To predict CO2 adsorptive capture, as a vital environmental issue, using different zeolites including 5A, 13X, T-Type, SSZ-13, and SAPO-34, different models have been developed by implementing ...artificial intelligence algorithms. Hybrid adaptive neuro-fuzzy inference system (Hybrid-ANFIS), particle swarm optimization-adaptive neuro-fuzzy inference system (PSO-ANFIS) and the least-squares support vector machine (LSSVM) modeling optimized with the coupled simulated annealing (CSA) optimization have been employed for the models. The developed models, validated by utilizing various graphical and statistical methods exhibited that the Hybrid-ANFIS model estimations for the gas adsorption on 5A, T-Type, SSZ-13, and SAPO-34 zeolites with average absolute relative deviation (AARD) % of 8.21, 1.92, 4.99 and 2.26, and PSO ANFIS model estimations for the gas adsorption on zeolite 13X with an AARD of 4.85% were in good agreement with corresponding experimental data. It could be deduced that the proposed models were more prosperous and efficient in favor of the design and analysis of adsorption processes than previous ones.
•Computational estimation of CO2 capture by zeolites is prosperous for greenhouse gas control.•Machine-learning techniques could predict greenhouse gas adsorption on zeolites.•Hybrid-ANFIS, PSO-ANFIS and LSSVM models were developed to estimate CO2 adsorption.•The models predictions were assessed by various graphical and statistical techniques.
Abstract
Catalytic solvent regeneration has attracted broad interest owing to its potential to reduce energy consumption in CO
2
separation, enabling industry to achieve emission reduction targets of ...the Paris Climate Accord. Despite recent advances, the development of engineered acidic nanocatalysts with unique characteristics remains a challenge. Herein, we establish a strategy to tailor the physicochemical properties of metal-organic frameworks (MOFs) for the synthesis of water-dispersible core-shell nanocatalysts with ease of use. We demonstrate that functionalized nanoclusters (Fe
3
O
4
-COOH) effectively induce missing-linker deficiencies and fabricate mesoporosity during the self-assembly of MOFs. Superacid sites are created by introducing chelating sulfates on the uncoordinated metal clusters, providing high proton donation capability. The obtained nanomaterials drastically reduce the energy consumption of CO
2
capture by 44.7% using only 0.1 wt.% nanocatalyst, which is a ∽10-fold improvement in efficiency compared to heterogeneous catalysts. This research represents a new avenue for the next generation of advanced nanomaterials in catalytic solvent regeneration.
CO2 emissions from industrial processes and their adverse implications on the climate is of major concern. Carbon capture and storage (CCS), especially using chemical-absorption-based processes, has ...been regarded as one of the most realistic pathways to curtail global warming and climate change. However, the energy-intensive nature of CO2 capture and therefore its expensive cost of operation has been regarded as the main barrier halting its widespread implementation among the portfolio of low-carbon energy technologies currently available. Recently, catalytic solvent regeneration has drawn significant attention as a new class of technology for energy-efficient CO2 capture with great potential for large-scale implementation. In this review, recent progress and developments associated with catalyst-aided solvent regeneration for low-temperature energy-efficient CO2 desorption is presented. A detailed discussion of heterogeneous acid–base catalyst is undertaken and the specific privileges, drawbacks, and challenges of each catalyst identified and commented upon. In keeping with the latest investigations, the promotion mechanism of catalytic CO2 desorption and the role of Lewis acids, Brønsted acids, and basic active sites are scrutinized. The performance of solid acid–base catalysts in different primary and blended amine solutions associated with their physicochemical properties is also reviewed. Finally, the status of catalytic solvent regeneration for post-combustion CO2 capture is comprehensively analyzed and a clear pathway for future research investigations is provided.
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•A series of novel GlyK/DMF/H2O solvents was successfully developed for CO2 capture.•NMR spectroscopy was used to identify the species at different phases.•The upper liquid phase of ...developed solvent was free from CO2-containing species.•The heat duty of solvent was reduced by 59.1% compared to the aqueous solvent.
The energy penalty is a primary limitation for the implementation of the aqueous solvents for large-scale post-combustion CO2 capture processes. In this study, a novel aqueous-based phase change solvent, composed of potassium glycinate (GlyK, reactive species), water (H2O, solvent) and dimethylformamide (DMF, antisolvent) was developed to improve the energy efficiency of CO2 capture. To examine the role of the antisolvent, a series of aqueous-based amino acid solvents (GlyK-X) with different DMF:H2O (X) volume ratios was prepared, fully characterized and assessed. It was observed that a CO2-free phase appeared at the top of the aqueous-based amino acid GlyK-X solvents after CO2 absorption which can be easily separated and recycled to the absorption column and save energy. The results showed that the GlyK-60 solvent with DMF:H2O volume ratio of 60:40 had a very high CO2-free phase volume (63%). Moreover, the GlyK-60 solvent exhibited 26.1% (0.433–0.546 mol CO2/mol GlyK) enhancement in CO2 absorption capacity, 38.5% (130–80 min) decrease in regeneration time and 59.1% reduction in relative heat duty compared to the conventional aqueous GlyK solvent. Overall, the outcomes confirmed that the aqueous-based phase change GlyK-60 solvent is a viable solvent option for large-scale CO2 capture with extra-low energy consumption and a key to the success of Paris Climate Accord.
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•The nanoporous carbons prepared from petroleum waste modified by melamine (M-IANC).•The adsorbents presented great surface area and mesopore volume up to 2693 m2/g and ...1.61 cm3/g.•The M-IANC samples contained remarkable N (1.05 wt.%), O (42.19 wt.%) and H (0.47 wt.%) functional groups.•The samples presented Superior performance for benzene and toluene adsorption capacity.•The M-IANCs also demonstrated impressive efficiency in cyclic regenerations at 25 °C.
In this work, a series of nanoporous carbon materials were synthesized using Iranian asphaltene as a low-cost carbon source and modified by melamine as a new nitrogen-rich promoter (M-IANC). The adsorption capacity of benzene and toluene on the synthesized M-IANCs was measured at low and high concentrations by an in-house built apparatus. The results demonstrated that the addition of melamine remarkably increased the mesoporous volume (up to 1.61 cm3/g) in the nanoporous carbon structure and, subsequently, created a large surface area (2692 m2/g) and pore volume (1.71 cm3/g). The resulting M-IANC-C nanostructure (melamine:PIA mass ratio of 1:2) depicted 228.18 wt.% and 82.08 wt.% adsorption capacity for benzene and toluene, respectively, which were 19.4 and 2.8 times higher than commercial activated carbon. In addition to the distinguished adsorptive behavior for benzene and toluene removal, M-IANC-C exhibited higher cyclic adsorption capacity than those of unmodified IANC sample after four consecutive cycles. The adsorption mechanism and the role of melamine groups in the adsorption of benzene and toluene were also studied by the density functional theory (DFT) calculations. Besides the inexpensive cost of the carbon source (asphaltene), results also indicate that the M-IANC can be a suitable candidate for VOC adsorption.
Direct removal of carbon dioxide (CO2) from the atmosphere, known as direct air capture (DAC) is attracting worldwide attention as a negative emission technology to control atmospheric CO2 ...concentrations. However, the energy‐intensive nature of CO2 absorption‐desorption processes has restricted deployment of DAC operations. Catalytic solvent regeneration is an effective solution to tackle this issue by accelerating CO2 desorption at lower regeneration temperatures. This work reports a one‐step synthesis methodology to prepare monodispersed carbon nanospheres (MCSs) using trisodium citrate as a structure‐directing agent with acidic sites. The assembly of citrate groups on the surface of MCSs enables consistent spherical growth morphology, reduces agglomeration and enhances water dispersibility. The functionalization‐assisted synthesis produces uniform, hydrophilic nanospheres of 100–600 nm range. This work also demonstrates that the prepared MCSs can be further functionalized with strong Brønsted acid sites, providing high proton donation ability. Furthermore, the materials can be effectively used in a wide range of amino acid solutions to substantially accelerate CO2 desorption (25.6% for potassium glycinate and 41.1% for potassium lysinate) in the DAC process. Considering the facile synthesis of acidic MCSs and their superior catalytic efficiency, these findings are expected to pave a new path for energy‐efficient DAC.
In this study, a conventional strategy is introduced for the preparation of monodispersed carbon spheres (MCSs). The findings shed light on the potential of amino acids as green solvents for the direct air capture of carbon dioxide (CO2) and reveal the superior performance of MCSs as a nanocatalyst to enable low‐temperature solvent regeneration and empower energy‐efficient CO2 capture.
The emerging environmental issues necessitate the engineering of novel and well-designed nanoadsorbents for advanced separation and purification applications. Despite recent advances, the facile ...synthesis of hierarchical micro-mesoporous metal-organic frameworks (MOFs) with tuned structures has remained a challenge. Herein, we report a simple defect engineering approach to manipulate the framework, induce mesoporosity, and crease large pore volumes in MIL-101(Cr) by embedding graphene quantum dots (GQDs) during its self-assembly process. For instance, MIL-101@GQD-3 (Vmeso: 0.68 and Vtot: 1.87 cm3/g) exhibited 300.0% and 53.3% more meso and total pore volume compared to those of the conventional MIL-101 (Vmeso: 0.17 and Vtot: 1.22 cm3/g), respectively, resulting in 1.7 and 2.8 times greater benzene and toluene loading at 1 bar and 25 °C. In addition, we found that MIL-101@GQD-3 retained its superiority over a wide range of VOC concentrations and operating temperature (25–55 °C) with great cyclic capacity and energy-efficient regeneration. Considering the simplicity of the adopted technique to induce mesoporosity and tune the nanoporous structure of MOFs, the presented GQD incorporation technique is expected to provide a new pathway for the facile synthesis of advanced materials for environmental applications.
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•A facile defect engineering approach was introduced to manipulate the physicochemical properties of MOFs.•GQD was used a superior nucleation site to induce mesoporosity into the MIL-101(Cr) structure during its self-assembly.•The MIL-101@GQD material displayed a hierarchical micro-mesoporous structure with a high pore volume (up to 1.87 cm3/g).•The MIL-101@GQD material exhibited an extra-high benzene and toluene adsorption capacity.
Interfacial modular assemblies of eco‐friendly metal–phenolic networks (MPNs) are of interest for surface and materials engineering. To date, most MPNs are assembled on water‐stable substrates; ...however, the self‐assembly of MPNs on highly water‐soluble substrates remains unexplored. Herein, a versatile approach is reported to engineer thickness‐tunable coatings (2–25 µm) on a water‐soluble substrate (i.e., urea) via the self‐assembly of MPNs in a nonaqueous solvent (i.e., acetonitrile). The coordination‐driven assembly of the MPN coatings in the nonaqueous solvent is distinct from that in aqueous systems, as the assembly is only achieved following the addition of urea granules into the iron–tannin solution. The coating occurs relatively rapidly (5–60 min), generating micrometer‐thick coatings from the adsorption of FeIII–TA complexes and micrometer‐sized FeIII–TA particles formed in solution. The straightforward nature of the present fabrication method in generating thick and robust coatings with high stability in nonaqueous environments (including at 60 °C) coupled with the broad range of available naturally abundant polyphenol–metal ion combinations expand the applicability of MPNs as coatings for water‐soluble materials, thus providing new opportunities for their broader application in a range of industrial processes and applications.
The coating of water‐soluble substrates (urea granules) with metal–phenolic networks (MPNs) via self‐assembly in a nonaqueous medium (acetonitrile) is presented. MPN formation in nonaqueous media results in thick (2–25 µm) and robust MPN coatings with tunable physicochemical properties.
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•MSZW of a quaternary solvent system was measured in batch cooling experiments.•Solubility of the solvent system was measured and validated using a ENRTL model.•Precipitates were ...qualitatively analysed.•Nucleation kinetics was evaluated using four approaches including the Nývlt relation.
Glycine promoted concentrated potassium carbonate (K2CO3) solvents are considered to have potential for use in carbon dioxide (CO2) capture processes. Understanding their precipitation behaviour, particularly nucleation kinetics, becomes important if the solvents are used as absorbents at concentrations of 40 wt% or greater. In this work, liquid-solid equilibrium of the quaternary solvent system glycine-potassium carbonate-potassium bicarbonate-water was investigated in an Optimax workstation 1001 at different temperatures. The results were interpreted using a regressed Electrolyte Non Random Two Liquids (ENRTL) thermodynamic model in Aspen PlusTM within an average deviation of 9.2%. Through X-ray diffraction (XRD), scanning electron microscopy (SEM), high performance liquid chromatography (HPLC) and total nitrogen elemental analysis, the precipitates confirmed that only kalicinite (KHCO3), and no glycine related products such as glycine solids and carbamates precipitated under the temperatures investigated. The metastable zone width (MSZW) of the solvent systems with different concentrations of glycine at different constant cooling rates was measured using focused beam reflectance measurement (FBRM), and four methods including Nývlt relation, Self-Nývlt relation, the CNT theory and the pseudo induction time method were used to evaluate nucleation kinetics. It was found that the introduction of glycine significantly increases the MSZW, resulting in fast nucleation kinetics. However, at a high concentration of glycine (1.36 mol/kg water) promoted 40 wt% K2CO3 with 0.4 CO2 loading, the maximum MSZW was achieved at an intermediate cooling rate (35 °C/h) rather than the highest cooling rate (60 °C/h), this may result from dual competing effects between strong ionic strength within the solvent system and superstation generated by cooling rates. Correspondingly, these traditional nucleation analysis methods cannot explain the nucleation kinetic behaviour for this specific case, and other theories are required to explain the obscured behaviour of the quaternary solvent system.
