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 - CONF A1 - Lange, T. A1 - Neher, F. A1 - Klemm, E. A1 - Heinrich, Sebastian A1 - Balcazar Pust, Emilio A1 - Liebner, Christian A1 - Hieronymus, Hartmut T1 - Heterogeneous catalysis meets micro reactors: Partial oxidations in the explosion regime N2 - Investigations on primary, secondary and tertiary explosion protection have been performed for micro reactors with slit-like channels which are coated with catalyst. Ethene/oxygen mixtures have been used as model gas mixtures representing explosion group IIB (DIN EN ISO 16852). It could be shown that the explosion regime can be significantly reduced when using micro reactors (primary explosion protection). Furthermore, safe Operation inside the explosion regime is possible with micro reactors (secondary explosion protection), but, at certain conditions thermal runaway and ignition of detonations are possible. An unexpected behaviour has been found, because thermal runaway occurred when Volumetrie flow rate was increased. This behaviour is completely opposite to that of multi tube fixed bed reactors which show an increase of safety when increasing volumetric flow rate. Micro reactors can be constructed pressure-resistant even when detonations occur inside (tertiary explosion protection). For the example of o-xylene oxidation it could be shown that space time yield can be increased significantly when entering explosion regime. T2 - DGMK International conference - Selective oxidation and functionalization: Classical and alternative routes and sources CY - Berlin, Germany DA - 13.10.2014 PY - 2014 SN - 978-3-941721-44-9 VL - 2014-3 SP - 97 EP - 105 AN - OPUS4-31759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liebner, Christian A1 - Hieronymus, Hartmut A1 - Heinrich, Sebastian A1 - Edeling, Florian A1 - Lange, T. A1 - Klemm, E. ED - Beyer, M. ED - Stolz, T. T1 - Zündung, Ausbreitung und Unterdrückung von Explosionen in einem Mikroreaktor N2 - Der vorliegende Beitrag behandelt spezifische Aspekte der Sicherheitstechnik bei heterogen katalysierten Oxidationsreaktionen. Ergebnisse von Explosionsuntersuchungen an Ethen-Sauerstoffgemischen in einem kontinuierlich betriebenen Mikroreaktor, die beispielsweise für den Ethylenoxidprozess relevant sind, werden vorgestellt. Der Anfangsdruck der untersuchten Eduktgemische lag zwischen 1000 hPa und 10000 hPa bei Anfangstemperaturen zwischen Umgebungstemperatur und einer Temperatur bis zu 673 K. Mikrostrukturierte Reaktoren bieten einen erweiterten Bereich von Betriebsbedingungen. Die Untersuchungen zielen auf den sicheren Betrieb eines Mikroreaktors bei Bedingungen, die bei konventionellen Reaktoren als innerhalb des Explosionsbereichs eingestuft werden, ab. In bestimmten Grenzen kann eine Unterdrückung von Explosionen in einem Mikroreaktor erreicht werden. Es ist jedoch nicht möglich, einen Mikroreaktor unter allen Bedingungen sicher zu betreiben. Aus diesen Gründen wurde die Explosionsausbreitung durch einen mikrostrukturierten Reaktor hindurch und die Zündung einer Gasphasenexplosion durch Hot-Spots in dem Reaktor untersucht. Die angewandten Untersuchungsmethoden sind Gegenstand aktueller Normungsaktivitäten. T2 - 13. BAM-PTB-Kolloquium zur chemischen und physikalischen Sicherheitstechnik CY - Braunschweig, Germany DA - 18.06.2013 KW - Micro Reactor KW - Explosion KW - Safety PY - 2013 SN - 978-3-95606-062-5 DO - https://doi.org/10.7795/210.20130910K SN - 1868-5838 SP - 90 EP - 98 AN - OPUS4-29849 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Recknagel, Sebastian A1 - Noack, Siegfried A1 - Steiger, Thomas A1 - Kipphardt, Heinrich A1 - Matschat, Ralf T1 - International comparability of determination of mass fractions of chromium, copper, iron, manganese and zinc in aluminium alloy: Comité consultatif pour la quantité de matière key comparison K42 N2 - The degree of equivalence within the participating national metrology institutes for the measurement results of the mass fractions of the analytes Cr, Cu, Fe, Mn and Zn in an aluminium alloy was assessed. This interlaboratory comité consultatif pour la quantité de matière key comparison (CCQM-K42) was organised as an activity of the Inorganic Analytical Working Group of CCQM. In total seven laboratories participated, six of them for all analytes. Measurands were the mass fractions of the analytes in a range of 0.05 and 0.2%. As an outcome the consistency of the results for all elements investigated was acceptable, hence satisfactory comparability was established. An aluminium based certified reference material—undisclosed to the analysts which one it was—was used as test sample. For the purpose of this study homogeneity was tested at BAM. Each laboratory was free to choose any analytical method they wanted to use for the analysis. Consequently various methods of measurement were employed: instrumental neutron activation analysis, X-ray fluorescence spectrometry (XRF) using fused cast-bead method combined with reconstitution technique, inductively coupled plasma optical emission spectrometry (ICP OES) and inductively coupled plasma mass spectrometry. Metrological traceability of the measurement results to the SI unit had to be demonstrated. Therefore, methods such as spark OES or XRF (without fused cast-bead technique)—both of them being most important methods for the analysis of metals and alloys in industrial laboratories—could not be used in the frame of the key comparison. KW - Aluminium alloy KW - International comparison KW - CCQM-K42 KW - Key comparison PY - 2010 DO - https://doi.org/10.1007/s00769-010-0641-5 SN - 0949-1775 SN - 1432-0517 VL - 15 IS - 7 SP - 401 EP - 407 PB - Springer CY - Berlin AN - OPUS4-21628 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Heinrich, Sebastian A1 - Liebner, Christian A1 - Hieronymus, Hartmut A1 - Klemm, E. T1 - Durchführung heterogen katalysierter Selektivoxidationen im Explosionsbereich unter Einsatz von Mikrostrukturreaktoren T2 - 10. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Deutschland DA - 2010-11-04 KW - Mikroreaktor KW - Oxidation KW - Explosion PY - 2010 SN - 978-3-89746-119-2 IS - P-03 SP - 1 EP - 6 CY - Frankfurt/M. AN - OPUS4-22359 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Heinrich, Sebastian T1 - Mikrostrukturreaktoren für heterogen katalysierte Selektivoxidationen im Explosionsbereich T2 - 10. Fachtagung Anlagen-, Arbeits- und Umweltsicherheit CY - Köthen, Germany DA - 2010-11-04 PY - 2010 AN - OPUS4-22366 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, Sebastian A1 - Plettig, M. A1 - Klemm, E. T1 - Role of the Ti(IV)-superoxide species in the selective oxidation of alkanes with hydrogen peroxide in the gas phase on titanium silicalite-1: an in situ EPR investigation N2 - The interaction of TS-1 with gaseous hydrogen peroxide at temperatures above 373 K has been investigated by in situ EPR measurements. Treatment of TS-1 with hydrogen peroxide in the gas phase leads to a strong EPR signal, assigned to the Ti(IV)-superoxide species. In contrast to investigations with liquid hydrogen peroxide, here only one Ti(IV)-superoxide species could be detected in the EPR spectrum. The time constant of the reaction of the Ti(IV)-superoxide species detected by in situ EPR measurements was much larger than that observed for the rate of consumption of propane or propene via gas chromatographic analysis. Thus, we conclude that the Superoxide species may take part in the oxidation reaction (via side reactions or the formation of unselective products), but is probably not the main responsible species in the oxidation of propane or propene. KW - Titanium silicalite-1 KW - EPR KW - Oxidation KW - Hydrogen peroxide KW - Superoxide KW - Alkanes PY - 2011 DO - https://doi.org/10.1007/s10562-010-0534-6 SN - 1011-372X VL - 141 IS - 2 SP - 251 EP - 258 PB - Kluwer CY - Dordrecht AN - OPUS4-23553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Recknagel, Sebastian A1 - Kipphardt, Heinrich A1 - Lange, Britta A1 - Hoppe, Marion T1 - Traceable analysis of impurities in metallic reference materials using GD-MS N2 - The traceabiiity requirements for certification analyses of reference materials are much more stringent than for routine analysis, where certified matrix reference materials (CRM) can be used for calibration and to establish traceabiiity. Although the ISO-Guides related to CRM production and certification are not fully clear concerning calibration, many established CRM-producers do not accept matrix-CRMs for calibration in case of certification analyses, e.g. to avoid circular reasoning. These requirements limit the methods used for certification to those that can be calibrated using Standards of known high purity and stoichiometry or mixtures of such Standards. Powerful solid sampling techniques such as glow discharge mass spectrometry (GD-MS) or spark-optical emission spectrometry (SOES), where usually compact CRMs are used for calibration, seem not be applicable for certification analyses. Especially GD-MS is a powerful tool for trace element determination of solid samples. Beside metallic impurities the use of specific gas mixtures enables also the determination of interesting nonmetallic impurities such as sulfur and phosphorus. Within BAM a calibration approach, was developed which enables to use mixtures of Standards of known high purity and stoichiometry also for GD-MS. Analogue to matrix adaption in solution based techniques, the calibration approach is based on doped pressed powder pellets. Approach and application on the certification analyses of copper and Steel CRMs are presented. T2 - CETAS 2011 - 8th International workshop on progress in analytical chemistry & materials characterisation in the steel and metal industries CY - Luxembourg, Luxembourg DA - 17.05.2011 PY - 2011 IS - OC53 SP - 361 EP - 365 AN - OPUS4-23762 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Recknagel, Sebastian A1 - Kipphardt, Heinrich A1 - Meckelburg, Angela ED - Angeli, J. T1 - Determination of nitrogen in ferritic electric heating steel ECRM 299-1 T2 - 7th International Workshop "Progress in Analytical Chemistry in the Steel and Metal Industries" CY - Luxembourg DA - 2006-05-16 PY - 2006 SN - 3-7739-6016-6 SP - 409 EP - 413 PB - VGE Verl. GmbH CY - Essen AN - OPUS4-12443 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lange, Britta A1 - Kipphardt, Heinrich A1 - Recknagel, Sebastian A1 - Meier, Klaus T1 - Preparation and analysis of a reference material for the measurement of oxygen in copper N2 - The preparation and analysis of the oxygen mass fraction of three pure copper reference materials (BAM-379/1, BAM-379/2, BAM-379/3) intended for the calibration of spark emission spectrometry are described here. Data of homogeneity testing and round robin certification in collaboration with 12 independent laboratories from metalworking industry and research are reported. Problems with the establishment of traceability in this special case are discussed. KW - Determination of oxygen KW - Copper KW - Reference material KW - Certification PY - 2002 DO - https://doi.org/10.1007/s00769-001-0413-3 SN - 0949-1775 SN - 1432-0517 VL - 7 IS - 1 SP - 19 EP - 23 PB - Springer CY - Berlin AN - OPUS4-10994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -