Effect of operating conditions on separation performance of reactive dye solution with membrane process

Microfluidic separators based on Deterministic Lateral Displacement (DLD) constitute a promising technique for the label-free detection and separation of mesoscopic objects of biological interest, ranging from cells to exosomes. Owing to the simultaneous presence of different forces contributing to particle motion, a feasible theoretical approach for interpreting and anticipating the performance of DLD devices is yet to be developed. By combining the results of a recent study on electrostatic effects in DLD devices with an advection–diffusion model previously developed by our group, we here propose a fully predictive approach (i.e., ideally devoid of adjustable parameters) that includes the main physically relevant effects governing particle transport on the one hand, and that is amenable to numerical treatment at affordable computational expenses on the other. The approach proposed, based on ensemble statistics of stochastic particle trajectories, is validated by comparing/contrasting model predictions to available experimental data encompassing different particle dimensions. The comparison suggests that at low/moderate values of the flowrate the approach can yield an accurate prediction of the separation performance, thus making it a promising tool for designing device geometries and operating conditions in nanoscale applications of the DLD technique.

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Membrane process treatment for greywater recycling: investigations on direct tubular nanofiltration

Water Science & Technology ◽

10.2166/wst.2010.435 ◽

2010 ◽

Vol 62 (7) ◽

pp. 1544-1550 ◽

Cited By ~ 8

Author(s):

F. Hourlier ◽

A. Massé ◽

P. Jaouen ◽

A. Lakel ◽

C. Gérente ◽

...

Keyword(s):

Urban Areas ◽

Membrane Filtration ◽

Potable Water ◽

Anionic Surfactants ◽

Oxygen Demand ◽

Operating Conditions ◽

Membrane Process ◽

Constant Concentration ◽

Recycle And Reuse ◽

Do So

On-site greywater recycling and reuse is one of the main ways to reduce potable water requirement in urban areas. Direct membrane filtration is a promising technology to recycle greywater on-site. This study aimed at selecting a tubular nanofiltration (NF) membrane and its operating conditions in order to treat and reuse greywater in buildings. To do so, a synthetic greywater (SGW) was reconstituted in order to conduct experiments on a reproducible effluent. Then, three PCI NF membranes (AFC30, AFC40 and AFC80) having distinct molecular weight cut-offs were tested to recycle this SGW with a constant concentration at 25°C at two different transmembrane pressures (20 and 35 bar). The best results were obtained with AFC80 at 35 bar: the flux was close to 50 L m−2 h−1, retentions of 95% for chemical oxygen demand and anionic surfactants were observed, and no Enterococcus were detected in the permeate. The performances of AFC80 were also evaluated on a real greywater: fluxes and retentions were similar to those observed on SGW. These results demonstrate the effectiveness of direct nanofiltration to recycle and reuse greywater.

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Multiphase CFD Model Development for a Rotating Centrifugal Separator

Volume 8: Turbomachinery, Parts A, B, and C ◽

10.1115/gt2012-69881 ◽

2012 ◽

Author(s):

Daniel DeMore ◽

William Maier

Keyword(s):

Separation Efficiency ◽

Fluid Dynamic ◽

Model Development ◽

Modeling Method ◽

Operating Conditions ◽

Cfd Modeling ◽

Separation Performance ◽

Centrifugal Separator ◽

Wide Range ◽

The Impact

The present paper describes the development of a Computational Fluid Dynamic (CFD) modeling approach suitable for the analysis, design, and optimization of rotating centrifugal separator stage geometries. The Homogeneous Multiple Size Group (MUSIG) model implemented in the commercial code CFX V13.0 was utilized as a basis for the CFD modeling method. The model was developed through a series of studies to understand the impact of droplet size distribution, particle coalescence, rotor/stator interface treatment, and mesh resolution on the prediction of separation efficiency for a given rotating separator geometry. This model was then validated against the OEM’s extensive in-house experimental separation testing database. The resulting CFD modeling method is shown to adequately reproduce observed trends in separation performance over a wide range of operating conditions.

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Acidic Gases Separation from Gas Mixtures on the SILMs Providing the Facilitated and Solution-Diffusion Transport Mechanisms

10.20944/preprints201811.0331.v1 ◽

2018 ◽

Author(s):

Alsu I. Akhmetshina ◽

Alla Mochalova ◽

Maxim M. Trubyanov ◽

Artem A. Atlaskin ◽

Nail R. Yanbikov ◽

...

Keyword(s):

Operating Conditions ◽

Separation Performance ◽

Factors Affecting ◽

Acidic Gases ◽

Membrane Performance ◽

Ideal Selectivity ◽

Counter Ions ◽

Supported Ionic Liquid Membranes ◽

Selection Of

Nowadays, the imidazolium-based ionic liquids containing acetate counter-ions are attracting much attention as both highly selective absorbents of the acidic gases and CO2 carriers in the supported ionic liquid membranes. In this regard, the investigation of the gas transport properties of such membranes may be appropriate for better understanding of various factors affecting the separation performance and the selection of the optimal operating conditions. In this work, we have tested CH4, CO2 and H2S permeability across the SILM impregnated by 1-butyl-3-methylimidazolium acetate (bmim[ace]) with the following determination of the ideal selectivity in order to compare the facilitated transport membrane performance with the SILM that dissolves acidic gases physically, namely, containing 1-butyl-3-methylimidazolium tetrafluoroborate (bmim[BF4]). Both SILMs have showed modest individual gases permeability and ideal selectivity of CO2/CH4 and H2S/CH4 separation that achieves values up to 15 and 32, respectively. The effect of the feed gas mixture composition on the permeability of acidic gases and permeselectivity of the gas pair was investigated. It turned out that the permeation behavior for the bmim[ace]-based SILM toward the binary CO2/CH4, H2S/CH4 and ternary CO2/H2S/CH4 mixtures was featured with high acidic gases selectivity due to the relatively low methane penetration through the liquid phase saturated by acidic gases.

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Numerical Study on the Influence of Length-Diameter Ratio on the Performance of Dynamic Pressure Oil-Air Separator

International Journal of Chemical Engineering ◽

10.1155/2021/6649128 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Xiaobin Zhang ◽

Xiaofeng Zhang ◽

Delin Gu ◽

Lei Lang ◽

Na Gao

Keyword(s):

Aspect Ratio ◽

Separation Efficiency ◽

Dynamic Pressure ◽

Diameter Ratio ◽

Operating Conditions ◽

Maximum Efficiency ◽

Separation Performance ◽

Cylinder Length ◽

Cylinder Diameter ◽

Air Separator

In order to study the separation characteristics of the aeroengine dynamic pressure oil-air separator, this paper uses the coupling method of PBM and CFD two-fluid model to study the influencing factors such as cylinder diameter, cylinder length, and other factors on the separator performance. The flow field structure, velocity, gas volume distribution, separation efficiency, and gas and liquid holdup rate in the separator under different operating conditions are analyzed. Combined with the analysis results of the cylinder diameter and the cylinder length, the influence law of length-diameter ratio on separation efficiency is summarized. The optimum length-to-diameter ratio that maximizes the separation performance of the separator is obtained in this research, which provides a reference for the design and improvement of the separator. The results show that, as the diameter of the cylinder increases, the separation efficiency increases first and then decreases. When dsep = 16 mm and dsep = 18 mm, the separator reaches its maximum efficiency, which is about 93%. With the increase of the cylinder length, the separation efficiency first increases and reaches the maximum when l2 = 90 mm and then decreases slowly. When the separator cylinder is either too long or too short, it will cause the separation performance to decrease. There is an optimal aspect ratio. There is an optimal aspect ratio, and the separation performance of the separator is the best when the aspect ratio is between 5 and 6.

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CARBON CAPTURE AND STORAGE ENERGY CONSUMPTION AND PERFORMANCE OPTIMIZATION USING METAMODELS AND RESPONSE SURFACE METHODOLOGY

Journal of Energy Resources Technology ◽

10.1115/1.4051679 ◽

2021 ◽

pp. 1-28

Author(s):

Ali Allahyarzadeh-Bidgoli ◽

Nayereh Hamidishad ◽

Jurandir Itizo Yanagihara

Keyword(s):

Power Consumption ◽

Co2 Emissions ◽

Performance Optimization ◽

Operating Conditions ◽

Design Parameters ◽

Separation Performance ◽

Co2 Removal ◽

Operating Pressure ◽

Heating And Cooling ◽

And Storage

Abstract Oil and gas industries have high carbon dioxide (CO2) emissions, which is a great environmental concern. Monoethanolamine (MEA) is widely used as a solvent in CO2 capture and storage (CCS) systems. The challenge is that MEACCS itself is an energy-intensive process that requires optimum configuration and operation, and numerous design parameters and heat demands must be considered. Thus, the current work evaluates the energy distributions and CO2 removal efficiency of a CCS installed in floating production storage and offloading units under different operating conditions of a power- and heat-generation hub. The optimization procedures are implemented using highly accurate surrogate models for the following responses: 1) overall power consumption of CCS, 2) CCS separation performance, and 3) CCS heating and cooling demands. The input variables considered in the present research include the following: 1) the exhaust gas compositions and mass flow rate, 2) the operating pressure and temperature parameters of CCS and the injection compression unit, 3) the structural parameters of absorber and stripper columns, and 4) MEA solution parameters. The optimum CCS configuration significantly reduces the total heating and cooling demands by 62.77% (7 × 106 kW) and the overall power consumption by 8.65 % (1.8 MW), and it increases the CCS separation performance by 4.46% (97.46%) and mitigates the CO2 emissions of proper CCS by 1.02 t/h compared with conventional operating conditions.

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Dry beneficiation of +0.5mm-5.6mm South African coal using an air dense medium fluidization bed

10.21203/rs.3.rs-678819/v1 ◽

2021 ◽

Author(s):

Elmarie Sunette Diedericks ◽

Marco Le Roux ◽

Quentin Peter Campbell

Keyword(s):

Particle Size ◽

Fluidized Bed ◽

Separation Efficiency ◽

Solid Phase ◽

Poor Performance ◽

Operating Conditions ◽

High Mass ◽

Dense Medium ◽

Separation Performance ◽

Coal Particles

Abstract The separation performance of solid phase bed material, at various particle size ranges, in an air dense medium fluidized bed (ADMFB), were evaluated during this study. The coal particles were separated into +0.5mm-1mm, +1mm-2mm, +2mm-2.8mm, +2.8mm-4mm, +4mm-4.75mm and +4.75mm-5.6mm particle size ranges and fed to the fluidized bed in these fractions. Along with the six coal particle size ranges, three dense media to coal ratios and the addition of vibration was tested to identify the best operating conditions. Adequate results were obtained for larger particle size ranges down to and including +2.0mm-2.8mm coal particles, after which the separation performance decreased significantly. Density stratification was irregular and not obvious for coal particles below 2.0mm and maintaining a consistent fluidization state also proved to be challenging, especially when dense medium was added. The coal particles separated vertically along the bed height because of differences in particle and bed density, while particle size proved to have a notable influence on the degree of separation. An air fluidization velocity of between 1.1 to 1.4Umf was shown as the best performing velocity, which yielded the maximum ash differential between the top and bottom layers of the bed for all the particle size ranges tested. For +2.0mm-5.6mm coal particles, low cumulative ash yields were obtained at high mass yields, however the ash yields increased for -2mm coal. Vibration and dense medium have, in some cases, enhanced the separation efficiency of the ADMFB. The -2.0mm particles experienced stronger particle-particle interactions as well as elevated levels of bubbling and back mixing than that of the +2.0mm particles, which explains the poor performance of the small particle sizes.

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Effects of Geometric and Operating Parameters on the Separation Performance of Air-Injected De-Oil Hydrocyclone

Volume 2: Ocean Engineering and Polar and Arctic Sciences and Technology ◽

10.1115/omae2006-92531 ◽

2006 ◽

Author(s):

Lixin Zhao ◽

Minghu Jiang ◽

Feng Li ◽

Hua Song ◽

Shumeng Liu

Keyword(s):

Produced Water ◽

Field Tests ◽

Field Research ◽

Operating Conditions ◽

Separation Performance ◽

Liquid Ratio ◽

Split Ratio ◽

Optimum Diameter ◽

Vortex Finder ◽

Treatment Facilities

A new type hydrocyclone, air-injected de-oil hydrocyclone (AIDOH), was developed. Basic separation principle of the AIDOH, prototype structure, experimental technical process and facilities are introduced. The effect of different geometric parameters, including vortex finder diameter and length, micro-pore diameter, and different operating conditions, such as flowrate, split ratio, gas-liquid ratio, and air-injecting position, were studied. Laboratory experiments were carried out first to provide basis for field tests. The field research indicates that, for around 1000 mg/l polymer-flooding oily produced-water, the optimum flowrate is 4.20 m3/h for the testing prototype, the split ratio should be 30%; gas-liquid ratio 0.45. It also shows that 20–40 µm micro-pore materials are optimum diameter for hydrocyclonic separation enhancement Research indicates that the AIDOH has satisfied separation effect, which is feasible for emulsified oil treatment. The AIDOH will have better application prospect in petrochemical, environmental field, especially for offshore application, to reduce space occupied by normal water treatment facilities.

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Simulation of Human Small Intestinal Digestion of Starch Using an In Vitro System Based on a Dialysis Membrane Process

Foods ◽

10.3390/foods9070913 ◽

2020 ◽

Vol 9 (7) ◽

pp. 913

Author(s):

Carol González ◽

Daniela González ◽

Rommy N. Zúñiga ◽

Humberto Estay ◽

Elizabeth Troncoso

Keyword(s):

Small Intestine ◽

Membrane Fouling ◽

Operating Conditions ◽

Membrane Process ◽

Dialysis Membrane ◽

Human Small Intestine ◽

Intestinal Digestion ◽

Food Matrices ◽

The Impact

This work deepens our understanding of starch digestion and the consequent absorption of hydrolytic products generated in the human small intestine. Gelatinized starch dispersions were digested with α-amylase in an in vitro intestinal digestion system (i-IDS) based on a dialysis membrane process. This study innovates with respect to the existing literature, because it considers the impact of simultaneous digestion and absorption processes occurring during the intestinal digestion of starchy foods and adopts phenomenological models that deal in a more realistic manner with the behavior found in the small intestine. Operating the i-IDS at different flow/dialysate flow ratios resulted in distinct generation and transfer curves of reducing sugars mass. This indicates that the operating conditions affected the mass transfer by diffusion and convection. However, the transfer process was also affected by membrane fouling, a dynamic phenomenon that occurred in the i-IDS. The experimental results were extrapolated to the human small intestine, where the times reached to transfer the hydrolytic products ranged between 30 and 64 min, according to the flow ratio used. We consider that the i-IDS is a versatile system that can be used for assessing and/or comparing digestion and absorption behaviors of different starch-based food matrices as found in the human small intestine, but the formation and interpretation of membrane fouling requires further studies for a better understanding at physiological level. In addition, further studies with the i-IDS are required if food matrices based on fat, proteins or more complex carbohydrates are of interest for testing. Moreover, a next improvement step of the i-IDS must include the simulation of some physiological events (e.g., electrolytes addition, enzyme activities, bile, dilution and pH) occurring in the human small intestine, in order to improve the comparison with in vivo data.

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An Investigation of a Micro-Scale Ranque-Hilsch Vortex Tube

Fluids Engineering ◽

10.1115/imece2006-14711 ◽

2006 ◽

Cited By ~ 3

Author(s):

Amar F. Hamoudi ◽

Amir Fartaj ◽

Gary W. Rankin

Keyword(s):

Reynolds Number ◽

Vortex Tube ◽

Operating Conditions ◽

Tube Length ◽

Orifice Diameter ◽

Working Fluid ◽

Dimensionless Temperature ◽

Separation Performance ◽

Micro Scale ◽

Cold Mass

The results of an experimental investigation of the energy separation performance of a micro-scale Ranque-Hilsch vortex tube are presented in this paper. The micro-scale vortex tube is 2 mm in diameter and constructed using a layered technique from multiple pieces of Plexiglas and aluminum. Four inlet slots, symmetrically located around the tube, form the vortex. The hydraulic diameter of each inlet slot and the orifice diameter for the cold exit are 229 and 800 microns respectively. The working fluid is low pressure, non-dehumidified compressed air at room temperature. The rate of the hot gas flow is varied by means of a control valve to achieve different values of cold mass fraction. The mass flow rates, temperatures and pressures of the supply and outlet flows are measured and the performance of the device presented. The supply channel Reynolds number is varied over a considerable range which extends into the laminar regime in order to determine the operating conditions for cooling. An increase in dimensionless temperature is found in both the cold and hot outlets as supply nozzle Reynolds number increases from zero. Maximum values occur at a Reynolds number of approximately 500 and the cold flow dimensionless temperature becomes negative at about 2500. Although the optimum cold mass ratio is higher than the conventional tubes, the effect on performance of tube length and cold exit diameter is similar to the conventional devices.

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