Experimental Study of Hydrate Crystal Growth from Methane, Carbon Dioxide, and Methane + Propane Mixtures

1998 ◽  
Vol 12 (2) ◽  
pp. 212-215 ◽  
Author(s):  
S.-Y. Lee ◽  
E. McGregor ◽  
G. D. Holder
Keyword(s):  
Carbon Dioxide ◽  
Experimental Study ◽  
Crystal Growth ◽  
Hydrate Crystal ◽  
Methane Carbon

scholarly journals Crystal growth of clathrate hydrates formed with methane + carbon dioxide mixed gas at the gas/liquid interface and in liquid water

2015 ◽  
Vol 39 (11) ◽  
pp. 8254-8262 ◽  
Author(s):  
Hiroki Ueno ◽  
Hotaka Akiba ◽  
Satoru Akatsu ◽  
Ryo Ohmura
Keyword(s):  
Carbon Dioxide ◽  
Crystal Growth ◽  
Liquid Water ◽  
Liquid Interface ◽  
Clathrate Hydrates ◽  
Mixed Gas ◽  
Hydrate Crystal ◽  
Methane Carbon

Observations of CH4 + CO2 hydrate crystal growth formed at the gas/liquid interface and in liquid water were made.

scholarly journals Conversion of Agricultural Waste (Maize) into Energy using Biogas Technology

2019 ◽  
Author(s):  
Roksana Aftab Ruhi ◽  
Nusrat Jahan Methela ◽  
Abul Khayer ◽  
Fatiha Sultana Eti ◽  
DR. Chayan Kumer Saha
Keyword(s):  
Carbon Dioxide ◽  
Experimental Study ◽  
Agricultural Waste ◽  
Point Of View ◽  
Maize Silage ◽  
Biogas Yield ◽  
Biogas Productivity ◽  
Mesophilic Conditions ◽  
Biogas Technology ◽  
Methane Carbon

The aim of the study was to examine the biogas and methane yield of maize silage, a wastes in agricultural point of view and compare it to the biogas productivity of commonly used mixture of maize silage and mixed fodder with water. The experimental study was carried out into 2 parts. Firstly, the batch experiment was conducted in Mesophilic conditions (35°C), at five different hydraulic retention times (HRT): 6 DAT, 11 DAT 20 DAT 29 DAT and 41 DAT. The results revealed that maize silage was generated the highest biogas yield of 537 mL /241 mL at the HRT of 6days /41 days. Mixed fodder produced the highest biogas yield of 421 mL at the HRT of 6th days and the lowest one was 252 mL at the HRT of 20th days. Finally, the methane, carbon dioxide and hydrogen sulphide of biogas produced from maize silage and mixed fodder were analyzed using a gas chromatography. The results shown that biogas from maize silage precedes the gas less than the mixed fodder. In the field level experiment proved that from mixed fodder produced gas which would be enough for 7 member’s family used 3 months for the purpose of their cooking.

scholarly journals Mechanisms, Growth Rates, and Morphologies of Gas Hydrates of Carbon Dioxide, Methane, and Their Mixtures

Methane ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 2-23
Author(s):  
Camilo Martinez ◽  
Juan F. Sandoval ◽  
Nathalia Ortiz ◽  
Sebastian Ovalle ◽  
Juan G. Beltran
Keyword(s):  
Carbon Dioxide ◽  
Crystal Growth ◽  
Growth Mechanism ◽  
Gas Hydrates ◽  
Growth Rates ◽  
Driving Forces ◽  
Interesting Phenomenon ◽  
Euhedral Crystal ◽  
Partial Dissociation ◽  
Methane Carbon

Mechanisms of growth and dissociation, growth rates, and morphology of gas hydrates of methane, carbon dioxide, and two CH4:CO2 mixtures (80:20 and 30:70 nominal concentration) were studied using using high resolution images and very precise temperature control. Subcooling and a recently proposed mass transfer-based driving force were used to analyze the results. When crystal growth rates did not exceed 0.01 mm/s, all systems showed faceted, euhedral crystal habits at low driving forces. At higher driving forces and growth rates, morphologies were different for all systems. These results solve apparent contradictions in literature about the morphology of hydrates of methane, carbon dioxide, and their mixtures. Differences in the growth mechanism of methane-rich and carbon dioxide-rich hydrates were elucidated. It was also shown that hydrate growth of methane, carbon dioxide, and their mixtures proceed via partial dissociation of the growing crystal. Temperature gradients were used to dissociate hydrates at specific locations, which revealed a most interesting phenomenon: On dissociation, carbon dioxide-rich hydrates propagated onto the bare substrate while drawing water from the opposite side of the sample. Furthermore, it was shown that an abrupt change in morphology common to all systems could be correlated to a change in the slope of growth rate data. This change in morphology was explained by a shift in the crystal growth mechanism.

Alkyl-chain disorder in tetraisohexylammonium bromide

2012 ◽  
Vol 68 (4) ◽  
pp. o152-o155 ◽  
Author(s):  
Malcolm A. Kelland ◽  
Amber L. Thompson
Keyword(s):  
Crystal Structure ◽  
Crystal Growth ◽  
Alkyl Chain ◽  
Growth Inhibitor ◽  
Ammonium Cation ◽  
Asymmetric Unit ◽  
Bromide Anion ◽  
Alkyl Chains ◽  
Hydrate Crystal ◽  
Structure Ii Clathrate Hydrate

Tetraisohexylammonium bromide [systematic name: tetrakis(4-methylpentyl)azanium bromide], C24H52N+·Br−, is a powerful structure II clathrate hydrate crystal-growth inhibitor. The crystal structure, in the space groupP3221, contains one ammonium cation and one bromide anion in the asymmetric unit, both on general positions. At 100 K, the ammonium cation exhibits one ordered isohexyl chain and three disordered isohexyl chains. At 250 K, all four isohexyl chains are disordered. In an effort to reduce the disorder in the alkyl chains, the crystal was thermally cycled, but the disorder remained, indicating that it is dynamic in nature.

scholarly journals Local structure and distortions of mixed methane-carbon dioxide hydrates

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Bernadette R. Cladek ◽  
S. Michelle Everett ◽  
Marshall T. McDonnell ◽  
Matthew G. Tucker ◽  
David J. Keffer ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Exchange Process ◽  
Carbon Dioxide Sequestration ◽  
Distribution Functions ◽  
Atomic Scale ◽  
Mixed Gas ◽  
Pure Compounds ◽  
Dynamics Simulations ◽  
Pair Distribution Functions ◽  
Methane Carbon

AbstractA vast source of methane is found in gas hydrate deposits, which form naturally dispersed throughout ocean sediments and arctic permafrost. Methane may be obtained from hydrates by exchange with hydrocarbon byproduct carbon dioxide. It is imperative for the development of safe methane extraction and carbon dioxide sequestration to understand how methane and carbon dioxide co-occupy the same hydrate structure. Pair distribution functions (PDFs) provide atomic-scale structural insight into intermolecular interactions in methane and carbon dioxide hydrates. We present experimental neutron PDFs of methane, carbon dioxide and mixed methane-carbon dioxide hydrates at 10 K analyzed with complementing classical molecular dynamics simulations and Reverse Monte Carlo fitting. Mixed hydrate, which forms during the exchange process, is more locally disordered than methane or carbon dioxide hydrates. The behavior of mixed gas species cannot be interpolated from properties of pure compounds, and PDF measurements provide important understanding of how the guest composition impacts overall order in the hydrate structure.

Sign in / Sign up

Export Citation Format

Share Document