Carbon Dioxide Sorption Research Articles

Synthesis, characterization and selective hysteretic sorption property of metal–organic frameworks with 3,5-di(pyridine-4-yl)benzoate

Three new metal–organic frameworks (MOFs) {[Zn(L)(HCOO)(H2O)]·H2O}n (1), {Cd(L)2}n (2) and {Co(L)(BDC)0.5(H2O)}n (3) [HL = 3,5-di(pyridine-4-yl)benzoic acid, H2BDC = 1,4-benzenedicarboxylic acid] were synthesized by hydro/solvothermal reactions and characterized by elemental analysis, thermogravimetric analysis, IR spectroscopy, powder and single crystal X-ray diffraction. Complex 1 is a two-dimensional (2D) network with {63} topology, which is further assembled into a three-dimensional (3D) supramolecular architecture through hydrogen bonding interactions. Complex 2 is a 2-fold interpenetrating 3D framework with a point (Schlafli) symbol of {63}{67·83}, while 3 is a 3D net formed by interpenetration of 2D bilayers (2D + 2D → 3D) with a point (Schlafli) symbol of {63}{66}. Selective and hysteretic sorption of carbon dioxide (CO2) was found for 3 at 195 K, and the photoluminescence properties of 1 and 2 were investigated.

CO2-ECBM and CO2 Sequestration in Polish Coal Seam – Experimental Study

ABSTRACT Purpose Methane recovery is interesting not only because of its clean combustion; it is also beneficial for the environment because of the reduction of the amount of methane emitted into the atmosphere, which is important because of methane’s significant impact on the greenhouse effect. However, desorption of methane is a slow process, significantly dependent on the coalification of coal, its porosity and petrographic composition. Injection of carbon dioxide into the coal bed under sufficient pressure might be a factor in stimulating the efficiency of this process, as – because of preferential sorption – carbon dioxide displaces methane molecules previously absorbed in the coal matrix. Methods The measurements were made for Polish low-rank coal used for the analysis of methane recovery from Polish coal mines. Coal samples were collected from sites used for geological, sorption and petrographic research, as well as for the assessment of the reservoir’s genetic origin CH4 content. Experimental studies of sorption were performed with the use of the volumetric method at a lower and higher gas pressure. Results The methane isothermes show more than double the reduction of adsorption along with increasing temperature. The most significant changes of sorption capacity due to temperature variations can be seen when observing the difference in the course of the hysteresis of sorption/desorption of the gas as a function of temperature. In cases where there is a temperature of 323 K, a temperature hysteresis loop might indicate larger quantities of methane trapped in the porous structure of coal. In cases of carbon dioxide as sorbate, a similar shape of sorption isotherms occurred at both temperatures, while the temperature increase caused approximately double the reduction of sorption capacity. Also the isotherm’s shape is similar for both temperatures of measurement, indicating no effect of temperature on the amount of gas within the structure of the tested coal. High-pressure isotherms of CO2 and CH4 are confirmed in the literature, proving that carbon dioxide is the gas that allows the best penetration of the internal structure of bituminous coal. The critical temperature of CO2 (304.5 K) is so high, that sorption measurements can be performed at room temperatures (293, 298 K), where activated diffusion is relatively fast. Practical implications Understanding the sorption of gases is the primary issue, related to the exploitation of coal seams, when explaining the mechanism of gas deposition in coal seams and its relationship with outbursts of rocks and gases in mines. Originality/value The results indicate successful sorption of carbon dioxide in each experiment. This provides the rationale to study the application of the coal tested to obtain methane genetic origin genetic methane with the use of the CO2 injection.

POSS-based luminescent porous polymers for carbon dioxide sorption and nitroaromatic explosives detection

Luminescent porous polymers based on octavinylsilsequioxane and triphenylamine units show tunable porosity and luminescence, a moderate uptake of CO2 and high sensitivity for TNT.

Effects of structural properties of silicon carbide-derived carbons on their electrochemical double-layer capacitance in aqueous and organic electrolytes

High surface area silicon carbide-derived carbons (Si-CDCs) synthesized by chlorination of beta silicon carbide (βSiC) with two different particle sizes (6 μm and 50 nm) show different porosities with graphitic structure. Transmission electron microscopy, Raman spectroscopy and argon (Ar) and carbon dioxide (CO2) sorption analyses are used to examine the textural properties of the Si-CDCs. The results show that the particle size of the precursor affects the surface area and porosity of carbons. Furthermore, an additional heat treatment of the Si-CDC with 50-nm particle size for 24 h at 1,000 °C results in a collapse of the pore structure and reduces the surface area. The capacitive behaviours are investigated in H2SO4 and in tetraethyl ammonium tetrafluoroborate (TEABF4)/acetonitrile (AN). The electrochemical performance of the Si-CDCs is influenced by the particle size, surface area, pore volume and pore size distribution. The Si-CDCs exhibit capacitances in 1 M H2SO4 of up to 179 F g−1 and very stable charge–discharge performance over 5,000 cycles. This study shows the crucial importance of ultramicropores less than 1 nm combined with nanosized particles for achieving high capacitance in aqueous electrolyte. Moreover, the graphitic degree at the surface of the Si-CDCs enhances considerably the rate capability and stability in both electrolytes.

Sorption and Diffusion Behavior of Carbon Dioxide into Poly(l-lactic acid) Films at Elevated Pressures

Equilibrium sorption amount, desorption diffusion coefficients and sorption diffusion coefficients of CO2 in poly(l-lactic acid) (PLLA) films at elevated pressures were determined by the gravimetric method, in which the Fick's diffusion model was applied to analyze both the desorption and sorption processes. The equilibrium sorption amount of CO2 in PLLA increased with lowering temperature and elevating pressure at the temperature range from 40 to 60 °C and pressure from 104 to 2×104 kPa. Desorption diffusion coefficients were greatly influenced by the equilibrium sorption amount, and they were in the same order of magnitude as the sorption diffusion coefficients. The scan electron microscope (SEM) photos demonstrated that there was no foaming phenomenon of the PLLA film during desorption and sorption processes. The XRD spectra implied that the crystalline degree of PLLA film decreased after CO2 processing. It was concluded that PLLA polymer could be well swollen and plasticized by supercritical CO2.

Amine Distribution and Carbon Dioxide Sorption Performance of Amine Coated Silica Aerogel Sorbents: Effect of Synthesis Methods.

Tetraethylenepentamine (TEPA) modified silica aerogel CO2 adsorbents were prepared by two methods: evaporative precipitation and wet-impregnation. The distribution of amine on the support and CO2 adsorption performance of these sorbents were studied by nitrogen porosimetry, thermogravimetric analysis, transmission electron microscopy, and CO2 gravimetric adsorption analysis to understand the synthesis-structure-CO2 adsorption property relationships of the silica aerogel supported amine sorbents. The sorbents prepared by evaporative precipitation showed slightly better distributions of TEPA and adsorption performance relative to the wet impregnated analogues. The enhancements observed, however, were unexpectedly small suggesting that the two methods of amine immobilization result in similar TEPA distributions. It appears that the thermodynamic limitation toward lowering the free energy of the system is causing the TEPA to consolidate inside the aerogel network, suggesting that methods of impregnation are of little influence on amine distribution within the pore network of the support.

Carbon dioxide sorption on polish ortholignite coal in low and elevated pressure

Measurements of CO2 sorption are taken by the weighting method, using the specialist equipment: a low-pressure microbalance (Sartorius). Experiments are performed at 3 temperatures: 272, 298 and 313K. Low-pressure sorption data for the coal–gas systems are compared with results obtained at elevated pressures. Coal sample come from the brown coal mine in Belchatow (Poland). Experimental data supported by the IST method are used to transform the isotherms to obtain the general isotherm and to generate the absolute sorption isotherms. It appears that the method agrees well with experimental data, which means that it well captures the behavior of the coal–CO2 system.

Methane and carbon dioxide adsorption in clay-like slit pores by Monte Carlo simulations

Shale is composed of two distinct permeable media: (1) inorganic, and (2) organic. Both media may contribute to the amount of hydrocarbon and non-hydrocarbon species in shale. In this work, we investigate sorption in clay minerals which may constitute most of the inorganic matter in shale. We represent the inorganic matter by the montmorillonite clays with different charges for different atoms. Sorption of methane and carbon dioxide is investigated by Monte Carlo simulations. In this work, we assume that methane is structureless and CO2 is assumed to have structure and we assign partial charges to its atoms. Our results indicate that charge affects the orientation of CO2 molecules close to the surface and plays an important role in CO2 sorption. Methane sorption is found to be mainly a function of surface area. We also incorporate cation exchange in clay description and model its effect on sorption. Cation exchange increases CO2 sorption at low pressure significantly and as pressure increases, the effect becomes less pronounced. Cation exchange also affects orientation of CO2 molecules near the surface. Results from our simulation are expected to provide insight into phase behavior in clays, a major constituent of shale media.

Graphene–terpyridine complex hybrid porous material for carbon dioxide adsorption

A graphene-based porous material for carbon dioxide sorption was designed and fabricated through an azide–alkyne click reaction between alkynyl group modified graphene oxide (alkynyl-GO) and azido-terpyridine complex. In the preparation of graphene terpyridine complex hybrid porous materials (GTCF), alkynyl-GO sheets were synthesized and used as the building blocks, which were then cross-linked with azido-terpyridine complexes through a copper (I) ion-catalyzed click reaction (Huisgen cycloaddition reaction). The incorporation of the non-planar terpyridine complexes between graphene sheets increases the porosity in the GTCF materials. Meanwhile, three kinds of nitrogen-containing groups (amine, triazole, and terpyridine groups) were introduced or formed during the modification and cross-linking, which offer more basic sites for the acidic gas sorption. Gas sorption analysis shows that the GTCF hybrid porous materials possess high specific surface area and their carbon dioxide capacity could reach up to 11.7wt.% at 273K.

Sorption and diffusion of carbon dioxide and nitrogen in poly(methyl methacrylate)

Molecular dynamics simulations are performed to determine the solubility and diffusion coefficient of carbon dioxide and nitrogen in poly(methyl methacrylate) (PMMA). The solubilities of CO2 in the polymer are calculated employing our grand canonical ensemble simulation method, fixing the target excess chemical potential of CO2 in the polymer and varying the number of CO2 molecules in the polymer matrix till establishing equilibrium. It is shown that the calculated sorption isotherms of CO2 in PMMA, employing this method well agrees with experiment. Our results on the diffusion coefficients of CO2 and N2 in PMMA are shown to obey a common hopping mechanism. It is shown that the higher solubility of CO2 than that of N2 is a consequence of more attractive interactions between the carbonyl group of polymer and the sorbent. While the residence time of CO2 beside the carbonyl group of polymer is about three times higher than that of N2, the diffusion coefficient of CO2 in PMMA is higher than that of N2. The higher diffusion coefficient of CO2, compared to N2, in PMMA is shown to be due to the higher (≈3 times) swelling of polymer upon CO2 uptake.

Nonporous Titanium–Oxo Molecular Clusters That Reversibly and Selectively Adsorb Carbon Dioxide

Nonporous titanium(IV) clusters supported by carboxylate ligands show selective sorption of carbon dioxide even in the amorphous phase. A ring-type Ti8 cluster with a permanent inner pore also adsorbs gases, but not selectively.

High-pressure CH4 and CO2 sorption isotherms as a function of coal maturity and the influence of moisture

Methane (CH4) and carbon dioxide (CO2) sorption isotherms have been measured on an Australian subbituminous, a German high-volatile bituminous and a German anthracite coal in the dry and moisture-equilibrated state. The purpose was to study the variation of CH4 and CO2 sorption capacities of the dry coals as a function of rank and the influence of water on the sorption properties. Methane sorption isotherms were measured at 303, 308, 318 and 334K (30, 35, 45 and 61°C), and CO2 isotherms at 318, 334 and 349K (45, 61 and 76°C).The excess sorption capacity of coals is always higher for CO2 than for CH4. The CO2 and CH4 sorption capacity of dry coals as a function of rank follows a parabolic trend reported in earlier studies, with a minimum at ~1% vitrinite reflectance. This trend is more pronounced for CO2 than for CH4. For moisturised coals a linear increase in CO2 and CH4 sorption capacity with coal rank was observed. Moisture reduces the gas sorption capacity of coals significantly. Moisture content therefore is a first-order control for the gas sorption capacity of low rank coals up to bituminous rank, with much higher impact than temperature or maturity. The moisture-induced reduction in CO2 and CH4 sorption capacity decreases with increasing coal rank. It correlates linearly with the oxygen content, which in turn correlates qualitatively with the amount of hydrophilic and carboxylic functional groups as evidenced by FTIR analysis.The influence of sorbed water on the sorption capacity is highest at low pressures (low surface coverage θ<0.3). The dry/moist sorption capacity ratios converge towards 1 with increasing pressure (high surface coverage θ≈0.7).

Ultrahigh Gas Storage both at Low and High Pressures in KOH-Activated Carbonized Porous Aromatic Frameworks

The carbonized PAF-1 derivatives formed by high-temperature KOH activation showed a unique bimodal microporous structure located at 0.6 nm and 1.2 nm and high surface area. These robust micropores were confirmed by nitrogen sorption experiment and high-resolution transmission electron microscopy (TEM). Carbon dioxide, methane and hydrogen sorption experiments indicated that these novel porous carbon materials have significant gas sorption abilities in both low-pressure and high-pressure environments. Moreover the methane storage ability of K-PAF-1-750 is among the best at 35 bars, and its low-pressure gas adsorption abilities are also comparable to the best porous materials in the world. Combined with excellent physicochemical stability, these materials are very promising for industrial applications such as carbon dioxide capture and high-density clean energy storage.

The Coalbed Methane (CBM) Potential and CO2 Storage Capacity of the Santa Terezinha Coalfield, Paraná Basin, Brazil – 3D Modelling, and Coal and Carbonaceous Shale Characteristics and Related Desorption and Adsorption Capacities in Samples from Exploration Borehole CBM001-ST-RS

This study investigates the CBM generation and CO2 storage capacity of the coal-bearing Permian age Rio Bonito Formation in the Santa Terezinha Coalfield, Paraná Basin, Brazil. In order to assess the volumetrics of the coal seams a fourth-order sequence stratigraphic framework of the coal-bearing succession was established based on parasequence boundaries. A 3D geometric model based on data from 36 well logs was developed, and enabled subdivision of the study area into regions with very different CBM potential, due to variable cumulative coal thickness, depths and presence/absence of diabase. Strata of the coal-bearing Rio Bonito Formation were penetrated in well CBM001-ST-RS at a depth of 575.70 to 638.35 m, from which twelve coal seams and carbonaceous shales, ranging in thickness from 0.15 to 1.77 m, were retrieved for analysis. Gas desorption values range from 0.3 to 2.2 cm3/g. Gas composition is dominated by methane (&gt; 94 Vol%). Gas isotopic analyses suggest a mixed biogenic and thermogenic origin. Vitrinite reflectance indicate a rank of high volatile A bituminous coal, with semi-anthracite occurring in contact with igneous rocks. The majority of the samples has vitrinite group contents &gt; 50 Vol%, mineral matter-free basis. Ash yields range from 42.1 to 92.8 wt.%, whereas sulphur contents range from 0.1 to 7.7 wt.%. Volatile matter and calorific values (dry ash-free) range from 37.6 to 79.4 wt.%, and 2352 to 8107 kcal/kg, respectively. Mineral composition of the samples is dominated by quartz and kaolinite, whereas major element analyses show that SiO2 is most abundant. The 3D model allowed volumetric calculation for the coal seams and formed the basis for calculations of gas content and CO2 storage capacity. According to the 3D model the four coal-bearing parasequences of the study area contain a coal volume on the order of 3212 × 10 6 m3 suggesting a resource base of 5.5 × 109 m3 of methane associated with the coal seams and carbonaceous shales of the study area. The methane and carbon dioxide sorption capacities show a high positive correlation with TOC content. The coal seams appear to be undersaturated, since sorption capacity is significantly higher than the desorbed gas volume. The CO2 sorption capacity at mean reservoir pressure was up to 7 times higher than the methane sorption capacity. Based upon sorption capacities and reservoir conditions, a storage potential of 13.8 Gt CO2 in coal seams and carbonaceous shales of the study area is estimated.

Thermodynamics of hydrogen production from urea by steam reforming with and without in situ carbon dioxide sorption

The thermodynamic effects of molar steam to carbon ratio (S:C), of pressure, and of having CaO present on the H2 yield and enthalpy balance of urea steam reforming were investigated. At a S:C of 3 the presence of CaO increased the H2 yield from 2.6 mol H2/mol urea feed at 940 K to 2.9 at 890 K, and decreased the enthalpy of bringing the system to equilibrium. A minimum enthalpy of 180.4 kJ was required to produce 1 mol of H2 at 880 K. This decreased to 94.0 kJ at 660 K with CaO-based CO2 sorption and, when including a regeneration step of the CaCO3 at 1170 K, to 173 kJ at 720 K. The presence of CaO allowed widening the range of viable operation at lower temperature and significantly inhibited carbon formation. The feasibility of producing H2 from renewable urea in a low carbon future is discussed.

One-step fabrication of ZIF-8/polymer composite spheres by a phase inversion method for gas adsorption

This paper reports a phase inversion method for the preparation of macroporous polysulfone (PS) composite spheres through a single orifice spinneret. Surfactant F127 was pre-added in the polymer solution as a surface pore-forming agent, and different amount of zeolitic imidazolate framework-8 (ZIF-8) particles were incorporated to form the ZIF-8/polysulfone (ZIF-8/PS)-composite spheres. ZIF-8 and polymer acted as the adsorbent and binder in the final composite spheres, respectively. The fabrication conditions, such as the types of the surfactant, the amount of the surfactant, and ZIF-8 added in the polymer solution, were investigated. Nitrogen and carbon dioxide sorption analysis indicated the ZIF-8/PS composite spheres had similar properties as the pure ZIF-8 particles, and the active sites of ZIF-8 in the polymer composites were well exposed. The composite spheres exhibited advantages of easy handling and recycling over ZIF-8 particles, and this phase inversion method can be extended to prepare other polymer composite spheres.

Sorption of Pure N2O to Biochars and Other Organic and Inorganic Materials under Anhydrous Conditions

Suppression of nitrous oxide (N2O) emissions from soil is commonly observed after amendment with biochar. The mechanisms accounting for this suppression are not yet understood. One possible contributing mechanism is N2O sorption to biochar. The sorption of N2O and carbon dioxide (CO2) to four biochars was measured in an anhydrous system with pure N2O. The biochar data were compared to those for two activated carbons and other components potentially present in soils-uncharred pine wood and peat-and five inorganic metal oxides with variable surface areas. Langmuir maximum sorption capacities (Qmax) for N2O on the pine wood biochars (generated between 250 and 500 °C) and activated carbons were 17-73 cm(3) g(-1) at 20 °C (median 51 cm(3) g(-1)), with Langmuir affinities (b) of 2-5 atm(-1) (median 3.4 atm(-1)). Both Qmax and b of the charred materials were substantially higher than those for peat, uncharred wood, and metal oxides [Qmax 1-34 cm(3) g(-1) (median 7 cm(3) g(-1)); b 0.4-1.7 atm(-1) (median 0.7 atm(-1))]. This indicates that biochar can bind N2O more strongly than both mineral and organic soil materials. Qmax and b for CO2 were comparable to those for N2O. Modeled sorption coefficients obtained with an independent polyparameter-linear free-energy relationship matched measured data within a factor 2 for mineral surfaces but underestimated by a factor of 5-24 for biochar and carbonaceous surfaces. Isosteric enthalpies of sorption of N2O were mostly between -20 and -30 kJ mol(-1), slightly more exothermic than enthalpies of condensation (-16.1 kJ mol(-1)). Qmax of N2O on biochar (50000-130000 μg g(-1) biochar at 20 °C) exceeded the N2O emission suppressions observed in the literature (range 0.5-960 μg g(-1) biochar; median 16 μg g(-1)) by several orders of magnitude. Thus, the hypothesis could not be falsified that sorption of N2O to biochar is a mechanism of N2O emission suppression.

Enhanced continuum poromechanics to account for adsorption induced swelling of saturated isotropic microporous materials

Abstract Poromechanics offers a consistent theoretical framework for describing the mechanical response of porous solids fully or partially saturated with a fluid phase. When dealing with fully saturated microporous materials, which exhibit pores of the nanometer size, effects due to adsorption and confinement of the fluid molecules in the smallest pores must be accounted for. From the mechanical point of view, these phenomena result into volumetric deformations of the porous solid, the so-called “swelling” phenomenon. The present work investigates how the poromechanical theory may be refined in order to describe such adsorption and confinement induced effects in microporous solids. Poromechanics is revisited in the context of isotropic microporous materials with generic pore size distributions. The new formulation introduces an effective pore pressure, defined as a thermodynamic variable at the representative volume element scale (mesoscale), which is related to the overall mechanical work of the confined fluid. Accounting for the thermodynamic equilibrium of the system, we demonstrate that the effective pore pressure depends on macroscopic variables, such as the bulk fluid pressure, the temperature and the total and excess adsorbed quantity of fluid. As an illustrating example, we apply the model to compute strains and variations of porosity in the case of the methane and carbon dioxide sorption on coal. Agreement with experimental data found in the literature is observed.

Comparison of high-pressure CO2 sorption isotherms on Central Appalachian and San Juan Basin coals

Accurate estimation of carbon dioxide (CO2) sorption capacity of coal is important for planning the CO2 sequestration efforts. In this work, we investigated the sorption and swelling behavior of several Eastern and Western US coal samples from the Central Appalachian Basin and from the San Juan Basin. The CO2 sorption isotherms have been completed at 55°C for wet and dry samples. The role of mineral components in coal, coal swelling, effects of temperature and moisture, and the error propagation have been analyzed. Changes in void volume due to dewatering and other factors such as caging of carbon dioxide molecules in coal matrix were identified among the main factors affecting accuracy of the carbon dioxide sorption isotherms. The (helium) void volume in the sample cells was measured before and after the sorption isotherm experiments and was used to build the volume-corrected data plots.

The Applications of Lithium Zirconium Silicate at High Temperature for the Carbon Dioxide Sorption and Conversion to Syn-gas

The applications of different samples of lithium zirconium silicate contributing to CO2 sorption and conversion of CO2 to syn-gas at high temperatures were investigated. Several samples of lithium zirconium silicate prepared by solid–solid fusion method were calcined in air or nitrogen atmosphere at 900 °C for 3 h. The lithium zirconium silicate samples were characterized by acidity/alkalinity, surface area, XRD pattern, SEM images, and CO2 sorption. The alkalinity and surface area of the samples of lithium zirconium silicate were found to be in the range of 15.1 to 20.0 mmol g−1 and 0.05 to 2.13 m2 g−1, respectively. The temperature profile of CO2 sorption by samples of lithium zirconium silicate was given for the range 100 to 700 °C. The CO2 sorption was found to be in the range of 12.81 to 18.04 wt.% at 550 °C for samples of lithium zirconium silicate with different Li/Zr/Si mole ratios from 1 to 6. The crystalline phases in the samples of the lithium zirconium silicate, Li6Si2O7, ZrSiO4, Li2SiO3, Li2ZrO3, Li4ZrO4, and Li4SiO4 could contribute to CO2 capture. The conversion of CO2 by methane to syn-gas over the lithium silicate samples and PdO (5 wt.%)/Al2O3 at 500 °C with the gas hourly space velocities 6,000, 12,000, and 36,000 mL h−1 g−1 of methane and 6,000 mL h−1 g−1 of CO2 was explored. However, the higher conversion of CO2 to syn-gas was observed at the low gas hourly space velocity of 6,000 mL h−1 g−1 of methane.