Role of adsorbent heterogeneity on mixed gas adsorption

1991 ◽  
Vol 30 (5) ◽  
pp. 1032-1039 ◽  
Author(s):  
Shivaji Sircar
Keyword(s):  
Gas Adsorption ◽  
Mixed Gas ◽  
Adsorbent Heterogeneity

Cyclotetrabenzoin Acetate: A Macrocyclic Porous Molecular Crystal for CO2 Separations by Pressure Swing Adsorption

2021 ◽  
Author(s):  
Yao-Ting Wang ◽  
Corie M. McHale ◽  
Xiqu Wang ◽  
Chung-Kai Chang ◽  
Yu-Chun Chuang ◽  
...  
Keyword(s):  
Molecular Crystal ◽  
Pressure Swing Adsorption ◽  
Gas Adsorption ◽  
Close Packing ◽  
Separation Performance ◽  
Mixed Gas ◽  
Water Tolerance ◽  
Pressure Swing ◽  
Breakthrough Experiments ◽  
Group Play

A porous molecular crystal (PMC) assembled by close-packing of macrocyclic cyclotetrabenzoin acetate is an efficient adsorbent for selective CO<sub>2</sub> capture. The 7.1´7.1 Å square pore of PMC and its ester C=O group play important roles in improving its affinity for CO<sub>2</sub> molecules. Thermodynamically, the benzene walls of macrocycle strongly promote CO<sub>2</sub> adsorption via [p···p] interactions at low pressure. In addition, the polar carbonyl groups pointing inward the square channels reduce the size of aperture to a 5.0´5.0 Å square, which offers kinetic selectivity for CO<sub>2</sub> capture. The PMC features water tolerance and high structural stability under vacuum and various gas adsorption conditions, which are rare among intrinsically porous organic molecules. In mixed-gas breakthrough experiments, it exhibits efficient CO<sub>2</sub>/N<sub>2</sub> and CO<sub>2</sub>/CH<sub>4</sub> separations under kinetic flow conditions. Most importantly, the moderate adsorbate–adsorbent interaction allows the PMC to be readily regenerated, and therefore applied to pressure swing adsorption (PSA) processes. The eluted N<sub>2</sub> and CH<sub>4</sub> are obtained with over 99.9% and 99.8% purity, respectively, and the separation performance is stable for 30 cycles. Coupled with its easy synthesis, these properties make cyclotetrabenzoin acetate a promising adsorbent for CO<sub>2</sub> separations from flue and natural gases.

Assessment of surface energetic heterogeneity of synthetic Na- saponites. The role of layer charge

Clay Minerals ◽  
2002 ◽  
Vol 37 (1) ◽  
pp. 39-57 ◽  
Author(s):  
L. J. Michot ◽  
F. Villiéras
Keyword(s):  
Aspect Ratio ◽  
Gas Adsorption ◽  
High Energy ◽  
Layer Charge ◽  
Adsorption Mechanisms ◽  
Energetic Heterogeneity ◽  
Complex Adsorption ◽  
Adsorption Energy Distribution ◽  
Synthetic Saponite

AbstractHigh-resolution gas adsorption techniques were used to analyse the evolution of the aspect ratio and adsorption energy distribution on synthetic saponite samples with increasing layer charge. Using Ar as a gaseous probe, the aspect ratio of the saponite particles can be determined easily by decomposing the derivative adsorption isotherms and taking into account high-energy sites which can be assigned to talc-like ditrigonal cavities. Changes in the shape of the elementary particles are observed for layer charges above 1.30, i.e. when all the ditrigonal cavities contain at least one Al atom substituting for Si. When N2 is used as a probe, high-energy sites that could be wrongly interpreted as micropores on the basis of classical t-plot treatments are observed whatever the layer charge. Using the information obtained from both Ar and N2, schemes for describing adsorption can be proposed for all layer charges and suggest complex adsorption mechanisms for charged clay minerals.

Critical role of water stability in metal–organic frameworks and advanced modification strategies for the extension of their applicability

2020 ◽  
Vol 7 (5) ◽  
pp. 1319-1347 ◽  
Author(s):  
Botao Liu ◽  
Kumar Vikrant ◽  
Ki-Hyun Kim ◽  
Vanish Kumar ◽  
Suresh Kumar Kailasa
Keyword(s):  
Drug Delivery ◽  
Water Purification ◽  
Gas Adsorption ◽  
Critical Role ◽  
Metal Organic Frameworks ◽  
Water Stability ◽  
Metal Organic

Metal–organic frameworks (MOFs) are well known for their versatile applications in diverse fields (e.g., gas adsorption, water purification, sensing, drug delivery, and catalysis).

The adsorbate-adsorbate association model in mixed gas adsorption on homogeneous solid surfaces

1980 ◽  
Vol 69 (3) ◽  
pp. 369-378 ◽  
Author(s):  
M. Borówko ◽  
M. Jaroniec ◽  
W. Rudziński
Keyword(s):  
Gas Adsorption ◽  
Solid Surfaces ◽  
Association Model ◽  
Mixed Gas

MIXED-GAS ADSORPTION ON HETEROGENEOUS SUBSTRATES IN THE PRESENCE OF LATERAL AD-AD INTERACTIONS

2003 ◽  
Author(s):  
A. J. RAMIREZ-PASTOR ◽  
F. M. BULNES ◽  
J. L. RICCARDO
Keyword(s):  
Gas Adsorption ◽  
Mixed Gas

Mixed-gas model for predicting decompression sickness in rats

2000 ◽  
Vol 89 (6) ◽  
pp. 2107-2116 ◽  
Author(s):  
R. S. Lillo ◽  
E. C. Parker
Keyword(s):  
Animal Species ◽  
Decompression Sickness ◽  
Mixed Gas ◽  
Increased Risk ◽  
New Findings ◽  
Model Predictions ◽  
Future Evaluation ◽  
Different Gases ◽  
Random Scatter

A mixed-gas model for rats was developed to further explore the role of different gases in decompression and to provide a global model for possible future evaluation of its usefulness for human prediction. A Hill-equation dose-response model was fitted to over 5,000 rat dives by using the technique of maximum likelihood. These dives used various mixtures of He, N2, Ar, and O2 and had times at depth up to 2 h and varied decompression profiles. Results supported past findings, including 1) differences among the gases in decompression risk (He < N2 < Ar) and exchange rate (He > Ar ≈ N2), 2) significant decompression risk of O2, and 3) increased risk of decompression sickness with heavier animals. New findings included asymmetrical gas exchange with gas washout often unexpectedly faster than uptake. Model success was demonstrated by the relatively small errors (and their random scatter) between model predictions and actual incidences. This mixed-gas model for prediction of decompression sickness in rats is the first such model for any animal species that covers such a broad range of gas mixtures and dive profiles.

Modelling of Mixed-Gas Adsorption and Diffusion in Coalbed Reservoirs

2008 ◽  
Author(s):  
Ji-Quan Shi ◽  
Sevket Durucan
Keyword(s):  
Gas Adsorption ◽  
Mixed Gas ◽  
And Diffusion

Mixed-gas adsorption

AIChE Journal ◽  
2001 ◽  
Vol 47 (5) ◽  
pp. 1141-1159 ◽  
Author(s):  
Flor R. Siperstein ◽  
Alan L. Myers
Keyword(s):  
Gas Adsorption ◽  
Mixed Gas
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