Formation, vaporization and accumulation of liquid hydrocarbon products during FTS in a single catalyst pore.

Catalytic selective hydrogenation reactions are important for refinery processes, petrochemical applications as well as for the fine chemicals industry. For polyunsaturated hydrocarbons, one of the possible intermediates is in most cases the product of choice. Thus, the main goal in catalyst research is to increase the selectivity to the desired intermediate, whilst minimizing loss of activity. Using the concept of a solid catalyst with an ionic liquid layer (SCILL), where the internal surface of a heterogeneous catalyst is coated with a thin film of ionic liquid (IL), the selectivity to such intermediates can be increased significantly. Moreover, the design of the IL allows minimization of the activity loss of the SCILL-catalyst in comparison to the uncoated catalyst. In this article the SCILL-concept is shown for the selective gas phase hydrogenation of 1,3-butadiene. With regard to overall butene selectivity (trans-2-, cis-2-, 1-), the performance of a commercial Pd-catalyst was enhanced to above 99% when transformed into a Pd-SCILL-catalyst by coating with IL 1,3-dimethylimidazolium dimethyl phosphate ([C1MIM][DMP]) at the expense of activity. Even at high residence time or hydrogen partial pressure the outcome of the reaction (S-butenes>99%) did not change. The influence of the IL cation structure on regaining activity is presented, and the role of the interplay between catalytically active metal and ionic liquid is investigated to understand the SCILL-effect.

The activity of solid catalysts is often reduced by the formation of coke. Thus, regeneration by coke burn-off is needed from time to time. A new method to monitor in situ the coke load during coking and decoking by electrical sensors is presented, which could be used as a controlling instrument of high value. Single particles of an Al2O3 catalyst were electrically contacted and characterised by impedance spectroscopy. A clear relationship between coke load and the impedance is observed. The sensor was tested by regeneration experiments both with single particles and in a coked fixed bed reactor. The results show that the coke burn-off within a single coked catalyst particle can be monitored and that it is possible to distinguish how strong the decoking of a single particle is influenced by pore diffusion. For a fixed bed, the axial coke profile can be monitored by means of axially distributed sensors, and the velocity of the reaction front and the length of the reaction zone are directly deduced by the local change of the coke profile with time. (c) 2010 Elsevier B.V. All rights reserved.

The separation of low concentrated sulfur compounds such as H2S, SO2 and tetrahydrothiophene (widely used as natural gas odorant) was studied by means of supported ionic liquid membranes (SILMs). Stable liquid membranes were prepared, characterized and applied in lab-scale experiments.. The influence of main process parameters - sulfur concentration, pressure, temperance and water content - on the degree of desulfurization of (model) natural gas, biogas or flue gas was determined. The experimental results are in good agreement with the solution-diffusion-model. The modelling shows that an efficient deep desulfurization of natural gas for the use in peripheral fuel cell systems can be achieved.

Chemie Ingenieur TechnikVolume 81, Issue 8 p. 1083-1084 PosterFree Access Membranen aus ionischen Flüssigkeiten zur Reinigung von Gasen T. Glöckner Dipl.-Chem., T. Glöckner Dipl.-Chem. thorsten.gloeckner@uni-bayreuth.de Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 Bayreuth, GermanySearch for more papers by this authorC. Kern Dr.-Ing., C. Kern Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 Bayreuth, GermanySearch for more papers by this authorA. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 Bayreuth, GermanySearch for more papers by this authorA. Seeberger Dipl.-Ing., A. Seeberger Dipl.-Ing. SepaPro GmbH, An der Heide 16, D-92353 Postbauer-Pavelsbach, GermanySearch for more papers by this author T. Glöckner Dipl.-Chem., T. Glöckner Dipl.-Chem. thorsten.gloeckner@uni-bayreuth.de Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 Bayreuth, GermanySearch for more papers by this authorC. Kern Dr.-Ing., C. Kern Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 Bayreuth, GermanySearch for more papers by this authorA. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 Bayreuth, GermanySearch for more papers by this authorA. Seeberger Dipl.-Ing., A. Seeberger Dipl.-Ing. SepaPro GmbH, An der Heide 16, D-92353 Postbauer-Pavelsbach, GermanySearch for more papers by this author First published: 19 August 2009 https://doi.org/10.1002/cite.200950239AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume81, Issue8Special Issue: ProcessNet-Jahrestagung und 27. Jahrestagung der BiotechnologenAugust, 2009Pages 1083-1084 RelatedInformation

Chemie Ingenieur TechnikVolume 80, Issue 9 p. 1262-1262 PosterFree Access Modellierung der Porendiffusion in Fischer-Tropsch-Katalysatoren A. Jung Dipl.-Ing., A. Jung Dipl.-Ing. anke.jung@uni-bayreuth.de Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this authorC. Kern Dr.-Ing., C. Kern Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this authorA. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this author A. Jung Dipl.-Ing., A. Jung Dipl.-Ing. anke.jung@uni-bayreuth.de Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this authorC. Kern Dr.-Ing., C. Kern Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this authorA. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this author First published: 12 September 2008 https://doi.org/10.1002/cite.200750529AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume80, Issue9Special Issue: ProcessNet Jahrestagung 2008September, 2008Pages 1262-1262 RelatedInformation

AbstractKohlenstoff‐Nanotubes und ‐fasern sind interessante Materialien für viele Anwendungen, angefangen von der Kunststofftechnik bis zur Katalyse. Bisher existiert aber noch kein technischer Herstellungsprozess. Die vorliegende Arbeit soll eine Übersicht über die Grundlagen der Synthese von Kohlenstoff‐Nanotubes und ‐fasern geben. Das Hauptaugenmerk liegt dabei auf der Kinetik und Reaktionstechnik der Herstellung durch katalytische Gasphasenabscheidung aus Kohlenmonoxid und Ethen.

Chemie Ingenieur TechnikVolume 77, Issue 8 p. 985-986 Poster Bestimmung der elektrischen Leitfähigkeit und der Viskosität von ionischen Flüssigkeiten W. Korth Dr., W. Korth Dr. wolfgang.korth@uni-bayreuth.de Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorA. Jess Prof. Dr., A. Jess Prof. Dr. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorC. Kern Dr., C. Kern Dr. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this author W. Korth Dr., W. Korth Dr. wolfgang.korth@uni-bayreuth.de Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorA. Jess Prof. Dr., A. Jess Prof. Dr. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorC. Kern Dr., C. Kern Dr. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this author First published: 10 August 2005 https://doi.org/10.1002/cite.200590235AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume77, Issue8Special Issue: GVC/DECHEMA-JahrestagungenAugust, 2005Pages 985-986 RelatedInformation

Chemie Ingenieur TechnikVolume 77, Issue 8 p. 1230-1230 Poster Kinetische und reaktionstechnische Untersuchungen zur Synthese von Kohlenstoff- Nanotubes und -Nanofasern K. Schrögel Dipl.-Ing., K. Schrögel Dipl.-Ing. Kathrin.schroegel@uni-bayreuth.de Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorA. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorC. Kern Dr.-Ing., C. Kern Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorA. Jung, A. Jung Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorW. Schütz Dr. rer. nat., W. Schütz Dr. rer. nat. FutureCarbon GmbH, Gottlieb-Keim-Straße 60, D-95448 BayreuthSearch for more papers by this authorT. Schubert Dipl.-Ing, T. Schubert Dipl.-Ing FutureCarbon GmbH, Gottlieb-Keim-Straße 60, D-95448 BayreuthSearch for more papers by this author K. Schrögel Dipl.-Ing., K. Schrögel Dipl.-Ing. Kathrin.schroegel@uni-bayreuth.de Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorA. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorC. Kern Dr.-Ing., C. Kern Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorA. Jung, A. Jung Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, Universitätsstraße 30, D-95447 BayreuthSearch for more papers by this authorW. Schütz Dr. rer. nat., W. Schütz Dr. rer. nat. FutureCarbon GmbH, Gottlieb-Keim-Straße 60, D-95448 BayreuthSearch for more papers by this authorT. Schubert Dipl.-Ing, T. Schubert Dipl.-Ing FutureCarbon GmbH, Gottlieb-Keim-Straße 60, D-95448 BayreuthSearch for more papers by this author First published: 10 August 2005 https://doi.org/10.1002/cite.200590096AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume77, Issue8Special Issue: GVC/DECHEMA-JahrestagungenAugust, 2005Pages 1230-1230 RelatedInformation

The regeneration of a coked naphtha reforming catalyst (Pt/Re–Al2O3) was studied by kinetic investigations on the effective rate of coke burn-off. For temperatures of industrial relevance for the catalyst, i.e., below 550∘C (deactivation), the coke burn-off within the cylindrical particles (dP≈2mm) is determined by the interplay of chemical reaction and pore diffusion; limitation by external mass transfer can be excluded for T<750∘C. Based on the parameters of the intrinsic kinetics and of the structure of the catalyst (porosity, tortuosity), the regeneration process is modelled and discussed both on the level of a single particle and in a technical fixed bed reactor. The results of modelling are compared with data from lab-scale investigations (coke profiles within the particles) and the performance data of the regeneration in an industrial fixed bed reactor (moving reaction zone); the agreement of calculation and measurement is in both cases complete.

Chemie Ingenieur TechnikVolume 76, Issue 9 p. 1352-1352 Poster Messung der Löslichkeit und des Stofftransports von CO2 in polymeren Werkstoffen mit Hilfe einer Magnetschwebewaage C. Kern Dr.-Ing., christoph.kern@uni-bayreuth.de Search for more papers by this authorA. Jess Prof. Dr.-Ing., Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this authorV. Altstädt Prof. Dr. Ing., Lehrstuhl für Polymere Werkstoffe, Universität Bayreuth; D-95447 BayreuthSearch for more papers by this authorD. Langenfelder Dipl.-Ing., Lehrstuhl für Polymere Werkstoffe, Universität Bayreuth; D-95447 BayreuthSearch for more papers by this authorF. Wöllecke Dipl.-Ing., Lehrstuhl für Polymere Werkstoffe, Universität Bayreuth; D-95447 BayreuthSearch for more papers by this author C. Kern Dr.-Ing., christoph.kern@uni-bayreuth.de Search for more papers by this authorA. Jess Prof. Dr.-Ing., Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this authorV. Altstädt Prof. Dr. Ing., Lehrstuhl für Polymere Werkstoffe, Universität Bayreuth; D-95447 BayreuthSearch for more papers by this authorD. Langenfelder Dipl.-Ing., Lehrstuhl für Polymere Werkstoffe, Universität Bayreuth; D-95447 BayreuthSearch for more papers by this authorF. Wöllecke Dipl.-Ing., Lehrstuhl für Polymere Werkstoffe, Universität Bayreuth; D-95447 BayreuthSearch for more papers by this author First published: 01 October 2004 https://doi.org/10.1002/cite.200490252AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume76, Issue9September, 2004Pages 1352-1352 RelatedInformation

Chemie Ingenieur TechnikVolume 76, Issue 9 p. 1351-1352 Poster Einsatz einer Magnetschwebewaage zur Bestimmung der Gaslöslichkeit und des Stofftransports in ionischen Flüssigkeiten C. Kern Dr.-Ing., C. Kern Dr.-Ing. christoph.kern@uni-bayreuth.de Search for more papers by this authorA. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this authorW. Korth Dr., W. Korth Dr. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this author C. Kern Dr.-Ing., C. Kern Dr.-Ing. christoph.kern@uni-bayreuth.de Search for more papers by this authorA. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this authorW. Korth Dr., W. Korth Dr. Lehrstuhl für Chemische Verfahrenstechnik, Universität Bayreuth, D-95447 BayreuthSearch for more papers by this author First published: 01 October 2004 https://doi.org/10.1002/cite.200490345AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume76, Issue9September, 2004Pages 1351-1352 RelatedInformation

As a contribution to a better basic understanding and an accurate modelling of the regeneration of coked catalyst particles, the following investigations were done with pure Al2O3 as a model catalyst: (1) determination of the intrinsic and effective kinetics of coke burn-off; (2) characterisation of the catalyst's morphology with respect to the influence of the carbon load on the surface area, porosity, pore diameter, and tortuosity; (3) measurement of radial coke profiles within partly regenerated particles; (4) numerical simulation of the regeneration within coked particles and comparison with experimental data of radial coke profiles and the time needed for a certain degree of burn-off.For the modelling of coke burn-off within single particles, the chemical reaction rate, pore diffusion, radial gradients of the O-2- and the carbon-concentration, and the influence of the carbon load on the porosity and tortuosity have to be considered. Only the resistances of external heat and mass transfer and of intraparticle heat conduction can be neglected, at least for particle sizes and temperatures of technical relevance for fixed beds (<5 mm, <700 degreesC). The measured and numerically simulated data according to this model presented in detail are in good agreement.The results show that temperatures above about 400 degreesC are needed to achieve regeneration within an acceptable timeframe. On the other hand, a temperature of more than about 500 degreesC will not anymore accelerate the burn-off, at least in case of fixed bed reactors with particles in the region of mm. This effect can be attributed to the increasing strength of pore diffusion resistance, and eventually the complete resistance is confined to the outer carbon-free shell. (C) 2004 Elsevier B.V. All rights reserved.

Chemie Ingenieur TechnikVolume 75, Issue 8 p. 1032-1032 Poster Regeneration koksbeladener Katalysatoren – Von den kinetischen Basisdaten zur Modellierung eines technischen Festbettreaktors A. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. jess@uni-bayreuth.de Search for more papers by this authorC. Kern Dipl.-Ing., C. Kern Dipl.-Ing.Search for more papers by this author A. Jess Prof. Dr.-Ing., A. Jess Prof. Dr.-Ing. jess@uni-bayreuth.de Search for more papers by this authorC. Kern Dipl.-Ing., C. Kern Dipl.-Ing.Search for more papers by this author First published: 26 August 2003 https://doi.org/10.1002/cite.200390203AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume75, Issue8August, 2003Pages 1032-1032 RelatedInformation

A series of naphtha reforming catalysts from different stages of the deactivation (coking) and the regeneration (decoking) processes were investigated by NMR and chemical engineering methods. The dependence of the tortuosity on the coke content was determined for both processes by NMR measurements of the intraparticle self-diffusion coefficients of adsorbed liquid n-heptane. The shrinkage of the accessible pore volume as a function of increasing coke content due to the deactivation process is compared to nitrogen adsorption (BET) measurements which show an equivalent behavior. A crude model was adapted to predict qualitatively the relationship between the tortuosity and the average pore diameter. Longitudinal (T1) and transverse (T2) NMR relaxation times measured for protons of adsorbed liquid n-heptane, provide information on the pore morphology changes which can be corroborated by the tortuosity measurements. The chemical composition of the coke layer, which was investigated by 1H magic angle spinning (MAS) and 13C cross polarization (CP)/MAS NMR spectroscopy, is shown to change during both deactivation and decoking processes. Moreover, the micro-structure of the fresh catalyst and the fully regenerated catalyst was investigated by scanning electron microscopy (SEM). The experimental results indicate that a full recovery of the activity of the clean catalyst is not achieved by the regeneration process, and that the quality of regeneration depends on the coke content reached during the deactivation/regeneration cycle.

The coking and regeneration of a reforming catalyst was studied by physical characterization methods (pore volume, tortuosity, porosity, carbon distribution) as well as by kinetic investigations on the reaction rate of coke burn-off. For temperatures of industrial relevance for the Pt/Re-Al(2)O(3) catalyst, i.e. below 550degreesC (deactivation), the burn-off rate is determined by the interplay of chemical reaction and pore diffusion; limitation by external mass transfer can be excluded. Based on the kinetic parameters, the process of the regeneration of a technical reactor is discussed.

The kinetics of decoking of two commercial naphtha reforming catalysts (Pt-Re-Al(2)O(3)) were investigated under isothermal conditions as well as with the non-isothermal ignition point method. The reaction rate of decoking is first order with respect both to the concentration of oxygen and to the bon load. Two types of coke can be distinguished: A very reactive coke, which is rapidly burned off, and a coke, which is by a factor of 100 less reactive. The amount of the more reactive coke, which is (according to literature) formed on the metal sites, is small (0.3 g(c)/100 g(cat)). The decoking process is therefore determined by the reactivity of the coke formed on the acidic sites, especially for initial carbon loads, which are typical for the decoking of an industrial catalyst (> 10 g(c)/100 g(cat)). The reactivity of the coke, which is almost equal for both catalysts, is quite high and in the order of a typical activated char coal. The kinetic parameters (activation energy, pre-exponential factor) are given. At temperatures of more than 400 degrees C, pore diffusion limitations have to be considered. External diffusion limitations can be neglected, at least for temperatures of technical relevance, as the temperature should not exceed 550 degrees C to avoid an irreversible deactivation of the catalyst.