TY - JOUR A1 - Lange, T. A1 - Heinrich, Sebastian A1 - Liebner, Christian A1 - Hieronymus, Hartmut A1 - Klemm, E. T1 - Reaction engineering investigations of the partial oxidation of o-xylene in the explosion regime - microfixed bed versus catalyst coating N2 - The selective gas phase oxidation of o-xylene was investigated inside of the explosion regime using a microstructured reactor. The V2O5/TiO2 catalyst was used as microfixed bed and as catalyst coating. There were no significant losses of the selectivity to phthalic anhydride with feed compositions up to 7 vol % o-xylene observable. Above 7 vol % the selectivity decreased due to total oxidation, especially for the microfixed bed, which was probably caused by a hotspot. KW - Catalysis KW - Microreactors KW - Partial oxidation KW - Xylene KW - o-Xylene KW - Explosion regime PY - 2013 DO - https://doi.org/10.1002/cite.201200197 SN - 0009-286X SN - 1522-2640 VL - 85 IS - 4 SP - 461 EP - 466 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-30298 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tschirschwitz, Rico A1 - Bernardy, Christopher A1 - Wagner, Patrick A1 - Rappsilber, Tim A1 - Liebner, Christian A1 - Hahn, S.-K. A1 - Krause, U. T1 - Harmful effects of lithium-ion battery thermal runaway: scale-up tests from cell to second-life modules N2 - For a comprehensive safety assessment of stationary lithium-ion-battery applications, it is necessary to better understand the consequences of thermal runaway (TR). In this study, experimental tests comprising twelve TR experiments including four single-cell tests, two cell stack tests and six second-life module tests (2.65 kW h and 6.85 kW h) with an NMC-cathode under similar initial conditions were conducted. The temperature (direct at cells/modules and in near field), mass loss, cell/module voltage, and qualitative vent gas composition (Fourier transform infrared (FTIR) and diode laser spectroscopy (DLS) for HF) were measured. The results of the tests showed that the battery TR is accompanied by severe and in some cases violent chemical reactions. In most cases, TR was not accompanied by pregassing of the modules. Jet flames up to a length of 5 m and fragment throwing to distances to more than 30 m were detected. The TR of the tested modules was accompanied by significant mass loss of up to 82%. The maximum HF concentration measured was 76 ppm, whereby the measured HF concentrations in the module tests were not necessarily higher than that in the cell stack tests. Subsequently, an explosion of the released vent gas occurred in one of the tests, resulting in the intensification of the negative consequences. According to the evaluation of the gas measurements with regard to toxicity base on the “Acute Exposure Guideline Levels” (AEGL), there is some concern with regards to CO, which may be equally as important to consider as the release of HF. KW - Large-scale tests KW - Lithium-ion battery KW - Gas emission KW - Thermal runaway KW - Consequences PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-579054 DO - https://doi.org/10.1039/D3RA02881J SN - 2046-2069 VL - 13 IS - 30 SP - 20761 EP - 20779 PB - Royal Society of Chemistry (RSC) CY - Cambridge, UK AN - OPUS4-57905 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Balcazar Pust, Emilio A1 - Neher, F. A1 - Liebner, Christian A1 - Hieronymus, Hartmut A1 - Klemm, E. T1 - Determination of ignition temperature in micro reactors N2 - Explosion protection of oxidation reactions in micro reactors was investigated. Lange et al. (2014) reported on the possibilities of operating oxidation reactions in catalyst coated micro reactors within the explosion regime, but also warned about hotspot induced thermal runaway and detonation ignition at certain conditions. Methane and ethene, representing the explosion groups IIA1 and IIB (DIN EN ISO 16852), were used in stoichiometric oxygen mixtures with respect to total oxidation, which represents the worst case scenario in terms of safety assessment. Using laser radiation on a ceramic target inside of the micro channel, an artificial, controllable hotspot was generated. The ignition temperatures of fuel gas/oxygen mixtures inside a micro reactor were measured and their dependencies on initial pressure, initial temperature, volumetric flow rate, and micro channel height were examined. Deflagration reactions prior to the detonation were observed for the first time inside a micro reactor. KW - Explosion safety KW - Explosionsschutz KW - Zündtemperatur KW - Mikroverfahrenstechnik KW - Thermisches Durchgehen KW - Micro process engineering KW - Autoignition temperature KW - Hotspot KW - Thermal Runaway PY - 2016 DO - https://doi.org/10.3303/CET1648092 SN - 2283-9216 SN - 1974-9791 VL - 48 SP - 547 EP - 552 PB - AIDIC CY - Milano AN - OPUS4-34164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gödde, M. A1 - Liebner, Christian A1 - Hieronymus, Hartmut T1 - Sicherheit in der Mikroreaktionstechnik N2 - Die Mikroverfahrenstechnik beschäftigt sich mit Apparaten, deren innere Abmessungen kleiner als ein Millimeter sind. Mikroreaktoren sind zurzeit Gegenstand intensiver Forschungsarbeit. Aus Sicht der chemischen Sicherheitstechnik besteht eines von mehreren Zielen bei der Entwicklung von Mikroreaktoren darin, schwer beherrschbare Reaktionen bei Reaktionsbedingungen zu realisieren, die in konventionellen Chemieanlagen wegen ihrer besonderen Gefährlichkeit nicht mehr beherrscht werden können. Der große spezifische Wärmeaustausch kann das thermische Durchgehen der Reaktion verhindern, die engen Abmessungen können die Ausbreitung von Explosionen unterdrücken. Bei mehrstufigen Synthesen kann die Lagerung giftiger oder zersetzungsfähiger Zwischenprodukte durch unverzügliche weitere Umsetzung in einem folgenden Reaktionsschritt vermieden werden. Der vorliegende Beitrag widmet sich sicherheitstechnischen Aspekten der Mikroverfahrenstechnik. KW - Deflagration KW - Detonation KW - Mikroreaktionstechnik KW - Mikroreaktoren KW - Sicherheitstechnik PY - 2009 DO - https://doi.org/10.1002/cite.200800176 SN - 0009-286X SN - 1522-2640 VL - 81 IS - 1-2 SP - 73 EP - 78 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-19121 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fischer, J. A1 - Liebner, Christian A1 - Hieronymus, Hartmut A1 - Klemm, A. T1 - Maximum safe diameters of microcapillaries for a stoichiometric ethene/oxygen mixture KW - Combustion KW - Explosions KW - Microstructure KW - Safety KW - Ethene KW - Oxygen PY - 2009 DO - https://doi.org/10.1016/j.ces.2009.03.038 SN - 0009-2509 VL - 64 IS - 12 SP - 2951 EP - 2956 PB - Elsevier CY - Amsterdam AN - OPUS4-19446 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hieronymus, Hartmut A1 - Fischer, J. A1 - Heinrich, Sebastian A1 - Liebner, Christian A1 - Lange, T. A1 - Klemm, E. T1 - Sicherheitstechnische Untersuchungen zum Betrieb von Mikroreaktoren im Explosionsbereich N2 - Es wird eine Methode zur sicherheitstechnischen Untersuchung von Mikroreaktoren und mikrostrukturierten Komponenten, die im Explosionsbereich betrieben werden sollen, vorgestellt. Mikrostrukturierte Reaktoren sind nicht inhärent sicher, wenngleich der Bereich der sicheren Betriebsbedingungen gegenüber konventionellen Reaktoren erweitert ist. Der Explosionsbereich kann durch die Mikrostrukturen eingeengt werden. Am Beispiel von Ethylen/Sauerstoff-Gemischen und Ethylen/N2O-Gemischen wird hinsichtlich der Ausbreitung von Detonationen durch Kapillarrohre gezeigt, dass die sogenannte λ/3-Regel angewandt werden kann. Darüber hinaus werden erste Ergebnisse der Untersuchung der Ausbreitung von Explosionen durch einen Mikroreaktor mit rechteckigem Strömungskanal vorgestellt. KW - Detonationszellbreite KW - Explosionsgrenzen KW - Mikroreaktoren KW - Sicherheitstechnik KW - Detonation cell width KW - Explosion limit KW - Microreactor KW - Saftey engineering PY - 2011 DO - https://doi.org/10.1002/cite.201100112 SN - 0009-286X SN - 1522-2640 VL - 83 IS - 10 SP - 1742 EP - 1747 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-24486 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Roduner, E. A1 - Kaim, W. A1 - Sarkar, B. A1 - Urlacher, V.B. A1 - Pleiss, J. A1 - Gläser, R. A1 - Einicke, W.-D. A1 - Sprenger, G.A. A1 - Beifuß, U. A1 - Klemm, E. A1 - Liebner, Christian A1 - Hieronymus, Hartmut A1 - Hsu, S.-F. A1 - Plietker, B. A1 - Laschat, s. T1 - Selective catalytic oxidation of C-H bonds with molecular oxygen N2 - Although catalytic reductions, cross-couplings, metathesis, and oxidation of C=C double bonds are well established, the corresponding catalytic hydroxylations of C–H bonds in alkanes, arenes, or benzylic (allylic) positions, particularly with O2, the cheapest, 'greenest', and most abundant oxidant, are severely lacking. Certainly, some promising examples in homogenous and heterogenous catalysis exist, as well as enzymes that can perform catalytic aerobic oxidations on various substrates, but these have never achieved an industrial-scale, owing to a low space-time-yield and poor stability. This review illustrates recent advances in aerobic oxidation catalysis by discussing selected examples, and aims to stimulate further exciting work in this area. Theoretical work on catalyst precursors, resting states, and elementary steps, as well as model reactions complemented by spectroscopic studies provide detailed insight into the molecular mechanisms of oxidation catalyses and pave the way for preparative applications. However, O2 also poses a safety hazard, especially when used for large scale reactions, therefore sophisticated methodologies have been developed to minimize these risks and to allow convenient transfer onto industrial scale. KW - Coupling reactions KW - Feedstocks KW - Hydroxylation KW - Molecular oxygen KW - Oxidation KW - Catalytic oxidation KW - Micro reactor KW - Explosion KW - Safety PY - 2013 DO - https://doi.org/10.1002/cctc.201200266 SN - 1867-3880 VL - 5 IS - 1 SP - 82 EP - 112 PB - Wiley-VCH CY - Weinheim AN - OPUS4-27637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rappsilber, Tim A1 - Krüger, Simone A1 - Raspe, Tina A1 - Wagner, Patrick A1 - Liebner, Christian A1 - Strzyz, Thaddeus A1 - Tschirschwitz, Rico T1 - Hazard classification of different lithium-ion battery types after triggering thermal runaway N2 - For a better understanding of relevant parameters influencing the thermal runaway, this work classifies the behavior of six different types of lithium-ion batteries. Based on 145 repeatable tests, this research has created a unique and detailed database of battery behavior during thermal runaway. It contains information about changes in cell temperature, voltage, mass loss, smoke gas release and gas pressure. When it comes to characterizing the thermal runaway behavior across different cell types, this work eliminates the need for complex meta-analyses, which can only provide limited information due to the different test conditions in different test benches. In a pressure-resistant 100 dm³ autoclave and an 8-m³ room with connected multi gas analysis, 24 setups were examined under identical conditions. The investigations were carried out as a function of the variation parameters cell geometry, cathode active material, state of charge and initiation method of thermal runaway. The analysis of the measurement data reveals clear differences in the thermal runaway behavior of the tested cell types and can be used as a reference for determining the hazard potential in individual assessment categories of different cells. All measured values from both test benches as well as the visual evaluation of the cell behavior during the test runs in the 8 m³ room are made available in a comprehensive data table in the supplementary material. KW - Lithium Ion KW - Thermal Runaway KW - State of charge KW - Hazard classification KW - gas emission PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634429 DO - https://doi.org/10.1016/j.jlp.2025.105691 SN - 0950-4230 VL - 97 SP - 1 EP - 15 PB - Elsevier B.V. CY - Amsterdam AN - OPUS4-63442 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shenton, Martyn James A1 - Liebner, Christian A1 - Wanrooij, Jeroen Robert T1 - Basic design principles of flame arrestors for decomposable gases N2 - Flame Arrestors are safety relevant devices in chemical plants. If despite all the safety measures an explosion is initiated, they prevent damage, fatalities, and complete losses of production plants by hindering the explosion from propagating throughout the complete installation. Depending on the explosion propagation characteristics of the gas or gas mixture in question, the flame arrestors need to fulfil certain different operating requirements. In case of decomposable gases like acetylene and tetrafluoroethylene in some respect it might become necessary to violate the advice given in the standards concerning flame arrestor’s design. KW - Decomposition KW - Tetrafluoroethylene KW - Flame arrestor KW - Explosion PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648995 DO - https://doi.org/10.1016/j.psep.2025.107289 SN - 0957-5820 VL - 200 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-64899 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Liebner, Christian A1 - Shenton, M. T1 - Identifying hazardous conditions for compression heat igniting the chemically unstable gas Tetrafluoroetyhlene in industrial scale N2 - Tetrafluoroethylene (TFE) is an industrial scale starting material e.g. for polymer production (PTFE, FEP). When ignited the chemically unstable TFE is capable of decomposing in an explosive way. Explosion propagation through pipe systems of production plants have led to damage and fatalities within the last seven decades. Incident analyses identified compression heat a relevant source of ignition. Chemical plants consist of pipes, vessels, separating valves, strainers and other components. Before restarting the process after maintenance work, different parts of the plant components could be filled with TFE, nitrogen or air at different initial pressures ranging from vacuum or atmospheric to TFE at operating pressure. Valve opening procedures may cause a temperature increase in the gas phase. Compression takes place at polytropic conditions. Heat losses cannot be neglected. The temperature development in the gas depends upon the surface to volume ratio of the enclosure, geometrical influences, the state of gas flow, how fast the valve opens, and the heat capacity of the gas being compressed. Laboratory scale tests (Meyer, 2009) revealed ignition of TFE/air due to compression heat. Tests in pipes of 28 mm inner diameter, i.e. already industrial scale, were performed by (Kluge et. al., 2016). In the present contribution initial test results from a 63 mm pipe will be compared with existing 28 mm pipe data. A description of the experimental setup as well as an explanation of the hazard diagram will be given. Furthermore, a method allowing for the identification of hazardous conditions will be discussed. T2 - Konferenz LossPrevention 20149 CY - Delft, Netherlands DA - 16.06.2019 KW - Tetrafluoroethylene KW - Explosion KW - Safety PY - 2019 UR - https://www.aidic.it/cet/19/77/000.html SN - 978-88-95608-74-7 DO - https://doi.org/10.3303/CET1977026 SN - 2283-9216 VL - 77 SP - 151 EP - 156 PB - AIDIC - Associazione Italiana di Ingegneria Chimica CY - Milano AN - OPUS4-49564 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -