The Experts below are selected from a list of 291 Experts worldwide ranked by ideXlab platform
Yoshinori Kawase - One of the best experts on this subject based on the ideXlab platform.
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dynamic simulation of multicomponent gas separation by hollow fiber membrane module nonideal Mixing flows in permeate and residue sides using the tanks in series model
Separation and Purification Technology, 2011Co-Authors: Takashi Katoh, Hidemi Yoshikawa, Masahiro Tokumura, Yoshinori KawaseAbstract:A new simulation model for the dynamic performance of gas separation membrane modules is presented. In order to take account of nonideal Mixing flows in permeate and residue sides a tanks-in-series model is utilized. As a stable computational scheme, the relaxation method is applied to solve the governing ordinary differential equations for transport across the membrane, mass balance and pressure distributions in a hollow-fiber membrane module. The proposed simulation model and scheme are validated using the experimental data and simulation results hydrogen gas separation and air separation in the literature. Using the proposed simulation model and scheme the dynamic performance of membrane gas separation processes, hydrogen recovery process and two-stage methane separation process with residue recycle, is examined by varying the operating conditions, i.e., the bulk Mixing degree (Perfect Mixing, plug flow and intermediate Mixing), pressure drop and recycle ratio. The computational results indicate that effect of Mixing degree in the feed side is more significant as compared with that in the permeate side and less Mixing in the feed side results in higher performance. The retentate recycle is found to improve methane recovery efficiency. The proposed simulation model considering nonideal Mixing in the membrane module provides more reliable examination of unsteady-state behaviors of hollow-fiber membrane gas separation modules.
F. Dupret - One of the best experts on this subject based on the ideXlab platform.
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Non-isothermal simulation of the resin transfer moulding press
Composites Part A: Applied Science and Manufacturing, 1998Co-Authors: A. Couniot, F. DupretAbstract:The resin transfer moulding (RTM) of thin components is investigated by means of numerical simulation. The effect of mechanical dispersion in the gapwise direction is taken into account in the energy and species balances, while no Mixing is considered along the midsurface. In a first model, incomplete Mixing is considered in the gap, while Perfect Mixing is assumed in a second model. Several examples are analysed, which highlight the effect of mechanical dispersion on the general heat transfer. (C) 1997 Elsevier Science Limited
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Non-isothermal simulation of the resin transfer moulding process
Composites Part A: Applied Science and Manufacturing, 1998Co-Authors: O. Mal, A. Couniot, F. DupretAbstract:The resin transfer moulding (RTM) of thin components is investigated by means of numerical simulation. The effect of mechanical dispersion in the gapwise direction is taken into account in the energy and species balances, while no Mixing is considered along the midsurface. In a first model, incomplete Mixing is considered in the gap, while Perfect Mixing is assumed in a second model. Several examples are analysed, which highlight the effect of mechanical dispersion on the general heat transfer. © 1997 Elsevier Science Limited.
Kang Li - One of the best experts on this subject based on the ideXlab platform.
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Use of an internally staged permeator in the enrichment of methane from biogas
Journal of Membrane Science, 1993Co-Authors: Kang LiAbstract:An internally staged membrane permeator of a bench scale type has been employed in a study of methane enrichment from biogas. The permeator contains two membranes of the same type; therefore, the overall driving force between feed and permeate side in the permeator is divided into two parts through these two membranes. Theoretical studies were conducted using mathematical models based on Perfect Mixing and cocurrent flow patterns. The effects of operating variables such as feed pressure, overall stage cut and flow patterns in the permeator on the extent of separation and membrane area requirement have been examined. The observed experimental results from bench scale studies agree well with theoretical predictions based on Perfect Mixing model. Simulation results show that the optimal performance of the permeator can be obtained by properly selecting the stage cut parameter, Eφ and stage pressure parameter, Er, which are functions of individual stage cut and intermediate pressure respectively. A comparative study between the internally staged permeator and a conventional single-stage permeator indicates that, under the same energy consumption, the former offers higher product recovery, but requires much larger membrane area.
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Internal staging for membrane gas separation: comparison with conventional membrane permeators
Chemical Engineering Science, 1993Co-Authors: Kang Li, R. HughesAbstract:Abstract A comparison was made between the performances of an internally staged permeator, a two-stage cascade permeator and a conventional single-stage permeator for the separation of CO2/N2 mixtures. Silicone rubber was used as the membrane material and the separation was investigated experimentally and by simulation. The experimental results obtained from these permeators agree well with theoretical predictions based on Perfect Mixing models. Simulation studies on both the internally staged permeator and the two-stage cascade indicate that the optimum performance for these two separation schemes can be obtained by properly selecting the stage-cut parameter Eϕ and stage-pressure parameter Er, which are functions of individual stage cut and intermediate pressure, respectively. Finally, a comparative simulation study of the internally staged permeator with the two-stage cascade and the single-stage permeator was performed and the results are discussed in detail.
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Theoretical analysis of ternary gas mixture separation in an internally staged permeator
Chemical Engineering Science, 1992Co-Authors: Kang LiAbstract:Mathematical models based on Perfect Mixing and cocurent flow patterns have been developed to describe the separation of a ternary gas mixture in an internally staged permeator. Separate recovery/enrichment of carbon dioxide and methane from a gas mixture of CO2CH4N2 has been considered in the simulation. The results indicated that the internally staged permeator can achieve a ternary gas separation and, under the operating conditions studied, each product stream generated by the permeator is enriched in a different gas component. A parametric study reveals that, in order to maximise the degree of separation, the values of both stage cuts and the pressure ratio across each membrane have to be properly selected. Results from a comparison study between the two flow patterns considered show that the performance based on cocurrent flow pattern is generally better than that of the Perfect Mixing.
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Performance of a cellulose acetate permeator with permeability-influenced feed
Aiche Journal, 1990Co-Authors: Kang Li, D.r. Acharya, R. HughesAbstract:We study the effect of variable permeabilities on the performance of a permeator employing a cellulose acetate type of membrane. The experiments were conducted using a CO 2 -N 2 mixture. The variation in the permeabilities of CO 2 and N 2 with the pressure and the feed composition has been measured experimentally, and statitical models have been fitted to the data. The experimental data have been compared with theoretical results obtained using a Perfect Mixing model which incorporated variable permeabilities.
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Membrane gas separation with permeate purging
Gas Separation & Purification, 1990Co-Authors: Kang Li, D.r. Acharya, R. HughesAbstract:Abstract The effect of purging with an impermeable gas on the permeate side of a flat sheet permeator has been investigated. A three component gas mixture was used in the separation. It has been shown that a small stream of purge can improve the degree of separation achieved and reduce the need to maintain a high pressure ratio across the membrane. Excellent agreement has been obtained between the experimental and the predicted data from a Perfect Mixing model.
M. Aghajari - One of the best experts on this subject based on the ideXlab platform.
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Influence of water level on oil-water separation by residence time distribution curves investigations
Separation and Purification Technology, 2008Co-Authors: Jamshid Behin, M. AghajariAbstract:The separation of crude oil and water mixtures is an important process in the oil and chemical industries. This work studied the flow behavior of crude oil and water in a pilot scale oil-water separator. This gravity separator (diameter of 1.2 m and length of 5.2 m) was operated by Drood oil of the Iranian Offshore Oil Company (IOOC) located in Kharg Island (Iran). The residence time distribution (RTD) curves were acquired in this separator by radioactive tracer (131I) injection. Experimental results showed that the separator operational performance increased with the water level in the vessel. Perfect Mixing tanks-in-series (with a dead zone) have been used to describe the liquid behavior, and the experimental results were in good agreement with this model. Increasing the water level in the vessel from 0.5 m to 0.9 m increases the number of Mixing tanks-in-series of both organic and aqueous phases, from 9.0 to 9.1 and from 8 to 8.3, respectively. The dead volume of the organic phase path decreased with water level, but this trend was reversed for the aqueous phase path. Less than 3% of the volume of the separator is active. The separator's optimum efficiency occurred when the water level in the separator was about 0.7 m. © 2008 Elsevier B.V. All rights reserved.
Takashi Katoh - One of the best experts on this subject based on the ideXlab platform.
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dynamic simulation of multicomponent gas separation by hollow fiber membrane module nonideal Mixing flows in permeate and residue sides using the tanks in series model
Separation and Purification Technology, 2011Co-Authors: Takashi Katoh, Hidemi Yoshikawa, Masahiro Tokumura, Yoshinori KawaseAbstract:A new simulation model for the dynamic performance of gas separation membrane modules is presented. In order to take account of nonideal Mixing flows in permeate and residue sides a tanks-in-series model is utilized. As a stable computational scheme, the relaxation method is applied to solve the governing ordinary differential equations for transport across the membrane, mass balance and pressure distributions in a hollow-fiber membrane module. The proposed simulation model and scheme are validated using the experimental data and simulation results hydrogen gas separation and air separation in the literature. Using the proposed simulation model and scheme the dynamic performance of membrane gas separation processes, hydrogen recovery process and two-stage methane separation process with residue recycle, is examined by varying the operating conditions, i.e., the bulk Mixing degree (Perfect Mixing, plug flow and intermediate Mixing), pressure drop and recycle ratio. The computational results indicate that effect of Mixing degree in the feed side is more significant as compared with that in the permeate side and less Mixing in the feed side results in higher performance. The retentate recycle is found to improve methane recovery efficiency. The proposed simulation model considering nonideal Mixing in the membrane module provides more reliable examination of unsteady-state behaviors of hollow-fiber membrane gas separation modules.