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2021

  • Effect of Crosslinking on the Properties of QPVA/PDDA Anion Exchange Membranes for Fuel Cells Application

    Samsudin, A. M. & Hacker, V.

    Anion exchange membranes (AEMs) consisting of quaternary ammonium poly(vinyl alcohol) (QPVA) and poly(diallyldimethylammonium chloride) (PDDA) were prepared by a solution casting method. The influence of the concentration of the chemical crosslinker on the properties and performance of AEMs was investigated. Morphology, chemical structures, thermal and mechanical properties of AEMs were characterized by SEM, FTIR, TGA, and UTM. The performance of AEMs was evaluated by water uptake, swelling degree, ion exchange capacity, and OH- conductivity measurement. The tensile strength, water uptake, and OH- conductivity of AEMs were enhanced with the increase of the crosslinker concentration. By introducing 12.5% glutaraldehyde (GA), the QPVA/PDDA AEMs achieved the highest tensile strength, water uptake, and OH- conductivity of 46.21 MPa, 90.6% and 53.09 ms cm−1 at ambient condition, respectively. The investigations show that crosslinked QPVA/PDDA AEMs are a potential candidate for anion exchange membrane fuel cells.

    SEM image (left) and ion exchange capacity and conductivity (right) of a QPVA/PDDA anion exchange membrane [Samsudin and Hacker, 2021].

    Journal of the Electrochemical Society, 2021, Volume 168, 27 p., 044526.

    doi.org/10.1149/1945-7111/abf781

  • Poly(vinyl alcohol)-Based Anion Exchange Membranes for Alkaline Direct Ethanol Fuel Cells

    Samsudin, A. M. Wolf, S., Roschger, M. & Hacker, V.

    Cross-linked anion exchange membranes (AEMs) made of poly(vinyl alcohol) (PVA) as a backbone polymer and different approaches to introduce functional groups were prepared by solution casting with thermal and chemical cross-linking. Characterisation of the membranes was carried out by SEM, FTIR and thermogravimetric analyses. The performance of the AEMs was evaluated by water uptake, degree of swelling, ion exchange capacity, OH conductivity and single cell tests. A combination of quaternised ammonium poly(vinyl alcohol) (QPVA) and poly(diallyldimethylammonium chloride) (PDDMAC) showed the highest conductivity, water uptake and swelling among the other functional group sources. This study shows that PVA-based AEMs have the potential for the application of alkaline direct ethanol fuel cells (ADEFCs).

     

     

    SEM image (left) and ion conductivity (right) of a PVA-based anion exchange membrane [Samsudin et al., 2021].

    International Journal of Renewable Energy Development, 2021, Volume 10, Issue 3, p 435-443.

    Doi.org/10.14710/ijred.2021.33168

  • Efficient Chitosan/Nitrogen-doped Reduced Graphene Oxide Composite Membranes for Direct Alkaline Ethanol Fuel Cells

    Gorgieva, S., Osmić, A., Hribernik, S., Božič, M., Svete, J., Hacker, V., Wolf, S. & Genorio, B.

    Herein, we prepared a series of nanocomposite membranes based on chitosan (CS) and three compositionally and structurally different N-doped graphene derivatives. Two-dimensional (2D) and quasi 1D N-doped reduced graphene oxides (N-rGO) and nanoribbons (N-rGONRs), as well as 3D porous N-doped graphitic polyenaminone particles (N-pEAO), were synthesized and characterized fully to confirm their graphitic structure, morphology, and nitrogen (pyridinic, pyrrolic, and quaternary or graphitic) group contents. The largest (0.07%) loading of N-doped graphene derivatives impacted the morphology of the CS membrane significantly, reducing the crystallinity, tensile properties, and the KOH uptake, and increasing (by almost 10-fold) the ethanol permeability. Within direct alkaline ethanol test cells, it was found that CS/N rGONRs (0.07 %) membrane (Pmax. = 3.7 mWcm −2) outperformed the pristine CS membrane significantly (Pmax. = 2.2 mWcm −2), suggesting the potential of the newly proposed membranes for application in direct ethanol fuel cells.

    SEM image (left) and DEAFC cell voltage and power density (right) of a chitosan/graphene-based composite membrane [Gorgieva et al., 2021].

    International Journal of Molecular Sciences. Volume 22, Issue 4, p. 1-25 25 p., 1740.

    Doi.org/10.3390/ijms22041740

  • Modeling liquid absorption of highly cross-linked epoxy resins in aqueous electrolyte solutions

    Krenn, P., Zimmermann, P., Fischlschweiger, M. & Zeiner, T.

    The solvent absorption of an epoxy o-cresol novolac resin composite has been measured in different aqueous electrolyte solutions (NaCl, CaCl2 and MgCl2) at different salt concentrations from 0.1 to 0.3 mg/l. Next to the total solvent uptake, which was measured by a gravimetric measurement, the absorption of ions was determined by ion chromatography and by atomic absorption spectroscopy. The measured solvent absorption in equilibrium was calculated by combining the ePC-SAFT equation of state with a network term, which takes into account elastic forces in the polymer network counteracting a further solvent absorption. In order to model the solvent absorption kinetics, the equation of state was combined with a Maxwell-Stefan diffusion approach and the viscoelastic Kelvin-Voigt model for chain relaxation. The model parameters were only fitted to the absorption in pure water, what was only possible because the epoxy resin absorbed a neglectable amount of ions. The fully predictively calculated values for the absorption in electrolyte solutions are in qualitative agreement to the measured data.

    Fluid Phase Equilibria., 2021, Volume 529, Article number 112881

    doi.org/10.1016/j.fluid.2020.112881

  • The Faculty of Technical Chemistry, Chemical & Process Engineering and Biotechnology has worldwide partnerships that serve student exchange and personnel mobility in the fields of teaching and research. Within the Erasmus+ program alone, there are currently about 30 specific agreements with partner universities. In addition, the individual institutes have a large number of specific cooperation agreements with foreign universities in the area of research.

    Study Abroad Video

    More Information

    ASEA-UNINET (OeAD)

  • Surrogate generation and evaluation of gasolines

    Grubinger, T., Lenk, G., Schubert, N. & Wallek, T.

    Fuel surrogates are substitute mixtures that are developed to reproduce real fuels’ physical and chemical properties. These mixtures are created with a small number of components, considering their application in various types of simulations and for bench tests. In the present paper, new gasoline surrogates are proposed by extending and applying an algorithm which was previously developed and successfully used to create diesel surrogates.
    The five target properties chosen for surrogate optimization include the true boiling point curve (TBP), the research octane number (RON), the liquid density, the carbon-to-hydrogen (C/H) ratio and the oxygenate content.
    The algorithm is applied to three target fuels, comprising two reference fuels from the FACE working group and one typical oxygenated gasoline that is commercially available in Europe. The proposed surrogates consist of six chemical components which are also represented in reaction kinetics for fuel combustion. An experimental comparison of the boiling point curves, densities and RONs among the surrogates and their respective target fuels provided evidence that the proposed surrogates excellently reproduce the real fuels' properties.

    Fuel, 2021, Volume 283, 118642

    doi.org/10.1016/j.fuel.2020.118642

     

  • The Kinetics of Droplet Sedimentation in Liquid‐Liquid Extraction

    Bol, P., Rudelstorfer, G., Grafschafter, A. & Siebenhofer, M.

    Liquid-liquid extraction is a major separation process in chemical industry. Beside appropriate design of mass transfer equipment, successful design of phase separation equipment is an important issue. Therefore, the separation of liquid-liquid dispersions was investigated and modeled with kinetic approaches to gain information for settler design. A modified first-order sedimentation rate model, a first-order consecutive step rate model, and a mixed-order rate model were applied and compared to the experimental data. The advantage of kinetic modeling of the rate of sedimentation, specifically addressing the impact of viscosity and electrolyte concentration, was successfully demonstrated.

    Chemie-Ingenieur-Technik, 2021, Volume 3, Issue 1-2, p. 260-272 13 p.

    doi.org/10.1002/cite.202000126

  • Research on Next Generation Fuel Cell and Hydrogen Technologies

    Due to current efforts being made in the reduction of greenhouse gas emissions and the associated political focus on hydrogen as a clean energy carrier, methods for sustainable hydrogen production and efficient utilization are again in great demand. In the coming years, fundamental and industry-related research as well as innovative ideas are essential to meet the ambitious goals with regard to efficiency, service life and sustainability of the whole process chain. The fuel cells and hydrogen working group is currently focusing on several approaches to tackle these challenges.

    Wasserstoff – der Stromspeicher der Zukunft?

    Soll unser Energiesystem umweltfreundlicher werden, so führt kein Weg an Wasserstoff als Energieträger vorbei. Dessen sind sich Forschende weltweit sicher. Rund 160 Wissenschafterinnen und Wissenschafter arbeiten an der TU Graz an Methoden der Erzeugung, Speicherung, des Transports und der Nutzung von Wasserstoff in mobilen, stationären und industriellen Anwendungen


2020

  • Continuous Neutralization of NaOH Solution with CO2 in an Internal-Loop Airlift Reactor

    Pichler, T. M., Stoppacher, B., Kaufmann, A., Siebenhofer, M. & Kienberger, M.

    The neutralization of NaOH with CO2 in a continuously operated airlift reactor with gas flow rates up to 10 NL min−1 and gas phase recycle was investigated. Neutralization experiments were performed at 25 °C and the amount of absorbed CO2, as well as the NaOH feed rate, were recorded. The reaction rate was calculated based on the two‐film theory and empirical equations for several parameters. The calculations of the volumetric mass transfer coefficient, the liquid phase circulation velocity, and the gas holdup were experimentally validated. The reaction rate and the process efficiency were modeled with a deviation of 5 %.

    Journal of Chemical Engineering & Technology, 2021, Volume 44, Issue 1, p. 38-47 10 p.

    doi.org/10.1002/ceat.202000319

  • SAFT-Based Maxwell-Stefan Approach to Model the Diffusion through Epoxy Resins

    Krenn, P., Zimmermann, P., Fischlschweiger, M. & Zeiner, T.

    Epoxy resins are often applied to prevent sensitive electronics to come into contact with solvents. Therefore, it is necessary to know the diffusion through the epoxy resins to determine the thickness of the epoxy resins layer for different applications. In this work a diffusion model is developed on the basis of the Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) equation of state. To consider the polymer network, PC-SAFT is combined with an elastic term. The driving force for the diffusion is the gradient of the chemical potential, but additionally the viscoelastic polymer relaxation below the glass transition temperature is considered. The model is applied to calculate the diffusion of water, isopropyl alcohol, and heptane through the epoxy resin at different temperatures. The modeled diffusion processes are in good agreement with experimentally determined data. Even highly anomalous absorption kinetics, which were measured for isopropyl alcohol diffusion, could be explained and calculated on the basis of the developed diffusion model.


    Journal of Chemical & Engineering Data, 2020, Volume 65, Issue 12, p. 5677-5687 11 p.

    doi.org/10.1021/acs.jced.0c00668

  • Polyaniline/Platinum Composite Cathode Catalysts Towards Durable Polymer Electrolyte Membrane Fuel Cells

    Katharina Kocher and Viktor Hacker

    Polymer stabilization proved to be a promising approach to increase the catalytic performance of common platinum/carbon based cathode catalysts (Pt/C) used in polymer electrolyte membrane fuel cells (PEMFCs). Platinum and polyaniline composite catalysts (Pt/C/PANI) were prepared by combining chemical polymerization reactions with anion exchange reactions. Electrochemical ex‐situ characterizations of the decorated Pt/C/PANI catalysts show high catalytic activity toward the oxygen reduction reaction (ORR) and, more importantly, a significant enhanced durability compared to the undecorated Pt/C catalyst. Transmission electron microscopy (TEM) investigations reveal structural benefits of Pt/C/PANI for ORR catalysis. All studies confirm high potential of Pt/C/PANI for practical fuel cell application.

     

    image

    Figure: Illustration of Pt/C/PANI catalyst. ©TU Graz/CEET

    ChemistryOpen (November 5, 2020)

    doi.org/10.1002/open.202000119

  • Development of Advanced Models for Analysis and Simulation of
    Fuel Cells

    The guest editors Prof. Katrašnik and Prof. Hacker invite you to submit articles for a special issue of Energies on “Development of Advanced Models for Analysis and Simulation of Fuel Cells”. To address the requirements on shorter product development cycles and reduced development costs, while boosting power density, efficiency, service life and safety, it is necessary to rely on advanced simulation models in the development process of fuel cells, their components, and fuel-cell-based systems. Simulation models are also indispensable for the analysis of fuel cells and for precise online monitoring.

    Special Issue Flyer

    Special Issue Homepage

  • Modeling liquid absorption of highly cross-linked epoxy resins in aqueous electrolyte solutions

    Patrick Krenn, Patrick Zimmermann, Michael Fischlschweiger and Tim Zeiner

    The solvent absorption of an epoxy o-cresol novolac resin composite has been measured in different aqueous electrolyte solutions (NaCl, CaCl2 and MgCl2) at different salt concentrations from 0.1 to 0.3 mg/l. Next to the total solvent uptake, which was measured by a gravimetric measurement, the absorption of ions was determined by ion chromatography and by atomic absorption spectroscopy. The measured solvent absorption in equilibrium was calculated by combining the ePC-SAFT equation of state with a network term, which takes into account elastic forces in the polymer network counteracting a further solvent absorption. In order to model the solvent absorption kinetics, the equation of state was combined with a Maxwell-Stefan diffusion approach and the viscoelastic Kelvin-Voigt model for chain relaxation. The model parameters were only fitted to the absorption in pure water, what was only possible because the epoxy resin absorbed a neglectable amount of ions. The fully predictively calculated values for the absorption in electrolyte solutions are in qualitative agreement to the measured data.

    Fluid Phase Equilibria, Volume 529, 1 February 2021, 112881

    doi.org/10.1016/j.fluid.2020.112881

  • Internship abroad despite corona crisis: At Nedstack B.V. in Arnhem, the Netherlands, TU Graz student Niklas Mayr further developed analytical measurement methods for fuel cell research.

    Here's his report:

    English: https://www.tugraz.at/en/tu-graz/services/news-stories/talking-about/singleview/article/zwei-monate-brennstoffzellenforschung0/

    German: https://www.tugraz.at/tu-graz/services/news-stories/talking-about/einzelansicht/article/zwei-monate-brennstoffzellenforschung/

  • Wasserstoff – Antrieb für Klimaschutz und Wirtschaft / Hydrogen - Drive for climate protection and economy

    In order to achieve the climate targets, the use of hydrogen is necessary. Numerous experts from industry and science agree on this. In recent years Graz has become a veritable hotspot for fuel cell and hydrogen research. We asked the top developers what makes hydrogen so interesting and why it can be a driver not only for climate protection but also for the economy.

     

    Wirtschaftsnachrichten Süd, 10/2020, 54-57

  • Cluster-Based Thermodynamics of Interacting Dice in a Lattice

    Christoph Mayer and Thomas Wallek

    ©TU Graz/CEET

    In this paper, a model for two-component systems of six-sided dice in a simple cubic lattice is developed, based on a basic cluster approach previously proposed. The model represents a simplified picture of liquid mixtures of molecules with different interaction sites on their surfaces, where each interaction site can be assigned an individual energetic property to account for cooperative effects. Based on probabilities that characterize the sequential construction of the lattice using clusters, explicit expressions for the Shannon entropy, synonymously used as thermodynamic entropy, and the internal energy of the system are derived. The latter are used to formulate the Helmholtz free energy that is minimized to determine thermodynamic bulk properties of the system in equilibrium. The model is exemplarily applied to mixtures that contain distinct isomeric configurations of molecules, and the results are compared with the Monte-Carlo simulation results as a benchmark. The comparison shows that the model can be applied to distinguish between isomeric configurations, which suggests that it can be further developed towards an excess Gibbs-energy, respectively, activity coefficient model for chemical engineering applications.

    Entropy 2020, 22(10), 1111;

    doi.org/10.3390/e22101111

     

  • Screening of reactive extractants for the lignosulfonate extraction from lignosulfonate model solution and spent sulfite liquor

    Demmelmayer, P., Hilgert, J., Wijaya, R. & Kienberger, M.

    Crud formation during reactive extraction hinders phase separation and makes the application of conventional extraction equipment more challenging. This study investigates the influence of amines as a reactive extractant, pH value, and temperature on the crud formation and extraction efficiency for the reactive extraction of lignosulfonates from the Ca–lignosulfonate model solution and spent sulfite liquor. The overall extraction efficiency for different amines dissolved in 1-octanol increased in the order quaternary < tertiary < secondary < primary amines for both the model solution and the spent liquor. Phase equilibria for dioctylamine and trioctylamine showed that the temperature increase from 25 to 50 °C had no effect on the extraction efficiency but clearly reduced the crud formation in the extraction step. No crud was observed during back extraction into deionized water, 0.3 M NaOH, or 0.3 M NaHCO3. The pH value highly influences the phase equilibrium; the extraction step has to be performed at low pH values and the back extraction step at high pH values.


    Industrial & Engineering Chemistry Research, 2020, Volume 59, Issue 37, p. 16420-16426 7 p.

    doi.org/10.1021/acs.iecr.0c02525

     

  • Dezentraler Wasserstoff aus Biomasse / Decentralized hydrogen from biomass

    Bernd Stoppacher, Robert Zacharias, Michael Lammer, Sebastian Bock, Karin Malli and Viktor Hacker

    Der Reformer Steam Iron Cycle (RESC), eine Weiterentwicklung des Eisen-Dampf-Prozesses, bietet eine effiziente und kostengünstige Möglichkeit der dezentralen Wasserstoffherstellung. Das auf Reduktions- und Oxidationsreaktionen basierende Chemical Looping System ist in der Lage, hochreinen Wasserstoff aus Biogas, vergaster Biomasse und gasförmigen Kohlenwasserstoffen zu erzeugen. Da eine Reinheit von > 99.999 % bereits im RESC Prozess erreicht wird, sind im Gegensatz zu konventionellen Verfahren, wie Dampfreformierung oder autotherme Reformierung, keine weiteren Reinigungsschritte im System notwendig. Zudem kann das System, durch Abscheidung von hochreinem Stickstoff und Kohlenstoffdioxid, wertvolle Nebenprodukte erzeugen und als Negativemissionstechnologie betrieben werden.

    The Reformer Steam Iron Cycle (RESC), a further development of the iron-steam process, offers an efficient and cost-effective option for decentralized hydrogen production. The chemical looping system based on reduction and oxidation reactions is capable of producing high-purity hydrogen from biogas, gasified biomass and gaseous hydrocarbons. Since a purity of > 99.999 % is already achieved in the RESC process, no further purification steps are necessary in the system, in contrast to conventional processes such as steam or autothermal reforming. In addition, the system can generate valuable by-products by separating high purity nitrogen and carbon dioxide and can be operated as a negative emission technology.

     

    Der RESC im Kontext verschiedener Wasserstoffproduktionstechnologien / The RESC in the context of different hydrogen production technologies (Copyright TU Graz)

    gwf Gas+Energie, 09/2020, ISSN 2366-9594, Seite 62-69

    https://www.gwf-gas.de/produkte/2020-gwf-gas-energie-09-2020/

  • Electrochemical characterization of polymer electrolyte membrane fuel cells and polarization curve analysis

    M. Mohsin, R. Raza, M. Mohsin-ul-Mulk, A. Yousaf, V. Hacker

     

    In this paper the diagnostic results of single polymer electrolyte membrane fuel cell assemblies are presented, which are characterized by polarization curves. Single PEM fuel cell assemblies were investigated by accelerated voltage cycling tests at different humidity levels. The cells are discussed in this paper with analysis results at different humidity values and different atmospheric pressures. The decrease in relative humidity can result in slower electrode kinetics, including electrode reaction and mass diffusion rates, and higher membrane resistance.

     

    International Journal of Hydrogen Energy, Volume 45, Issue 45, 24093-24107.

    https://doi.org/10.1016/j.ijhydene.2019.08.246

  • Screening of Reactive Extractants for the Lignosulfonate Extraction from Lignosulfonate Model Solution and Spent Sulfite Liquor

    Paul Demmelmayer, Julio Hilgert, Robby Wijaya, and Marlene Kienberger

    Crud formation during reactive extraction hinders phase separation and makes the application of conventional extraction equipment more challenging. This study investigates the influence of amines as a reactive extractant, pH value, and temperature on the crud formation and extraction efficiency for the reactive extraction of lignosulfonates from the Ca–lignosulfonate model solution and spent sulfite liquor. The overall extraction efficiency for different amines dissolved in 1-octanol increased in the order quaternary < tertiary < secondary < primary amines for both the model solution and the spent liquor. Phase equilibria for dioctylamine and trioctylamine showed that the temperature increase from 25 to 50 °C had no effect on the extraction efficiency but clearly reduced the crud formation in the extraction step. No crud was observed during back extraction into deionized water, 0.3 M NaOH, or 0.3 M NaHCO3. The pH value highly influences the phase equilibrium; the extraction step has to be performed at low pH values and the back extraction step at high pH values.

    Demmelmayer et al.(2020), published by American Chemical Society

    Ind. Eng. Chem. Res. 2020, 59, 37, 16420–16426

    https://doi.org/10.1021/acs.iecr.0c02525

  • Surrogate generation and evaluation of gasolines

    Tobias Grubinger, Georg Lenk,  Nikolai Schubert and Thomas Wallek

    Fuel surrogates are substitute mixtures that are developed to reproduce real fuels’ physical and chemical properties. These mixtures are created with a small number of components, considering their application in various types of simulations and for bench tests. In the present paper, new gasoline surrogates are proposed by extending and applying an algorithm which was previously developed and successfully used to create diesel surrogates.

    The five target properties chosen for surrogate optimization include the true boiling point curve (TBP), the research octane number (RON), the liquid density, the carbon-to-hydrogen (C/H) ratio and the oxygenate content.

    The algorithm is applied to three target fuels, comprising two reference fuels from the FACE working group and one typical oxygenated gasoline that is commercially available in Europe. The proposed surrogates consist of six chemical components which are also represented in reaction kinetics for fuel combustion. An experimental comparison of the boiling point curves, densities and RONs among the surrogates and their respective target fuels provided evidence that the proposed surrogates excellently reproduce the real fuels' properties.

    Grubinger et al. (2021) - Published by Elsevier

     

    Fuel, Volume 283, 1 January 2021, 118642

    https://doi.org/10.1016/j.fuel.2020.118642

  • Hydrogen production with fixed bed chemical looping systems (Chapter 10)

    Michael Lammer and Viktor Hacker

     

    Chemical circulation processes require high-tech materials as oxygen carriers in the fixed-bed reactor. These consist of the reactive iron-based species and inert additives to maintain the functionality of the process. This chapter contains data on various materials and on the chemical reactions and reaction mechanisms. Side reactions and their respective influence on the product gas quality, i.e. the purity, are discussed in detail. Emphasis is placed on the sustainability aspects of this technology by providing information on the pre-pressurization of hydrogen and the sequestration of carbon dioxide.

    Published in Current Trends and Future Developments on (Bio-) Membranes: New Perspectives on Hydrogen Production, Separation, and Utilization, A. Iulianelli & A. Basile (eds), 1st edn, Elsevier B.V., Amsterdam, pp. 225-240.

    Elsevier

  • Contribution in ORF Styria: Liquid manure as valuable fertilizer

    The fact that liquid manure stinks and pollutes the groundwater is no big news. But that it can be converted into valuable fertiliser is perhaps. In a pilot project, nitrogen is removed from the liquid manure and what remains are the pure raw materials.

    https://steiermark.orf.at/stories/3059060/

  • The impact of manufacturing methods on the performance of pelletized, iron-based oxygen carriers for fixed bed chemical looping hydrogen in long term operation

     

    Robert Zacharias, Sebastian Bock and Viktor Hacker

     

    The successful application of fixed bed chemical looping for hydrogen production in industrial scale demands highly stable oxygen carrier pellets. The vast experience of the research group on the steam iron process enabled the researchers to identify the most crucial differences and challenges in the preparation of suitable oxygen carriers.

    The goal of this work was the realistic long-term characterization of pelletized oxygen carriers in a fixed bed reactors, which revealed a high temperature gradient, decreased oxygen exchange capacity and a rapid increase in system pressure caused by to powder formation for some samples. The experimental results of this study indicate that the long-term redox cycling seems to outweigh the impact of oxygen carrier preparation methods that may be overvalued in the long run.

    Zacharias et al. (2020) – Published by Elsevier, licensed under CC BY 4.0 © TU Graz / Lunghammer
    Zacharias et al. (2020) – Published by Elsevier, licensed under CC BY 4.0     © TU Graz / Lunghammer

    Fuel Processing Technology, 2020, 208.

    https://doi.org/10.1016/j.fuproc.2020.106487

  • World's first prototype already running in Graz. INNOVATION BELT GRAZ: New system for area-wide availability of green hydrogen

     

    Hydrogen researchers at Graz University of Technology, together with the Graz-based Start-Up Rouge H2 Engineering, have developed a cost-effective process for the decentralized production of high-purity hydrogen. The research success resulted in a compact and space-saving On-Site-On-Demand-System (OSOD) for filling stations and energy plants, which is developed and distributed by Rouge H2 Engineering.

    The inner workings of the OSOD H2 generator. The blue cuboid is the core development: a gas furnace with four tubular reactors in which the chemical looping process for hydrogen production takes place (Photo RGH2 in magazine KLIPP, June/July 2020).

    The inner workings of the OSOD H2 generator. The blue cuboid is the core development: a gas furnace with four tubular reactors in which the chemical looping process for hydrogen production takes place (Photo RGH2 in magazine KLIPP, June/July 2020).

    KLIPPonline

    TU Graz Planet Research

  • Impact of bioethanol impurities on steam reforming for hydrogen production: A review

     

    Nestor Sanchez, Ruth Ruiz, Viktor Hacker and Martha Cobo

     

    The bioethanol produced by biomass fermentation contains large quantities of water and can be used directly in the ethanol steam reformer without any purification steps. However, such bioethanol samples contain a broad spectrum of impurities that make the reformation process more difficult. This overview defines options to reduce impurities with negative influence on the reforming process and to increase the positive ones during pre-treatment and fermentation of the biomass.

    International Journal of Hydrogen Energy, 45(21).

    https://doi.org/10.1016/j.ijhydene.2020.02.159

  • Electrical Engineering: Fundamentals

     

    Viktor Hacker and Chistof Sumereder

     

    Fundamentals of Electrical Engineering is an excellent introduction into the areas of electricity, electronic devices and electrochemistry. The book covers aspects of electrical science including Ohm and Kirkoff's laws, P-N junctions, semiconductors, circuit diagrams, magnetic fields, electrochemistry, and devices such as DC motors. This textbook is particularly useful for students of chemical, materials, and mechanical engineering.

    De Gruyter Textbook , 224 pages

    https://doi.org/10.1515/9783110521115

    https://www.degruyter.com/view/title/524744

  • Modeling Highly Cross-Linked Epoxy Resins in Solvents of Different Polarities with PC-SAFT

     

    Patrick Krenn, Patrick Zimmermann, Michael Fischlschweiger and Tim Zeiner

     

    The solvent uptake in equilibrium of a highly cross-linked epoxy o-cresol novolac resin in water, isopropanol, and heptane was experimentally measured and modeled with the perturbed-chain statistical association fluid theory (PC-SAFT) equation of state. As suggested in the literature, PC-SAFT was combined with a network term, which takes additional elastic forces into account. The model parameters of the epoxy resin were generated by fitting them to the measured solvent uptake in pure substances and to the density of the epoxy resin, which provided a very good agreement with the experimental data. Furthermore, the solvent uptake in the mixtures isopropanol/water and isopropanol/heptane was predicted in very good agreement to the experimental data. For the first time, a thermodynamic model was developed to calculate the solvent uptake in an epoxy resin.

    Industrial and Engineering Chemistry Research, 59(11), 5133-5141.

    https://doi.org/10.1021/acs.iecr.9b06499

  • The reaction kinetics of CO2 methanation on a bifunctional Ni/MgO catalyst

     

    Astrid Loder, Matthäus Siebenhofer and Susanne Lux

     

    A bifunctional Ni/MgO catalyst was prepared to catalyze CO2 methanation and make use of CO2 as an abundant hydrogen storage facility. The effect of Ni loading and MgO quality on the rate of methanation was tested in a temperature range of 533–648 K. The Ni loading was varied between 0 to 27 wt.% on MgO. To investigate the impact of matrix elements, a MgO/CaO support was tested with 21 wt.%. nickel loading. Further, the role of MgO in the bifunctional catalyst was proven. The reaction kinetics was modeled with a Langmuir–Hinshelwood approach considering the bifunctional character of the catalyst. Nickel provides the adsorbent capacity for hydrogen and is highly selective for methane. MgO activates CO2 through chemisorption. Increasing Ni loading of the catalyst increased the rate of CO2 conversion. According to the results, the mechanism of CO2 methanation did not change with Ni loading. The Ni/MgO catalyst acted as a robust, active and highly selective catalyst for CO2 methanation. With CO2 conversion of 87%, the selectivity to methane was ≥99%. Besides excellent catalytic activity the catalysts suffice the necessity of simple catalyst preparation, usage and recyclability for industrial applicability of CO2 methanation.

    Loder et al. (2020) – Published by Elsevier B.V. All rights reserved.

    Loder et al. (2020) – Published by Elsevier B.V. All rights reserved.

    Journal of Industrial and Engineering Chemistry, 2020, Volume 85.

    https://doi.org/10.1016/j.jiec.2020.02.001

  • Co-production of pure hydrogen, carbon dioxide and nitrogen in a 10 kW fixed-bed chemical looping system

     

    Sebastian Bock, Robert Zacharias and Viktor Hacker

     

    The transition of our current carbon-based economy towards a sustainable energy system poses major challenges for all stakeholders. Harmful carbon dioxide emissions have to be substantially decreased and even negative emissions are mandatory to avoid a global mean temperature rise above 2 °C unless stringent regulatory measures are taken within the next decade. Chemical looping is an effective method to sequestrate pure carbon dioxide from fossil and renewable energy resources within the framework of carbon capture and storage (CCS) or utilization (CCU) technologies.

    The presented study demonstrates the generation of high-purity hydrogen exceeding 99.997% as a zero-emission energy carrier with the inherent co-generation of pure carbon dioxide (99%) and nitrogen (98.5%) in the largest fixed-bed chemical looping research system worldwide with a feedstock utilization of up to 60%. The use of renewable primary energy sources as biogas qualifies the process as a negative emission technology (NET) if carbon dioxide is appropriately utilized.

    Bock et al. (2020) - Published by The Royal Society of Chemistry, licensed under CC BY 3.0 © TU Graz / Lunghammer

    Sustainable Energy Fuels, 2020,4, 1417-1426.

    https://doi.org/10.1039/C9SE00980A

  • Alkaline Ethanol Oxidation Reaction on Carbon Supported Ternary PdNiBi Nanocatalyst using Modified Instant Reduction Synthesis Method

     

    Bernd Cermenek, Boštjan Genorio, Thomas Winter, Sigrid Wolf, Justin G. Connell, Michaela Roschger, Ilse Letofsky-Papst, Norbert Kienzl, Brigitte Bitschnau and Viktor Hacker

     

    Direct ethanol fuel cells (DEFC) still lack active and efficient electrocatalysts for the alkaline ethanol oxidation reaction (EOR). In this work, a new instant reduction synthesis method was developed to prepare carbon supported ternary PdNiBi nanocatalysts with improved EOR activity. Synthesized catalysts were characterized with a variety of structural and compositional analysis techniques in order to correlate their morphology and surface chemistry with electrochemical performance. The modified instant reduction synthesis results in well-dispersed, spherical Pd85Ni10Bi5 nanoparticles on Vulcan XC72R support (Pd85Ni10Bi5/C(II-III)), with sizes ranging from 3.7 ± 0.8 to 4.7 ± 0.7 nm.

    J. Electrocatalysis 11, 203–214.

    https://doi.org/10.1007/s12678-019-00577-8

  • Biobased Support Layers for the Fractionation and Selective Extraction of Lignosulfonates

     

    Marlene Kienberger, Paul Demmelmayer, Michael Weißl, Armin Zankl and Stefan Spirk

     

    The paper presents an experimental study on the preparation and characterization of cellulose films and their use for reactive lignosulfonate extraction. The extraction of lignosulfonates leads to emulsion and crud formation when standard equipment is applied. By using cellulose films as a support layer between the aqueous feed phase and the organic extractant phase, emulsion formation is prevented. The results showed that selective separation and a fractionation of the lignosulfonates can be realized with this novel approach simultaneously.

     

    Solvent Extraction and Ion Exchange, Volume 38, 2020 - Issue 1.

    https://doi.org/10.1080/07366299.2019.1691764


2019

  • Preparation and Characterization of PVA/PDDA/Nano-Zirconia Composite Anion Exchange Membranes for Fuel Cells

     

    Asep Muhamad Samsudin and Viktor Hacker

    Anion exchange membranes (AEMs) contribute significantly to enhance the performance and efficiency of alkaline polymer electrolyte fuel cells (APEFCs). A sequence of composite anion exchange membranes (AEMs) consisting of poly(vinyl alcohol) (PVA), poly(diallyldimethylammonium chloride) (PDDA), and nano-zirconia (NZ) has been prepared by a solution casting technique. The effect of zirconia mass ratio on attribute and performance of composite AEMs was investigated.

    The chemical structures, morphology, thermal, and mechanical properties of AEMs were characterized by FTIR, SEM, thermogravimetric analysis, and universal testing machine, respectively. The performance of composite AEMs was verified using water uptake, swelling degree, ion-exchange capacity, and OH− conductivity measurement. The nano-zirconia was homogeneously dispersed in the PVA/PDDA AEMs matrix. The mechanical properties of the composite AEMs were considerably enhanced with the addition of NZ. Through the introduction of 1.5 wt.% NZ, PVA/PDDA/NZ composite AEMs acquired the highest hydroxide conductivity of 31.57 mS·cm−1 at ambient condition. This study demonstrates that the PVA/PDDA/NZ AEMs are a potential candidate for APEFCs application.

    J. Polymers 2019, 11(9), 1399

    https://doi.org/10.3390/polym11091399

  • Landespreis „Energy Globe Styria Award" für Projekt RedK – Reduzierende Kalzinierung vom Institut für Chemische Verfahrenstechnik und Umwelttechnik

Den Landespreis „Energy Globe Styria Award" konnte sich in diesem Jahr das Projekt Reduzierende Kalzinierung unter der Leitung von Susanne Lux in Kooperation mit der voestalpine Stahl GmbH und der VA Erzberg GmbH sichern. Dabei gewannen sie den „Energy Globe Styria Award" in der Kategorie „Forschung“ und holten sich auch das „goldene Ticket" für den nationalen „Energy Globe Austria Award" in Linz.

Ziel des Projekts ist es, die Veredelung von Eisenerz zu Eisenoxid nicht wie derzeit üblich durch Sintern unter oxidierenden Bedingungen, sondern unter reduzierenden Bedingungen in Wasserstoffatmosphäre stattfinden zu lassen. Durch dieses Konzept können deutliche Emissions- und Energieeinsparungen erreicht werden.

https://www.youtube.com/watch?v=eEGd1-dA9FA&t=10s

  • CEET Konkret 2019

Im CEET Konkret 2019 präsentieren wir euch unsere aktuellen Forschungsergebnisse und bieten einen Überblick über unsere Themengebiete. Zusätzlich gibt es einen Einblick in unsere internationalen Aktivitäten, sowie das Institutsleben abseits von Forschung und Lehre.

Wir wünschen euch viel Spaß beim Lesen!

CEET Konkret 2019

2018

  • Eseia International Summer School

Biorefineries' Processes and Sustainability

  • CEET Konkret 2018:

Das CEET-Konkret bietet einen Überblick über aktuelle Forschungsthemen und Instituts-Ereignisse aus dem vergangenen Jahr.

Wir wünschen euch viel Spaß beim Lesen!

CEET-Konkret 2018

2017

  • Award Houska 2017

 

  • Reward "Mobilität 2017"

Fig.: Presentation of the national reward "Mobilität 2017" (bmvit, 27.01.2017) by the Federal Minister for the research project "H2 Mobility".

  • IEA Workshop (Annex 31 35)

Over 70 participants from 13 countries (Austria, China, Denmark, Germany, Italy, Israel, Japan, Finland, France, Slovenia, South Africa, Sweden, and USA) attended the exciting workshop “Highlights of International Fuel Cell Research 2017” on May 15, 2017.

Prof. Harald Kainz, Rector of Graz University of Technology, opened the workshop and welcomed the renowned scientists. Theodor Zillner, representative of the Austrian Ministry for Transport, Innovation and Technology (bmvit), pointed out the importance of the international network IEA and the international cooperation in science and technology.

D.J. Liu, Argonne National Laboratory USA and Operating Agent of Annex 31 and Fabio Matera, Consiglio Nazionale delle Ricerche Italy and Operating Agent of Annex 35, introduced the IEA Technology Collaboration Programme and the Annexes. Prof. Viktor Hacker, Institute of Chemical Engineering and Environmental Technologies of TU Graz and local organiser of the workshop, gave a short overview of research groups in the field of fuel cells in Austria.

In the main session, the experts presented and discussed in 15 lectures the results and scientific breakthroughs of international fuel cell development. In the evening, the poster session gave the opportunity for discussion with the experts and national representatives of the annexes.

  • BioRefinery Engineering – ab WS 2017 ein neues englischsprachiges Masterstudium

Im Rahmen des Horizon 2020 Projektes BioEnergyTrain (grant agreement N 656760) wurden zwei Masterstudiengänge in dem Umfeld der biobasierten Industrie / biobasierten Energieerzeugung entwickelt, BioRefinery Engineering und BioResource Value Chain Optimization. Der Masterstudiengang BioRefinery Engineering wird ab dem Wintersemester 2017/2018 an der Technischen Universität Graz angeboten. Weiterführende Informationen sind hier https://www.tugraz.at/studium/studienangebot/masterstudien/biorefinery-engineering/) zu finden.

  • Ein Solarkraftwerk für den Balkon

Dipl.-Ing. Dr. tech. Bsc. Christoph Grimmer hat gemeinsam mit Kollegen am Institut für Chemische Verfahrenstechnik und Umwelttechnologien ein Plug&Play Speichersystem für Haushalte entwickelt. Weiteres unter...

  • Vortragspreis des Dechema Fachausschusses "Kristallisation"

Msc. Thomas Goetsch hat mit seinem Vortrag " Vorhersage und experimentelle Überprüfung des Oiling out-Effektes bei der Trennung von Isomeren" den Vortragspreises des Dechema Fachausschusses Kristallisation (6.-7. März 2017 in Köln) bekommen. Die Co-autoren des Vortrages sind Patrick Zimmermann (Karlsruhe Institute of Technology), Rebecca van den Bongardt (TU Dortmund), Amelie Köhler (TU Dortmund), Sabine Enders (Karlsruhe Institute of Technology) und Tim Zeiner.


(c) Verbund

Office
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Bettina Koch
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Tel. +43 (316) 873 - 7461
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Jutta Freißmuth
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Tel. +43 (316) 873 - 7462
Fax +43 (316) 873 - 107462
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