Isotherms and thermodynamics of CO2 adsorption on a novel carbon-magnetite composite sorbent

Raganati, Federica; Alfè, Michela; Gargiulo, Valentina; Chirone, Riccardo; Ammendola, Paola

doi:10.1016/j.cherd.2018.04.037

Cited by 160 publications

(92 citation statements)

References 78 publications

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“…This model considers the following assumptions: (i) the molecules are adsorbed to a fixed number of active sites, which are well defined; (ii) the adsorption forms a single monolayer; (iii) each site can contain a single molecule of adsorbate and adsorbed grindings will not change the adsorption site; (iv) each adsorption site possesses the same energy, therefore, there are definite and energetically equivalent numbers of adsorption sites, and thus the surface of the adsorbent is homogeneous; (v) there is no interaction between the adsorbed molecules in nearby sites and (vi) the adsorption system is in equilibrium. Therefore, the adsorption constant is equal to the desorption constant [8]. The model of the Langmuir isotherm is reported in Equation (6), as follows: where q L is the maximum capacity of adsorption in the monolayer, P CO 2 (atm) is the pressure at the equilibrium of the adsorbed gas, and K L (atm −1 ) is the Langmuir adsorption constant or the affinity constant related to the energy of adsorption [40].…”

Section: Langmuir Modelmentioning

confidence: 99%

“…The adsorption of molecules on a surface that has a constant interaction energy is not common since most solids have a heterogeneous surface [8]. The Freundlich model [41] is described by an empirical equation used for systems with a high degree of heterogeneity.…”

Section: Freundlich Modelmentioning

confidence: 99%

“…The strength of the bonds is not homogeneous due to the physicochemical characteristics of the adsorption sites or the number of molecules already adsorbed. In particular, as more molecules join to a site and it is less likely that another molecule will join the same site because it requires a higher (exponentially) energy [8]. The model of the Freundlich isotherm is reported in Equation (7), as follows:…”

Section: Freundlich Modelmentioning

confidence: 99%

“…where K s (atm −1 ) is the constant of the Sips isotherm, q s (mmol g −1 ) reflects the maximum adsorption constant, and m s is the heterogeneity factor that represents the deviation of the linearity of adsorption [8]. A value of m s close to or equal to 1 is given in adsorbents with homogeneous active sites [45], while a value of m s close to 0 occurs in biosorbents that possess the heterogeneously distributed active sites [46].…”

Section: Sips Modelmentioning

confidence: 99%

“…About 60% of the effects of global warming are due to CO 2 , even though methane and chlorofluorocarbons have a much greater greenhouse effect in relation to the mass of the gases. CO 2 emission has increased in recent years [2], and the international panel on climate change (IPCC) stated that the average concentration of CO 2 could rise to 570 ppm by 2100, causing a 1.9 • C increase in the average global temperature and a 38 cm increase in sea level [8]. For this reason, CO 2 has become a threat to the environment [2].…”

Section: Introductionmentioning

confidence: 99%

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Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Romero

Moreno–Piraján

Gutiérrez

2018

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In this work, aerogels were prepared using resorcinol-formaldehyde as a precursor in two synthetic routes, one basic and one acidic, to perform the adsorption of CO 2 at 0 • C and atmospheric pressure. Aerogels were Characterization by N 2 and CO 2 Physisorption, Raman Spectroscopy, Scanning Electron Microscopy, and Infrared Spectroscopy. In general, was found that aerogels have a polymeric, disordered, three-dimensional structure and have a microporous surface. Langmuir, Freundlich, Sips and Toth equilibrium models present a good data fit of CO 2 adsorption at relative pressure ranging between 1 × 10 −4 and 3 × 10 −2 . The diffusion intra-particle kinetic model explains the setps of this process; the Elovich model also showed a good fit, therefore, there are an energetic heterogeneity of the CO 2 superficial adsorption sites. The aerogel carbonized in basic medium at 1050 • C (ACB 1050) material was the best adsorbent of this pollutant, reaching an adsorption capacity of 6.43 mmol g −1 .Achieving economic and favorable separation of CO 2 from gas mixtures represents one of the main technological and environmental problems facing our society today [10]. The most studied post-combustion technology is chemical adsorption. Monoethanol amine (MEA) has been the chemical most used for this purpose. Alternative solvents, such as piperazine and ammonia, have also been proposed to achieve this objective [6]. The advantage of this method is the low partial pressure that is used because the CO 2 molecules are easily absorbed over liquids in flue gas streams [11]. The disadvantage is that the use of amine alkoxysilanes is very expensive [12], and the method requires high regeneration energy due to the large emission of combustion gases and the costs of repairing the process equipment [4]. Other common methods to achieve CO 2 sequestration include separation in membranes, cryogenic and biological methods, and physical adsorption [13].Capture and storage technology has been considered the best option to reduce carbon dioxide emissions from large sources, and particularly adsorption is considered a promising process to separate gas mixtures [14]. This process is inexpensive, requires less regeneration energy, is easy to handle, has fast kinetics, and has a high capacity of CO 2 adsorption and selectivity [4]. The adsorbents provide a high surface area, which is a fundamental parameter in this process. Among the different adsorbents, 13X zeolite has been investigated to adsorb CO 2 by oscillating the pressure [6]. It is generally recognized that CO 2 is physically adsorbed to activated carbon, mainly by condensation or liquefaction in pores with widths that are less than 1 nm [15]. The adsorption of this greenhouse gas in nanopore materials has also been investigated in zeolites exchanged with alkali metals, amino-modified and modified alkaline, mesoporous silicas, microporous polymers, carbons, and metalorganic structures [10]. It has also been established that the chemical properties of activated carbon play a relevant role in...

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Section: Langmuir Modelmentioning

confidence: 99%

Section: Freundlich Modelmentioning

confidence: 99%

Section: Freundlich Modelmentioning

confidence: 99%

Section: Sips Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Romero

Moreno–Piraján

Gutiérrez

2018

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Natural Products Derived Porous Carbons for CO₂ Capture

Khosrowshahi,

Mashhadimoslem,

Shayesteh

et al. 2023

Advanced Science

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As it is now established that global warming and climate change are a reality, international investments are pouring in and rightfully so for climate change mitigation. Carbon capture and separation (CCS) is therefore gaining paramount importance as it is considered one of the powerful solutions for global warming. Sorption on porous materials is a promising alternative to traditional carbon dioxide (CO2) capture technologies. Owing to their sustainable availability, economic viability, and important recyclability, natural products‐derived porous carbons have emerged as favorable and competitive materials for CO2 sorption. Furthermore, the fabrication of high‐quality value‐added functional porous carbon‐based materials using renewable precursors and waste materials is an environmentally friendly approach. This review provides crucial insights and analyses to enhance the understanding of the application of porous carbons in CO2 capture. Various methods for the synthesis of porous carbon, their structural characterization, and parameters that influence their sorption properties are discussed. The review also delves into the utilization of molecular dynamics (MD), Monte Carlo (MC), density functional theory (DFT), and machine learning techniques for simulating adsorption and validating experimental results. Lastly, the review provides future outlook and research directions for progressing the use of natural products‐derived porous carbons for CO2 capture.

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Effective adsorptive removal of trace CO₂ from olefin using alkanolamine‐polyethylenimine‐functionalized fumed silica

Huang,

Yu,

Fan

et al. 2023

AIChE Journal

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The purification of gaseous olefins, such as C2H4 and C3H6, requires the efficient removal of trace CO2 impurities. However, the development of ideal adsorbents with high CO2/olefin selectivity has remained a challenge. In this study, we synthesized a novel adsorbent, denoted as PEI/DEA@FS, by modifying fumed silica (FS) with a combination of polyethylenimine (PEI) and diethanolamine (DEA). At 298 K and 0.0004 bar, PEI/DEA@FS presented the highest CO2 adsorption capacity among previously studied adsorbents, with a value of 2.12 mmol/g. Notably, PEI/DEA@FS demonstrated very high ideal adsorption solution theory selectivity for CO2/C2H4 (>1010) and CO2/C3H6 (>107) at 298 K and 0.01 bar. Breakthrough experiments revealed its excellent separation performance, producing olefins (C2H4 and C3H6) with ultra‐high purity (>99.9%) from a CO2/olefin (1/99) mixture. Moreover, PEI/DEA@FS exhibited outstanding stability over 20 adsorption and desorption cycles, and its CO2 adsorption performance remained almost unchanged under 75% relative humidity in the feed stream.

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Isotherms and thermodynamics of CO2 adsorption on a novel carbon-magnetite composite sorbent

Cited by 160 publications

References 78 publications

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Natural Products Derived Porous Carbons for CO₂ Capture

Effective adsorptive removal of trace CO₂ from olefin using alkanolamine‐polyethylenimine‐functionalized fumed silica

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Isotherms and thermodynamics of CO2 adsorption on a novel carbon-magnetite composite sorbent

Cited by 160 publications

References 78 publications

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Kinetic and Equilibrium Study of the Adsorption of CO2 in Ultramicropores of Resorcinol-Formaldehyde Aerogels Obtained in Acidic and Basic Medium

Natural Products Derived Porous Carbons for CO2 Capture

Effective adsorptive removal of trace CO2 from olefin using alkanolamine‐polyethylenimine‐functionalized fumed silica

Contact Info

Product

Resources

About

Natural Products Derived Porous Carbons for CO₂ Capture

Effective adsorptive removal of trace CO₂ from olefin using alkanolamine‐polyethylenimine‐functionalized fumed silica