scholarly journals Comparison of Supported Ionic Liquid Membranes and Polymeric Ultrafiltration and Nanofiltration Membranes for Separation of Lignin and Monosaccharides

Membranes ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 29 ◽  
Author(s):  
Ricardo Abejón ◽  
Javier Rabadán ◽  
Aurora Garea ◽  
Angel Irabien

Lignin is one of the three main components of lignocellulosic biomass and must be considered a raw material with attractive applications from an economic and ecological point of view. Therefore, biorefineries must have in mind the most adequate processing to obtain high-quality lignin and the separation tasks that play a key role to improve the purity of the lignin. Separation techniques based on membranes are a promising way to achieve these requirements. In this work, the separation performance of the SILM (Supported Ionic Liquid Membrane) formed with [BMIM][DBP] as IL (Ionic Liquid) and PTFE as membrane support was compared to a nanofiltration (NF) membrane (NP010 by Microdyn-Nadir) and two ultrafiltration (UF) membranes (UF5 and UF10 by Trisep). The SILM showed selective transport of Kraft lignin, lignosulphonate, xylose, and glucose in aqueous solutions. Although it was stable under different conditions and its performance was improved by the integration of agitation, it was not competitive when compared to NF and UF membranes, although the latter ones suffered fouling. The NF membrane was the best alternative for the separation of lignosulphonates from monosaccharides (separation factors around 75 while SILM attained only values lower than 3), while the UF5 membrane should be selected to separate Kraft lignin and monosaccharides (separation factors around 100 while SILM attained only values below 3).

2020 ◽  
Vol 39 (1) ◽  
pp. 101
Author(s):  
Zenon Ziobrowski ◽  
Adam Rotkegel

The separation of CO2/N2  by supported ionic liquid membranes (SILMs) is presented. SILMs have been developed by impregnation of the ceramic support nanopores of  commercial PDMS (polidimethylosiloxane) membranes (made by Pervatech BV) and commercial microfiltration membranes (made by Inopor) with 1-ethyl-3-methylimidazolium acetate ([Emim][Ac]). Comparison of separation efficiency of SILMs prepared on the same ceramic support shows that SILMs based on PDMS membranes show good stability and very high CO2/N2 selectivity. Yhe obtained results present an inexpensive alternative in selective CO2/N2 separation by SILMs, especially when the choice of selectivity is the first priority. The comparison with Robeson upper bond correlation and literature data shows that applying the ionic liquid and appropriate impregnating method to the PDMS membranes results in significant improvement of separation performance.


Membranes ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
Alsu Akhmetshina ◽  
Nail Yanbikov ◽  
Artem Atlaskin ◽  
Maxim Trubyanov ◽  
Amal Mechergui ◽  
...  

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 supported ionic liquid membranes impregnated by 1-butyl-3-methylimidazolium acetate (bmim[OAc]) with the following determination of the ideal selectivity in order to compare the facilitated transport membrane performance with the supported ionic liquid membrane (SILM) that provides solution-diffusion mechanism, 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[OAc]-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.


Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 359
Author(s):  
László Koók ◽  
Piroska Lajtai-Szabó ◽  
Péter Bakonyi ◽  
Katalin Bélafi-Bakó ◽  
Nándor Nemestóthy

Hydrophobic ionic liquids (IL) may offer a special electrolyte in the form of supported ionic liquid membranes (SILM) for microbial fuel cells (MFC) due to their advantageous mass transfer characteristics. In this work, the proton and ion transfer properties of SILMs made with IL containing imidazolium cation and [PF6]− and [NTf2]− anions were studied and compared to Nafion. It resulted that both ILs show better proton mass transfer and diffusion coefficient than Nafion. The data implied the presence of water microclusters permeating through [hmim][PF6]-SILM to assist the proton transfer. This mechanism could not be assumed in the case of [NTf2]− containing IL. Ion transport numbers of K+, Na+, and H+ showed that the IL with [PF6]− anion could be beneficial in terms of reducing ion transfer losses in MFCs. Moreover, the conductivity of [bmim][PF6]-SILM at low electrolyte concentration (such as in MFCs) was comparable to Nafion.


2009 ◽  
Vol 328 (1-2) ◽  
pp. 81-85 ◽  
Author(s):  
Antonia P. de los Ríos ◽  
Francisco J. Hernández-Fernández ◽  
Hugo Presa ◽  
Demetrio Gómez ◽  
Gloria Víllora

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