scholarly journals Selective Separation of Acetic and Hexanoic Acids across Polymer Inclusion Membrane with Ionic Liquids as Carrier

2019 ◽  
Vol 20 (16) ◽  
pp. 3915 ◽  
Author(s):  
Bao-Ying Wang ◽  
Na Zhang ◽  
Zhen-Yu Li ◽  
Qiao-Lin Lang ◽  
Bing-Hua Yan ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Quaternary Ammonium ◽  
Volatile Fatty Acids ◽  
Separation Efficiency ◽  
Feed Solution ◽  
Selective Separation ◽  
Hexanoic Acid ◽  
Separation Performance ◽  
Initial Ph ◽  
Hcl Concentration

This paper first reports on the selective separation of volatile fatty acids (VFAs) (acetic and hexanoic acids) using polymer inclusion membranes (PIMs) containing quaternary ammonium and phosphonium ionic liquids (ILs) as the carrier. The affecting parameters such as IL content, VFA concentration, and the initial pH of the feed solution as well as the type and concentration of the stripping solution were investigated. PIMs performed a much higher selective separation performance toward hexanoic acid. The optimal PIM composed of 60 wt% quaternary ammonium IL with the permeability coefficients for acetic and hexanoic acid of 0.72 and 4.38 µm s−1, respectively, was determined. The purity of hexanoic acid obtained in the stripping solution increased with an increase in the VFA concentration of the feed solution and decreasing HCl concentration of the stripping solution. The use of Na2CO3 as the stripping solution and the involvement of the electrodialysis process could dramatically enhance the transport efficiency of both VFAs, but the separation efficiency decreased sharply. Furthermore, a coordinating mechanism containing hydrogen bonding and ion exchange for VFA transport was demonstrated. The highest purity of hexanoic acid (89.3%) in the stripping solution demonstrated that this PIM technology has good prospects for the separation and recovery of VFAs from aqueous solutions.

Field testing CFD-based predictions of storage chamber gross solids separation efficiency

1999 ◽  
Vol 39 (9) ◽  
pp. 161-168 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul ◽  
Andrew Drinkwater ◽  
Ian Clifforde
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Settling Velocity ◽  
Separation Efficiency ◽  
Flow Patterns ◽  
Total Efficiency ◽  
Separation Performance ◽  
Storage Chamber ◽  
Solids Separation ◽  
Simulated Flow

The use of computational fluid dynamics-based techniques for predicting the gross solids and finely suspended solids separation performance of structures within urban drainage systems is becoming well established. This paper compares the result of simulated flow patterns and gross solids separation predictions with field measurements made in a full size storage chamber. The gross solids retention efficiency was measured for six different storage chambers in the field and simulations of these chambers were undertaken using the Fluent computational fluid dynamics software. Differences between the observed and simulated flow patterns are discussed. The simulated flow fields were used to estimate chamber efficiency using particle tracking. Efficiency results are presented as efficiency cusps, with efficiency plotted as a function of settling velocity. The cusp represents a range of efficiency values, and approaches to the estimation of an overall efficiency value from these cusps are briefly discussed. Estimates of total efficiency based on the observed settling velocity distribution differed from the measured values by an average of ±17%. However, estimates of steady flow efficiency were consistently higher than the observed values. The simulated efficiencies agreed with the field observations in identifying the most efficient configuration.

Miscible blend polyethersulfone/polyimide asymmetric membrane crosslinked with 1,3-diaminopropane for hydrogen separation

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nur’ Adilah Abdul Nasir ◽  
Ameen Gabr Ahmed Alshaghdari ◽  
Mohd Usman Mohd Junaidi ◽  
Nur Awanis Hashim ◽  
Mohamad Fairus Rabuni ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Chemical Characterization ◽  
Gas Permeation ◽  
Separation Performance ◽  
Membrane Composition ◽  
Asymmetric Membrane ◽  
Wet Phase Inversion ◽  
Pair Performance ◽  
Improved Performance ◽  
Physical And Chemical

Abstract Efficient purification technology is crucial to fully utilize hydrogen (H2) as the next generation fuel source. Polyimide (PI) membranes have been intensively applied for H2 purification but its current separation performance of neat PI membranes is insufficient to fulfill industrial demand. This study employs blending and crosslinking modification simultaneously to enhance the separation efficiency of a membrane. Polyethersulfone (PES) and Co-PI (P84) blend asymmetric membranes have been prepared via dry–wet phase inversion with three different ratios. Pure H2 and carbon dioxide (CO2) gas permeation are conducted on the polymer blends to find the best formulation for membrane composition for effective H2 purification. Next, the membrane with the best blending ratio is chemically modified using 1,3-diaminopropane (PDA) with variable reaction time. Physical and chemical characterization of all membranes was evaluated using field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR). Upon 15 min modification, the polymer membrane achieved an improvement on H2/CO2 selectivity by 88.9%. Moreover, similar membrane has demonstrated the best performance as it has surpassed Robeson’s upper bound curve for H2/CO2 gas pair performance. Therefore, this finding is significant towards the development of H2-selective membranes with improved performance.

Efficient selective separation of yttrium from holmium and erbium using carboxyl functionalized ionic liquids

2021 ◽  
pp. 118774
Author(s):  
Kaibo Hu ◽  
Hongshuai Gao ◽  
Yi Nie ◽  
Haifeng Dong ◽  
Junjun Yan ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Selective Separation

Multilevel/hierarchical nanocomposite imprinted regenerated cellulose membranes for high-efficiency separation: A selective recognition method with Au/PDA-loaded surface

2021 ◽  
Author(s):  
Ming Yan ◽  
Yilin Wu ◽  
Rongxin Lin ◽  
Faguang Ma ◽  
Zhongyi Jiang
Keyword(s):  
Molecular Imprinting ◽  
High Efficiency ◽  
Selective Separation ◽  
Selective Recognition ◽  
Regenerated Cellulose ◽  
Separation Performance ◽  
Recognition Method ◽  
Membrane Materials ◽  
Loaded Surface ◽  
Cellulose Membranes

Although many researchers have done lots of studies on improving the selective separation performance of membrane materials, conceptions and applications of membrane-based molecular imprinting separation&recognition with both high permselectivity and...

scholarly journals Separation of Radionuclides from a Rare Earth-Containing Solution by Zeolite Adsorption

Minerals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 20
Author(s):  
Deniz Talan ◽  
Qingqing Huang
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Contact Time ◽  
Separation Efficiency ◽  
Ph Value ◽  
Solid Phase ◽  
Separation Performance ◽  
Solution Ph ◽  
Zeolite Sample ◽  
Alternative Sources

The increasing industrial demand for rare earths requires new or alternative sources to be found. Within this context, there have been studies validating the technical feasibility of coal and coal byproducts as alternative sources for rare earth elements. Nonetheless, radioactive materials, such as thorium and uranium, are frequently seen in the rare earths’ mineralization, and causes environmental and health concerns. Consequently, there exists an urgent need to remove these radionuclides in order to produce high purity rare earths to diversify the supply chain, as well as maintain an environmentally-favorable extraction process for the surroundings. In this study, an experimental design was generated to examine the effect of zeolite particle size, feed solution pH, zeolite amount, and contact time of solid and aqueous phases on the removal of thorium and uranium from the solution. The best separation performance was achieved using 2.50 g of 12-µm zeolite sample at a pH value of 3 with a contact time of 2 h. Under these conditions, the adsorption recovery of rare earths, thorium, and uranium into the solid phase was found to be 20.43 wt%, 99.20 wt%, and 89.60 wt%, respectively. The Freundlich adsorption isotherm was determined to be the best-fit model, and the adsorption mechanism of rare earths and thorium was identified as multilayer physisorption. Further, the separation efficiency was assessed using the response surface methodology based on the development of a statistically significant model.

scholarly journals Influence of Vortex Finder Structure on Separation Performance of Double-Overflow Three-Product Hydrocyclones

Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 79
Author(s):  
Yuekan Zhang ◽  
Jiangbo Ge ◽  
Lanyue Jiang ◽  
Hui Wang ◽  
Junru Yang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Experimental Research ◽  
Separation Efficiency ◽  
Structural Parameters ◽  
Separation Performance ◽  
Insertion Depth ◽  
Flow Field Characteristics ◽  
Vortex Finder ◽  
Fine Classification

In view of the difficulty of traditional hydrocyclones to meet the requirements of fine classification, a double-overflow three-product (internal overflow, external overflow and underflow) hydrocyclone was designed in this study. Numerical simulation and experimental research methods were used to investigate the effects of double-overflow flow field characteristics and structural parameters (i.e., internal vortex finder diameter and insertion depth) on separation performance. The research results showed that the larger the diameter of the internal vortex finder, the greater the overflow yield and the larger the cut size. The finest internal overflow product can be obtained when the internal vortex finder is 30 mm longer than the external vortex finder. The separation efficiency is highest when the internal vortex finder is 30 mm shorter than the external vortex finder.

Long alkyl chain quaternary ammonium-based ionic liquids and potential applications

2006 ◽  
Vol 8 (9) ◽  
pp. 798 ◽  
Author(s):  
Juliusz Pernak ◽  
Marcin Smiglak ◽  
Scott T. Griffin ◽  
Whitney L. Hough ◽  
Timothy B. Wilson ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Quaternary Ammonium ◽  
Alkyl Chain ◽  
Potential Applications ◽  
Long Alkyl Chain

Selective separation of zwitterionic phospholipid homologues with functional ionic liquids as extractants

RSC Advances ◽  
2015 ◽  
Vol 5 (95) ◽  
pp. 77581-77588 ◽  
Author(s):  
Jingzhu Zhang ◽  
Kun Yu ◽  
Qiwei Yang ◽  
Zongbi Bao ◽  
Zhiguo Zhang ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Selective Separation

A novel extractive method using hydroxyl-functional ILs as extractants was developed for the separation of zwitterionic phospholipid homologues.

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