OS5-7 Gas Separation of Mixed Gases by Hydrate Formation after Steam Reforming

2007 ◽  
Vol 2007.12 (0) ◽  
pp. 275-276
Author(s):  
Hiroaki MURAKAMI ◽  
Ryo NOZAWA ◽  
Kazuhiko MURAKAMI ◽  
Hajime ENDOU ◽  
Masahiro OTA
Keyword(s):  
Gas Separation ◽  
Steam Reforming ◽  
Hydrate Formation ◽  
Mixed Gases

Gas Separation of Mixed Gases by Hydrate Formation

2004 ◽  
Vol 2004.9 (0) ◽  
pp. 345-346
Author(s):  
Yoshrnori HASHIMOTO ◽  
Hiroyuki NISHIMOTO ◽  
Masahiro OTA
Keyword(s):  
Gas Separation ◽  
Hydrate Formation ◽  
Mixed Gases

scholarly journals A Molecular Simulation Study of Silica/Polysulfone Mixed Matrix Membrane for Mixed Gas Separation

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2199
Author(s):  
Khadija Asif ◽  
Serene Sow Mun Lock ◽  
Syed Ali Ammar Taqvi ◽  
Norwahyu Jusoh ◽  
Chung Loong Yiin ◽  
...  
Keyword(s):  
Transport Properties ◽  
Molecular Simulation ◽  
Gas Separation ◽  
Membrane Separation ◽  
Gas Transport ◽  
Mixed Matrix ◽  
Mixed Gas ◽  
Gas Transport Properties ◽  
Simulation Results ◽  
Mixed Gases

Polysulfone-based mixed matrix membranes (MMMs) incorporated with silica nanoparticles are a new generation material under ongoing research and development for gas separation. However, the attributes of a better-performing MMM cannot be precisely studied under experimental conditions. Thus, it requires an atomistic scale study to elucidate the separation performance of silica/polysulfone MMMs. As most of the research work and empirical models for gas transport properties have been limited to pure gas, a computational framework for molecular simulation is required to study the mixed gas transport properties in silica/polysulfone MMMs to reflect real membrane separation. In this work, Monte Carlo (MC) and molecular dynamics (MD) simulations were employed to study the solubility and diffusivity of CO2/CH4 with varying gas concentrations (i.e., 30% CO2/CH4, 50% CO2/CH4, and 70% CO2/CH4) and silica content (i.e., 15–30 wt.%). The accuracy of the simulated structures was validated with published literature, followed by the study of the gas transport properties at 308.15 K and 1 atm. Simulation results concluded an increase in the free volume with an increasing weight percentage of silica. It was also found that pure gas consistently exhibited higher gas transport properties when compared to mixed gas conditions. The results also showed a competitive gas transport performance for mixed gases, which is more apparent when CO2 increases. In this context, an increment in the permeation was observed for mixed gas with increasing gas concentrations (i.e., 70% CO2/CH4 > 50% CO2/CH4 > 30% CO2/CH4). The diffusivity, solubility, and permeability of the mixed gases were consistently increasing until 25 wt.%, followed by a decrease for 30 wt.% of silica. An empirical model based on a parallel resistance approach was developed by incorporating mathematical formulations for solubility and permeability. The model results were compared with simulation results to quantify the effect of mixed gas transport, which showed an 18% and 15% percentage error for the permeability and solubility, respectively, in comparison to the simulation data. This study provides a basis for future understanding of MMMs using molecular simulations and modeling techniques for mixed gas conditions that demonstrate real membrane separation.

scholarly journals Experimental Investigation of the Hydrate-Based Gas Separation of Synthetic Flue Gas with 5A Zeolite

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4556
Author(s):  
Xiaoya Zang ◽  
Na Zhang ◽  
Xuebing Zhou ◽  
Lihua Wan ◽  
Deqing Liang
Keyword(s):  
Water Content ◽  
Gas Separation ◽  
Flue Gas ◽  
Gas Adsorption ◽  
Physical Adsorption ◽  
Hydrate Formation ◽  
Co2 Separation ◽  
Type B ◽  
Influence Of Water ◽  
5A Zeolite

Coal combustion flue gas contains CO2, a greenhouse gas and driver of climate change. Therefore, CO2 separation and removal is necessary. Fortunately, 5A zeolites are highly porous and can be used as a CO2 adsorbent. In addition, they act as nuclei for hydrate formation. In this work, a composite technology, based on the physical adsorption of CO2 by 5A zeolite and hydrate-based gas separation, was used to separate CO2/N2 gas mixtures. The influence of water content, temperature, pressure, and particle size on gas adsorption and CO2 separation was studied, revealing that the CO2 separation ability of zeolite particles sized 150–180 μm was better than that of those sized 380–830 μm at 271.2 K and 273.2 K. When the zeolite particles were 150–180 μm (type-B zeolite) with a water content of 35.3%, the gas consumption per mole of water (ngas/nH2O ) reached the maximum, 0.048, and the CO2 separation ratio reached 14.30%. The CO2 molar concentration in the remaining gas phase (xCO2gas) was lowest at 271.2 K in the type-B zeolite system with a water content of 47.62%. Raman analysis revealed that CO2 preferentially occupied the small hydrate cages and there was a competitive relationship between N2 and CO2.

scholarly journals Study on Mass Transfer Characteristics of Hydrate-based Gas Absorber

2021 ◽  
Vol 333 ◽  
pp. 04002
Author(s):  
Shun Takano ◽  
Ryosuke Ezure ◽  
Yusuke Takahashi ◽  
Hiroyuki Komatsu ◽  
Kazuaki Yamagiwa ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Gas Separation ◽  
Bubble Column ◽  
Hydrate Formation ◽  
Continuous Operation ◽  
Gas Absorption ◽  
Volumetric Mass Transfer Coefficient ◽  
Type Apparatus

Hydrated-based gas separation is a method capable of selectively separating and recovering greenhouse gases. Although a conventional hydrate-based gas separation apparatus is a batch or a semi-batch system, continuous operation is preferable to increase the throughput of gas without changing the apparatus volume. Recently, we proposed a flow type apparatus to allow continuous operation of hydrate formation (absorption) and subsequent decomposition (desorption). The aim of this study is to investigate the mass transfer characteristics of the continuous apparatus using the HFC134a-N2 mixed gas system. The volumetric mass transfer coefficient was calculated especially during a steady state of gas absorption. Besides, we compared mass transfer performance between the hydrate-based gas absorber and a conventional bubble column. Sodium dodecyl sulfate was used as a hydrate dispersant. In the flow type apparatus, the gas-liquid contact was good and the hydrate slurry state was observed during hydrate formation. In the surfactant solution, the volumetric mass transfer coefficient increased in comparison with that in water. The volumetric mass transfer coefficient with hydrate was higher than that of the bubble column. These results suggest that hydrate formation improves gas absorption performance.

scholarly journals Hydrate formation as a method for natural gas separation into single compounds: a brief analysis of the process potential

2021 ◽  
Vol 14 (10) ◽  
Author(s):  
Alberto Maria Gambelli ◽  
Federico Rossi
Keyword(s):  
Natural Gas ◽  
Gas Separation ◽  
Hydrate Formation ◽  
Calorific Value ◽  
Process Efficiency ◽  
Gas Reservoirs ◽  
Original Solution ◽  
Gas Treatment ◽  
Thermodynamic Conditions ◽  
Natural Gas Reservoirs

AbstractIn both natural gas and petroleum reservoirs, the extracted gas is not only composed of methane: a variable and significant quantity of other compounds, such as different hydrocarbons (ethane, butane, pentane, propane, etc.), inert gas (nitrogen), and toxic and corrosive molecules (i.e., carbon dioxide and hydrogen sulfide), are present. In order to reach commercial specifications, natural gas has to be treated, in particular for reaching the minimum gross calorific value required and decreasing CO2 and H2S presence under the respective tolerance values. To do this, several different treatments are commonly applied, like inlet separation, sweetening, mercury removal, dehydration, liquid recovery, and, finally, compression for its transportation. Considering the growing demand and the necessity of exploiting also lower quality natural gas reservoirs, in the present paper, an original solution, for performing a gas treatment, is proposed and analyzed. It consists of promoting hydrates formation for both different compounds separation and gas storage. The greatest part of chemicals commonly present in natural gas is capable to form hydrates, but at different thermodynamic conditions than others. Parameters such as the typology of stored compound and the formation process efficiency are mainly related to partial pressure of each element. Here, the present strategy has been explored and the results achievable were shown. In particular, different possible natural gas compositions were taken into account and specifications required for gas commercialization were considered target of the process. Results led to different possibilities of raw gas treatment: in some cases, gas separation led to contemporary CH4 storage into hydrate structures, while, in the presence of different mixture compositions, contaminants were trapped into water cages and methane (and, eventually, other hydrocarbon compounds) remained in the gas phase.

Gas Separation by Clathrate-Hydrate Produced from Mixed Gases

2003 ◽  
Vol 2003.3 (0) ◽  
pp. 363-364
Author(s):  
Hiroyuki NISHIMOTO ◽  
Masahiro OTA ◽  
Hajime ENDOU
Keyword(s):  
Gas Separation ◽  
Clathrate Hydrate ◽  
Mixed Gases

scholarly journals Examination of the Heat Transfer Model in Gas–Liquid–Solid Three Phases in Presence of Gas Hydrate Particle

2021 ◽  
Vol 333 ◽  
pp. 04001
Author(s):  
Ryosuke Ezure ◽  
Yusuke Takahashi ◽  
Shun Takano ◽  
Hiroyuki Komatsu ◽  
Kazuaki Yamagiwa ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Gas Separation ◽  
Gas Hydrate ◽  
Hydrate Formation ◽  
Gaseous Mixture ◽  
Surfactant Solution ◽  
Heat Transfer Model ◽  
Transfer Model ◽  
Efficient Operation ◽  
Simple Assumption

Hydrate-based gas separation is often investigated using batch or semi-batch operations. To increase the throughput of the gas mixture without increasing the apparatus volume, it is preferable to perform a continuous operation of hydrate-based gas separation. Therefore, we proposed a flow-type apparatus for performing continuous formation with passing gaseous mixture and subsequently decomposition with passing gas hydrate particles. Characteristics of multiple fluid and heat and mass transfer of hydrate slurry are essential for the efficient operation of the apparatus. In this study, we focused on heat transfer characteristics in the presence of bubbles in water and surfactant solution. First, an apparent overall heat transfer coefficient under pressure during steady operation of the apparatus was calculated on a simple assumption. Next, to control the hydrate amount and position of hydrate-decomposition and hydrate-formation in the apparatus, we focused on the temperature profile of the inside fluid. A heat transfer model using heat balance of defining heat of hydrate-formation and heat transfer of agitation of fluid was made for hydrate-based gas separation apparatus. To evaluate the validity of the heat transfer model, a calculation value is compared with the experimental value.

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