scholarly journals Thermodynamics of Methane Adsorption on Copper HKUST-1 at Low Pressure

2015 ◽  
Vol 6 (13) ◽  
pp. 2439-2443 ◽  
Author(s):  
Di Wu ◽  
Xiaofeng Guo ◽  
Hui Sun ◽  
Alexandra Navrotsky
Keyword(s):  
Low Pressure ◽  
Methane Adsorption

scholarly journals Effects of Pore Structures of Different Maceral Compositions on Methane Adsorption and Diffusion in Anthracite

2019 ◽  
Vol 9 (23) ◽  
pp. 5130 ◽  
Author(s):  
Jincheng Zhao ◽  
Yong Qin ◽  
Jian Shen ◽  
Binyang Zhou ◽  
Chao Li ◽  
...  
Keyword(s):  
Coalbed Methane ◽  
Pore Diameter ◽  
Fractal Theory ◽  
Effective Diffusion ◽  
Low Pressure ◽  
Methane Adsorption ◽  
Isothermal Adsorption ◽  
Diffusion Capacity ◽  
Pore Structures ◽  
Study Results

The pore structure of coal reservoirs is the main factor influencing the adsorption–diffusion rates of coalbed methane. Mercury intrusion porosimetry (MIP), low-pressure nitrogen adsorption (LP-NA), low-pressure carbon dioxide adsorption (LP-CA), and isothermal adsorption experiments with different macerals were performed to characterize the comprehensive pore distribution and methane adsorption–diffusion of coal. On the basis of the fractal theory, the pore structures determined through MIP and LP-NA can be combined at a pore diameter of 100 nm to achieve a comprehensive pore structural splicing of MIP, LP-NA, and LP-CA. Macro–mesopores and micro-transitional pores had average fractal dimensions of 2.48 and 2.18, respectively. The Langmuir volume (VL) and effective diffusion coefficients (De) varied from 31.55 to 38.63 cm3/g and from 1.42 to 2.88 × 10−5 s−1, respectively. The study results showed that for super-micropores, a higher vitrinite content led to a larger specific surface area (SSA) and stronger adsorption capacity but also to a weaker diffusion capacity. The larger the average pore diameter (APD) of micro-transitional pores, the stronger the diffusion capacity. The diffusion capacity may be controlled by the APD of micro-transitional pores.

Using Low-Pressure Methane Adsorption Isotherms for Higher-Throughput Screening of Methane Storage Materials

2020 ◽  
Vol 12 (36) ◽  
pp. 40318-40327
Author(s):  
Kyle J. Korman ◽  
Gerald E. Decker ◽  
Michael R. Dworzak ◽  
Meaghan M. Deegan ◽  
Alexandra M. Antonio ◽  
...  
Keyword(s):  
Adsorption Isotherms ◽  
Low Pressure ◽  
Methane Adsorption ◽  
Methane Storage ◽  
Storage Materials

scholarly journals Isothermal characteristics of methane adsorption and changes in the pore structure before and after methane adsorption with high-rank coal

2020 ◽  
Vol 38 (5) ◽  
pp. 1409-1427 ◽  
Author(s):  
Teng Li ◽  
Caifang Wu ◽  
Ziwei Wang
Keyword(s):  
Pore Structure ◽  
Adsorption Capacity ◽  
Low Pressure ◽  
Methane Adsorption ◽  
High Rank ◽  
Excess Adsorption ◽  
Before And After ◽  
Test Pressure ◽  
Isothermal Measurement ◽  
Isothermal Characteristics

The pore structure is an essential factor that influences the isothermal characteristics of methane adsorption of coal, and the pore structure is altered after methane adsorption. In this study, a high-rank coal sample was investigated via methane adsorption isothermal measurement, and changes in the pore structure were studied using low-pressure N2 adsorption and low-pressure CO2 adsorption before and after the methane adsorption. The excess adsorption capacity exhibits a rapid increase at low pressure, reaching a maximum when the test pressure is approximately 8 MPa. Following that, the excess adsorption capacity of the high-rank coal tends to decrease. After the methane adsorption, the pore volume and specific surface area of the micro-, meso-, and macropores increase as compared to those before the methane adsorption, especially for micropores with apertures greater than 0.8 nm and mesopores with apertures below 10 nm. This is mainly caused by high pressure in the methane adsorption, indicating a pressure effect on the pore structure after the methane adsorption. After the methane adsorption, the ratio of pores with various sizes in the high-rank coal is enhanced, but the connectivity for meso- and macropores presents a slight decrease.

scholarly journals Effects of Pore Structure of Different Rank Coals on Methane Adsorption Heat

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1971
Author(s):  
Haijian Li ◽  
Shengcheng Wang ◽  
Qiang Zeng ◽  
Jianhong Kang ◽  
Weiming Guan ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Low Pressure ◽  
Methane Adsorption ◽  
Adsorption Heat ◽  
Maximum Adsorption Capacity

Adsorption thermodynamic characteristics are an important part of the methane adsorption mechanism, and are useful for understanding the energy transmission mechanism of coalbed methane (CBM) migration in coal reservoirs. To study the effect of coal pore characteristics on methane adsorption heat, five different types of rank coals were used for low-pressure nitrogen, low-pressure carbon dioxide, and methane adsorption experiments. Pore structure and adsorption parameters, including maximum adsorption capacity and adsorption heat, were obtained for five coal samples, and their relationships were investigated. The results show that the low-pressure nitrogen adsorption method can measure pores within 1.7–300 nm, while the low-pressure carbon dioxide adsorption method can measure micropores within 0.38–1.14 nm. For the five coal samples, comprehensive pore structure parameters were obtained by combining the results of the low-pressure nitrogen and carbon dioxide adsorption experiments. The comprehensive results show that micropores contribute the most to the specific surface area of anthracite, lean coal, fat coal, and lignite, while mesopores contribute the most to the specific surface area of coking coal. Mesopores contribute the most to the pore volume of the five coal samples. The maximum adsorption capacity has a significant positive correlation with the specific surface area and pore volume of micropores less than 2 nm, indicating that methane is mainly adsorbed on the surface of micropores, and can also fill the micropores. The adsorption heat has a significant positive correlation with the specific surface area and pore volume of micropores within 0.38–0.76 nm, indicating that micropores in this range play a major role in determining the methane adsorption heat.

Effects of Electrical Discharges in Low Pressure Gases on the Morphology of Polyethylene Crystals

1974 ◽  
Vol 32 ◽  
pp. 544-545
Author(s):  
L.H. Bolz ◽  
D.H. Reneker
Keyword(s):  
Power Distribution ◽  
Electrical Discharge ◽  
Dielectric Breakdown ◽  
Ionic Species ◽  
Low Pressure ◽  
Polymer Surfaces ◽  
Electrical Discharges ◽  
Adhesive Bonds ◽  
Power Distribution Lines ◽  
Modification Of The Surface

The attack, on the surface of a polymer, by the atomic, molecular and ionic species that are created in a low pressure electrical discharge in a gas is interesting because: 1) significant interior morphological features may be revealed, 2) dielectric breakdown of polymeric insulation on high voltage power distribution lines involves the attack on the polymer of such species created in a corona discharge, 3) adhesive bonds formed between polymer surfaces subjected to such SDecies are much stronger than bonds between untreated surfaces, 4) the chemical modification of the surface creates a reactive surface to which a thin layer of another polymer may be bonded by glow discharge polymerization.

Field ion microscopy

1988 ◽  
Vol 46 ◽  
pp. 434-435
Author(s):  
Gert Ehrlich
Keyword(s):  
Low Temperature ◽  
Sample Surface ◽  
Low Pressure ◽  
Radius Of Curvature ◽  
Field Ion Microscopy ◽  
Phosphor Screen ◽  
Ion Microscopy ◽  
Field Ion Microscope

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.

Low pressure improves ink jets

Nature ◽  
2005 ◽  
Author(s):  
Philip Ball
Keyword(s):  
Low Pressure
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