Automation in the simulation of processes with Aspen HYSYS: An academic approach

Aspen HYSYS is a typical tool used in some Master in Chemical Engineering courses at the University of Castilla-La Mancha like “Analysis and Optimization of Chemical Processes” and “Dynamic of Process: Regulation of Chemical Plants.” Automation is the process of linking commercial software to third-parties applications built in EXCEL-Visual Basic for Applications. The capability of automation as a powerful tool for simulating unprecedented complex processes suggests that it could be a relevant background complement to the classical one offered by a university. In this sense, a seminar about automation based on the study of two cases: a refrigeration process and a production one taken from literature, has been proposed at the University of Castilla-La Mancha. The analysis of the survey performed for the subject evaluation resulted to be very positive. Students consider the methodology of the course and the potentiality of automation for developing their research and professional skills appropriately. However, more examples are required to better understand the automation concept and its potential application to other situations. Finally, they declare that the concept of automation requires a lot of expertise and deep knowledge of programming and the correct application of numerical methods for solving complex problem

Improvement of the NOx selectivity for a planar YSZ sensor

International audienceIn recent years planar yttria-stabilized zirconia (YSZ) based electrochemical gas sensors for automotive exhaust applications have become a major source of interest. The present work aims to develop a sensor for industrialisation. For this reason planar YSZ-based electrochemical sensors using two metallic electrodes (platinum and gold) were fabricated using screen-printing technology and tested in a laboratory test bench for different concentrations of pollutant gas such as CO, NO, NO2 and hydrocarbons in oxygen rich atmosphere. It was furthermore shown that the selectivity towards NOx could be highly reinforced by deposing a catalytic filter consisting of 1.7-4.5 wt.% Pt dispersed on alumina directly on the sensing elements. This filter was characterized by the use of SEM, TPD and XRD

Improvement of the NOx selectivity for a planar YSZ

International audienceThe present work aims to develop a sensor that can leave the laboratory and be industrialised. For this reason potentiometric sensors based on a solid electrolyte YSZ and 2 metallic electrodes (platinum and gold) were fabricated by screenprinting technology and were tested in a laboratory test bench for different concentrations of CO, NO and NO2 in oxygen rich atmosphere. By deposing a catalytic filter consisting of 1.7%Pt dispersed in alumina directly on the electrodes, it was shown that the selectivity towards NOx could be highly reinforced. This filter was characterized by the use of SEM, TPD, and XRD technology

Highly efficient and stable Ru/K-OMS-2 catalyst for NO oxidation

The influence of addition of a series of non noble and noble metals to a manganese oxide octahedral molecular sieve (OMS) with a cryptomelane structure (K-OMS-2) has been studied for NO oxidation in view of fast selective catalytic reduction applications. Fe, Cu, Zn, Pt, Pd, Ru and Ag were selected as dopant metals with a metal loading around 2 wt.%. The catalysts were characterized in detail by ICP-OES, N2 adsorption/desorption at 77 K, XRD, H2-TPR and HR-TEM. The highest NO conversion was obtained for a K-OMS-2 catalyst modified with ruthenium, showing a reaction rate up to 5.3 μmol g−1 s−1 at 584 K. A markedly higher catalyst reducibility upon incorporation of ruthenium can be proposed as an underlying reason for the enhanced catalytic performance.Se ha estudiado la influencia de la adición de una serie de metales nobles y no nobles a un tamiz molecular octaédrico (OMS) de óxido de manganeso con estructura de criptomelano (K-OMS-2) para la oxidación de NO con vistas a aplicaciones de reducción catalítica selectiva rápida. Se seleccionaron Fe, Cu, Zn, Pt, Pd, Ru y Ag como metales dopantes con una carga de metal de alrededor del 2 % en peso. Los catalizadores se caracterizaron en detalle por ICP-OES, adsorción/desorción de N 2 a 77 K, XRD, H 2 -TPR y HR-TEM. La mayor conversión de NO se obtuvo para un catalizador K-OMS-2 modificado con rutenio , mostrando una velocidad de reacción de hasta 5,3 μmol g - 1 s - 1 a 584 K. Se puede proponer una reducibilidad del catalizador marcadamente más alta tras la incorporación de rutenio como una razón subyacente para el rendimiento catalítico mejorado

Manganese oxide-based catalysts for toluene oxidation

Four different catalysts based on manganese oxide were prepared: a perovskite (LaMnO3), via sol-gel method; Mn2O3, rapid method and an Octahedral Molecular Sieve (OMS-2) by two different preparation methods, via solid state (OMSs) and hydrothermal method (OMSh). The physicochemical properties of these catalysts were characterized by X-ray diffraction (XRD), N2 adsorption–desorption at −196 °C, thermogravimetric and differential thermal analysis (TGA/DTA), inductively coupled plasma optical emission spectroscopy (ICP-OES) and temperature-programmed reduction with hydrogen (H2-TPR). Their catalytic performances were evaluated in the catalytic oxidation of toluene. Three consecutive catalytic cycles were performed for each catalyst in order to reach steady state performances. In order to assess the stability of the catalysts under reaction conditions, the catalytic performances were studied upon long term experiments running for 24 h at 25% of toluene conversion. For comparison purposes, the catalytic activity of the present manganese oxide catalysts was compared with that of typical industrial catalysts such as a commercial Pd/Al2O3 catalyst containing 0.78% Pd. The crystalline features detected in the XRD patterns, are well-consistent with the formation of the desired structures. Based on their specific surface area and their low-temperature reducibility, the catalysts were ranked as follows: OMSs > Mn2O3 > OMSh > LaMnO3. This trend was in good agreement with the performances observed in the catalytic removal of toluene. A kinetic model was proposed and a good agreement was obtained upon fitting with the experimental data.Se prepararon cuatro catalizadores diferentes a base de óxido de manganeso : una perovskita (LaMnO 3 ), por el método sol-gel; Mn 2 O 3 , método rápido y Tamiz Molecular Octaédrico (OMS-2) por dos métodos de preparación diferentes, vía estado sólido (OMS s ) e hidrotermal (OMS h ). Las propiedades fisicoquímicas de estos catalizadores se caracterizaron por difracción de rayos X (XRD), adsorción-desorción de N 2 a −196 °C, análisis termogravimétrico y térmico diferencial (TGA/DTA), espectroscopia de emisión óptica de plasma acoplado inductivamente (ICP-OES) y reducción a temperatura programada con hidrógeno (H 2-TPR). Sus actuaciones catalíticas se evaluaron en la oxidación catalítica de tolueno. Se realizaron tres ciclos catalíticos consecutivos para cada catalizador con el fin de alcanzar rendimientos de estado estable. Para evaluar la estabilidad de los catalizadores en las condiciones de reacción, se estudiaron los rendimientos catalíticos en experimentos a largo plazo durante 24 h al 25 % de conversión de tolueno. Con fines comparativos, la actividad catalítica de los presentes catalizadores de óxido de manganeso se comparó con la de los catalizadores industriales típicos, como el Pd/Al 2 O 3 comercial.catalizador que contiene 0,78% Pd. Las características cristalinas detectadas en los patrones XRD son consistentes con la formación de las estructuras deseadas. Según su área de superficie específica y su reducibilidad a baja temperatura, los catalizadores se clasificaron de la siguiente manera: OMS s > Mn 2 O 3 > OMS h > LaMnO 3 . Esta tendencia estaba en buen acuerdo con los rendimientos observados en la eliminación catalítica de tolueno. Se propuso un modelo cinético y se obtuvo un buen acuerdo al ajustar con los datos experimentales

Hydrogenation de l'aldehyde cinnamique: controle de la selectivite en alcool insature

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Destruction de composés organiques volatils par procédés catalytique ou biologique

L objectif de cette étude était de comparer l efficacité de procédés pour l élimination des COV, présents à l état de traces dans l air. Dans un premier temps, nous avons comparé l activité catalytique de trois réacteurs de configuration différente, mais utilisant le même catalyseur Pt/g-Al2O3, pour l oxydation totale du propène et du toluène. Le réacteur à membrane catalytique traversée a montré une efficacité supérieure à celles des réacteurs conventionnels (lit fixe et monolithique) grâce à un meilleur contact entre les réactifs et les sites actifs. Dans un deuxième temps, l étude de la dégradation du toluène et du me thanol par biofiltration a montré qu un tel procédé était efficace, surtout à faibles concentrations en COV. Cependant, le méthanol était dégradé plus facilement que le toluèneThe objective of this study was to compare the efficiency of different VOC abatement processes in air. In a first part, catalytic activity of three reactors, presenting different configurations but containing the same catalytic system, i.e. Pt/g-Al2O3 was compared for propene and toluene deep oxidation. It was found that membrane reactor exhibited highest efficiency than conventionnal ones (fixe-bed and monolithic), due to optimized contacts between reactants and active sites. In a second part, toluene and methanol abatements were investigated and results have shown that biofiltration process was effective, especially at low VOC concentrations. However, methanol was eliminated more easily than tolueneLYON1-BU.Sciences (692662101) / SudocSudocFranceF

Biodiesel from microalgae lipids: from inorganic carbon to energy production

SSCI-VIDE+CARE:INGENIERIE+MVE:AGFInternational audienceFollowing the United Nations Conference on Climate Change, COP21 (Paris, France), several countries have attempted to reduce their greenhouse gas emissions. In order to reach this objective, microalgae could be used to capture carbon dioxide and transform it into a biomass composed essentially of lipids, carbohydrates and proteins. Moreover, cultivating microalgae does not require arable land, in opposition to several oleaginous plants used to produce biofuels. Despite the fact that microalgae could be transformed into several biofuels such as bioethanol (by fermentation of hydrocarbons) and biomethane (by anaerobic digestion), transforming lipids into biodiesel could allow the reduction of oil-based diesel consumption. However, microalgae biodiesel production costs remain high for a short-term commercialization. The microalgae lipids can be transesterified into biodiesel in the presence of catalysts (homogeneous or heterogeneous). In order to commercialize biodiesel from microalgae, biodiesel physicochemical properties must respect the American Society for Testing and Materials (ASTM) standards. The aim of the study was to describe the current technologies available to produce biodiesel from microalgae

Effect of Calcination Conditions on Co₃O₄ Catalysts in the Total Oxidation of Toluene and Propane

Co3O4 catalysts were prepared via carbonate precipitation and subsequent calcination under specific conditions. The different catalysts were characterized as received using several techniques and tested in the total oxidation of toluene or propane. Calcination at low temperature or under dynamic conditions resulted in Co3O4 catalysts with small crystallite sizes and large surface areas. The performances of the Co3O4 catalysts appeared to be closely related to the low-temperature reducibility. The best catalyst, Co-350D, showed a toluene oxidation rate of 44.5 nmol g−1 s−1 at 200 °C and a propane oxidation rate of 54.0 nmol g−1 s−1 at 150 °C. Meanwhile, Co-350D exhibited excellent cycling stability and decent long-term durability in both reactions