OntoKin: An Ontology for Chemical Kinetic Reaction Mechanisms.

An ontology for capturing both data and the semantics of chemical kinetic reaction mechanisms has been developed. Such mechanisms can be applied to simulate and understand the behavior of chemical processes, for example, the emission of pollutants from internal combustion engines. An ontology development methodology was used to produce the semantic model of the mechanisms, and a tool was developed to automate the assertion process. As part of the development methodology, the ontology is formally represented using a web ontology language (OWL), assessed by domain experts, and validated by applying a reasoning tool. The resulting ontology, termed OntoKin, has been used to represent example mechanisms from the literature. OntoKin and its instantiations are integrated to create a knowledge base (KB), which is deployed using the RDF4J triple store. The use of the OntoKin ontology and the KB is demonstrated for three use cases-querying across mechanisms, modeling atmospheric pollution dispersion, and as a mechanism browser tool. As part of the query use case, the OntoKin tools have been applied by a chemist to identify variations in the rate of a prompt NOx formation reaction in the combustion of ammonia as represented by four mechanisms in the literature

Improved methodology for performing the inverse Abel transform of flame images for color ratio pyrometry.

A new method is presented for performing the Abel inversion by fitting the line-of-sight projection of a predefined intensity distribution (FLiPPID) to the recorded 2D projections. The aim is to develop a methodology that is less prone to experimental noise when analyzing the projection of axisymmetric objects-in this case, co-flow diffusion flame images for color ratio pyrometry. A regression model is chosen for the light emission intensity distribution of the flame cross section as a function of radial distance from the flame center line. The forward Abel transform of this model function is fitted to the projected light intensity recorded by a color camera. For each of the three color channels, the model function requires three fitting parameters to match the radial intensity profile at each height above the burner. This results in a very smooth Abel inversion with no artifacts such as oscillations or negative values of the light source intensity, as is commonly observed for alternative Abel inversion techniques, such as the basis-set expansion or onion peeling. The advantages of the new FLiPPID method are illustrated by calculating the soot temperature and volume fraction profiles inside a co-flow diffusion flame, both being significantly smoother than those produced by the alternative inversion methods. The developed FLiPPID methodology can be applied to numerous other optical techniques for which smooth inverse Abel transforms are required

Deshidrogenación oxidativa de propano con materiales a base de cobalto, tungsteno y molibdeno

RESUMEN: La deshidrogenación oxidativa de propano es una alternativa interesante para la obtención de olefinas. En este trabajo se presentan los resultados obtenidos en la deshidrogenación oxidativa de propano utilizando dos materiales a partir de cobalto, tungsteno y molibdeno. Los materiales fueron caracterizados utilizando Difracción de Rayos X (XRD), espectroscopia infrarroja con transformada de Fourier (FTIR), análisis termogravimétrico (TGA) y análisis térmico diferencial (DTA). El material CoMoϕy al ser calcinado a 623 K se transforma en la fase β-CoMoO4 (CoMoϕy623), la misma fase es obtenida cuando el material se calcina a 873 K (CoMoϕy873). CoMoϕy623 muestra un buen desempeño en la deshidrogenación oxidativa de propano, se obtuvo un rendimiento a propeno de 3,4% a una temperatura de 623 K y una velocidad espacial de 100 mL g-1 min-1. El material CoWsϕy fue calcinado a 673 K, obteniéndose una fase wolframita de baja cristalinidad. Este material presenta una alta selectividad a propeno y un bajo rendimiento. CoMoϕy873 presenta una buena actividad y selectividad, comparable con otros materiales reportados en la literatura, y su potencial como catalizador en la deshidrogenación oxidativa de propano se hace más evidente con la prueba que muestra ser estable durante 24 h de operación continua a 773 K. Palabras clave: Calidad del agua, análisis multivariado, emisarios submarinos, variación espacial, variación temporal.ABSTRACT: Oxidative dehydrogenation of propane is a reliable alternative for olefins production. This paper presents the results obtained on oxidative dehydrogenation of propane by using two materials based on cobalt, tungsten, and molybdenum. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), temperature programmed reduction (TPR), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). The CoMoϕy material was calcined at 623 K, transforming itself to β-CoMoO4 phase (CoMoϕ623), the same phase is observed when the material is calcined at 873 K (CoMoϕy873). CoMoϕy623 showed the best performance in oxidative dehydrogenation of propane, a yield to propene of 3.4% was obtained at 623 K using a space velocity of 100 mLg-1min-1. CoWsϕy was calcined at 673 K, a low crystallinity wolframite was obtained. This material has a high selectivity to propene and low yield. CoMoϕy873 has a selectivity and conversion within the range of the results reported in the literature. This is a prospective catalyst for the oxidative dehydrogenation of propane; it was stable for 24 h of continuous operation at 773 K. Keywords: Water quality, Multivariate statistical techniques, submarine outfall, spatial variation, temporal variatio

Uso de zeolita faujasita para adsorción de iones en aguas residuales municipales

En este trabajo se sintetizó una zeolita tipo faujasita a partir de aluminio y sílica gel, por el método sol-gel. Dicho procedimiento se realizó por medio de espectroscopía de infrarrojo (FTIR por su nombre en inglés), difracción de rayos X (XRD por su nombre en inglés), análisis termogravimétrico (TGA por su nombre en inglés) y microscopía de electrónica de barrido (SEM por su nombre en inglés). Se identificó el material sintetizado como zeolita tipo faujasita X. Se evaluó la capacidad de remoción de materia orgánica, nitrógeno amoniacal, dureza y metales pesados (Fe, Cu, Zn, Pb) utilizando aguas residuales municipales (ARM) y agua sintética. La afinidad de la zeolita tipo faujasita X, por los iones metálicos estudiados presenta el siguiente comportamiento: Zn2+ > Cu2+ > Pb2+ > Fe3+ en ARM, con alta concentración de materia orgánica. Se observó que la dosis de zeolita, el tipo de ion, la concentración de las especies catiónicas y el tamaño del catión hidratado fueron factores determinantes en el proceso de adsorción. Se obtuvo una mayor capacidad de adsorción de la zeolita para iones de Ca2+ y Mg2+ (dureza), y nitrógeno amoniacal en ARM. La sencillez del proceso y la efectividad conseguida por la zeolita para la remoción de distintos iones con porcentajes de remoción mayores al 70%, la convierten en una alternativa viable como adsorbente de iones metálicos, dureza y nitrógeno amoniacal en ARM. Lo anterior conduce a la posibilidad de implementar columnas de adsorción a gran escala para el tratamiento de ARM

Estudio Preliminar de la Capacidad de Remoción de Iones Inorgánicos de Una Zeolita Sintética Tipo Faujasita

La remoción de iones inorgánicos presentes en aguas residuales se realiza por medios fisicoquímicos como adsorción e intercambio iónico. Las zeolitas, como la faujasita, poseen características físicas, químicas y estructurales que los hacen materiales potencialmente útiles para la remoción de contaminantes de cuerpos de agua. Se sintetizó una zeolita tipo faujasita a partir de Al puro y sílica gel por el método sol-gel; se caracterizó por difracción de rayos X (DRX) y espectroscopía de infrarrojo (FTIR). Se determinó la capacidad de remoción de materia orgánica, sulfatos, fosfatos, nitrógeno amoniacal, dureza y alcalinidad presentes en aguas residuales domésticas (ARD) típicas de la ciudad de Florencia Caquetá y en aguas sintéticas. El trabajo experimental mostró buenos resultados a escala de laboratorio, con posible aplicación a escala real. Se identificó el material sintetizado como zeolita tipo faujasita Na-X. Debido al carácter básico de la zeolita sintetizada, solamente se observa remoción de cationes representados en dureza (Ca+2 y Mg+2), nitrógeno amoniacal y materia orgánica (Demanda Química de Oxígeno, DQO). La remoción es debida a intercambio catiónico y a procesos de adsorción de material coloidal.  La remoción de material contaminante en orden descendente es dureza (Ca+2 y Mg+2)   Material coloidal (materia orgánica)

The role of dimethyl ether as substituent to ethylene on particulate formation in premixed and counter-flow diffusion flames

The role of dimethyl ether (DME) as substituent to ethylene on particulate formation has been evaluated in premixed and counter-flow diffusion flames. In the premixed flame, the equivalence ratio has been changed from 1.95 to 2.61 and dimethyl ether has been added from 2% to 30% of the total carbon fed. In the counter-flow diffusion flame, the addition of DME has been from 0% to 60% of total carbon fed. Laser induced fluorescence and incandescence have been used to follow the soot formation process: UV and visible fluorescence signals have been attributed to aromatic macromolecules and incipient nanoparticles, respectively, whereas incandescence has been attributed to soot particles and aggregates. In premixed flames results evidence that the formation of soot precursors is not so sensitive to DME addition. In very rich combustion environments, DME addition cannot completely avoid the formation of small precursors, although it can slow down the formation process. This behavior has been observed for all the equivalence ratios investigated. In the pyrolysis region of counter-flow diffusion flames, the formation of aromatic small precursors and soot particles is increased for small DME percentages, up to 20%. Then, the precursors are suppressed for larger amounts, going below the detection limit when 60% of DME is used. This suggests that DME can enhance the production of radicals and small reactive molecules in the pyrolytic side when it is added in small concentrations. For larger amounts of DME, oxidative pathways prevail and the conversion of carbon to precursors and then to soot is inhibited. In the oxidative region DME starts to effectively decrease the particle reduction also for amounts as small as 10-15

Uso de materiales laminares tipo cobalto-molibdato como potenciales catalizadores en la transformación de limoneno

Se llevó a cabo la transformación catalítica de limoneno usando cuatro materiales basados en molibdeno y cobalto. Dos de ellos se prepararon mediante síntesis hidrotérmica y co-precipitación, obteniéndose sólidos laminares (CoMoΦx, CoMoΦy), y los otros dos se obtuvieron mediante la calcinación de los sólidos laminares (CoMoΦx500 y CoMoΦy350). Los catalizadores se caracterizaron mediante difracción de rayos X (XRD), infrarrojo con transformada de Fourier (FTIR), reducción con H2 a temperatura programada (TPR), análisis termogravimétrico (TGA), análisis térmico diferencial (DTA) y espectroscopía de absorción atómica (AAS). La mayor selectividad se obtuvo para los óxidos de limoneno (26%) con CoMoΦ[email protected] of layered cobalt molybdate materials like potential catalysts in the transformation of limonene. Limonene catalytic transformation was carried-out with four cobalt and molybdenum-based materials: two of them were prepared by hydrothermal synthesis and co-precipitation, whereby layered materials were obtained (CoMoΦx and CoMoΦy). The two remaining materials were obtained by means of calcination of the layered solids (CoMoΦx500 y CoMoΦy350). The catalysts were characterized by X-ray Diffraction (XRD), Fourier Transformed Infrared Spectroscopy (FTIR), H2 Temperature-Programmed Reduction (TPR), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and Atomic Absorption Spectroscopy (AAS). The better selectivity was 26% for limonene oxide with CoMoΦx500

Research data supporting 'The effect of poly(oxymethylene) dimethyl ethers (PODE3) on soot formation in ethylene/PODE3 laminar coflow diffusion flames'

The data are relevant to the ISF-4 coflow 3 (Condition C) laminar diffusion flame. The measurments were performed along the centre-line of the flame. All the methodology and data has been reported in the literature under the publication 'Yong Ren Tan, Maurin Salamanca, Laura Pascazio, Jethro Akroyd, Markus Kraft, The effect of poly(oxymethylene) dimethyl ethers (PODE3) on soot formation in ethylene/PODE3 laminar coflow diffusion flames, Fuel, Volume 283, 2021, 118769, https://doi.org/10.1016/j.fuel.2020.118769. The description for each of the files are as below: 'ISF4_coflow3c_C2H4_PSD_Raw.csv' - This contains the Cambustion DMS500 particle size distribution (PSD) data, which has been averaged for the repeats performed at a certain height above the burner (HAB). 'ISF4_coflow3c_C2H4_PSD_Processed.csv' - This contains the processed PSD data from 'ISF4_coflow3c_C2H4_PSD_Raw.csv', undergoing correction according to the total dilution factor and excluding data points which we have some questions on the data reliability. 'ISF4_coflow3c_C2H4_PSD_PSize.csv' - This contains the average particle size at the corresponding HAB with the geometric standard deviation of the measurement

Research data supporting ''structural effects of C3 oxygenated fuels on soot formation in ethylene coflow diffusion flames''

Chemical mechanisms used in structural effects of C3 oxygenated fuels on soot formation in ethylene coflow diffusion flames. The zipped folder contains three sub-folders with chemical mechanisms of dimethoxymethane (DMM), dimethyl carbonate (DMC), isopropanol (IPA). Within each of the sub-folders, there are three txt files with the chemical mechanism file, thermo file and transport file in CHEMKIN format. The txt files can be readily used without alterations in the kinetics software to run plug flow reactor simulations. The details of the simulation conditions can be found in the manuscript

An experimental laminar flame investigation of dual-fuel mixtures of C4 methyl esters with C2–C4 hydrocarbon base fuels

Salamanca Guzmán M, Wullenkord J, Graf I, Schmitt S, Ruwe L, Kohse-Höinghaus K. An experimental laminar flame investigation of dual-fuel mixtures of C4 methyl esters with C2–C4 hydrocarbon base fuels. Proceedings of the Combustion Institute. 2019;37(2):1725-1732