HIGH PERFORMANCE VAPOUR PERMEATION WITH ORGANIC MEMBRANES FOR DEWATERING ETHANOL AND OTHER ORGANIC SOLVENTS

Major advantages of the vapourpermeation in a distillation hybrid-process in comparison to molecular sieve adsorption are lower operating costs and steady state behaviour. Polymeric membranes are also cheap in production costs compared to inorganic membrane types. Disadvantages of state of the art organic membrane dewatering technology are sensitivity, unreliability and insufficient purified product quality. GKSS has developed a new organic/inorganic membrane (based on polyvinylalcohol), which is longterm stable to common organic solvents (methanol, ethanol, isopropanol, etc.), temperatures up to 130°C and 15wt-% water in the feed. Higher temperatures and feed water-contents are being investigated currently in longterm tests. Above 5wt-% water in the feed the permeat flux is significantly higher than the permeate flux of inorganic NaA and silica membranes. At 15wt-% water in the feed the permeate flux of 25kg/m²h is approx. twice as high as with a industrially produced NaA membrane [1]. These results are obtained at 120°C, 4bar retentate pressure and 0.02bar permeate pressure. Although below 5wt-% feed water-content the water fraction in the permeat (90wt-% at 1wt-% water in feed) is lower as for the NaA membrane (97wt-% at 1wt-% water in feed), low price and high packing density of the GKSS membrane are probably compensating this drawback. The new GKSS membrane can be easily produced in industrial scale. During the membrane production it is straightforward to manipulate the flux and selectivity for different solvents and separation problems. GKSS has developed envelope type membrane modules in recent years (0.49 to 1.25m long and 0.31m in diameter) with a high packing density, low pressure drop and easy to maintain. Customised GKSS envelope type modules can be assembled with up to 184 membrane envelopes of the new GKSS membrane (total active membrane area approx. 22m²). Upscaling the production capacity can be done by upnumbering this modular technology. For example, a distillation column top flux of 500kg/h with 85wt-% ethanol, 120°C and 4bar needs a membrane area of 17m² to reach a product quality of 99.6wt-% ethanol with a product flux of 420kg/h. In this simulation pressure drops in permeate and retentate side as well as polarisation effects are considered. The whole pilot stage production process of membrane and module will be comercialised by GKSS partners. [1] H. Richter, I. Voigt und J.-T. Kühnert, Dewatering of ethanol by pervaporation and vapour permeation with industrial scale NaA-membranes, Desalination 199 (2006) 92-9

Use of catalytic membrane reactors for in situ reaction and separation

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Study of the Effect of Inorganic Particles on the Gas Transport Properties of Glassy Polyimides for Selective CO2 and H2O Separation

[EN] Three polyimides and six inorganic fillers in a form of nanometer-sized particles were studied as thick film solution cast mixed matrix membranes (MMMs) for the transport of CO2, CH4, and H2O. Gas transport properties and electron microscopy images indicate good polymer-filler compatibility for all membranes. The only filler type thatdemonstrated good distribution throughout the membrane thickness at 10 wt.% loading was BaCe0.2Zr0.7Y0.1O3 (BCZY). The influence of this filler on MMM gas transport properties was studied in detail for 6FDA-6FpDA in a filler content range from one to 20 wt.% and for Matrimid((R)) and P84((R)) at 10 wt.% loading. The most promising result was obtained for Matrimid((R))10 wt.% BCZY MMM, which showed improvement in CO2 and H2O permeabilities accompanied by increased CO2/CH4 selectivity and high water selective membrane at elevated temperatures without H2O/permanent gas selectivity loss.This work was financially supported by the Spanish Government (SEV-2016-0683, SVP-2014-068356, Project ENE2014-57651-R and IJCI-2016-28330 grants) and GeneralitatValenciana (PROMETEO/2018/006 grant) and Helmholtz-Zentrum Geesthacht (HZG) through the technology transfer project program and by the Helmholtz Association of German Research Centers through the Helmholtz Portfolio MEMBRAIN.Escorihuela-Roca, S.; Valero, L.; Tena, A.; Shishatskiy, S.; Escolástico Rozalén, S.; Brinkmann, T.; Serra Alfaro, JM. (2018). Study of the Effect of Inorganic Particles on the Gas Transport Properties of Glassy Polyimides for Selective CO2 and H2O Separation. Membranes. 8(4). https://doi.org/10.3390/membranes8040128S84KULPRATHIPANJA, S. (2003). Mixed Matrix Membrane Development. Annals of the New York Academy of Sciences, 984(1), 361-369. doi:10.1111/j.1749-6632.2003.tb06012.xRobeson, L. M. (2008). The upper bound revisited. Journal of Membrane Science, 320(1-2), 390-400. doi:10.1016/j.memsci.2008.04.030Baker, R. W. (2010). Research needs in the membrane separation industry: Looking back, looking forward. Journal of Membrane Science, 362(1-2), 134-136. doi:10.1016/j.memsci.2010.06.028Stünkel, S., Drescher, A., Wind, J., Brinkmann, T., Repke, J.-U., & Wozny, G. (2011). Carbon dioxide capture for the oxidative coupling of methane process – A case study in mini-plant scale. Chemical Engineering Research and Design, 89(8), 1261-1270. doi:10.1016/j.cherd.2011.02.024Cheng, Y., Wang, Z., & Zhao, D. (2018). Mixed Matrix Membranes for Natural Gas Upgrading: Current Status and Opportunities. 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O., Rafael-Galindo, G., de Lourdes Froto Madariaga, M., & Balagurusamy, N. (2018). Sustainable Production of Biogas from Renewable Sources: Global Overview, Scale Up Opportunities and Potential Market Trends. Sustainable Biotechnology- Enzymatic Resources of Renewable Energy, 325-354. doi:10.1007/978-3-319-95480-6_13Baker, R. W., & Lokhandwala, K. (2008). Natural Gas Processing with Membranes:  An Overview. Industrial & Engineering Chemistry Research, 47(7), 2109-2121. doi:10.1021/ie071083wZhang, Y., Sunarso, J., Liu, S., & Wang, R. (2013). Current status and development of membranes for CO2/CH4 separation: A review. International Journal of Greenhouse Gas Control, 12, 84-107. doi:10.1016/j.ijggc.2012.10.009Rezakazemi, M., Ebadi Amooghin, A., Montazer-Rahmati, M. M., Ismail, A. F., & Matsuura, T. (2014). State-of-the-art membrane based CO2 separation using mixed matrix membranes (MMMs): An overview on current status and future directions. Progress in Polymer Science, 39(5), 817-861. doi:10.1016/j.progpolymsci.2014.01.003Angelidaki, I., Treu, L., Tsapekos, P., Luo, G., Campanaro, S., Wenzel, H., & Kougias, P. G. (2018). Biogas upgrading and utilization: Current status and perspectives. Biotechnology Advances, 36(2), 452-466. doi:10.1016/j.biotechadv.2018.01.011Jeon, Y.-W., & Lee, D.-H. (2015). Gas Membranes for CO2/CH4 (Biogas) Separation: A Review. Environmental Engineering Science, 32(2), 71-85. doi:10.1089/ees.2014.0413Murali, R. S., Sankarshana, T., & Sridhar, S. (2013). Air Separation by Polymer-based Membrane Technology. Separation & Purification Reviews, 42(2), 130-186. doi:10.1080/15422119.2012.686000Kanehashi, S., Chen, G. Q., Ciddor, L., Chaffee, A., & Kentish, S. E. (2015). The impact of water vapor on CO2 separation performance of mixed matrix membranes. Journal of Membrane Science, 492, 471-477. doi:10.1016/j.memsci.2015.05.046Kreuer, K. D. (2003). Proton-Conducting Oxides. 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Science, 353(6299), 563-566. doi:10.1126/science.aag0274IZA Structure Comissionhttp://www.iza-structure.org/Lillepärg, J., Georgopanos, P., Emmler, T., & Shishatskiy, S. (2016). Effect of the reactive amino and glycidyl ether terminated polyethylene oxide additives on the gas transport properties of Pebax® bulk and thin film composite membranes. RSC Advances, 6(14), 11763-11772. doi:10.1039/c5ra22026bZhang, C., Dai, Y., Johnson, J. R., Karvan, O., & Koros, W. J. (2012). High performance ZIF-8/6FDA-DAM mixed matrix membrane for propylene/propane separations. Journal of Membrane Science, 389, 34-42. doi:10.1016/j.memsci.2011.10.003Fernández-Barquín, A., Casado-Coterillo, C., Palomino, M., Valencia, S., & Irabien, A. (2016). Permselectivity improvement in membranes for CO2/N2 separation. Separation and Purification Technology, 157, 102-111. doi:10.1016/j.seppur.2015.11.032Sabetghadam, A., Seoane, B., Keskin, D., Duim, N., Rodenas, T., Shahid, S., … Gascon, J. (2016). 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Gas Separation Properties of Polyimide Thin Films on Ceramic Supports for High Temperature Applications

[EN] Novel selective ceramic-supported thin polyimide films produced in a single dip coating step are proposed for membrane applications at elevated temperatures. Layers of the polyimides P84 (R), Matrimid 5218 (R), and 6FDA-6FpDA were successfully deposited onto porous alumina supports. In order to tackle the poor compatibility between ceramic support and polymer, and to get defect-free thin films, the effect of the viscosity of the polymer solution was studied, giving the entanglement concentration (C*) for each polymer. The C* values were 3.09 wt. % for the 6FDA-6FpDA, 3.52 wt. % for Matrimid (R), and 4.30 wt. % for P84 (R). A minimum polymer solution concentration necessary for defect-free film formation was found for each polymer, with the inverse order to the intrinsic viscosities (P84 (R) >= Matrimid (R) >> 6FDA-6FpDA). The effect of the temperature on the permeance of prepared membranes was studied for H-2, CH4, N-2, O-2, and CO2. As expected, activation energy of permeance for hydrogen was higher than for CO2, resulting in H-2/CO2 selectivity increase with temperature. More densely packed polymers lead to materials that are more selective at elevated temperatures.This work was financially supported by the Spanish Government through predoctoral training grants for Centres/units of Excellence "Severo Ochoa" (SEV-2016-0683), which gave S. Escorihuela the opportunity to undertake a research stay at Helmholtz-Zentrum Geesthacht (HZG), Spanish Ministry of Economy and Competitiveness (Project ENE2014-57651-R) and Helmholtz-Zentrum Geesthacht (HZG) through the technology transfer project program and by the Helmholtz Association of German Research Centers through the Helmholtz Portfolio MEMBRAIN. The authors thank M. Schieda and P. Merten for the support in the coating process and viscosity determination, and the microscopy service at Universitat Politecnica de Valencia (UPV) for the FE-SEM images.Escorihuela-Roca, S.; Tena, A.; Shishatskiy, S.; Escolástico Rozalén, S.; Brinkmann, T.; Serra Alfaro, JM.; Abetz, V. (2018). Gas Separation Properties of Polyimide Thin Films on Ceramic Supports for High Temperature Applications. Membranes. 8(1). https://doi.org/10.3390/membranes8010016S8

Net‐Zero CO 2 Germany - A Retrospect From the Year 2050

Germany 2050: For the first time Germany reached a balance between its sources of anthropogenic CO2 to the atmosphere and newly created anthropogenic sinks. This backcasting study presents a fictional future in which this goal was achieved by avoiding (∼645 Mt CO2), reducing (∼50 Mt CO2) and removing (∼60 Mt CO2) carbon emissions. This meant substantial transformation of the energy system, increasing energy efficiency, sector coupling, and electrification, energy storage solutions including synthetic energy carriers, sector-specific solutions for industry, transport, and agriculture, as well as natural-sink enhancement and technological carbon dioxide options. All of the above was necessary to achieve a net-zero CO2 system for Germany by 2050

Zero-Discharge Process for Recycling of Tetrahydrofuran–Water Mixtures

The sustainable design of separation and polymer synthesis processes is of great importance. Therefore, an energy-efficient process for the purification of tetrahydrofuran (THF)–water (H2O) solvent mixtures from an upstream polymer synthesis process in pilot scale was developed with the aim to obtain high purity separation products. The advantages and limitations of a hybrid process in the pilot scale were studied utilizing an Aspen Plus Dynamics® simulation at different pressures to prove the feasibility and energy efficiency. For the rough separation of the two components, distillation was chosen as the first process step. In this way, a separation of a water stream of sufficient quality for further precipitations after polymer synthesis could be achieved. In order to overcome the limitations of the distillation process posed by the azeotropic point of the mixture, a vapor permeation is used, which takes advantage of the heat of evaporation already used in the distillation column. For the purpose of achieving the required low water contents, an adsorption column is installed downstream for final THF purification. This leads to a novel hybrid separation process that is energy efficient and thus allows also the use of the solvents again for upstream polymer synthesis achieving the high purity requirements in a closed-loop process

Membrane-Assisted Methanol Synthesis Processes and the Required Permselectivity

Water-selective membrane reactors are proposed in the literature to improve methanol yield for a standalone reactor. However, the methanol productivity is not a precise metric to show the system improvement since, with this approach, we do not consider the amount of energy loss through the undesirable co-permeation of H2, which could otherwise remain on the reaction side at high pressure. In other words, the effectiveness of this new technology should be evaluated at a process flowsheet level to assess its advantages and disadvantages on the overall system performance and, more importantly, to identify the minimum required properties of the membrane. Therefore, an equation-based model for a membrane reactor, developed in Aspen Custom Modeler, was incorporated within the process flowsheet of the methanol plant to develop an integrated process framework to conduct the investigation. We determined the upper limit of the power-saving at 32% by exploring the favorable conditions wherein a conceptual water selective membrane reactor proves more effective. Using these suboptimal conditions, we realized that the minimum required H2O/H2 selectivity is 190 and 970 based on the exergy analysis and overall power requirement, respectively. According to our results, the permselectivity of membranes synthesized for this application in the literature, showing improvements in the one-pass conversion, is well below the minimum requirement when the overall methanol synthesis process flowsheet comes into consideration