Increased productivity of Clostridium acetobutylicum fermentation of acetone, butanol, and ethanol by pervaporation through supported ionic liquid membrane

Pervaporation proved to be one of the best methods to remove solvents out of a solvent producing Clostridium acetobutylicum culture. By using an ionic liquid (IL)-polydimethylsiloxane (PDMS) ultrafiltration membrane (pore size 60 nm), we could guarantee high stability and selectivity during all measurements carried out at 37C. Overall solvent productivity of fermentation connected with continuous product removal by pervaporation was 2.34 g l(-1) h(-1). The supported ionic liquid membrane (SILM) was impregnated with 15 wt% of a novel ionic liquid (tetrapropylammonium tetracyano-borate) and 85 wt% of polydimethylsiloxane. Pervaporation, accomplished with the optimized SILM, led to stable and efficient removal of the solvents butan-1-ol and acetone out of a C. acetobutylicum culture. By pervaporation through SILM, we removed more butan-1-ol than C. acetobutylicum was able to produce. Therefore, we added an extra dose of butan-1-ol to run fermentation on limiting values where the bacteria would still be able to survive its lethal concentration (15.82 g/l). After pervaporation was switched off, the bacteria died from high concentration of butan-1-ol, which they produced

Liquid - liquid flows in microchannels

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.In this work the flow patterns are investigated during the flow of an ionic liquid and deionized water mixture in a glass microchannel (0.2mm I.D) for two different inlet configurations (T- and Yjunction). The density, viscosity and surface tension of the ionic liquid [C4mim][NTf2] are 1420kg/m3 , 0.029Pa·s and 31.92mN/m respectively. The water phase has a density of 1000kg/m3, a viscosity of 0.001Pa·s and a surface tension of 73,69mN/m. In most of the patterns observed water was the continuous phase with the ionic liquid forming plugs or a mixture of plugs and drops within it. With the Y-junction and at high mixture velocities a separated pattern was observed with the two fluids flowing in parallel along the channel for the middle range of ionic liquid fractions, while water dispersed as drops was found at high ionic liquid fractions. Pressure drop was measured during regular plug flow which revealed that for the same ionic liquid superficial velocity the pressure drop was lower when it flowed in a mixture with water than when it was on its own in the channel. For a xonstant ionic liquid flow rate, pressure drop decreased as the ionic liquid fraction increased.The project is funded by the Engineering and Physical Sciences Research Council (EPSRC) and the Energy Institute at UCL

Advanced Supported Liquid Membranes for Carbon Dioxide Control in Extravehicular Activity Applications

There is disclosed a portable life support system with a component for removal of at least one selected gas. In an embodiment, the system includes a supported liquid membrane having a first side and a second side in opposition to one another, the first side configured for disposition toward an astronaut and the second side configured for disposition toward a vacuum atmosphere. The system further includes an ionic liquid disposed between the first side and the second side of the supported liquid membrane, the ionic liquid configured for removal of at least one selected gas from a region housing the astronaut adjacent the first side of the supported liquid membrane to the vacuum atmosphere adjacent the second side of the supported liquid membrane. Other embodiments are also disclosed

CO2 capture on NiO supported imidazolium-based ionic liquid

CO2 capture on NiO supported imidazolium-based ionic liquid, NiO/[emim][HSO4]/SiO2 as an adsorbent was investigated using gas adsorption analyzer and physicochemical properties of the adsorbent were characterized using X-ray powder diffraction (XRD), surface area analyzer (BET method) and temperature-program-desorption analysis (TPD). Immobilization of ionic liquid on silica, [emim][HSO4]/SiO2 slightly decreased the surface area compared to bare silica from 266 to 256 m2/g due to the pore blocking by the confinement of IL in SiO2 pore. Interestingly, introduction of NiO on supported ionic liquid, NiO/[emim][HSO4]/SiO2 was increased the surface area as well as pore volume from 256 to 356 m2/g and 0.14 to 0.38 cm3/g, respectively. The enhancement of surface area and pore volume was significantly increased the CO2 adsorption performance with capacity of 48.8 mg CO2/g adsorbent compared to [emim][HSO4]/SiO2 27.3 mg CO2/g adsorbent)

Solvent free hydrostannation and Stille reactions using ionic liquid supported organotin reagents

Hydrostannation reactions were performed cleanly using ionic liquid supported organotin reagents. These green reducing agents were used both under free radical and palladium-catalyzed conditions. One of the new ionic liquid supported organotin reagents so obtained was evaluated successfully in Stille cross-coupling reactions to give aryl-substituted allylic alcohols in solvent free conditions

Biodiesel via in situ wet microalgae biotransformation: Zwitter-type ionic liquid supported extraction and transesterification

The production of biodiesel derived from microalgae is among the most forthcoming technologies that provide an ecologic alternative to fossil fuels. Herein, a method was developed that enables the direct extraction and conversion of algal oil to biodiesel without prior isolation. The reaction occurs in aqueous media catalyzed by immobilized Candida antarctica lipase B (Novozyme 435). Zwitter-type ionic liquids were used as cocatalyst to improve the selectivity and reactivity of the enzyme. In a model reaction with sunflower oil, 64% biodiesel was obtained. Applying this method to a slurry of whole-cell Chlorella zof ingiensis in water resulted in 74.8% of lipid extraction, with 27.7% biotransformation products and up to 16% biodiesel. Factors that reduced the lipase activity with whole-cell algae were subsequently probed and discussed. This "in situ" method shows an improvement to existing methods, since it integrates the oil extraction and conversion into an one-pot procedure in aqueous conditions. The extraction is nondisruptive, and is a model for a greener algae to biodiesel process

Transport of lignin and other lignocellulosic components through supported ionic liquid membranes

Wood can be considered as the main renewable raw material. Until now, the production of cellulose has been the main target of wood transformation. However, the other components, mainly hemicellulose and lignin, must be taken into account for sustainable implementation of bio-refineries. The transition from low to high value added applications, specifically for lignin, requires the development of new separation processes. Supported ionic liquid membranes can be a promising option to separate and purify lignocellulosic components. The extraction from the feed phase to the stripping phase in only one stage allows the compaction of the system, without high energy demand. The main objective of this work was the analysis of the potential of supported ionic liquid membranes for lignin extraction and purification. [BMIM]MeSO4, [EMIM]EtSO4 and CYPHOS 108 were the ionic liquids chosen to impregnate PVDF membranes. The obtained results demonstrated that lignin can be extracted, but the SILMs were not selective and further study is required to determine their stability and the transport mechanisms involved.This research has been financially supported by the Spanish Ministry of Economy and Competitiveness (MINECO) through CTQ2014-56820-JIN Project, co-financed by FEDER funds

Synthesis Of Buckypaper Supported Ionic Liquid Membrane For Pervaporation Process

Membran cecair berpenyokong adalah salah satu konfigurasi membran cecair yang menggunakan bahan fasa cecair sebagai membran dan diperangkap ke dalam substrat berliang. Sejak kebelakangan ini, idea tentang penggunaan membran cecair berpenyokong dalam proses penyejattelapan telah menarik tumpuan ramai penyelidik. Tetapi penggunaan membran cecair berpenyokong menghadapi masalah ketidakstabilan yang berpunca daripada kehilangan membran cecair. Kajian ini bertujuan untuk membangunkan membran cecair berpenyokong dengan kestabilan yang tinggi dengan menggunakan kertas-bucky sebagai substrat berliang dan diperangkap dengan cecair ionik 1-butil-metilimidazolium tetrafluoroborat [Bmim][BF4] untuk membentuk membran cecair ionik berpenyokong kertas-bucky. Kertas-bucky terdiri daripada kelompok nano-tiub karbon dinding berlapis mampu memerangkap membran cecair ionik secara berkesan disebabkan oleh saiz liang yang kecil and struktur liang yang berliku-liku. Untuk meningkatkan lagi kestabilan membran, [Bmim][BF4] telah dicampur dengan polivinil alkohol sebelum diperangkap dalam kertas-bucky. Struktur membran cecair ionik berpenyokong kertas-bucky yang terhasil didapati berbeza dengan membran asimetrik, di mana fasa membran dan sokongan telah digabungkan dalam satu lapisan. Struktur tersebut membolehkan pembentukan membran simetri yang tipis tanpa menjejaskan sifat mekanikal membran. Prestasi membran cecair ionik berpenyokong kertas-bucky dalam proses penyejattelapan yang melibatkan campuran perduaan yang terdiri daripada etilena glikol dan air menunjukkan keupayaan membran tersebut dalam penyahhidratan larutan akueus etilena glikol. Kewujudan kertas-bucky dan [Bmim][BF4] didapati telah meningkatkan prestasi pemisahan dan kebolehtelapan intrinsik membran. Membran cecair ionik berpenyokong kertas-bucky telah menunjukkan prestasi penyejattelapan yang tinggi dengan fluks penelapan yang bernilai 102 g∙m-2∙j-1, faktor pemisahan setinggi 1014, kebolehtelapan air yang bernilai 13106 GPU dan kememilihan membran untuk air yang bernilai 13 dengan berat air dalam kepekatan larutan suapan sebanyak 10% pada suhu 30 °C dan 5 mmHg tekanan hiliran. Di samping itu, membran cecair ionik berpenyokong kertas-bucky juga mampu untuk memisahkan campuran pertigaan; etil asetat, etanol dan air yang membentuk azeotrop. Fluks penelapan sebanyak 385 g∙m-2∙j-1, faktor pemisahan yang bernilai 247, kebolehtelapan air 4730 GPU dan kememilihan membran untuk air yang bernilai 39 telah diperolehi pada suhu 30 °C dan 5 mmHg tekanan hiliran. Membran cecair ionik berpenyokong kertas-bucky telah mempamerkan prestasi yang tekal dalam operasi selama 120 jam. Pekali resapan etilena glikol dan air pada operasi parameter yang berlainan telah dianggar dengan menggunakan model matematik semi-empirikal berdasarkan pengubahsuaian persamaan Maxwell-Stefan. Dengan merujuk pada pekali resapan yang dianggar, pemisahan membran cecair ionik berpenyokong kertas-bucky dalam proses penyejahttelapan bagi penyahhidratan campuran perduaan etilena glikol/air adalah dikawal oleh proses resapan. ________________________________________________________________________________________________________________________ Supported liquid membrane (SLM) is one of the liquid membrane configurations that employ a liquid phase substances as membrane and immobilized in a porous supporting membrane. Recently, the idea of using SLM in pervaporation process has attracted a great deal of research attention. However the use of SLM in pervaporation has always suffered from instability problem which is mainly due to the displacement of liquid membrane. In the present research work, it is aimed to develop a high stability SLM by employing buckypaper (BP) as supporting membrane and immobilized with an ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate [Bmim][BF4] to form a buckypaper supported ionic liquid membrane (BP-SILM). The BP, which is composed of entangled assemblies of multi-walled carbon nanotubes (CNTs), can effectively entrap the infiltrated the ionic liquid membrane due to its smaller pore size and highly tortuous porous structure. In order to further enhance the membrane stability, the [Bmim][BF4] was blended with polyvinyl alcohol (PVA) prior to the immobilization in the BP. The resulted BP-SILM structure, in which the membrane and support phase were merged into a single layer, was found to be different from that of conventional asymmetric membranes. The BP-SILM structure allows the formation of a thinner symmetric membrane without compromising its mechanical properties. The pervaporation performances of the BP-SILM in the binary mixture of ethylene glycol and water showed an excellent capability to dehydrate ethylene glycol aqueous solutions. The presence of BP and [Bmim][BF4] was observed to significantly enhance the separation performance and the intrinsic membrane permeability. The BP-SILM exhibited high pervaporation performance with a permeation flux of 102 g∙m-2∙h-1, separation factor as high as 1014, water permeance of 13106 GPU and membrane selectivity of 13 for water with 10 wt.% feed concentration of water at 30 °C and 5 mmHg downstream pressure. On the other hand, the BP-SILM was also capable to break ternary azeotropic mixtures of ethyl acetate, ethanol and water. A permeation flux of 385 g∙m-2∙h-1, separation factor of 247, water permeance of 4730 GPU and membrane selectivity of 39 for water were obtained at 30 °C and 5 mmHg downstream pressure. The BP-SILM also demonstrated a robust pervaporation performance over an operation of 120 hours. The diffusion coefficients of ethylene glycol and water at different operating parameter were estimated using a semi-empirical mathematical model based on modified Maxwell-Stefan equation. Based on the estimated diffusion coefficient obtained, the separation of BP-SILM in pervaporation dehydration of ethylene glycol/water binary mixture is more on diffusion control