scholarly journals CO2 Absorption with NaOH Solution through the Porous PVDF Hollow Fibre Membrane Contactor

2017 ◽  
Vol 12 (1) ◽  
Author(s):  
A. Mansourizadeh ◽  
A. F. Ismail
Keyword(s):  
Flow Rate ◽  
Hollow Fiber ◽  
Phase Inversion ◽  
Co2 Flux ◽  
Operating Conditions ◽  
Co2 Absorption ◽  
Membrane Contactor ◽  
Hydrophobic Membrane ◽  
Transfer Resistance ◽  
Naoh Solution

In this study, porous hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membranes were fabricated via a wet phase inversion process. In order to improve the phase inversion rate and provide porous membranes, 4 wt.% lithium chloride (LiCl) was used in the spinning dope. The prepared membrane morphology was studied using field emission scanning electron microscopy (FESEM). Chemical CO2absorption by NaOH solution (1M) was conducted through the PVDF hollow fiber membrane contactor. The effect of the main operating condition such as absorbent temperature, CO2 pressure and absorbent flow rate on the performance of CO2 absorption was investigated. From FESEM examination, the membrane possesses an almost sponge–like structure with ultra thin skin layer. Results of CO2absorption test showed that by increasing the absorbent flow rate the CO2 flux increased which confirmed the existence of liquid side mass transfer resistance. It was found that by increasing the absorbent temperature the CO2 flux considerably improved. Meanwhile, the effect of CO2 pressure on the absorption rate was insignificant. Therefore, it can be concluded that by applying a porous hydrophobic membrane with improved structure and optimizing the operating conditions, high CO2 removal efficiency can be achieved through gas–liquid membrane contactors

Improvement of CO2 Separation Performance by Blended Aqueous Solutions of DEA+AMP in Hollow Fiber Membrane Contactor (HFMC)

2012 ◽  
Vol 512-515 ◽  
pp. 2308-2316 ◽  
Author(s):  
Zhen Wang ◽  
Meng Xiang Fang ◽  
Shui Ping Yan ◽  
Yi Li Pang ◽  
Zhong Yang Luo
Keyword(s):  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Co2 Flux ◽  
Positive Influence ◽  
Separation Performance ◽  
Co2 Absorption ◽  
Membrane Contactor ◽  
Fiber Membrane ◽  
High Concentration ◽  
Carbon Dioxide Co2

Absorption of carbon dioxide (CO2) by blended diethanolamine (DEA) + 2-amino-2- methyl-1-propanol (AMP) and single DEA solvents were compared using hollow fiber membrane contactor (HFMC). Experimental results showed AMP additive has positive influence to improve CO2 absorption flux and the optimum AMP/DEA mass concentration ratio is between 0.2 and 0.4. Decreasing gas liquid ratio could greatly promote CO2 absorption, and operating temperature has weak effect on CO2 flux. Besides, large CO2 flux can be achieved with high concentration of DEA+0.2AMP solution due to the decrease of liquid phase resistance to mass transfer, but the optimal DEA concentration was recommended to be about 15% for DEA+0.2AMP solution considering the costs of amines in HFMC.

scholarly journals Effects of Absorbent Flow Rate on Co2 Absorption through a Super Hydrophobic Hollow Fiber Membrane Contactor

2017 ◽  
Vol 8 (8) ◽  
pp. 1429 ◽  
Author(s):  
Sutrasno Kartohardjono ◽  
Angeline Paramitha ◽  
Aulia Andika Putri ◽  
Ryan Andriant
Keyword(s):  
Flow Rate ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Co2 Absorption ◽  
Membrane Contactor ◽  
Fiber Membrane

scholarly journals CO2 absorption in flat membrane microstructured contactors of different wettability using aqueous solution of NaOH

2018 ◽  
Vol 7 (6) ◽  
pp. 471-476 ◽  
Author(s):  
Achilleas Constantinou ◽  
Simon Barrass ◽  
Asterios Gavriilidis
Keyword(s):  
Mass Transfer ◽  
Removal Efficiency ◽  
Residence Time ◽  
Single Channel ◽  
Co2 Absorption ◽  
Membrane Contactor ◽  
Transfer Resistance ◽  
Ptfe Membrane ◽  
Naoh Solution ◽  
Flat Membrane

Abstract CO2 absorption in solutions of sodium hydroxide (NaOH) was performed in three membrane/mesh microstructured contactors: a single-channel polytetrafluoroethylene (PTFE) membrane contactor, a nickel mesh contactor and an eight-channel PTFE membrane contactor. A membrane/mesh was used to achieve gas/liquid mass transfer without dispersion of one phase within the other. The PTFE membrane consisted of a pure PTFE layer 20 μm thick laminated onto a polypropylene (PP) layer of 80 μm thickness. The pure PTFE layer contained pores of ~0.5 to 5 μm diameter and was hydrophobic, while the PP layer consisted of rectangular openings of 0.8 mm×0.324 mm and was hydrophilic. The nickel mesh was 25 μm thick and contained pores of 25 μm diameter and was hydrophilic. Experiments were performed with a 2 m NaOH solution and an inlet feed of 20 vol % CO2/N2 gas mixture. Numerical simulations matched reasonably well the experimental data. CO2 removal efficiency increased by increasing the NaOH concentration, the gas residence time and the exchange area between gas and liquid. Higher removal of CO2 was achieved when the PP was in the gas side rather than in the liquid side, due to lower mass transfer resistance of the gas phase. For the same reason, CO2 removal efficiency was higher for the eight-channel PTFE contactor compared to the nickel mesh contactor. Average CO2 flux was higher for the eight-channel contactor (8×10−3 mol/min·cm2 with PP on the gas side) compared to the nickel mesh contactor (3×10−3 mol/min·cm2) for the same gas and liquid residence times. The eight-channel PTFE membrane contactor removed around 72% of CO2 in 1.2 s gas residence time, demonstrating the potential for CO2 absorption using flat membrane contactors.

scholarly journals CO2 Absorption Using Hollow Fiber Membrane Contactors: Introducing pH Swing Absorption (pHSA) to Overcome Purity Limitation

Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 496
Author(s):  
Sayali Ramdas Chavan ◽  
Patrick Perré ◽  
Victor Pozzobon ◽  
Julien Lemaire
Keyword(s):  
Hollow Fiber ◽  
Recovery Rate ◽  
Hollow Fiber Membrane ◽  
Operating Conditions ◽  
Co2 Removal ◽  
Co2 Absorption ◽  
Fiber Membrane ◽  
Residual Content ◽  
Membrane Contactors ◽  
Ph Swing

Recently, membrane contactors have gained more popularity in the field of CO2 removal; however, achieving high purity and competitive recovery for poor soluble gas (H2, N2, or CH4) remains elusive. Hence, a novel process for CO2 removal from a mixture of gases using hollow fiber membrane contactors is investigated theoretically and experimentally. A theoretical model is constructed to show that the dissolved residual CO2 hinders the capacity of the absorbent when it is regenerated. This model, backed up by experimental investigation, proves that achieving a purity > 99% without consuming excessive chemicals or energy remains challenging in a closed-loop system. As a solution, a novel strategy is proposed: the pH Swing Absorption which consists of manipulating the acido–basic equilibrium of CO2 in the absorption and desorption stages by injecting moderate acid and base amount. It aims at decreasing CO2 residual content in the regenerated absorbent, by converting CO2 into its ionic counterparts (HCO3− or CO32−) before absorption and improving CO2 degassing before desorption. Therefore, this strategy unlocks the theoretical limitation due to equilibrium with CO2 residual content in the absorbent and increases considerably the maximum achievable purity. Results also show the dependency of the performance on operating conditions such as total gas pressure and liquid flowrate. For N2/CO2 mixture, this process achieved a nitrogen purity of 99.97% with a N2 recovery rate of 94.13%. Similarly, for H2/CO2 mixture, a maximum H2 purity of 99.96% and recovery rate of 93.96% was obtained using this process. Moreover, the proposed patented process could potentially reduce energy or chemicals consumption.

scholarly journals Preparation and characterization of different geometrical shapes of multi-bore hollow fiber membranes and application in vacuum membrane distillation

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Elham M. El-Zanati ◽  
Eman Farg ◽  
Esraa Taha ◽  
Ayman El-Guindi ◽  
Heba Abdallah
Keyword(s):  
Mechanical Properties ◽  
Flow Rate ◽  
Hollow Fiber ◽  
Amorphous Structure ◽  
Membrane Distillation ◽  
Operating Conditions ◽  
Hollow Fiber Membranes ◽  
Preparation Conditions ◽  
Geometrical Shapes ◽  
Fiber Membranes

Abstract Multi-bore hollow fiber membranes were prepared through phase inversion spinning process using new locally designed spinnerets of various geometrical shapes. The spun cylindrical-like, rectangular or ribbon-like, and triangular-like are prepared, dried, and characterized by scanning electronic microscope. Fibers of circular (seven, five, and four bores) shape, rectangular of five bores, and triangular of three bores were chosen to study the effect of both geometrical configuration and the number of bores on the amorphous structure and the mechanical properties of the membranes. Membrane geometry, surface amorphous, and bore arrangements are very sensitive to the operating conditions, especially the extrusion and drawing rates. Three polymeric blends of different compositions are used to prepare multi-bore hollow fiber membranes. This study revealed that the blend composition of PES 16%, PVP 2%, PEG 2%, diethylene glycol 2%, and NMP 78% gives excellent mechanical properties. Optimization of the preparation conditions also developed, where the dope flow rate, the bore flow rate, and the air gap were 1.14 cm3 s−1, 1.1 cm3 s−1, and 0 cm, respectively. Furthermore, this study proved that the circular arrangement has high mechanical strength. The prepared seven-MBHF membranes were applied in the membrane distillation process, a solution of 35 g/l NaCl was used to test the membrane performance, and the achieved flux and rejection were 28.32 L/m2 h and 98.9%, respectively. This performance demonstrated that the prepared membrane in this way is suitable to compete with conventional reverse osmosis technology that uses single track hollow fibers.

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