scholarly journals Molecular Investigation of CO2/CH4 Competitive Adsorption and Confinement in Realistic Shale Kerogen

Nanomaterials ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1646 ◽  
Author(s):  
Wenning Zhou ◽  
Zhe Zhang ◽  
Haobo Wang ◽  
Xu Yang

The adsorption behavior and the mechanism of a CO2/CH4 mixture in shale organic matter play significant roles to predict the carbon dioxide sequestration with enhanced gas recovery (CS-EGR) in shale reservoirs. In the present work, the adsorption performance and the mechanism of a CO2/CH4 binary mixture in realistic shale kerogen were explored by employing grand canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations. Specifically, the effects of shale organic type and maturity, temperature, pressure, and moisture content on pure CH4 and the competitive adsorption performance of a CO2/CH4 mixture were investigated. It was found that pressure and temperature have a significant influence on both the adsorption capacity and the selectivity of CO2/CH4. The simulated results also show that the adsorption capacities of CO2/CH4 increase with the maturity level of kerogen. Type II-D kerogen exhibits an obvious superiority in the adsorption capacity of CH4 and CO2 compared with other type II kerogen. In addition, the adsorption capacities of CO2 and CH4 are significantly suppressed in moist kerogen due to the strong adsorption strength of H2O molecules on the kerogen surface. Furthermore, to characterize realistic kerogen pore structure, a slit-like kerogen nanopore was constructed. It was observed that the kerogen nanopore plays an important role in determining the potential of CO2 subsurface sequestration in shale reservoirs. With the increase in nanopore size, a transition of the dominated gas adsorption mechanism from micropore filling to monolayer adsorption on the surface due to confinement effects was found. The results obtained in this study could be helpful to estimate original gas-in-place and evaluate carbon dioxide sequestration capacity in a shale matrix.

2018 ◽  
Author(s):  
Jaya Prakash Madda ◽  
Pilli Govindaiah ◽  
Sushant Kumar Jena ◽  
Sabbhavat Krishna ◽  
Rupak Kishor

<p>Covalent organic Imine polymers with intrinsic meso-porosity were synthesized by condensation reaction between 4,4-diamino diphenyl methane and (para/meta/ortho)-phthaladehyde. Even though these polymers were synthesized from precursors of bis-bis covalent link mode, the bulk materials were micrometer size particles with intrinsic mesoporous enables nitrogen as well as carbon dioxide adsorption in the void spaces. These polymers were showed stability up to 260<sup>o</sup> centigrade. Nitrogen gas adsorption capacity up to 250 cc/g in the ambient pressure was observed with type III adsorption characteristic nature. Carbon dioxide adsorption experiments reveal the possible terminal amine functional group to carbamate with CO<sub>2</sub> gas molecule to the polymers. One of the imine polymers, COP-3 showed more carbon dioxide sorption capacity and isosteric heat of adsorption (Q<sub>st</sub>) than COP-1 and COP-2 at 273 K even though COP-3 had lower porosity for nitrogen gas than COP-1 and COP-2. We explained the trends in gas adsorption capacities and Qst values as a consequence of the intra molecular interactions confirmed by Density Functional Theory computational experiments on small molecular fragments.</p>


2012 ◽  
Vol 189 ◽  
pp. 69-74
Author(s):  
Wei Hu ◽  
Zhen Zhang ◽  
Hui Yun Liu ◽  
Ru Wang

The adsorption behaviors of V(V) and Mo(VI) on the collagen fiber immobilized bayberry tannin (IBT), a new kind of adsorption, were investigated. It was found that at 323K, pH=2.0, the adsorption capacities of V(V) on 0.100g adsorbent was 1.03mmol/g in 100ml of 1.960mmol/L V(V) solution, and that of Mo(VI) was 0.86mmol/g at 323K, pH=4.0, with 100ml of 1.042 mmol/L Mo(VI) solution. The effect of pH on the adsorption capacity of V(V) and Mo(VI) was conspicuous. The adsorption capacity of Mo(VI) decreased with pH increasing, and the maximal adsorption capacity of V(V) was observed at pH4.0. Langmuir equation was used for the description of adsorption isotherms of V(V), while Freundlich equation could be well described that of Mo(VI). The adsorption kinetics of V(V) and Mo(VI) can be well described by the pseudo-second-order-rate model and the adsorption capacities calculated by this model are very close to those experimentally determined. The adsorbent can be regenerated by using 0.1mol/L HCl and 0.02mol/L EDTA in tune as desorption agent after the adsorption of V(V) and Mo(VI). In the desorption process V(V) and Mo(VI) were utilized respectively. These facts implies that the adsorbent can be used for the separation of V(V) and Mo(VI) in aqueous.


2018 ◽  
Author(s):  
Jaya Prakash Madda ◽  
Pilli Govindaiah ◽  
Sushant Kumar Jena ◽  
Sabbhavat Krishna ◽  
Rupak Kishor

<p>Covalent organic Imine polymers with intrinsic meso-porosity were synthesized by condensation reaction between 4,4-diamino diphenyl methane and (para/meta/ortho)-phthaladehyde. Even though these polymers were synthesized from precursors of bis-bis covalent link mode, the bulk materials were micrometer size particles with intrinsic mesoporous enables nitrogen as well as carbon dioxide adsorption in the void spaces. These polymers were showed stability up to 260<sup>o</sup> centigrade. Nitrogen gas adsorption capacity up to 250 cc/g in the ambient pressure was observed with type III adsorption characteristic nature. Carbon dioxide adsorption experiments reveal the possible terminal amine functional group to carbamate with CO<sub>2</sub> gas molecule to the polymers. One of the imine polymers, COP-3 showed more carbon dioxide sorption capacity and isosteric heat of adsorption (Q<sub>st</sub>) than COP-1 and COP-2 at 273 K even though COP-3 had lower porosity for nitrogen gas than COP-1 and COP-2. We explained the trends in gas adsorption capacities and Qst values as a consequence of the intra molecular interactions confirmed by Density Functional Theory computational experiments on small molecular fragments.</p>


Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3136 ◽  
Author(s):  
Deneb Peredo-Mancilla ◽  
Imen Ghouma ◽  
Cecile Hort ◽  
Camelia Matei Ghimbeu ◽  
Mejdi Jeguirim ◽  
...  

The aim of the present work is to study the effect of different activation methods for the production of a biomass-based activated carbon on the CO 2 and CH 4 adsorption. The influence of the activation method on the adsorption uptake was studied using three activated carbons obtained by different activation methods (H 3 PO 4 chemical activation and H 2 O and CO 2 physical activation) of olive stones. Methane and carbon dioxide pure gas adsorption experiments were carried out at two working temperatures (303.15 and 323.15 K). The influence of the activation method on the adsorption uptake was studied in terms of both textural properties and surface chemistry. For the three adsorbents, the CO 2 adsorption was more important than that of CH 4 . The chemically-activated carbon presented a higher specific surface area and micropore volume, which led to a higher adsorption capacity of both CO 2 and CH 4 . For methane adsorption, the presence of mesopores facilitated the diffusion of the gas molecules into the micropores. In the case of carbon dioxide adsorption, the presence of more oxygen groups on the water vapor-activated carbon enhanced its adsorption capacity.


2010 ◽  
Vol 156-157 ◽  
pp. 900-907 ◽  
Author(s):  
Hong Yu Wang ◽  
Hui Fei Huang

The individual and competitive adsorption capacities of Pb2+, Cu2+ and Zn2+ on clinoptilolite and polymeric Al/Fe modified clinoptilolite were studied. In single systems, adsorption capacity of Pb2+ exceeded that of Cu2+ and Zn2+, and the adsorption capacities of Pb2+, Cu2+ and Zn2+ by polymeric Al/Fe modified clinoptilolite were greater than clinoptilolite. In binary isometric competition adsorption, adsorption capacities of Pb2+, Cu2+ and Zn2+ by clinoptilolite and polymeric Al/Fe modified clinoptilolite decreased compared with single systems. In binary non -isometric competition adsorption, adsorption of Zn2+ from solutions containing a fixed Zn2+ concentration was severely depressed (34%, 26% by clinoptilolite and polymeric Al/Fe (PAFC) modified clinoptilolite, respectively) by increasing the concentration of Cu2+ in the solution, but inverting the roles of Cu2+ and Zn2+ caused only a relatively minor reduction in adsorption of Cu2+. What,s more in other non-equal competition binary systems, the effect of metal adsorption was little. In general, the strength of adsorption followed the order of Pb2+ > Cu2+ > Zn2+ and the order of PAFC modified clinoptilolite > clinoptilolite.


2013 ◽  
Vol 594-595 ◽  
pp. 240-244
Author(s):  
Nor Adilla Rashidi ◽  
Suzana Yusup ◽  
Azry Borhan

The objective of this research is to synthesize the microporous activated carbon and test its applicability for CO2gas capture. In this study, coconut shell-based and commercial activated carbon is used as the solid adsorbent. Based on the findings, it shows that the gas adsorption capacity is correlated to the total surface area of the materials. In addition, reduction in the adsorption capacity with respect to temperature proves that the physisorption process is dominant. Higher carbon dioxide (CO2) adsorption capacity in comparison to nitrogen (N2) capacity contributes to higher CO2/N2selectivity, and confirms its applicability in the post-combustion process. Utilization of abundance agricultural wastes and one-step physical activation process is attractive as it promotes a cleaner pathway for activated carbon production, and simultaneously, reduces the total operating cost.


Author(s):  
Hanna Abbo ◽  
Marvin Piet ◽  
Salam Titinchi ◽  
Wilhelm Schwieger ◽  
Olav Bolland

Amine-functionalized mesoporous silica has attracted much attention as a promising chemical sorbent for capturing carbon dioxide. It has the combination of several features viz., high adsorption capacity, high selectivity toward CO2, fast kinetics, mild conditions for desorption and should be stable under operating conditions. In this study, a chemical grafting route has been developed to synthesize mesoporous adsorbents with amines functionalization for CO2 capture. The initial silylation step was achieved by grafting of different silane linkers (3-aminopropyl)-trimethoxysilane (APS) and 3-chloropropyl)-trimethoxysilane (CPS) via direct condensation and hydrolysis reaction. After silylation the CPS-supports was reacted with tris(2-aminoethyl)amine (TREN) to introduce the amine group to increase the adsorptive capabilities for these sorbents. The synthesized sorbents were characterized by N2 adsorption/desorption, XRD, FTIR and HR-SEM. The adsorption capacities of the modified solid sorbents show a significant enhancement in their adsorption capacity by 3–4 times higher than that of the parent materials which indicate the affirmative impact of amines for CO2 adsorption after grafting.


2019 ◽  
Vol 48 (47) ◽  
pp. 17612-17619 ◽  
Author(s):  
Guangbo Wang ◽  
Yuliia Onyshchenko ◽  
Nathalie De Geyter ◽  
Rino Morent ◽  
Karen Leus ◽  
...  

Herein, we report the construction of a set of fluorinated microporous covalent triazine frameworks (FCTFs) with appropriate CO2-philic functionalities (N and F) and high porosities for effective gas adsorption and separation.


2005 ◽  
Vol 23 (3) ◽  
pp. 235-244 ◽  
Author(s):  
Lu Zhaoyang ◽  
Long Chao ◽  
Li Aimin ◽  
Jiang Zhenmao ◽  
Liu Wei ◽  
...  

A non-ionic polymer adsorbent (NPA) and its aminated polymeric adsorbent (APA) were prepared and characterized towards adsorption from aqueous solution. Two adsorbates, Reactive Brilliant Blue XBR and 2,4-diaminobenzene sulphonic acid (ABSA), were chosen as adsorbates for competitive adsorption from single-solute solution and binary-solute systems onto the two adsorbents prepared. The results showed that APA, the polymer obtained after amination, exhibited a higher adsorption capacity than NPA towards XBR from the single-solute solution. However, in binary-solute solution adsorption, the presence of ABSA reduced the adsorption capacity towards XBR due to direct competition between XBR and ABSA for the same adsorption sites. This resulted in similar adsorption capacities towards XBR for NPA and APA. Moreover, the adsorption selectivity coefficients obtained for XBR onto ABSA in simultaneous adsorption tests suggested that NPA exhibited more favourable adsorption properties towards the adsorption of XBR from binary-solute systems than APA.


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