Piezoelectric membranes for separation processes: Operating conditions and filtration performance

2013 ◽  
Vol 435 ◽  
pp. 226-232 ◽  
Author(s):  
M.T. Darestani ◽  
H.G.L. Coster ◽  
T.C. Chilcott
Keyword(s):  
Operating Conditions ◽  
Separation Processes ◽  
Filtration Performance

scholarly journals Evaluation of bio-coagulants for colour removal from dye synthetic wastewater: characterization, adsorption kinetics, and modelling approach

Water SA ◽  
2020 ◽  
Vol 46 (2 April) ◽  
Author(s):  
IA Obiora-Okafo ◽  
OD Onukwuli ◽  
NC Eli-Chukwu
Keyword(s):  
Adsorption Kinetics ◽  
Molecular Layer ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Organic Polymer ◽  
Good Prediction ◽  
Colour Removal ◽  
Separation Processes ◽  
Coagulant Dosage

Dye usage for industrial applications has been on the increase and these activities generate large amounts of dye-constituted wastewater that should be treated before environmental discharge or reuse. Various studies have shown the application of natural organic polymer (NOP) coagulants in dye removal from industrial wastewater. In this research, the coagulation performances of Vigna unguiculata (VU) and Telfairia occidentalis (TO) for colour removal from crystal Ponceau 6R dye synthetic wastewater was studied. The proximate compositions, structure, and surface morphologies of the coagulants were investigated using standard methods, i.e. Fourier-Transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Colour removal was evaluated through the time-dependent decrease in particle concentration and thus growth of flocs. Effects of the process parameters, including pH, coagulant dosage, dye concentration (DC), settling time, and temperature were preliminarily tested and the best range experimentally determined. The optimal operating conditions established were pH 2, 800 mg∙L−1 coagulant dosage, 100 mg∙L−1 dye concentration, 300 min, and 303 K. The order of greatest removal was VUC > TOC with optimum efficiency of 93.5% and 90.7%, respectively. The values of K and α obtained for VUC and TOC were 8.09 x 10−4 L∙mg−1∙min−1, 1.7 and 9.89 x 10-4 L∙mg−1∙min−1, 1.6, respectively. Coagulation time, Tag, calculated and deduced from the particle distribution plot, showed a rapid coagulation process. Coagulation-adsorption kinetics indicated agreement with the pseudo-second-order model deducing that chemisorption is the rate-controlling step. It further indicates that particle adsorption on the polymer surfaces occurred mostly as a mono-molecular layer and according to the chemisorption mechanism. Cross-validation showed good prediction of the experimental data. The selected coagulants have the potential for application as efficient coagulants while also showing significant adsorption characteristics. The application of kinetics and modelling in separation processes involving particle transfer is especially required in wastewater treatment.

scholarly journals Systematic Experimental Investigation of Segregation Direction and Layer Inversion in Binary Liquid-Fluidized Bed

Processes ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 177
Author(s):  
Alberto Di Renzo ◽  
Giacomo Rito ◽  
Francesco P. Di Maio
Keyword(s):  
Experimental Investigation ◽  
Operating Conditions ◽  
Industrial Processes ◽  
Process Unit ◽  
Separation Processes ◽  
Solids Concentration ◽  
Expansion Range ◽  
Surface Expansion ◽  
Density Ratios ◽  
Inversion Phenomenon

Multi-component liquid-fluidized beds are encountered in a variety of industrial processes. Often, segregation severely affects the performance of the process unit. Unfortunately, size-driven and density-driven separation processes may occur with a complex interplay, showing prevailing mechanisms that change with the operating conditions. For example, when the solids exhibit contrasting differences in size and density, even the direction of segregation can turn out hard to predict, giving rise for some systems to the so-called “layer inversion phenomenon”. A systematic experimental investigation is presented on 14 different binary beds composed of glass beads and ABS spheres with different size and density ratios and different bed composition. The analysis allows assessing the reliability of a model for predicting the segregation direction of fluidized binary beds (the Particle Segregation Model, PSM). By measurements of the solids’ concentration at the surface, expansion/segregation properties and the inversion voidage are compared with the PSM predictions, offering a direct means of model validation. Both the segregation direction throughout the expansion range and the value of the inversion voidage are compared. Extensive qualitative agreement is obtained for 12 out of 14 fluidized mixtures. Quantitatively, the average discrepancy between predicted and measured inversion voidage is below 5%, with a maximum of 17%.

Adaptive Calibration of a Capacitance Tomography System for Imaging Water Droplets Distribution

Volume 1 ◽  
2004 ◽  
Author(s):  
W. Q. Yang ◽  
A. Chondronasios ◽  
S. Nattrass ◽  
V. T. Nguyen ◽  
M. Betting ◽  
...  
Keyword(s):  
Operating Conditions ◽  
Electrode Pair ◽  
Liquid Droplets ◽  
Separation Processes ◽  
Low Concentration ◽  
Droplet Distribution ◽  
Adaptive Calibration ◽  
Wet Gas ◽  
Reference Measurements ◽  
Capacitance Tomography

A highly-sensitive electrical capacitance tomography (ECT) system based on an HP4284 impedance analyser has been developed and used to quantify low concentration multiphase flows in wet gas separation processes. The system hardware provides high accuracy (0.05%) and high resolution (10−17 F). The sensor was calibrated in an environmental chamber with solid samples of known permittivity over ranges of temperature and humidity. Adaptive calibration and adjacent electrode pair correction techniques were applied to image very low concentration profiles. This paper describes the techniques used and presents the experimental results obtained from a test flow rig called Twister, which has been designed to separate liquid droplets from wet gas streams. The test results over a range of operating conditions (20% to 95% humidity) demonstrate that the ECT system is capable of reconstructing clear images of the droplet distribution inside Twister. Changes as small as 1 gWater/kgAir in the droplets form liquid were detectable. It has also shown that the concentration of the condensable phase can be estimated quantitatively within 20% in comparison with the reference measurements.

Study on the Property Dynamic Filtration Performance of Anthranilic Acid Copper in Environment Engineering

2013 ◽  
Vol 340 ◽  
pp. 903-907
Author(s):  
Xiao Jing Wang ◽  
Fan Wang ◽  
Ji Jin
Keyword(s):  
Anthranilic Acid ◽  
Industrial Applications ◽  
Filter Press ◽  
Operating Conditions ◽  
Filtration Resistance ◽  
Filtration Performance ◽  
Dynamic Filtration ◽  
Efficient Regeneration ◽  
Saccharin Sodium ◽  
Filtration Experiment

Based on the filtration experiment of a rotary filter press equipped with the filtration fabric, this paper presents a study on the dynamic filtration performance and the filtration resistance of anthranilic acid copper during the production of saccharin sodium. The best possible operating condition is expected by examining the influence on the filtration rate and its attenuation in different operating conditions, which can provide guidance for future industrial applications, and an efficient regeneration method is proposed.

scholarly journals STOCHASTIC MODEL OF SEPARATION PROCESS OF COMPLEX HETEROGENEOUS DISPERSION SYSTEMS IN CENTRIFUGES WITH RADIAL-AXIAL FLOW

2019 ◽  
pp. 34-45
Author(s):  
Gennadiy Petrovich Kicha ◽  
Andrei Veniaminovich Nadezkin ◽  
Liudmila Anatolievna Semeniuk
Keyword(s):  
Internal Combustion Engines ◽  
Axial Flow ◽  
Detailed Examination ◽  
Operating Conditions ◽  
Fuel Oil ◽  
Centrifugal Field ◽  
Separation Processes ◽  
Stochastic Effects ◽  
Random Forces ◽  
Dispersion Systems

The article describes separation processes in apparatus with complex hydrodynamic conditions. The new approach to the theoretical study consists in taking into account the action of the centrifugal field and the field of random forces, as it was implemented earlier for the simplest structures, but also in a detailed examination of the radial and axial flows. The movement of particles is investigated in the cramped conditions of precipitation during their interaction with each other. The processes of separation in centrifugal devices of various types have been identified, subject to stochasticity, constrained movement of a set of real particles and the possibility of their dispersion and coagulation. The combined deterministic and stochastic effects on the dispersed phase in a centrifugal field are described by means of a differential equation, the solution of which makes it possible to calculate the fractional and total centrifugation efficiency with high accuracy. A semi-analytical method has been developed and implemented for one-and two-dimensional stochastic models for the approximate solution of non-stationary centrifugal boundary value problems. Compared to difference schemes Faedo-Galerkin method gives the solution of equation systems with a smaller number of unknowns defined in all values of the arguments. The use of the method is possible only in the case of homogeneous boundary conditions and is limited by the possibility of selecting a complete system of functions that would satisfy them. The proposed approach to identification of refining fuels and lubricants is preferable since it fully reflects the essence of the processes occurring in centrifuges with a radial-axial flow. Generalization of stochastic effects on centrifugation, taking into account the hydrodynamic features of the flow of shared media in a centrifugal field, allows calculating all indicators of cleaning fuels and oils from mechanical impurities without model experiments, predicting the total and fractional efficiency of fuel oil filters and oil filters of the internal combustion engines. The developed identification method of separating complex dispersed systems is aimed at the synthesis of systems and devices for oil purification and fuel oil preparation of increased efficiency with predetermined parameters of purification quality in operating conditions.

Development and Demonstration of Membrane Reformer System for Highly-Efficient Hydrogen Production from Natural Gas

2007 ◽  
Vol 539-543 ◽  
pp. 1403-1408 ◽  
Author(s):  
Isamu Yasuda ◽  
Yoshinori Shirasaki
Keyword(s):  
Hydrogen Production ◽  
Natural Gas ◽  
Technology Development ◽  
Production Capacity ◽  
Single Step ◽  
Operating Conditions ◽  
System Configuration ◽  
Separation Processes ◽  
Partial Load ◽  
Operation Test

A membrane reformer is composed of a steam reformer equipped with palladium-based alloy modules in its catalyst bed, and can perform steam reforming reaction and hydrogen separation processes simultaneously, without shift converters and purification systems. It thus can be configured much more compactly and can provide much higher efficiency than the conventional technologies. We have manufactured and tested a world-largest scale membrane reformer with a rated hydrogen production capacity of 40 Nm3/h. The operation test has successfully been proceeding for over 3,000 hours in one of the hydrogen refueling stations in Tokyo, which has demonstrated the potential advantages of the membrane reformer: simple system configuration as benefited by single-step production of high-purity (99.999% level) hydrogen from natural gas, compactness and energy efficiency as high as 70 to 76% under both the rated and partial-load operating conditions. The system has thus been proved to give the highest efficiency in producing hydrogen from natural gas among various competing technologies. The paper will present the latest achievements and the future plan of the membrane reformer technology development.

scholarly journals Thermodynamic Modeling of CO2 Separation Systems with Soluble, Redox-Active Capture Species

2021 ◽  
Author(s):  
Lauren E. Clarke ◽  
McLain E. Leonard ◽  
T. Alan Hatton ◽  
Fikile R. Brushett
Keyword(s):  
Thermodynamic Modeling ◽  
Target Material ◽  
Analytical Framework ◽  
Operating Conditions ◽  
Co2 Separation ◽  
Performance Bounds ◽  
Separation Processes ◽  
Separation Systems ◽  
Redox Active ◽  
The Impact

Electrochemical approaches hold promise for energy-efficient and modular carbon dioxide (CO2) separation systems that can make direct use of renewably-generated electricity. Here we employ a thermodynamic modeling approach to estimate the upper performance bounds of CO2 separation processes that use soluble, redox-active capture species. We contemplate the impact of tunable molecular and electrolyte properties on the thermodynamic and faradaic efficiencies of four characteristic system configurations. We find a tradeoff between these efficiency metrics, and propose a new metric, the combined efficiency, that can be used to further explore this tradeoff and identify desirable property sets that balance energy and materials requirements. Subsequently, we determine effective CO2 binding affinities of redox-active capture molecules and demonstrate how these values are dependent upon molecular properties, system format, and operating conditions. Overall, this analytical framework can help guide molecular discovery and electrolyte engineering in this emerging field by providing insight into target material properties.

scholarly journals Technologies for metal recycling from electrical - electronic wastes

2021 ◽  
Vol 62 (3b) ◽  
pp. 58-68
Author(s):  
Toi Trung Tran ◽  
Chinh Thi Vu ◽  
Nhung Thi Pham ◽  
Keyword(s):  
Precious Metals ◽  
Operating Conditions ◽  
Electronic Equipment ◽  
Chemical Extraction ◽  
Base Metals ◽  
Separation Processes ◽  
Physical Separation ◽  
Metal Recycling ◽  
New Directions ◽  
Extraction Processes

Wastes from electrical - electronic equipment (WEEE) are of huge concerns worldwide. With the decreasing life cycle of most electrical - electronic equipment (EEE), the WEEE growth rate is fast, about 3÷5% annually. This is considered as the fastest growing waste stream among municipal wastes. WEEE contains, in addition to plastic, glass etc., high contents of base metals and precious metals. They are regarded as potential secondary resources of metals in addition to primary resources of metals from metallic ores. Over the past decades, many metal recycling technologies from WEEE have been developed including physical separation processes and chemical extraction processes. This article summarizes the characteristics, recycling principles, separation processes and optimal operating conditions of the world's most currently common technologies for metal recycling from WEEE. So that one can derive new directions for metal recycling from electrical - electronic wastes in the Vietnam case.

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