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Ebrahim Ataeivarjovi, Zhigang Tang, Jian Chen
In this present work, a novel approach has been proposed by which a solvent absorption and membrane desorption methods can significantly reduce the carbon dioxide (CO2 ) emission and energy consumption. In this method, the CO2 capture processing is based on the combination of membrane and physical solvent. Here, dimethyl carbonate and polydimethylsiloxane (PDMS)-SiO2 nanocomposite were used as the physical solvent and desorption membrane, respectively. However, the main focus of this research was on the CO2 desorption behavior of PDMS-SiO2 hybrid membrane...
August 14, 2018: ACS Applied Materials & Interfaces
Hoda Azimi, Arian Ebneyamini, F Handan Tezel, Jules Thibault
The pervaporation separation of organic compounds from acetone-butanol-ethanol (ABE) fermentation model solutions was studied using activated carbon (AC) nanoparticle-poly (dimethylsiloxane) (PDMS) mixed matrix membranes (MMM). The effects of the operating conditions and nanoparticle loading content on the membrane performance have been investigated. While the separation factor increased continuously, with an increase in the concentration of nanoparticles, the total flux reached a maximum in the MMM with 8 wt % nanoparticle loading in PDMS...
July 10, 2018: Membranes
Faten Hassan Hassan Abdellatif, Jérôme Babin, Carole Arnal-Herault, Laurent David, Anne Jonquieres
Membranes made from cellulose acetate grafted with imidazolium or ammonium ionic liquids (ILs) containing different anions were considered for ethyl tert-butyl ether biofuel purification by pervaporation. The new cellulosic materials were obtained after bromide (Br- ) exchange by different anions (Tf2 N- , BF4 - , AcO- ). IL structure-membrane property relationships revealed that the membrane properties were strongly improved by varying the anion structure, molecular size and hydrogen bonding acceptor ability β in the Kamlet-Taft polarity scale...
September 15, 2018: Carbohydrate Polymers
Weibin Liang, Lin Li, Jingwei Hou, Nicholas D Shepherd, Thomas D Bennett, Deanna M D'Alessandro, Vicki Chen
Composite membranes with defective metal-organic frameworks (MOFs) connect the emerging fields of MOF topological modification, MOF-polymer interfacial engineering and composite material functionalization. Although defective MOFs can be fabricated via thermal or chemical treatment, the relationship between hierarchical MOF structure and their performance in a polymeric membrane matrix has so far not been investigated. Here we show how a modulator fumarate-based MIL-53(Al) microwave synthesis process results in defective MOFs...
April 14, 2018: Chemical Science
Siddhartha Moulik, Vani Bukke, S Chandrasekhar Sajja, Sridhar S
Present work reports the synthesis of a novel Chitosan-Polytetrafluoroethylene composite membrane with solvent resistant property for efficient separation of methanol/toluene mixture by pervaporation. The composite was crossed with tetraethyl orthosilicate (TEOS) to prevent or reduce membrane swelling and improve the separation factor. The synthesized membranes were characterized by SEM, FTIR and DSC analysis. Molecular dynamics (MD) simulation and computational fluid dynamics were coupled to predict the structural and diffusive properties besides concentration profile inside the membrane...
August 1, 2018: Carbohydrate Polymers
Ezra L Clark, Alexis T Bell
The electrochemical reduction of carbon dioxide is sensitive to electrolyte polarization, which causes gradients in pH and the concentration of carbon dioxide to form near the cathode surface. It is desirable to measure the concentration of reaction-relevant species in the immediate vicinity of the cathode because the intrinsic kinetics of carbon dioxide reduction depend on the composition of the local reaction environment. Meeting this objective has proven difficult because conventional analytical methods only sample products from the bulk electrolyte...
June 6, 2018: Journal of the American Chemical Society
Chao Zhu, Lijie Chen, Chuang Xue, Fengwu Bai
Background: Butanol derived from renewable resources by microbial fermentation is considered as one of not only valuable platform chemicals but alternative advanced biofuels. However, due to low butanol concentration in fermentation broth, butanol production is restricted by high energy consumption for product recovery. For in situ butanol recovery techniques, such as gas stripping and pervaporation, the common problem is their low efficiency in harvesting and concentrating butanol. Therefore, there is a necessity to develop an advanced butanol recovery technique for cost-effective biobutanol production...
2018: Biotechnology for Biofuels
Mashallah Rezakazemi, Azam Marjani, Saeed Shirazian
This work presents purification of cyclohexane using polydimethylsiloxane (PDMS) membranes in pervaporation (PV) process. The PDMS is a rubbery polymer and appropriate as membrane material for purification of cyclohexane. PV which is a low-energy separation process was chosen for purification of cyclohexane due to its superior advantages compared to other processes. Effect of feed concentration on separation factor was investigated in order to optimize the process. It was indicated that dehydration of 80 wt% cyclohexane mixture at a temperature of 300 K and a vacuum pressure of 10 mmHg could be effectively achieved and high separation factor of 2500 was obtained...
May 8, 2018: Environmental Science and Pollution Research International
Jie Liu, Jiding Li, Quan Chen, Xiaoduan Li
Polydimethylsiloxane (PDMS)/polyvinylidene fluoride (PVDF) composite membranes were fabricated and subsequently applied in ethanol recovery from an ethanol-water mixture by pervaporation (PV) using fractional condensation. The effects of feed temperature and feed flow velocity on the pervaporative properties of PDMS/PVDF composite membranes were investigated. Scanning electron microscopy (SEM) results showed that PDMS was coated uniformly on the surface of porous PVDF substrate, and the PDMS separation layer was dense with a thickness of 1...
April 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Inês T Meireles, Rosa M Huertas, Cristiana A V Torres, Isabel M Coelhoso, João G Crespo
The purpose of this work is the development and characterisation of new hybrid polysaccharide (FucoPol) membranes. These membranes were prepared by incorporation of a SiO2 network homogeneously dispersed by using a sol-gel method with GPTMS as a crosslinker silica precursor. They were further crosslinked with CaCl2 for reinforcement of mechanical properties and improvement of their permeation performance. They were characterised in terms of their structural, mechanical and thermal properties. They presented a dense and homogeneous structure, resistant to deformation, with a Tg of 43 °C and a thermal decomposition between 240 and 251 °C...
July 1, 2018: Carbohydrate Polymers
Anna Dawiec-Liśniewska, Antoni Szumny, Daria Podstawczyk, Anna Witek-Krowiak
The first article of a two-article series presents pervaporation (PV) of volatile aroma compounds from fruit juice hydrolates (plum, apple, blackcurrant and cherry). The purpose of this research was to evaluate the effectiveness of fruit juice hydrolates separation on a laboratory scale (inert gas flow pervaporation system) and semi-technical (vacuum pervaporation system) by means of pervaporation. To create precise matrices for hydrolates before and after pervaporation for each of the separated systems, solid phase microextraction (SPME) technique and the gas chromatography-mass spectrometry (GC-MS) was applied...
August 30, 2018: Food Chemistry
Hwi-Min Jung, Ju Yeon Lee, Jung-Hyun Lee, Min-Kyu Oh
A process of isobutanol production from sugarcane bagasse hydrolysates in Enterobacter aerogenes was developed here with a pervaporation-integrated procedure. Isobutanol pathway was overexpressed in a mutant strain with eliminated byproduct-forming enzymes (LdhA, BudA, and PflB). A glucose-and-xylose-coconsuming ptsG mutant was constructed for effective utilization of lignocellulosic biomass. Toxic effects of isobutanol were alleviated by in situ recovery via a pervaporation procedure. Compared to single-batch fermentation, cell growth and isobutanol titer were improved by 60% and 100%, respectively, in the pervaporation-integrated fermentation process...
July 2018: Bioresource Technology
Baojin Ma, Jing Han, Shan Zhang, Feng Liu, Shicai Wang, Jiazhi Duan, Yuanhua Sang, Huaidong Jiang, Dong Li, Shaohua Ge, Jinghua Yu, Hong Liu
Controllable osteoinduction maintained in the original defect area is the key to precise bone repair. To meet the requirement of precise bone regeneration, a hydroxyapatite (HAp) nanobelt/polylactic acid (PLA) (HAp/PLA) Janus membrane has been successfully prepared in this study by coating PLA on a paper-like HAp nanobelt film by a casting-pervaporation method. The Janus membrane possesses dual functions: excellent osteoinduction from the hydrophilic HAp nanobelt side and barrier function originating from the hydrophobic PLA film...
April 15, 2018: Acta Biomaterialia
Changjing Chen, Di Cai, Peiyong Qin, Biqiang Chen, Zheng Wang, Tianwei Tan
Hybrid process that integrated fermentation, pervaporation and esterification was established aiming to improve the economic feasibility of the conventional acetone-butanol-ethanol (ABE) fermentation process. Candida sp 99-125 cells were used as full-cell catalyst. The feasibility of batch and fed-batch esterification using the ABE permeate of pervaporation (ranging from 286.9 g/L to 402.9 g/L) as substrate were compared. Valuable butyl oleate was produced along with ethyl oleate. For the batch esterification, due to severe inhibition of substrate to lipase, the yield of butyl oleate and ethyl oleate were only 24...
June 2018: Bioresource Technology
J Y Chong, B Wang, K Li
Graphene oxide (GO) membranes have shown excellent selectivities in nanofiltration and pervaporation. However, the water transport mechanisms in the unique membrane laminar structure are still not well understood, especially in pervaporation which involves selective permeation and evaporation. Herein, water transport in GO membranes was tested under two different modes: pressure-driven permeation and pervaporation. The pure water flux was found to be 1-2 orders of magnitude higher in pervaporation due to the large capillary pressure induced by evaporation...
March 6, 2018: Chemical Communications: Chem Comm
Lucy Nandy, Cari S Dutcher
Water-soluble organic acids such as dicarboxylic acids are known to form a significant fraction of organic aerosol mass, yet the chemical composition and interactions between components in an organic acid-inorganic salt mixed particle remain unclear. In this study, phase behavior of different mixing ratios of the salt and organic acids, here 3-methyl glutaric acid and 3-methyl adipic acid, are investigated with respect to their water activity. A microfluidic pervaporation approach is used to study different phase transitions of internally mixed aqueous droplets...
April 5, 2018: Journal of Physical Chemistry. B
Holger Thiess, Axel Schmidt, Jochen Strube
In this study, an engineering tool for the design and optimization of pervaporation processes is developed based on physico-chemical modelling coupled with laboratory/mini-plant experiments. The model incorporates the solution-diffusion-mechanism, polarization effects (concentration and temperature), axial dispersion, pressure drop and the temperature drop in the feed channel due to vaporization of the permeating components. The permeance, being the key model parameter, was determined via dehydration experiments on a mini-plant scale for the binary mixtures ethanol/water and ethyl acetate/water...
January 15, 2018: Membranes
Baohe Wang, Yan Nie, Jing Ma
Combing molecular dynamics (MD) and Grand Canonical Monte Carlo (GCMC) simulation, the effect of bioadhesive transition layer on the interfacial compatibility of the pervaporation composite membranes, and the pervaporation performance toward penetrant molecules were investigated. In our previous experimental study, the structural stability and permeability selectivity of the composite membranes were considerably enhanced by the introduction of bioadhesive carbopol (CP). In the present study, the interfacial compatibility and the interfacial energies between the chitosan (CS) separation layer, CP transition layer and the support layer were investigated, respectively...
March 2018: Journal of Molecular Graphics & Modelling
Zhengqi Wu, Chun Zhang, Li Peng, Xuerui Wang, Qingqing Kong, Xuehong Gu
The practical application of pure-silica MFI zeolite membranes for ethanol/water separation by pervaporation is limited by its poor stability. Herein, we present the Si-OH eliminated MFI membranes by a simple dopamine modification, which can effectively prevent the chemical reaction between Si-OH groups and components, endowing the long-term pervaporation stability.
January 31, 2018: ACS Applied Materials & Interfaces
Svetlana V Kononova, Elena V Kruchinina, Valentina A Petrova, Yulia G Baklagina, Kira A Romashkova, Anton S Orekhov, Vera V Klechkovskaya, Yury A Skorik
Two-ply composite membranes with separation layers from chitosan and sulfoethylcellulose were developed on a microporous support based on poly(diphenylsulfone- N -phenylphthalimide) and investigated by use of X-ray diffraction and scanning electron microscopy methods. The pervaporation properties of the membranes were studied for the separation of aqueous alcohol (ethanol, propan-2-ol) mixtures of different compositions. When the mixtures to be separated consist of less than 15 wt % water in propan-2-ol, the membranes composed of polyelectrolytes with the same molar fraction of ionogenic groups (-NH₃⁺ for chitosan and -SO₃- for sulfoethylcellulose) show high permselectivity (the water content in the permeate was 100%)...
December 14, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
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