Surface Functionalization of Mesoporous Membranes: Impact on Pore Structure and Gas Flow Mechanisms

2020 ◽  
Vol 12 (35) ◽  
pp. 39388-39396
Author(s):  
Benjamin Besser ◽  
Simon Kunze ◽  
Michaela Wilhelm ◽  
Kurosch Rezwan ◽  
Jorg Thöming
Keyword(s):  
Pore Structure ◽  
Surface Functionalization ◽  
Gas Flow ◽  
Flow Mechanisms ◽  
Mesoporous Membranes

An Experimental Investigation of Airfoil Performance in Wet Gas Flow

2008 ◽  
Author(s):  
Trond G. Gru¨ner ◽  
Lars E. Bakken ◽  
Lars Brenne ◽  
Tor Bjo̸rge
Keyword(s):  
Experimental Investigation ◽  
Gas Flow ◽  
Boundary Layer Separation ◽  
Qualitative Description ◽  
Water Mixture ◽  
Surge Margin ◽  
Wet Gas ◽  
Flow Mechanisms ◽  
Wet Condition ◽  
Liquid Mass Flow Rate

Development of wet gas compressors is challenging due to the liquid phase impact on performance. Experimental investigation of airfoil behavior in wet condition contributes to a revised compressor design and increased understanding of multiphase flow mechanisms. The performance of an airfoil was investigated in wet gas flow. An air-water mixture was used as the experimental fluid. The influence of wet gas flow on airfoil performance was investigated at different angles of incidence and gas volume fractions. A qualitative description of the complex physical process observed when liquid is introduced into the flow field is given. Airfoil performance was degraded at increased liquid mass flow rate owing to premature boundary layer separation. The initiation of separation was observed as a local film thickening, followed by increased liquid film fluctuations. A continuity wave was observed surrounding the airfoil, forming a U shape of increased liquid concentration. The wave was initiated by deposited droplets and the formation of secondary droplets. The investigation reveals that compressor operating range, surge and stall margins are affected by the wet gas fluid. Reviewed literature and experiments confirm a reduced stall and surge margin when a compressor is exposed to wet gas. Further investigation will involve sub-scale impeller tests to determine the effects on the performance and stability ranges.

scholarly journals Gas flow mechanisms under the effects of pore structures and permeability characteristics in source rocks of coal measures in Qinshui Basin, China

2017 ◽  
Vol 35 (3) ◽  
pp. 338-355 ◽  
Author(s):  
Xiaowei Hou ◽  
Yanming Zhu ◽  
Shangbin Chen ◽  
Yang Wang
Keyword(s):  
Flow Regime ◽  
Mass Flux ◽  
Gas Flow ◽  
Slip Flow ◽  
Flow Regimes ◽  
Source Rocks ◽  
Cross Sectional ◽  
Direction Parallel ◽  
Permeability Characteristics ◽  
Flow Mechanisms

The gas flow mechanisms in source rocks of coal measures under the effects of the pore structures and permeability characteristics were investigated by field-emission scanning electron microscopy, low-pressure nitrogen gas adsorption, high-pressure mercury intrusion, and pressure pulse decay permeability method. Various flow regimes were distinguished in the pores and fractures of differing scales, and the mass fluxes through the same were calculated using the data obtained by the numerical and experimental investigations. Results indicated that mesopores predominated in shale, while coal contained well-developed mesopores and macropores. In addition, the permeabilities of coal and shale were observed to be significantly anisotropic and highly stress dependent. The cross-sectional area proportions of the pores per unit cross-sectional area of the matrix in the free molecular, transition, and slip flow regimes in shale and coal were determined to be, respectively, 0.2:0.7:0.1 and 0.15:0.6:0.25. In the free molecular and transition flow regimes, the mass flux decreased with increasing reservoir depth, while the reverse was the case in the slip flow regime. Further, in the continuum flow regime, the mass flux was unimodally distributed with respect to the reservoir depth. The total mass flux in coal was greater in the direction perpendicular to the bedding compared to the direction parallel to the bedding, while the reverse was the case in shale. In addition, the continuum flow regime predominated in coal in both the directions perpendicular and parallel to the bedding, but only in the direction parallel to the bedding in shale. This work presents a comprehensive model for the analysis of all the flow regimes in pores and fractures of differing scales, as well as the anisotropy. Findings of the study are meaningful for establishing the coupling accumulation mechanism of the Three Coal Gases and developing a unified exploration and exploitation program.

scholarly journals Petrophysical Characterizations of Shale Gas Reservoirs of the Ranikot Formation in the Lower Indus Basin, Pakistan

2021 ◽  
Vol 3 (2) ◽  
pp. 103-107
Author(s):  
Kazunori Abe ◽  
Nouman Zobby ◽  
Hikari Fujii
Keyword(s):  
Pore Structure ◽  
Pore Size ◽  
Density Functional ◽  
Gas Flow ◽  
Slip Flow ◽  
Indus Basin ◽  
Size Distributions ◽  
Gas Reservoirs ◽  
Lower Indus Basin ◽  
Pore Size Distributions

The complex pore structure with nano-pores of shale gas reservoirs has an impact on the hydrocarbon storage and transport systems. We examined the pore structure of the shales of the Ranikot Formation in the Lower Indus Basin, Pakistan to investigate the full scaled pore size distributions by using a combination of techniques, mercury injection capillary pressure analysis and low pressure gas adsorption methods using N2 and CO2. Isotherm curves obtained N2 and CO2 adsorptions were interpreted using density functional theory analysis for describing the nano-scaled pore size distributions. The pore geometry of the shales was estimated to be slit-type from the isotherm hysteresis loop shape. The pore size distributions determined the density functional theory showed the dominant pore size of below around 10 nm. The Micro-scale effects such as slippage and adsorption/desorption also significantly influence the gas flow in nano-pore structure. The gas flow regimes in shales are classified into four types Darcy flow, slip flow, transition flow, Knudsen flow based on the value of the Knudsen number. Applying the specific reservoir conditions in Ranikot shale and pore size distribution to the Knudsen number, the gas flow regimes of the Ranikot shales were estimated mostly within the transition and slip flow.

scholarly journals Surface Functionalization of Activated Carbon with Phosphonium Ionic Liquid for CO2 Adsorption

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 590 ◽  
Author(s):  
Xiaodong He ◽  
Jiamei Zhu ◽  
Hongmin Wang ◽  
Min Zhou ◽  
Shuangquan Zhang
Keyword(s):  
Ionic Liquid ◽  
Activated Carbon ◽  
Surface Functionalization ◽  
Gas Flow ◽  
Co2 Adsorption ◽  
Breakthrough Curves ◽  
X Ray Diffraction ◽  
Adsorption Selectivity ◽  
Adsorption Behaviors ◽  
Phosphonium Ionic Liquid

Immobilization of phosphonium ionic liquid (IL) onto activated carbon (AC) was synthesized via grafting and impregnated methods, and the modified materials were analyzed via Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction, thermal gravity analysis, scanning electron microscope, pore structure and CO2/N2 adsorption selectivity. The effect of the gas flow rate (100–500 mL/min) and adsorption pressure (0.2–0.6 MPa) on the dynamic adsorption behavior of mixture gas containing 15 vol.% CO2 and 85 vol.% N2 was explained using a breakthrough method. By analyzing the breakthrough curves, the adsorption capacity was determined. The results show that surface functionalization of activated carbon with phosphonium ionic liquid is conducive to improving CO2/N2 selectivity, especially ionic liquid-impregnated film. The different adsorption behaviors of impregnated and grafted adsorbents are observed under various conditions. The grafted AC had better CO2 adsorption and mass transfer due to a lower blockage of pores by ionic liquid.

Laboratory measurement and interpretation of nonlinear gas flow in shale

2015 ◽  
Vol 26 (06) ◽  
pp. 1550063 ◽  
Author(s):  
Yili Kang ◽  
Mingjun Chen ◽  
Xiangchen Li ◽  
Lijun You ◽  
Bin Yang
Keyword(s):  
Pore Pressure ◽  
Gas Flow ◽  
Gas Adsorption ◽  
Slip Flow ◽  
Transition Flow ◽  
Confining Stress ◽  
Slippage Effect ◽  
Longmaxi Shale ◽  
Close Relationship ◽  
Flow Mechanisms

Gas flow mechanisms in shale are urgent to clarify due to the complicated pore structure and low permeability. Core flow experiments were conducted under reservoir net confining stress with samples from the Longmaxi Shale to investigate the characteristics of nonlinear gas flow. Meanwhile, microstructure analyses and gas adsorption experiments are implemented. Experimental results indicate that non-Darcy flow in shale is remarkable and it has a close relationship with pore pressure. It is found that type of gas has a significant influence on permeability measurement and methane is chosen in this work to study the shale gas flow. Gas slippage effect and minimum threshold pressure gradient weaken with the increasing backpressure. It is demonstrated that gas flow regime would be either slip flow or transition flow with certain pore pressure and permeability. Experimental data computations and microstructure analyses confirm that hydraulic radius of flow tubes in shale are mostly less than 100 nm, indicating that there is no micron scale pore or throat which mainly contributes to flow. The results are significant for the study of gas flow in shale, and are beneficial for laboratory investigation of shale permeability.

Dense Gas Flow in Volcanic Ash Soil: Effect of Pore Structure on Density-Driven Flow

2008 ◽  
Vol 72 (2) ◽  
pp. 480-486 ◽  
Author(s):  
Shoichiro Hamamoto ◽  
Takeshi Tokida ◽  
Tsuyoshi Miyazaki ◽  
Masaru Mizoguchi
Keyword(s):  
Pore Structure ◽  
Gas Flow ◽  
Volcanic Ash ◽  
Dense Gas ◽  
Density Driven Flow ◽  
Volcanic Ash Soil

scholarly journals Relationship between pore structure and gas permeability in poplar (Populus deltoides CL.’55/65’) tension wood

2020 ◽  
Vol 77 (3) ◽  
Author(s):  
Yujing Tan ◽  
Jinbo Hu ◽  
Shanshan Chang ◽  
Yuan Wei ◽  
Gonggang Liu ◽  
...  
Keyword(s):  
Pore Structure ◽  
Tension Wood ◽  
Gas Flow ◽  
Populus Deltoides ◽  
Gas Permeability ◽  
Nitrogen Adsorption ◽  
Longitudinal Direction ◽  
High Fiber ◽  
Opposite Wood ◽  
Cell Tissue

Abstract Key message The important anatomical changes in tension wood, e.g., the high fiber ratio and rich mesopores, did not significantly increase the air and nitrogen flow; thus the gas permeability in the longitudinal direction of poplar (Populus deltoidesCL.’55/65′) tension wood is actually affected by the cell tissue macroporous porosity. Context Gas permeability is one of the most important physical properties of wood and is closely related to its internal microstructure, particularly porosity. Tension wood is widespread in woody plants and displays significant structural differences compared with opposite wood. Aims The study was designed to clarify the relationship between pore structure and gas permeability in poplar tension wood. Methods The gas permeability was measured using a self-made device. The meso- and macroporosity characteristics were measured by nitrogen adsorption–desorption and mercury intrusion porosimetry. The flow was simulated using ANSYS Fluent software to illustrate the role of pore structure on permeability. Results The morphological features of vessels have an effect on wood permeability. Compared with tension wood, opposite wood, which has higher vessel ratio, larger cell lumen diameter, and more rich pits, shows stronger gas permeability. Increasing the airflow path will actually reduce the gas permeability. The simulation results are consistent with the experimental results. Conclusion In hardwoods, the gas permeability in the longitudinal direction is mainly dictated by the vessels. The high fiber ratio and rich mesopore in tension wood do not significantly increase gas flow, suggesting the permeability of wood was actually determined by the cell tissue with macroporous porosity. Vessel tissue ratio, length and diameter, and intervessel pit size were found responsible for influencing the permeability in the longitudinal direction.

Sign in / Sign up

Export Citation Format

Share Document