Modeling and Experimental Study of Carbon Dioxide Absorption in a Flat Sheet Membrane Contactor
Nayef
Ghasem
Department of Chemical & Petroleum Engineering, UAE University, Al-Ain city, United Arab Emirates
author
Mohamed
Al-Marzouqi
Department of Chemical & Petroleum Engineering, UAE University, Al-Ain city, United Arab Emirates
author
text
article
2017
eng
comIn the present study, CO2 removal from natural gas stream has been studied using a flat sheet membrane contactor. A three dimensional mathematical model is developed to describe the process. The model considers the transport of a gas mixture containing carbon dioxide and methane through a flat sheet membrane contactor module. The model is based on the non-wetted mode of operation, in which the gas fills the membrane pores in a countercurrent gas-liquid contact. Simulation was performed using computational fluid dynamics (CFD) of the model material and momentum transport equations in the flat sheet membrane for laminar flow conditions. Physical and chemical absorptions were considered in the simulations for the absorption of CO2 in aqueous sodium hydroxide solution. Simulation predictions were in good agreement with the experimental data for different values of gas flow rates. The modeling predictions indicate that the removal of CO2 increased with increasing inlet liquid flow rate and increasing solvent temperature, by contrast, increase in inlet gas flow rate has negative effect.
Journal of Membrane Science and Research
FIMTEC & MPRL
2476-5406
3
v.
2
no.
2017
57
63
https://www.msrjournal.com/article_20226_b666555fc9acf637e046a79f79e846e3.pdf
dx.doi.org/10.22079/jmsr.2016.20226
Evaluation of Vapor Deposition Techniques for Membrane Pore Size Modification
Colin
Wolden
Department of Chemical & Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
author
Sanket
Kelkar
Department of Chemical & Biological Engineering, Colorado School of Mines, Golden, CO 80401, USA
author
text
article
2017
eng
The suitability of three vapor deposition techniques for pore size modification was evaluated using polycarbonate track etched membranes as model supports. A feature scale model was employed to predict the pore geometry after modification and the resulting pure water flux. Physical vapor deposition (PVD) and pulsed plasma-enhanced chemical vapor deposition (PECVD), naturally, form asymmetric nanopores that retain high flux as pore size is reduced. But PVD-modified supports exhibited poor control and reproducibility. In contrast, pulsed PECVD and plasma-enhanced atomic layer deposition (PEALD) were shown to deliver digital control over pore size. Moreover, good agreement was obtained between model predictions and flux measurements. Exposure limitations during PEALD introduce a degree of asymmetry, though net growth rates were 1-2 orders of magnitude smaller than pulsed PECVD and PVD. Filtration experiments using bovine serum albumin as a model solute showed that pulsed PECVD-modified membranes can be engineered to simultaneously deliver both high flux and high selectivity. For example, pulsed PECVD-modified supports were demonstrated to deliver high retention (~ 75%) while maintaining 70% of their initial pure water flux.
Journal of Membrane Science and Research
FIMTEC & MPRL
2476-5406
3
v.
2
no.
2017
64
70
https://www.msrjournal.com/article_20345_71b23a586d17b8972a51c83e35c2a594.pdf
dx.doi.org/10.22079/jmsr.2016.20345
Extraction-Stripping Patterns during Co-Extraction of Copper and Nickel from Ammoniacal Solutions into Emulsion Liquid Membranes Using LIX 84I®
Mathurkumar
Bhakhar
Gujarat Technological University, Ahmedabad
author
Bina
Sengupta
The Maharaja Sayajirao University of Baroda, Vadodara
author
Ranjan
Sengupta
The Maharaja Sayajirao University of Baroda, Vadodara
author
text
article
2017
eng
Extraction of nickel and its co-extraction with copper from ammoniacal media into emulsion liquid membrane systems (ELMs) was investigated using LIX 84I as the carrier. Measurement of the solute stripped in the internal phase of emulsion opened a new dimension in the study of the ELM extraction processes. The effect of operating parameters such as feed pH, initial feed concentration, and treat ratio of emulsion to feed and the effect of emulsion parameters such as internal phase stripping acid concentration, carrier concentration, and internal phase volume fraction were investigated. The optimal pH for extraction was 8.1. The overall extraction process was strongly favored by the factors that lead to enhancement of uptake of metal ions such as increase in the carrier concentration and the treat ratio. Investigations on the stripping patterns in W/O emulsions revealed that sulfuric acid of 1.0 M concentration was optimal for nickel stripping in ELMs but the process was slow. Stripping of copper was relatively fast and was favored by higher acid concentrations. The amount of nickel extracted declined in the presence of copper during co-extraction of copper and nickel and the amount of copper stripped in the internal phase of the emulsion was equivalent to the amount of nickel loaded by the emulsion. In general, almost 55% of the metal loaded in the emulsion was found to get stripped in the duration of the runs. Hence, there is scope to formulate emulsions and tune other operating parameters to achieve selective separation of one of the two metals co-extracted in the internal phase of the emulsion.
Journal of Membrane Science and Research
FIMTEC & MPRL
2476-5406
3
v.
2
no.
2017
71
77
https://www.msrjournal.com/article_20642_9c0ebd60f3cb579a1c5369f8581857ef.pdf
dx.doi.org/10.22079/jmsr.2016.20642
Correlated Effect of Air Gap and PVP Concentration on the Structure and Performance of PVDF Ultrafiltration Hollow Fiber Membrane
Yonggang
Gao
Global R&D center, Water Technologies, Industry Automation Division, Siemens Pte Ltd, 82 Toh Guan Road East, #C1-23 WaterHub, Singapore 608576
author
text
article
2017
eng
Polyvinylidene fluoride/polyvinylpyrrolidone (PVDF/PVP) hollow fiber membranes were fabricated by dry-jet wet-spinning process. The correlated effects of the air gap length and PVP concentration ((1) the air gap length effect at the low and high PVP concentration in the dope solutions, as well as (2) the effect of the PVP concentration at the same air gap length) on the cross-section structure and membrane performance were investigated. Results indicated that the air gap effect on hollow fiber membranes is more evident for the dope solution with the high PVP concentration than low PVP concentration. In other words, macro-voids grow inwards and mechanical properties decrease and pure water permeability increases as the air gap length decreases. With increasing the PVP concentration in dope solution, large macro-voids/cavities in hollow fiber membranes are suppressed to the finger-like macro-voids. Moreover, the outer separation layer is thickened, and the mechanical properties are increased, as well.
Journal of Membrane Science and Research
FIMTEC & MPRL
2476-5406
3
v.
2
no.
2017
78
83
https://www.msrjournal.com/article_22936_5094dc2caaddfd29ccc5a46c0e2f93be.pdf
dx.doi.org/10.22079/jmsr.2016.22936
Shortcut Node Classification for Membrane Residue Curve Maps
Neil
Stacey
University of the Witwatersrand
author
Diane
Hildebrandt
University of South Africa
author
David
Glasser
University of South Africa
author
Mark
Peters
University of South Africa
author
text
article
2017
eng
comNode classification within Membrane Residue Curves (M-RCMs) currently hinges on Lyapunov’s Theorem and therefore the computation of mathematically complex eigenvalues. This paper presents an alternative criterion for the classification of nodes within M-RCMs based on the total membrane flux at node compositions. This paper demonstrates that for a system exhibiting simple permeation behaviour, this flux criterion is mathematically identical to Lyapunov’s theorem for all possible values of relative permeability. This means that in membrane permeation systems with simple permeation, the stationary point with maximum flux is an unstable node while the stationary with minimum flux is a stable node and stationary points with intermediate fluxes are saddle points. This proof is also extended to two-membrane systems with simple permeation behaviour, resulting in a system of equations useful for finding membrane area ratios with desired node properties. It is also shown that the flux criterion does not hold for systems exhibiting complex permeation.
Journal of Membrane Science and Research
FIMTEC & MPRL
2476-5406
3
v.
2
no.
2017
84
89
https://www.msrjournal.com/article_21846_2e3b555cf9ba0762ccfd38716ec4e737.pdf
dx.doi.org/10.22079/jmsr.2016.21846
Preparation and Characterization of CA−PEG−TiO2 Membranes: Effect of PEG and TiO2 on Morphology, Flux and Fouling Performance
Chandan
Das
Indian Institute of Technology Guwahati, INDIA
author
Kibrom Alebel
Gebru
Indian Institute of Technology Guwahati, INDIA, PIN 781039
author
text
article
2017
eng
Modified cellulose acetate (CA) membranes were prepared by dissolving the polymers in a mixture of acetone (AC) and N, N dimethylacetamide (DMAc) (70:30) solvent and deionized (DI) water was used in the coagulation bath. The introduction of polyethylene glycol (PEG) additive and TiO2 nanoparticles (NPs) into the casting solution has changed the structures of the resulting membranes during the phase inversion process. Effects of PEG additive and TiO2 NPs on the preparation of the phase-inverted CA ultrafiltration membrane were investigated in terms of morphology, equilibrium water content (EWC), pure water flux (PWF), hydraulic resistance, thermal stability, water contact angle (WCA) and anti-fouling performance. Improvements in average pore size, porosity, thermal stability, and the hydrophilic nature of the CA membranes was detected after the introduction of PEG and TiO2 simultaneously to the polymer matrix. Thermo gravimetric analysis (TGA) results confirmed that the interaction between TiO2 and the degradation temperature of the CA membrane were significantly improved. The anti-fouling performance and the flux recovery potential of the membranes were investigated using the bovine serum albumin (BSA) protein. The M3 (CA-PEG-TiO2) membrane (10.5 Wt. % CA: 4 Wt. % PEG: 2 Wt. % TiO2) exhibited the highest BSA flux result and normalized flux recovery ratios (NFR) for the three fouling cycles.
Journal of Membrane Science and Research
FIMTEC & MPRL
2476-5406
3
v.
2
no.
2017
90
101
https://www.msrjournal.com/article_22820_1344e80b719f8ea88da455a7ee2e379c.pdf
dx.doi.org/10.22079/jmsr.2016.22820
Glycerin Removal from Ultrafiltration Flat Sheet Membranes by Filtration and Soaking
Sophie
Arenillas
EVEON-AMU
author
Maryse
Drouin
AMU
author
Emmanuel
Monnin
Eveon
author
Philippe
Moulin
Europole de l'Arbois, bat. Laennec, Hall C BP 80, 13545
author
text
article
2017
eng
comIn the case of pharmaceutical processes, the presence of preservatives can be problematic and the quantity is subject to stringent standards. So, the aim of this study is to quantify the removal of glycerin contained in ultrafiltration flat sheet membranes by filtration and soaking. This is carried out over a wide range of membranes with different characteristics. The selected flat sheet membranes (with a surface of 14.5 cm²) have a Molecular Weight Cut-Off (MWCO) ranging from 5 to 60 kDa. They are made of different organic materials (polyethersulfone, regenerated cellulose and etc.) and are manufactured by different suppliers (Millipore, Sartorius, GE Osmonics, Novasep, Pall). The density and therefore the glycerin concentration measurements are carried out in filtered distilled water (dead-end filtration) and distilled water of soaking (diffusion phenomenon). This study gives experi-mental information about the glycerin quantity as a function of membrane characteristics and the position of glycerin on the membrane (skin layer and support). The various studied parameters are the removal kinetic, the filtered volume, the filtration pressure and the contact time.
Journal of Membrane Science and Research
FIMTEC & MPRL
2476-5406
3
v.
2
no.
2017
102
108
https://www.msrjournal.com/article_23080_a667212de60542b491d7a223df6df9b7.pdf
dx.doi.org/10.22079/jmsr.2016.23080
Electric Power Generation with Reverse Electrodialysis
Yoshinobu
Tanaka
author
text
article
2017
eng
The computer simulation program of a practical scale reverse electrodialysis process has been developed based on the program for saline water electrodialysis. The program is applied to compute the performance of an industrial-scale reverse electrodialysis stack (effective membrane area S = 1 m × 1 m = 1 m2, cell pair number N = 300 pairs). The stack operatingconditions are optimized. Seawater and brackish water are supplied to compute the overall membrane pair characteristics, ion and solution flux across a membrane pair, ion transport efficiency, generation efficiency, electric current leakage, stack electric resistance, stack voltage, external current, electric power, power density, pressure drop, limiting current density, and etc. When seawater (35000 ppm) and brackish water (1000 ppm) are used, the maximum power density is 0.85 W/m2 (15 °C), 1.10 W/m2 (25 °C) and 1.35 W/m2 (35 °C). Membrane electric resistance is less than brackish water electric resistance. Electric current leakage increases the electric power generation of the RED unit. Limiting current density is very large, so the unit is operated stably. By arranging 12 stacks, a small-scale reverse electrdialysis plant (N= 12×300 = 3600 pairs) is assembled. The plant is operated to compute the performance changing external electric resistance.
Journal of Membrane Science and Research
FIMTEC & MPRL
2476-5406
3
v.
2
no.
2017
109
117
https://www.msrjournal.com/article_22128_55a08d0ea436351ac9fbe6f7c2b8cd8a.pdf
dx.doi.org/10.22079/jmsr.2016.22128