Examinando por Materia "Methanol"

Mostrando 1 - 4 de 4
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    Ítem
    Exploración de las características necesarias para el desarrollo de aplicaciones con celdas de combustible en Colombia
    (Universidad EAFIT, 2008) Palacio Vanegas, Sergio David; París Londoño, Luis Santiago
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    Ítem
    Región de Inestabilidad y Optimización de las Condiciones de Producción de Metanol en un Reactor Lurgi
    (Centro de Informacion Tecnologica, 2016-01-01) Gómez, M.Á.; Dobrosz-Gómez, I.; Gilpavas, E.; Gómez, M.Á.; Dobrosz-Gómez, I.; Gilpavas, E.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In the present work, the operational conditions for methanol synthesis in a Lurgi reactor are analyzed. The industrial data for a packed reactor (consisting of 1620 tubes of 7 m long) are the basis of this study. At first, the industrial reactor is simulated achieving excellent agreement with plant data. Then, the instability region is defined as a boundary in the conversion-temperature diagram and defines the conditions that must be avoided during reactor operation. The optimization of the operational conditions is performed based on the optimal temperature progression from the iso-reaction rate curves. Finally, it was found that the cooling fluid must be at 230 °C and that the heat transfer coefficient must guarantee a value of 118 J/(s.K.m2).
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    Ítem
    Structural characterization of the (MeSH)4 potential energy surface
    (SPRINGER, 2013-05-01) Gomez, Sara; Guerra, Doris; David, Jorge; Restrepo, Albeiro; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)
    A random walk on the PES for (MeSH)4 clusters produced 50 structural isomers held together by hydrogenbonding networks according to calculations performed at the B3LYP/6-311++G* * andMP2/6-311++G* * levels. The geometric motifs observed are somewhat similar to those encountered for the methanol tetramer, but the interactions responsible for cluster stabilization are quite different in origin. Cluster stabilization is not related to the number of hydrogen bonds. Two distinct, well-defined types of hydrogen bonds scattered over a wide range of distances are predicted. © Springer-Verlag Berlin Heidelberg 2012.
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    Ítem
    Structural characterization of the (methanol)4 potential energy surface
    (AMER CHEMICAL SOC, 2009-09-24) David, Jorge; Guerra, Doris; Restrepo, Albeiro; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)
    In this paper, we report the geometries and properties of the structural isomers obtained from a random walk of the potential energy surface (PES) of the methanol tetramer. Thirty-three structures were obtained after B3LYP/6-31+g* optimization of 94 candidate structures generated from a stochastic search of the PM3 conformational space. The random search was carried out using a recently proposed modified Metropolis acceptance test in the simulated annealing (SA) procedure. Corrections for the basis set superposition error (BSSE) show improvements on the binding energies of the clusters in an average of approximately 2.0 kcal/mol, while geometries are predicted to be less sensitive to BSSE corrections. MP2/aug-cc-pvdz calculations on representative structures did not change the geometries but predicted better binding energies. Highly correlated CCSD(T) energies were calculated on the B3LYP and MP2 stationary points and used to establish relative stabilities. We report several new conformations and group the structures into six distinct geometrical motifs. Only the cyclic tetramers with four primary hydrogen bonds in the same plane are predicted to have significant populations. Secondary hydrogen bonds, those for which the donated proton comes from an alkyl group, lead to a rich conformational space.