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Publisher: Springer-Verlag (Total: 2352 journals)

 Adsorption   [SJR: 0.774]   [H-I: 52]   [4 followers]  Follow         Hybrid journal (It can contain Open Access articles)    ISSN (Print) 1572-8757 - ISSN (Online) 0929-5607    Published by Springer-Verlag  [2352 journals]
• Removal of refractory organics from saline concentrate produced by
electrodialysis in petroleum industry using bone char
• Authors: Patrícia da Luz Mesquita; Maria Alexandra Pires Cruz; Cássia Ribeiro Souza; Nilza Tatiane G. Santos; Edson Romano Nucci; Sônia Denise Ferreira Rocha
Pages: 983 - 997
Abstract: In a scenario of hydric scarcity, water reuse is essential to minimize make-up; however, increased salinity comes along with recycling streams. Crystallization has been evaluated to remove dissolved ions; nevertheless, contaminants affect its efficiency. In this context, the removal of residual organics from the saline concentrate from electrodialysis applied for water reuse in a Brazilian petroleum refinery was investigated. Aiming at establishing a sustainable virtuous circle, bone char, a waste from food industry, 0.5–1.4 mm particle size, was used as adsorbent for refractory organics removal. Equilibrium adsorption time of 4 h was determined from batch experiments (through 72 h, at 25.0 ± 0.1 °C, pH 7.6 ± 0.5 and 200 ± 1 rpm, solid/liquid ratio of 10 g kg−1) in a shaker and a removal of 54% for dissolved chemical oxygen demand (COD) was observed. Adsorption kinetics (pseudo-first and pseudo-second order; Elovich equation) and equilibrium isotherms were evaluated. Pseudo-second order model for kinetics (R2 = 0.9993; k2 = 0.0184 mg−1 min−1; qe = 3.21 mg g−1) and Freundlich isotherm model best fitted to experimental data (R2 = 0.995), suggesting physisorption in multiple layers. The adsorbent thermal regeneration was evaluated (at 300, 500 and 700 °C, for 60, 120 and 180 min). Partial thermal regeneration was achieved at lower temperature and time demands (300 °C and 60 min—dissolved COD removal was around 40% after the first cycle of regeneration). Further investigation, including scaling-up and a cost-benefit analysis, is necessary in order to assess its use as a viable low-cost alternative for this type of effluent.
PubDate: 2017-11-01
DOI: 10.1007/s10450-017-9917-y
Issue No: Vol. 23, No. 7-8 (2017)

• Effect of Zr and Li on high temperature CO 2 sorption characteristics of
CaO
• Authors: Rajangam Vinodh; Aziz Abidov; Muthiahpillai Palanichamy; Wang Seog Cha; Hyun Tae Jang
Pages: 1033 - 1039
Abstract: In this work, a series of Zr and Li incorporated synthetic CaO based sorbents were prepared by a simple precipitation method for high temperature (600–800 °C) CO2 capture. After impregnation and subsequent calcination, the sorbents were characterized by N2 adsorption isotherm, scanning electron microscopy and X-ray diffraction techniques. The cyclic performance in CO2 processes was evaluated by breakthrough measurements. ZrCa3Li4O7 exhibited the maximum CO2 sorption of 28.4 wt% and it showed excellent stability. The CO2 performance of ZrCa3Li4O7 still remained stable when tested under a high decarbonation temperature of 900 °C.
PubDate: 2017-11-01
DOI: 10.1007/s10450-017-9915-0
Issue No: Vol. 23, No. 7-8 (2017)

• Functionalization of carbon silica composites via in-pore synthesis of
active sites for NH $$_3$$ 3 and SO $$_2$$ 2 adsorption
• Authors: Dushyant Barpaga; M. Douglas LeVan
Pages: 779 - 787
Abstract: To enhance the gas adsorption of toxic industrial chemicals such as NH $$_3$$ and SO $$_2$$ , a biphasic carbon silica composite (CSC) is functionalized with combinations of potassium carbonate or potassium phosphate and various metal chlorides with divalent cations. A precipitation reaction occurs within the pores of the CSC between non-monovalent cations and anions to create essentially insoluble active sites. The adsorption capacities of these functionalized materials are measured at atmospheric pressure and low concentrations of NH $$_3$$ and SO $$_2$$ . Along with capacity performance, the synthesized materials are characterized using X-ray diffraction, porosimetry and pH measurements to analyze the structure, the incorporation, and the effects of impregnation upon functionalization. Results show that successful incorporation of all insoluble precipitates enhances adsorption capacities compared to impregnant-free substrates. Furthermore, characterization results show reduced pore volumes and surface areas of functionalized materials with structural integrity maintained. Both NH $$_3$$ and SO $$_2$$ adsorption can be improved via dual salt functionalization of metal chlorides with potassium salts which form insoluble precipitates on CSC and MCM-41 adsorbent materials. In order to target both adsorbates effectively, the incorporation of K $$_2$$ CO $$_3$$ and ZnCl $$_2$$ to form ZnCO $$_3$$ provides the highest adsorption capacities for both NH $$_3$$ and SO $$_2$$ .
PubDate: 2017-08-01
DOI: 10.1007/s10450-017-9898-x
Issue No: Vol. 23, No. 6 (2017)

• Nitrogen substitution and vacancy mediated scandium metal adsorption on
carbon nanotubes
• Authors: Michael Rivera Mananghaya; Gil Nonato Santos; Dennis Yu
Pages: 789 - 797
Abstract: First-principle calculation reveals that N containing carbon nanotubes (CNTs) can support the functionalization of transition metals such as Sc on the CNT surface. For N-substituted CNTs without a vacancy, the enhanced adsorption results from large electron affinity difference of the N adjacent to C atom. In this case, the N atom activates nearby C atom and enhances its interaction with the Sc metal on the CNT surface. Meanwhile, the formation of a vacancy in CNTs causes local reconstruction of the surface near the vacancy site. Simulation and analysis show that vacancy mediated N substitution is a more favored scheme for Sc functionalization on the surface of CNTs that suppresses the clustering of Sc. The enhanced Sc adsorption in N-doped CNTs with mono- and di-vacancy defects was attributed to strong hybridization between the Scandium d orbital and nitrogen p orbital. The results explain theoretically the mechanism of enhanced functionalization of metals on N doped CNTs and suggests that Sc functionalized nitrogen doped CNTs with vacancies is an excellent candidate for the adsorption of small molecules.
PubDate: 2017-08-01
DOI: 10.1007/s10450-017-9901-6
Issue No: Vol. 23, No. 6 (2017)

• Adsorption of cesium on bound porous materials containing embedded
phosphotungstic acid
• Authors: Iuliia Little; Kenneth Seaton; Esther Alorkpa; Aleksey Vasiliev
Pages: 809 - 819
Abstract: The adsorption of cesium on mesoporous silica materials containing embedded phosphotungstic acid (PTA) was studied. The materials contained active adsorbent and binders: γ-Al2O3, kaolin, or charcoal. The presence of Keggin units of PTA in the bound materials was confirmed by FT-IR spectroscopy. Among all materials, the formulation with γ-Al2O3 demonstrated the highest porosity and effectiveness in adsorption. Pure PTA/SiO2 contained a significant fraction of small particles between 100 and 300 nm. However, in the alumina-bound material, they were not detected. SEM imaging showed that these particles occupied interparticle space between larger γ-Al2O3 particles. The material was stable up to 540 °C. In most materials, the adsorption of cesium decreased with increase of the binder contents but not proportionally. The adsorption capacity of all materials depended on the concentration of cesium in the solutions. Maximum adsorption was achieved after 1 h. The adsorption of cesium is controlled by intraparticle diffusion while its rate can be described by the pseudo-second-order model.
PubDate: 2017-08-01
DOI: 10.1007/s10450-017-9905-2
Issue No: Vol. 23, No. 6 (2017)

• A solid-state 1 H-NMR study of the dynamic structure of ZIF-8 and its role
in the adsorption of bulky molecules
• Authors: Takahiro Ueda; Masako Nakai; Tatsuya Yamatani
Pages: 887 - 901
Abstract: In order to clarify the adsorption mechanism of the zeolitic imidazolate framework, ZIF-8, for bulky molecules larger than its aperture diameter, the local structure of ZIF-8 and its host–guest interactions were studied by adsorption kinetics, potential energy analysis, and solid-state 1H nuclear magnetic resonance (1H-NMR) spectroscopy. Adsorption kinetics measurements lead to apparent diffusion coefficients for CS2, CDCl3, and CCl4 in ZIF-8 that provide residence times for each molecule in the ZIF-8 micropores. Potential energy analyses using van der Waals pairwise interactions reveal two kinds of feasible sites for bulky molecules in the ZIF-8 micropores, where there are minimal intermolecular interactions between an adsorbate and the pore wall. Each site lies on one of the four diagonal axes of the cubic lattice of the ZIF-8 unit cell. One set of sites corresponds to the side of the micropore where methyl groups form a bottleneck, and the other to the side where CH moieties form the bottleneck. Second-moment analysis of the 1H-NMR resonance line reveals that the 2-methylimidazolate rings undergo flip motions, with flip angles of ~55°, in addition to the rapid axial rotations of their methyl groups. Temperature-dependent spin–lattice relaxation time analyses indicate that adsorptions of these molecules reduce the motions of the 2-methylimidazolate rings. In particular, steric hindrance from bulky molecules such as CDCl3 and CCl4 significantly lowers the flipping frequency of the 2-methylimidazolate ring. The flipping of the 2-methylimidazolate ring results in instantaneous aperture expansion that enables bulky molecules to pass through the ZIF-8 aperture.
PubDate: 2017-08-01
DOI: 10.1007/s10450-017-9902-5
Issue No: Vol. 23, No. 6 (2017)

• Authors: Shivaji Sircar
Abstract: An alternative to the conventional ‘pore filling model’ for describing Gibbsian surface excess (GSE) isotherm from a liquid mixture on a porous adsorbent is proposed where the adsorbed phase volume is treated as a variable. The new model is tested using GSE isotherm data on various micro and mesoporous adsorbents. The adsorbed phase volume is found to be system specific but always less than the adsorbent pore volume, irrespective of the pore size.
PubDate: 2017-11-02
DOI: 10.1007/s10450-017-9914-1

• Quantum chemical description of formaldehyde (HCHO), acetaldehyde (CH 3
CHO) and propanal (CH 3 CH 2 CHO) pollutants adsorption behaviors onto the
bowl-shaped B 36 nanosheet
• Authors: Zeynab Mohsenpour; Ehsan Shakerzadeh; Morteza Zare
Abstract: The potential applicability of newly synthesized B36 nanosheet as a chemical sensor for formaldehyde (HCHO), acetaldehyde (CH3CHO) or propanal (CH3CH2CHO) pollutants detection is investigated by employing DFT calculations. The results indicate that although these pollutant molecules weakly interact with concave or convex sides of nanosheet, it remarkably adsorbed at the edge of B36 nanosheet. Indeed, the adsorption of one to six pollutant molecules at the edge of B36 nanosheet is considered to investigate adsorption capacity. The results reveal that the adsorption energies and electronic properties are affected by the number of adsorbed pollutant molecules. The B36 nanosheet is introduced as a chemical sensor for HCOH, CH3CHO or CH3CH2CHO detection due to producing an electrical signal which is sensitive to their concentration.
PubDate: 2017-10-24
DOI: 10.1007/s10450-017-9913-2

• Non-Arrhenius form of the Henry adsorption on inhomogeneous substrates:
the effect of frozen disorder
• Authors: V. N. Bondarev; V. V. Kutarov; Е. Schieferstein
Abstract: Usually, when considering sub-monolayer adsorption at different temperatures T, the logarithm of the Henry constant is represented as $$\ln {K_H}\sim {U_0}/T$$ with some constant “heat of adsorption” U 0 > 0. However, such Arrhenius-type form has a clear base only for an ideal translational-invariant crystal substrate. In more real situation, e.g. for a structurally disordered substrate, the “heat of adsorption” will be some random function of two-dimensional coordinates characterized by some distribution function of its different values. Starting from general principles of the theory of Gaussian fluctuations, we show that the adsorption at the substrate with bulk inhomogeneous structure leads to expression $$\ln {K_H}\sim {U_0}/T+{\Delta ^2}/{T^2}$$ with some fluctuation quantity Δ. A possibility to observe such “non-Arrhenius” additive seems most favorable at rather low temperatures for substrates modeled by substitutional solid solutions. The theoretical predictions are illustrated by comparison with the experimental data obtained for some disordered adsorbents.
PubDate: 2017-10-16
DOI: 10.1007/s10450-017-9909-y

• Adsorption of phosphoric acid anions on platinum (111)
• Authors: Lynndle C. Square; Christopher J. Arendse; Theophillus F. G. Muller
Abstract: The adsorption of phosphoric acid anions on the platinum (111) plane is investigated using Monte Carlo and density functional theory methods. The minimum energy structure is used to generate the adsorption configurations, indicating the preferred adsorption sites. The bond lengths was found from density functional theory calculations and used to gain further insight on the structure due to adsorption. From the density functional calculations the scanning tunnelling microscopy image of the specie with the lowest adsorption energy configuration and shortest bond length was produced.
PubDate: 2017-10-13
DOI: 10.1007/s10450-017-9912-3

• Adsorptive removal of carbonyl sulfide by Fe-modified activated carbon:
experiments and DFT calculations
• Authors: Shunzheng Zhao; Honghong Yi; Xiaolong Tang; Fengyu Gao; Jiangen Wang; Yonghai Huang; Zhongyu Yang
PubDate: 2017-10-09
DOI: 10.1007/s10450-017-9910-5

• Experimental adsorption isotherms of CO 2 and CH 4 on STT zeolite:
comparison with high- and pure-silica zeolites
• Authors: Hafez Maghsoudi; Azam Aidani
PubDate: 2017-10-06
DOI: 10.1007/s10450-017-9911-4

• Quantitative analysis porous structure of activated carbon with classical
density functional theory
• Authors: Guodong Wang; Jianchun Jiang
Abstract: Towards development of a more reliable theoretical procedure, we apply a modified classical density functional theory for porous analysis on solid heterogeneity. Such novel theoretical procedure has been used to analyze the pore size distribution (PSD) of five activated carbon samples and to predict the adsorption isotherms of these materials. As for the characterization sensitive with the adopted numerical algorithms, we evaluate the representative of the required PSD by three numerical methodologies with their predictive capability. It is notable that P1 method with B-spline function as prior PSD function form is suitable for the pore-size analysis of activated carbon for its smallest average deviation on isotherm fitting and prediction. Moreover, the effect of hypothesis form on solid heterogeneity is also discussed according to its contribution on the accuracy and stability of the numerical procedure. According to the proposed feature pore width range theory, we discuss the relationship between the numerical procedure and the predictive capability of the characterized PSD. With the fluctuated experimental temperature into consideration, we also make predictive calculation on adsorption capacity of activated carbon within certain error range, which is meaningful for the development of predictive functional in PSD model.
PubDate: 2017-10-03
DOI: 10.1007/s10450-017-9904-3

• Selective adsorption of carbon dioxide, methane and nitrogen using
resorcinol-formaldehyde-xerogel activated carbon
• Authors: Ahmed Awadallah-F; Shaheen A. Al-Muhtaseb; Hae-Kwon Jeong
Abstract: Resorcinol–formaldehyde xerogel was prepared, carbonized and activated in specific conditions to form resorcinol–formaldehyde activated carbon xerogel (RF-ACX) that was to produce microporous nanoparticles. RF-ACX was used in the adsorption of CO2, CH4, and N2 gases. Adsorption/desorption isotherms of CO2, CH4, and N2 gases onto RF-ACX adsorbent were measured gravimetrically by a magnetic suspension microbalance at five different temperatures (20, 30, 40, 50 and 60 °C) in the pressure range of 0–1 MPa. All adsorption/desorption isotherms were found to be favorable and well correlated with dual site Langmuir’s model. The adsorption capacities of the three adsorbates increased with increasing pressure or with decreasing temperature. Nonetheless, the corresponding increase of CO2 adsorption capacity was much higher than those of CH4 and N2. The fitting parameters deduced from dual site Langmuir’s model were used to provide approximate predictions of the adsorption equilibria and selectivities of the corresponding binary mixtures (CO2/CH4, CH4/N2 and CO2/N2), which relate to separation processes of high influence to various energy and environmental applications.
PubDate: 2017-09-15
DOI: 10.1007/s10450-017-9908-z

• Desorption characteristics of H 2 O and CO 2 from alumina F200 under
different feed/purge pressure ratios and regeneration temperatures
• Authors: Yun Fei Shi; Xiang Jun Liu; Yu Guo; Mohammad Ali Kalbassi; Ying Shu Liu
Abstract: Air pre-purification is an important process for industrial air separation with cryogenic distillation method. This process is typically realized by pressure swing adsorption or temperature swing adsorption. H2O and CO2 are the two major components to be removed among the contaminants. In this paper, we establish a mathematical model describing the mass and heat balances in the adsorption bed, and the double-component adsorption/desorption equilibriums of H2O/CO2 on alumina F200. To conduct desorption performance analysis, a one-cycle process consisting of feed, blowdown, and purge step under different operating conditions, such as feed/purge pressure ratio and regeneration temperature, is numerically studied. The effect of heat on the desorption performance of H2O and CO2 is investigated by changing the purge gas temperature within 30–200 °C under feed/purge pressure ratios of 6:1.1 and 10:1.1, respectively. Detailed results of the H2O and CO2 adsorption/desorption behaviors in the bed are demonstrated. The mass and heat transfer characteristics during desorption are also analyzed. Suggestions on the optimization of the heating temperature and duration of purge gas are also proposed.
PubDate: 2017-09-12
DOI: 10.1007/s10450-017-9907-0

critical conditions. Part III: Inorganic monatomic and diatomic species
data evaluation and modeling
• Authors: Dana Abouelnasr; Kevin F. Loughlin; Alaa Al Mousa
Abstract: The saturation loadings for subcritical adsorption of inorganic monatomic and diatomic species on 13X zeolite are modeled using the modified Rackett model of Spencer and Danner (J Chem Eng Data 17:236–240, 1972) for the saturated liquid densities combined with crystallographic data for the 13X zeolite. A similar equation is derived for supercritical adsorption involving supercritical adsorbate densities and crystallographic data for the 13X zeolite. Adsorption data from the literature are first critically evaluated and then compared to the model. Log–log plots are used to determine whether each isotherm is near saturation; isotherms that exhibit a $${{\left( {\partial \ln q} \right)} \mathord{\left/ {\vphantom {{\left( {\partial \ln q} \right)} {\left( {\partial \ln p} \right)}}} \right. \kern-0em} {\left( {\partial \ln p} \right)}}$$ slope of zero at the maximum pressure point are assumed to be saturated. The highest loading is used from each isotherm that approaches saturation. Unsaturated isotherms are not considered further. The theoretical equation satisfactorily models the available experimental data for the data that are subcritical. However, a steric factor is required in the model for iodine. 80% of the data for helium, nitrogen and oxygen are in the supercritical region; this data reveals a linear decreasing trend with increasing reduced temperature Tr. For this data a new supercritical model is developed using the reduced critical adsorbate temperature, TCAR, and the slope of the decreasing linear plot against Tr. The physical phenomena causing this effect is considered to be increasing molecular vibration in the cavity reducing the total molecular loading with temperature rise.
PubDate: 2017-08-22
DOI: 10.1007/s10450-017-9906-1

• Authors: Sina Salimi; Mohsen Gholami
Abstract: In this study, an innovative parallel radial adsorber (here after PRA) has been presented. The motivation behind developing such a configuration was to enhance the performance of adsorption bed by broadening the possible choices of adsorbent diameter. The proposed arrangement effectively reduces the pressure drop by increasing the gas flow contact area; thus, a smaller adsorbent can be applied in the PRA bed. To quantify the performance of the proposed configuration, the governing equations of the system including conservation of energy, mass (diffusion inside the particles and convection outside the particles) and momentum (Ergun equation) were developed and solved numerically. The pressure drop, break-through time, saturation percentage, and duration of regeneration step were chosen as the key factors for evaluating such a configuration. By applying the new configuration, a magnificent diminution of pressure drop resulted. Therefore, small particles which are opted as the adsorbing media will increase the mass transfer area and subsequently mass transfer rate. The capability of handling high flow rate by the proposed configuration offered good potential for reducing the cycle time. Besides showing this potential, owing to the size of the particles in PRA beds, this configuration enhanced the saturation percentage of the column from 88% (axial bed) to 98% for the case study of natural gas dehydration.
PubDate: 2017-07-31
DOI: 10.1007/s10450-017-9899-9

• Experimental and modelling studies of CO 2 /N 2 mixture separations using
amine functionalised silicas
• Authors: E. Tsalaporta; N. Brady; J. M. D. MacElroy
Abstract: A combined experimental and mathematical investigation of amine modified mesoporous silicas as adsorbent materials for carbon dioxide removal from CO2/N2 gaseous mixtures is undertaken. The experiments are designed to permit the determination of CO2 adsorption equilibria and, as appropriate, the assessment of transport and adsorption/desorption reaction kinetic parameters for CO2 interacting with immobilised mono-, di- and triamine moieties. Both forward and reverse breakthrough analysis techniques and cyclic Pressure Swing Adsorption are employed to highlight the significant importance of the role of adsorbent heterogeneity in the separation process.
PubDate: 2017-06-26
DOI: 10.1007/s10450-017-9896-z

• Adsorption isotherms of carbon dioxide and methane on CHA-type zeolite
synthesized in fluoride medium
• Authors: Zahra Pourmahdi; Hafez Maghsoudi
Abstract: High-silica CHA-type zeolite was synthesized in fluoride medium using fumed silica as silica source. Adsorption isotherms of CO2 and CH4 were measured over pressure range of 0–1100 kPa and at temperatures of 298, 323, 353, and 393 K. The isotherms follow a typical Type-I shape according to the BDDT classification. All adsorption isotherms are well described by Langmuir, Toth and Sips isotherms. Adsorptive performance of the zeolite was compared with other CHA-type zeolites, i.e. SAPO-34, Si-CHA and SSZ-13 using ideal adsorption solution theory. The modeling results revealed that the zeolite has a high CO2/CH4 selectivity, e.g. 6.70 for an equimolar mixture at 298 K and 100 kPa. Isosteric heats of adsorption for both CO2 and CH4 were reasonably constant (20.6 and 24.1 kJ mol−1 at loading of 0.02 mol kg−1 for CH4 and CO2, respectively) showing that the adsorbent is energetically homogenous.
PubDate: 2017-06-13
DOI: 10.1007/s10450-017-9894-1

• In silico investigation of the ozone (O 3 ) binding behavior to the B 36
bowl-shaped structure
• Authors: Elham Tahmasebi; Zeinab Biglari; Ehsan Shakerzadeh
Abstract: The binding of ozone molecule to the B36 bowl-shaped structure is scrutinized using the density functional theory (DFT) calculations. The interactions are investigated using B3LYP, B3LYP-D3, WB97XD, M06-2X and TPPSH methods. The ozone binding to the B36 structure is studied in terms of energetical, structural and electronic features. The results indicate that although ozone molecule weakly interacts with concave side of structure, it adds to the convex side and the edge of B36 structure. The ozone binding to the edge of B36 is more efficient than its convex side. The HOMO–LUMO gaps of the stable systems are reduced with respect to pure B36 sheet. This could be applied as a chemical signal. The obtained results introduce the B36 structure as an efficient ozone adsorbent.
PubDate: 2017-05-31
DOI: 10.1007/s10450-017-9891-4

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