@article{53079, author = {{Bierkandt, Thomas and Hemberger, Patrick and Oßwald, Patrick and Gaiser, Nina and Hoener, Martin and Krüger, Dominik and Kasper, Tina and Köhler, Markus}}, issn = {{1540-7489}}, journal = {{Proceedings of the Combustion Institute}}, keywords = {{Physical and Theoretical Chemistry, Mechanical Engineering, General Chemical Engineering}}, number = {{2}}, pages = {{1699--1708}}, publisher = {{Elsevier BV}}, title = {{{A combustion chemistry study of tetramethylethylene in a laminar premixed low-pressure hydrogen flame}}}, doi = {{10.1016/j.proci.2022.07.205}}, volume = {{39}}, year = {{2023}}, } @article{53077, abstract = {{Flame spray pyrolysis is intensively developing as a promising method of nanoparticle synthesis. The experimentally measured chemical and thermal structure of the spray flame is critically needed as a validation target for simulations of the synthesis of nanoparticles in these spray flames. This paper presents an experimental study of the chemical and thermal structure of the flame produced by the SpraySyn burner. The spatial distribution of the main species is obtained by microprobe sampling in combination with orthogonal time-of-flight mass spectrometry. The temperature distribution is obtained by a micro-thermocouple technique. The presented species and temperature data are discussed in the context of their experimental uncertainties and the plausibility of the flame structure.}}, author = {{Gonchikzhapov, Munko and Kasper, Tina}}, journal = {{Applications in Engery and Combustion Science}}, title = {{{Thermal and chemical structure of ethanol and 2-ethylhexanoic acid/ethanol SpraySyn flames}}}, doi = {{10.1016/j.jaecs.2023.100174}}, volume = {{15}}, year = {{2023}}, } @article{53080, abstract = {{Quantitative speciation data for alternative fuels is highly desired to assess their emission potential and to develop and validate chemical kinetic models. In terms of substitute choices for fossil diesel are oxymethylene ethers (OMEs) strongly discussed. Due to the absence of carbon-carbon bonds, soot emis-sions from combustion of OMEs are low, but significant emissions of unregulated pollutants such as alde-hydes emerge. The combustion behavior of OME fuels with different chain lengths, OME0-4, was investigated in lam-inar premixed low-pressure flames using complementary molecular-beam mass spectrometry (MBMS) techniques. MBMS sampling provides an in-situ access directly into the reaction zone of the flame. Al-most all chemical species involved in the oxidation process can be detected and quantified simultane-ously. Neat OME0-3 flames were analyzed by electron ionization (EI) MBMS with high mass resolution ( R approximate to 3900) providing exact elementary composition. To obtain isomer-specific information, an OME1- doped hydrogen flame and a stochiometric OME4 flame were studied by double-imaging photoelectron photoion coincidence (i2PEPICO) spectroscopy. Both, EI-MBMS detection and i2PEPICO spectroscopy, en-ables a complete overview of all intermediates. The results show a dominance of oxygenated intermediates for all measured conditions. Mole fraction profiles for the most important species are presented (i.e. formaldehyde, methanol, methyl formate and formic acid) and compared to modeling results. Hydrocarbons with more than four carbon atoms were not detected under the investigated conditions. Isomers such as ethanol/dimethyl ether (m/z = 46) and ethenol/acetaldehyde (m/z = 44) could be separated using threshold photoelectron spectra for clear iden-tification and photoionization efficiency curves for quantification. This investigation permits the discus-sion and analysis of systematic trends, including intermediate species, for the combustion of the studied series of oxymethylene ether fuels. (c) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.}}, author = {{Gaiser, Nina and Zhang, Hao and Bierkandt, Thomas and Schmitt, Steffen and Zinsmeister, Julia and Kathrotia, Trupti and Hemberger, Patrick and Shaqiri, Shkelqim and Kasper, Tina and Aigner, Manfred and Oßwald, Patrick and Köhler, Markus}}, issn = {{0010-2180}}, journal = {{Combustion and Flame}}, keywords = {{General Physics and Astronomy, Energy Engineering and Power Technology, Fuel Technology, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Investigation of the combustion chemistry in laminar, low-pressure oxymethylene ether flames (OME0–4)}}}, doi = {{10.1016/j.combustflame.2022.112060}}, volume = {{243}}, year = {{2022}}, } @article{53081, abstract = {{Recent progress in molecular combustion chemistry allows for detailed investigation of the intermediate species pool even for complex chemical fuel compositions, as occur for technical fuels. This study pro-vides detailed investigation of a comprehensive set of complex alternative gasoline fuels obtained from laminar flow reactors equipped with molecular-beam sampling techniques for observation of the com-bustion intermediate species pool in homogeneous gas phase reactions. The combination of ionization techniques including double-imaging photoelectron photoion coincidence (i2PEPICO) spectroscopy enables deeper mechanistic insights into the underlying reaction network relevant to technical fuels. The se-lected fuels focus on contemporary automotive engine application as drop-in fuels compliant to European EN 228 specification for gasoline. Therefore, potential alternative gasoline blends containing oxygenated hydrocarbons as octane improvers obtainable from bio-technological production routes, e.g., ethanol, iso- butanol, methyl tert -butyl ether (MTBE), and ethyl tert -butyl ether (ETBE), as well as a Fischer-Tropsch surrogate were investigated. The fuel set is completed by two synthetic naphtha fractions obtained from Fischer-Tropsch and methanol-to-gasoline processes alongside with a fossil reference gasoline. In total, speciation data for 11 technical fuels from two atmospheric flow reactor setups are presented. Detailed main and intermediate species profiles are provided for slightly rich ( 4) = 1.2) and lean ( 4) = 0.8) con-ditions for intermediate to high temperatures. Complementary, the isomer distribution on different mass channels, like m/z = 78 u fulvene/benzene, of four gasolines was investigated. Experimental findings are analyzed in terms of the detailed fuel composition and literature findings for molecular combustion chemistry. Influences of oxygenated fuel components as well as composition of the hydrocarbon frac-tions are examined with a particular focus on the soot precursor chemistry. This dataset is available for validation of chemical kinetic mechanisms for realistic gasolines containing oxygenated hydrocarbons.(c) 2021 The Combustion Institute. Published by Elsevier Inc. All rights reserved.}}, author = {{Zinsmeister, Julia and Gaiser, Nina and Melder, Jens and Bierkandt, Thomas and Hemberger, Patrick and Kasper, Tina and Aigner, Manfred and Köhler, Markus and Oßwald, Patrick}}, issn = {{0010-2180}}, journal = {{Combustion and Flame}}, keywords = {{General Physics and Astronomy, Energy Engineering and Power Technology, Fuel Technology, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{On the diversity of fossil and alternative gasoline combustion chemistry: A comparative flow reactor study}}}, doi = {{10.1016/j.combustflame.2021.111961}}, volume = {{243}}, year = {{2022}}, } @article{53084, abstract = {{AbstractThe thermal decomposition of Zr(acac)4 is studied in a SiC-microreactor on the micro-second time scale. By utilizing synchrotron radiation and photoelectron photoion coincidence spectroscopy, six important zirconium intermediates, as for instance Zr(C5H7O2)2(C5H6O2), and Zr(C5H6O2)2, are identified in the gas phase for the first time. The adiabatic ionization thresholds of intermediately formed zirconium species are estimated and the main products of their thermal decomposition, acetylacetone, acetylallene and acetone are characterized unambiguously and isomer-selectively. Based on all detected intermediates, we deduce the predominant pyrolysis pathways of the precursor in the temperature range from 400 to 900 K. Our findings are complemented by numerical simulations of the flow field in the microreactor, which show that the choice of dilution gas significantly influences the temperature profile and residence times in the microreactor, such that helium provides a more uniform flow field than argon and should preferentially be used. Graphical abstract Using a soft ionization method coupled to velocity map imaging (VMI), leads to valuable insights in the thermal decomposition of Zr(C5H7O2)4, used in the synthesis of functional nanomaterials and ceramic coatings. Thanks to the use of a microreactor, important gas}}, author = {{Grimm, Sebastian and Baik, Seung-Jin and Hemberger, Patrick and Kasper, Tina and Kempf, Andreas M. and Atakan, Burak}}, issn = {{0884-2914}}, journal = {{Journal of Materials Research}}, keywords = {{Mechanical Engineering, Mechanics of Materials, Condensed Matter Physics, General Materials Science}}, number = {{9}}, pages = {{1558--1575}}, publisher = {{Springer Science and Business Media LLC}}, title = {{{Insights into the decomposition of zirconium acetylacetonate using synchrotron radiation: Routes to the formation of volatile Zr-intermediates}}}, doi = {{10.1557/s43578-022-00566-6}}, volume = {{37}}, year = {{2022}}, } @article{53083, abstract = {{AbstractThe decomposition and reduction of ferrocene, an important precursor for iron chemical vapor deposition and catalyst for nanotube synthesis, is investigated in the gas‐phase. Reactive intermediates are detected to understand the underlying chemistry by using a microreactor coupled to a synchrotron light source. Utilizing soft photoionization coupled with photoelectron‐photoion coincidence detection enables us to characterize exclusive intermediates isomer‐selectively. A reaction mechanism for the ferrocene decomposition is proposed, which proceeds as a two‐step process. Initially, the molecule decomposes in a homogeneous surface reaction at temperatures <900 K, leading to products such as cyclopentadiene and cyclopentadienyl radicals that are immediately released to the gas‐phase. At higher temperatures, ferrocene rapidly decomposes in the gas‐phase, losing two cyclopentadienyl radicals in conjunction with iron. The addition of hydrogen to the reaction mixture reduces the decomposition temperature, and changes the branching ratio of the products. This change is mainly attributed to the H‐addition of cyclopentadienyl radicals on the surface, which leads to a release of cyclopentadiene into the gas‐phase. On the surface, ligand fragments may also undergo a series of catalytic H‐losses leading most probably to a high carbon content in the film. Finally, Arrhenius parameters for both global reactions are presented.}}, author = {{Grimm, Sebastian and Hemberger, Patrick and Kasper, Tina and Atakan, Burak}}, issn = {{2196-7350}}, journal = {{Advanced Materials Interfaces}}, keywords = {{Mechanical Engineering, Mechanics of Materials}}, number = {{22}}, publisher = {{Wiley}}, title = {{{Mechanism and Kinetics of the Thermal Decomposition of Fe(C5H5)2 in Inert and Reductive Atmosphere: A Synchrotron‐Assisted Investigation in A Microreactor}}}, doi = {{10.1002/admi.202200192}}, volume = {{9}}, year = {{2022}}, } @article{36815, abstract = {{Iso-octane is frequently used as a surrogate fuel or as a component in primary reference fuel blends when low-temperature combustion strategies in engines are investigated. To develop control strategies for these engines, the reaction kinetics of iso-octane must be known starting from the low temperatures and intermediate pressures before ignition to the high temperatures and pressures of combustion. This work adds new experimental data sets to the validation data for reaction mechanism development by investigating the oxidation of iso-octane in stoichiometric mixtures in a flow reactor at pressures of p = 1, 10, and 20 bar and 473K ≤ T ≤ 973 K. The experimental data are compared to simulations with recent reaction mechanisms [Atef et al., Combustion and Flame 178, (2017), Bagheri et al., Combustion and Flame 212, (2020), Cai et al., Proceedings of the Combustion Institute 37, (2018), Fang et al., Combustion and Flame 214, (2020)]. The comparison between experimental and simulated mole fractions as function of temperature show reasonable agreement for all investigated pressures. In particular, the experimentally observed onset of low-temperature reactivity above a certain pressure, the shift of the negative temperature coefficient (NTC) regime with increasing pressure to higher temperatures, and the acceleration of the high-temperature chemistry are captured well in the simulations. Deviations between experimental and simulated results are discussed in detail for the reactivity of iso-octane and some key intermediates such as 2,2,4,4-tetramethyl-tetrahydrofuran, iso-butene and acetone at low temperatures.}}, author = {{Shaqiri, S. and Kaczmarek, D. and vom Lehn, F. and Beeckmann, J. and Pitsch, H. and Kasper, Tina}}, issn = {{2296-598X}}, journal = {{Frontiers in Energy Research}}, keywords = {{Economics and Econometrics, Energy Engineering and Power Technology, Fuel Technology, Renewable Energy, Sustainability and the Environment}}, publisher = {{Frontiers Media SA}}, title = {{{Experimental Investigation of the Pressure Dependence of Iso-Octane Combustion}}}, doi = {{10.3389/fenrg.2022.859112}}, volume = {{10}}, year = {{2022}}, } @article{36817, author = {{Hoener, Martin and Kasper, Tina}}, issn = {{0010-2180}}, journal = {{Combustion and Flame}}, keywords = {{General Physics and Astronomy, Energy Engineering and Power Technology, Fuel Technology, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Nitrous acid in high-pressure oxidation of CH4 doped with nitric oxide: Challenges in the isomer-selective detection and quantification of an elusive intermediate}}}, doi = {{10.1016/j.combustflame.2022.112096}}, volume = {{243}}, year = {{2022}}, } @article{36810, author = {{Knyazkov, Denis A. and Cherepanov, Andrey V. and Kiselev, Vitaly G. and Gerasimov, Ilya E. and Kasper, Tina and Shmakov, Andrey G.}}, issn = {{1540-7489}}, journal = {{Proceedings of the Combustion Institute}}, keywords = {{Physical and Theoretical Chemistry, Mechanical Engineering, General Chemical Engineering}}, publisher = {{Elsevier BV}}, title = {{{Experimental and kinetic modeling study of the positive ions in premixed ethylene flames over a range of equivalence ratios}}}, doi = {{10.1016/j.proci.2022.07.157}}, year = {{2022}}, } @article{36814, author = {{Kaczmarek, D. and Bierkandt, T. and Rudolph, C. and Grimm, S. and Shaqiri, S. and Höner, M. and Gaiser, N. and Atakan, B. and Köhler, M. and Hemberger, P. and Kasper, Tina}}, issn = {{2666-352X}}, journal = {{Applications in Energy and Combustion Science}}, keywords = {{Fuel Technology, Energy (miscellaneous), Chemical Engineering (miscellaneous)}}, publisher = {{Elsevier BV}}, title = {{{Activation effect of ozone and DME on the partial oxidation of natural gas surrogates and validation of pressure-dependent ozone decomposition}}}, doi = {{10.1016/j.jaecs.2022.100107}}, year = {{2022}}, } @article{36811, author = {{Kaczmarek, Dennis and Rudolph, Charlotte and Atakan, Burak and Kasper, Tina}}, issn = {{1540-7489}}, journal = {{Proceedings of the Combustion Institute}}, keywords = {{Physical and Theoretical Chemistry, Mechanical Engineering, General Chemical Engineering}}, publisher = {{Elsevier BV}}, title = {{{Kinetic investigation of the ozone-assisted partial oxidation of fuel-rich natural gas mixtures at elevated pressure}}}, doi = {{10.1016/j.proci.2022.07.195}}, year = {{2022}}, } @article{36813, author = {{Bierkandt, Thomas and Hemberger, Patrick and Oßwald, Patrick and Gaiser, Nina and Hoener, Martin and Krüger, Dominik and Kasper, Tina and Köhler, Markus}}, issn = {{1540-7489}}, journal = {{Proceedings of the Combustion Institute}}, keywords = {{Physical and Theoretical Chemistry, Mechanical Engineering, General Chemical Engineering}}, publisher = {{Elsevier BV}}, title = {{{A combustion chemistry study of tetramethylethylene in a laminar premixed low-pressure hydrogen flame}}}, doi = {{10.1016/j.proci.2022.07.205}}, year = {{2022}}, } @article{32492, author = {{Lau, S. and Gonchikzhapov, M. and Paletsky, A. and Shmakov, A. and Korobeinichev, O. and Kasper, Tina and Atakan, B.}}, issn = {{0010-2180}}, journal = {{Combustion and Flame}}, keywords = {{General Physics and Astronomy, Energy Engineering and Power Technology, Fuel Technology, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Aluminum Diethylphosphinate as a Flame Retardant for Polyethylene: Investigation of the Pyrolysis and Combustion Behavior of PE/AlPi-Mixtures}}}, doi = {{10.1016/j.combustflame.2022.112006}}, volume = {{240}}, year = {{2022}}, } @article{29208, abstract = {{The parameters required to calculate the energy efficiency of household refrigerating appliances (i.e. refrigerators, freezers and their combinations) are determined by standard measurements. According to regulations, these measurements are carried out when the appliances are new. It is known from previous studies that various technical aging mechanisms can increase electrical energy consumption by up to 36 % over a product lifespan of 18 years. In order to determine the time dependence of the energy consumption of household refrigerating appliances, repeated measurements are carried out in this work. Eleven new appliances are examined under standard measurement conditions. After just two years of operation, an additional energy consumption of up to 11 % is determined. Furthermore, 21 older appliances that had previously been measured in new condition are tested again after up to 21 years of operation. For these older appliances, an average increase of energy consumption of 28 % is found. For individual appliances, the maximum increase is 36 %. An aging model is developed on the basis of these measurement results, which may help to predict the aging-related increase of energy consumption of household refrigerating appliances. This model shows an average increase in energy consumption of 27 % for an appliance age of 16 years. Supplemental performance tests of eight compressors do not show any significant aging effects related to these devices after two years of operation. Furthermore, measurements of the thermal conductivity of aged polyurethane foam test samples are carried out and an increase of its thermal conductivity of 26 % over a period of about three years is determined.}}, author = {{Paul, Andreas and Baumhögger, Elmar and Elsner, Andreas and Reineke, Michael and Hueppe, Christian and Stamminger, Rainer and Hoelscher, Heike and Wagner, Hendrik and Gries, Ulrich and Becker, Wolfgang and Vrabec, Jadran}}, issn = {{1359-4311}}, journal = {{Applied Thermal Engineering}}, keywords = {{Industrial and Manufacturing Engineering, Energy Engineering and Power Technology}}, publisher = {{Elsevier BV}}, title = {{{Impact of aging on the energy efficiency of household refrigerating appliances}}}, doi = {{10.1016/j.applthermaleng.2021.117992}}, volume = {{205}}, year = {{2022}}, } @article{30678, author = {{Javed, Muhammad Ali and Vater, Sebastian and Baumhögger, Elmar and Windmann, Thorsten and Vrabec, Jadran}}, issn = {{0021-9614}}, journal = {{The Journal of Chemical Thermodynamics}}, keywords = {{Physical and Theoretical Chemistry, General Materials Science, Atomic and Molecular Physics, and Optics}}, publisher = {{Elsevier BV}}, title = {{{Apparatus for the measurement of the thermodynamic speed of sound of diethylene glycol and triethylene glycol}}}, doi = {{10.1016/j.jct.2022.106766}}, year = {{2022}}, } @article{31808, author = {{Khider Abbas Abbas, Wameedh and Baumhögger, Elmar and Vrabec, Jadran}}, issn = {{2590-1745}}, journal = {{Energy Conversion and Management: X}}, keywords = {{Energy Engineering and Power Technology, Fuel Technology, Nuclear Energy and Engineering, Renewable Energy, Sustainability and the Environment}}, publisher = {{Elsevier BV}}, title = {{{Experimental investigation of organic Rankine cycle performance using alkanes or hexamethyldisiloxane as a working fluid}}}, doi = {{10.1016/j.ecmx.2022.100244}}, year = {{2022}}, } @article{33255, author = {{Betken, Benjamin and Beckmüller, Robin and Ali Javed, Muhammad and Baumhögger, Elmar and Span, Roland and Vrabec, Jadran and Thol, Monika}}, issn = {{0021-9614}}, journal = {{The Journal of Chemical Thermodynamics}}, keywords = {{Physical and Theoretical Chemistry, General Materials Science, Atomic and Molecular Physics, and Optics}}, publisher = {{Elsevier BV}}, title = {{{Thermodynamic Properties for 1-Hexene – Measurements and Modeling}}}, doi = {{10.1016/j.jct.2022.106881}}, year = {{2022}}, } @inproceedings{31243, author = {{Hami Dindar, Iman and Baumhögger, Elmar and Lutters, Nicole and Kenig, Eugeny}}, booktitle = {{Jahrestreffen der ProcessNet Fachgruppen Fluidverfahrenstechnik und Hochdruckverfahrenstechnik}}, location = {{Frankfurt am Main}}, title = {{{Wässrige Aminozuckerlösungen als neue Lösungsmittel zur CO2-Abscheidung}}}, year = {{2022}}, } @article{53082, author = {{Zinsmeister, Julia and Gaiser, Nina and Melder, Jens and Bierkandt, Thomas and Hemberger, Patrick and Kasper, Tina and Aigner, Manfred and Köhler, Markus and Oßwald, Patrick}}, issn = {{0010-2180}}, journal = {{Combustion and Flame}}, keywords = {{General Physics and Astronomy, Energy Engineering and Power Technology, Fuel Technology, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{On the diversity of fossil and alternative gasoline combustion chemistry: A comparative flow reactor study}}}, doi = {{10.1016/j.combustflame.2021.111961}}, volume = {{243}}, year = {{2022}}, } @article{53086, author = {{Zhang, Hao and Kaczmarek, Dennis and Rudolph, Charlotte and Schmitt, Steffen and Gaiser, Nina and Oßwald, Patrick and Bierkandt, Thomas and Kasper, Tina and Atakan, Burak and Kohse-Höinghaus, Katharina}}, issn = {{0010-2180}}, journal = {{Combustion and Flame}}, keywords = {{General Physics and Astronomy, Energy Engineering and Power Technology, Fuel Technology, General Chemical Engineering, General Chemistry}}, publisher = {{Elsevier BV}}, title = {{{Dimethyl ether (DME) and dimethoxymethane (DMM) as reaction enhancers for methane: Combining flame experiments with model-assisted exploration of a polygeneration process}}}, doi = {{10.1016/j.combustflame.2021.111863}}, volume = {{237}}, year = {{2021}}, }