.5 M PAZ absorbents outperform 2.5 M monoethanolamine (MEA) under various operating conditions, including the gas flow rate, liquid flow rate, CO2 concentration, and CO2-loaded absorbent. Based on these results, an expression for predicting the CO2 loading from the pH is proposed. The amount of cross-over confirmed that amino acids with high surface tension have better resistance to membrane wetting than 2.5 M MEA. In addition, empirical correlation expressions were established from the results of several operating parameters. The absolute average deviation (AAD) values were 6.50 %, 2.95 %, and 4.71 % for 2.5 M MEA, 2.5 M PSZ, and 2.5 M PAZ, respectively, suggesting good agreement between the theoretical and experimental results.

Hydrated carboxylate ionic liquids as chemical CO2 sorbents of high capacity and moderate enthalpy of absorption

Tetralkylphosphonium carboxylate ionic liquids are herein presented as efficient carbon dioxide chemisorbents in the presence of water. The ionic liquids tetrabutylphosphonium formate and acetate, tributylmethylphosphonium formate and a series of triethylalkylphosphonium formates and acetates, have been prepared by various synthetic procedures either from hydroxide or methylcarbonate precursors, or via multiple steps starting from the parent triethylphosphine. Their physicochemical properties, namely melting or glass transition temperatures, thermal decomposition behaviour, densities and viscosities have been determined. As dry substances, they are viscous liquids or low-melting solids, whereas they show little tendency to solidify in their hydrated forms. They were used mostly as monohydrates in CO2 solubility measurements, exhibiting highest capacities (3 mol L−1, i.e. ≈ 0.9 molCO2 molIL−1, at 5 bar, 25 °C) at equimolar H2O/ionic liquid ratios, approaching those of commercial aqueous amine sorbents. Carbon dioxide chemisorption into hydrogencarbonate takes place, as demonstrated by infrared spectroscopy with isotopic labelling. CO2 absorption isotherms were recorded at various temperatures and the data used to estimate the heat of absorption according to three different thermodynamic models. Enthalpies of CO2 absorption depended heavily on the model used. Rationalisation of this was done on the grounds of the expected relevance of physical and chemical sorption processes. Average heats of CO2 absorption lie between −40 and −45 kJ mol−1, in accordance with mild chemical absorption albeit significantly lower than those for typical chemical sorbents such as amines. This reinforces the feasibility of hydrated carboxylate ionic liquids for CO2 capture technologies of low regeneration energies.

Low-temperature desorption in thermomorphic solvents for CO2 capture: Systems with N-methylcyclohexylamine and N,N-dimethylcyclohexylamine

The significant energy consumption associated with the carbon capture process has long posed a substantial obstacle to the extensive industrial utilization of amine solutions. Therefore, it is imperative to investigate a low-energy-consumption carbon capture solvent. This study meticulously examined thermomorphic absorbents composed of N-methylcyclohexylamine(MCA) and N,N-Dimethylcyclohexylamine(DMCA), delving into its absorption and desorption performances. Initially, focusing on absorption efficiency, we tested six varying concentration ratios of absorbents for CO2 absorption, scrutinizing their absorption rate and capacity. The analysis revealed that the rapid saturation of the absorbent stemmed from its limited absorption capacity. Notably, the MCA:DMCA=1 M:1 M ratio exhibited outstanding absorption capability, at 0.7015 mol CO2/mol amine, surpassing the absorption capacity of 30 wt% Monoethanolamine by a factor of 1.525. Subsequent desorption trials on MCA:DMCA=1 M:1 M at temperatures of 333 K, 348 K, and 363 K indicated successful desorption at 333 K, achieving an efficiency of 82.77 %, which rose with increasing temperature. Lastly, the estimated energy consumption for the latent heat and evaporation heat of this absorbent was approximately 0.342GJ/t CO2, marking a ∼61.1 % decrease compared to liquid-liquid phase change absorbents. These findings underscore the industrial promise of thermomorphic absorbents as a viable option for carbon capture applications.

CO2 absorption mechanism and kinetic modeling of mixed amines with ionic liquid activation

AbstractIonic liquid (IL) can not only serve as solvents to reduce carbon capture energy consumption, but also may activate the CO2 absorption of amine solutions. Here, the absorption mechanism and kinetic modeling of IL‐activated single and mixed amines were studied in wetted wall column. N‐(2‐aminoethyl) ethanolamine (AEEA) and N,N‐diethylethanolamine (DEEA) were used as representatives to evaluate the IL activation effects on primary and tertiary amines. It was found that IL activated the reaction process of primary amine, but had no activation effect on tertiary amine. The activation energy of AEEA‐IL‐CO2 was 22.2 kJ/mol, which was 21.0% lower than AEEA‐CO2. Kinetic modeling of IL‐activated AEEA and mixed amines was established. Besides, the density functional theory calculations showed that IL can form hydrogen bonding and other interactions with AEEA and CO2 to activate the absorption reaction, which can reduce 29.3% activation energy during the zwitterion formation stage.

Catalytic behavior of aluminum-modified SAPO-34 catalysts for reducing the energy penalty of CO2-rich amine solutions regeneration

The goal of this research is to develop a potential strategy to significantly decrease the heat duty for the amine-based CO2 capture process. Here, a variety of Al2O3-modified SAPO-34 composite catalysts with varying Al2O3 contents are synthesized and utilized to catalytically facilitate the CO2 desorption process. The catalytic CO2 desorption characteristics of various catalysts, Al-SAPO-34, SAPO-34, and γ-Al2O3 are investigated in a CO2-loaded 5 M monoethanolamine (MEA) solution. The results indicate that all catalysts accelerate CO2 desorption, while the Al-SAPO-34 catalysts work better than the parent Al2O3 and SAPO-34 catalysts. Especially, the 15 % Al-SAPO-34 increases the CO2 desorption rate by 78.4 % and reduces the relative energy requirement by 37 % at a desorption time of 1440 s. The catalysts are characterized by different methods and their structure–activity relationship is analyzed. The increased acid sites and mesoporous surface area of the Al-SAPO-34 catalyst may be responsible for its greater catalytic activity. The intermediates of the catalytic CO2 desorption process are identified by FT-IR and NMR, and then a possible catalytic regeneration mechanism is put forward. Additionally, the cyclic stability of the Al-SAPO-34 catalyst for cyclic CO2 absorption–desorption is evaluated. This work demonstrates that the Al-SAPO-34 exhibits greater catalytic CO2 desorption performance, and outstanding stability, and has the opportunity to become an attractive industrial catalyst for the amine-based CO2 capture process.

Screening of environmental stimuli for the positive regulation of stomatal aperture in centipedegrass

Grasslands, the largest carbon pool in China, possess enormous potential for carbon sequestration. Increasing the stomatal aperture to increase the CO2 absorption capacity is a potential method to improve plant photosynthetic efficiency and ultimately enhance the carbon sequestration capacity of grass plants. Research on stomatal aperture regulation has focused mostly on Arabidopsis or crops, while research on grass plants in these areas is scarce, which seriously restricts the implementation of this grassland carbon sequestration strategy. Here, a widely used ecological grass, centipedegrass, was used as the experimental material. First, a convenient method for observing the stomatal aperture was developed. The leaves were floated in a potassium ion-containing open solution (67 mM KCl, pH 6.0) with the adaxial surface rather than the abaxial surface in contact with the solution and were cultivated under light for 1.5 h. Then, nail polish was applied on the adaxial surface, and a large number of open stomata were imprinted. Second, with the help of this improved method, the concentration‒response characteristics of the stomatal aperture to eleven environmental stimuli were tested. The stomatal aperture is dependent on these environmental stimuli in a concentration-dependent manner. The addition of 100 μM brassinolide led to the maximal stomatal aperture. This study provided a technical basis for manipulating stomatal opening to increase the carbon sequestration capacity of centipedegrass.