DECHEMA

About: DECHEMA is a nonprofit organization based out in Frankfurt am Main, Germany. It is known for research contribution in the topics: Corrosion & Oxide. The organization has 756 authors who have published 1307 publications receiving 25693 citations.

Charme und Chancen der Weißen Biotechnologie

Abstract: Die Weise Biotechnologie ist keine neue Disziplin, sondern fasst nur ein Segment der Biotechnologie zusammen, um sie von den beiden anderen grosen Segmenten – der Roten und der Grunen Biotechnologie – abzuheben. Sie ist in den Fokus geraten, weil bahnbrechende Verfahren zur Analyse biologischer Systeme eine Neubetrachtung der Potenziale der Biotechnologie zur Folge haben. Neue Entwicklungen sind abzusehen, wie uber genombasierte Daten mit Hilfe der Bioinformatik, der Molekularbiologie und der Bioverfahrenstechnik Prozesse in ganzheitlicher Betrachtung optimiert werden. Wegen relativ einfacher biologischer Systeme, aber vielfaltiger Anwendungen wird die Weise Biotechnologie als Vorreiterdisziplin ins Feld gefuhrt. Durch die Forderung interdisziplinarer Ansatze zur integralen Prozessentwicklung sollte die biotechnologisch orientierte Industrie in weitem Mase profitieren. Dies gilt insbesondere fur das wissenschaftliche Umfeld und die kleinen und mittleren Unternehmen, die mehr und mehr vom Zugang zu den modernen Methoden der Biotechnologie abhangen. Im internationalen Rahmen ist gerade auf dem Gebiet der Weisen Biotechnologie eine konkurrenzfahige Situation in Deutschland festzustellen. Es bedarf jedoch einer nachhaltigen und langfristigen Unterstutzung, damit sowohl die Wissenschaft als auch die Industrie nicht den Anschluss an die internationale Entwicklung der Weisen Biotechnologie verlieren.

Controlling the enantioselective hydrogenation of ethyl pyruvate using zeolites as catalyst support

Abstract: 5 wt-% Pt/carrier catalysts (carrier materials: NaY, mordenite, erionite and NaX as well as γ-Al 2 O 3 as a microporous, non-zeolitic support) combined with (-)cinchonidine as the chiral auxiliary were used successfully for the enantioselective hydrogenation of ethyl pyruvate to R(+)ethyl lactate. With acetic acid as the solvent, the catalysts Pt/NaY, Pt/mordenite and Pt/erionite produced high enantiomeric excesses (86 to 90% ee), whereas Pt/NaX (77% ee) and Pt/γ-Al 2 O 3 (67% ee) gave comparatively poor optical yields. With regard to the k 0 values, which were obtained from kinetic data of the hydrogenation related to the mass of the catalysts only, a correlation between enantioselectivity and catalytic activity was not discernible. This changed significantly, if referring to the k'value related to the mass of the catalyst and its specific Pt surface area (derived from volumetric CO chemisorption measurements). Then, the catalysts producing the highest enantiomeric excesses also resulted in the highest catalytic activities. Therefore, catalytic activity and enantioselectivity essentially depend on the specific Pt surface area of the catalyst. This means that Pt particles of appropriate geometry and size are necessary to generate high enantioselectivity and catalytic activity. Zeolites Y, mordenite and erionite turned out to be appropriate templates for the creation of such Pt particles during catalyst preparation. This was confirmed by temperature-programmed CO desorption measurements. Zeolite X was partially destroyed by acid solution during catalyst preparation, which was proved by DTA and XRD measurements. Therefore, zeolite X, as well as γ-Al 2 O 3 , could not act as a template for the creation of appropriate Pt particles.

Process for separation of traces of gaseous contaminants from waste gases by chemical absorption

Abstract: In the separation of traces of halogens and sulfur from a halogen- and/or sulfur-containing gas stream wherein the gas stream is contacted with a wash liquid to absorb the halogens and sulfur, the improvement which comprises including in the wash liquid heavy metal ions capable of forming difficultly soluble halides and sulfides. Preferably the heavy metal ions are silver or copper, and the insoluble heavy metal sulfide and/or halide is removed from the wash liquid which is recirculated. Almost quantitative removal is achieved in as little as 1 second of gas-wash liquid contact.

Oxidation behaviour of particle reinforced MoSi2 composites at temperatures up to 1700°C. Part II: Initial screening of the oxidation behaviour of MoSi2 composites

Abstract: The financial support of these investigations by the Bundes-ministerium fu¨r Bildung, Wissenschaft, Forschu ng und Tech-nologie (BMBF) (contract number 03 N 2015 C1) is gratefullyacknowledged by the authors.