A new char combustion kinetic model – Part 2: Empirical validation

Rojas, Andrés; Barraza, Juan; Barranco, Richelieu; Lester, Edward

doi:10.1016/j.fuel.2012.01.044

Cited by 11 publications

(7 citation statements)

References 40 publications

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“…20,22,[25][26][27][28][29] The formation of complex molecules, such as amino acids, from the irradiation of astrophysical ices in the interstellar medium seems to be a promising source of data on astrochemical processes. [30][31][32] Using 6 MeV 16 O 2+ , 220 MeV 16 O 7+ , 267 MeV 56 Fe 22+ and 606 MeV 70 Zn 26+ ion beams impacting on solid methane, Mejı ´a and de Barros 16,17 investigated the radiolysis of methane ice by fast heavy ions and subsequent synthesis of new molecular species with two and three carbon atoms. Previously, Libby radiolysed solid methane in liquid argon at 77 K using g-rays 33,34 and observed the polymerization of methane and formation of polycondensates with an average molecular formula of C 20 H 40 .…”

Section: Introductionmentioning

confidence: 99%

A theoretical study of three gas-phase reactions involving the production or loss of methane cations

Baptista

Silveira

2014

Phys. Chem. Chem. Phys.

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Hydrocarbon ions are important species in flames, spectroscopy and the interstellar medium. Their importance is reflected in the extensive body of literature on the structure and reactivity of carbocations. However, the geometry, electronic structure and reactivity of carbocations are difficult to assess. This study aims to contribute to the current knowledge of this subject by presenting a quantum mechanics description of methane cation dissociation using multiconfigurational methods. The geometric and electronic parameters of the minimum structure were determined for three main reaction paths: the dissociation CH4(+)→ CH2(+) + H2 and the dissociation-recombination processes CH4(+)↔ CH3(+) + H. The electronic and energetic effects of these reactions were analyzed, and it was found that each reaction path has a strong dependence on the methodology used as well as a strong multiconfigurational character during dissociation. The first doublet excited states are inner-shell excited states and may correspond to the ions that are expected to be formed after electron detachment. The rate coefficient for each reaction path was determined using variational transition state theory and RRKM/master equation calculations. The major dissociation paths, with their rate coefficients at the high-pressure limit, are CH4(+)(X(~)(2)B1) → CH3(+)(A(2)A1') + H((2)S) (k∞(T) = 1.42 × 10(+14) s(-1) exp(-37.12/RT)) and CH4(+)(X(~)(2)B1) → CH2(+)(A(2)A1) + H2((2)Σg(+)) (k∞(T) = 9.18 × 10(+14) s(-1) exp(-55.77/RT)). Our findings help to explain the abundance of ions formed from CH4 in the interstellar medium and to build models of chemical evolution.

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Section: Introductionmentioning

confidence: 99%

A theoretical study of three gas-phase reactions involving the production or loss of methane cations

Baptista

Silveira

2014

Phys. Chem. Chem. Phys.

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“…Estudios relacionados con la cinética química en procesos que involucran sustancias combustibles que han sido estudiados por investigadores en Colombia Descripción Referencia Análisis teórico (S. Gómez et al, 2013) Técnicas ab initio (Calderón et al, 2015;Juan F. Espinal et al, 2004, 2007Jimenez-Orozco et al, 2018;A. Montoya et al, 2000;Alejandro Montoya et al, 2001, 2002a, 2002bPalacio et al, 2018;Sanchez et al, 2019;Vélez et al, 2009) Mecanismos para uso en combustión (Quiceno et al, 2002) Mecanismos para uso en equipos de craqueo de fracciones de petróleo (López-Pérez, 2016) Sistemas de combustión complejos (Alvarado et al, 2009;Amador et al, 2017;Burbano et al, 2011b;Cardona Vargas & Amell-Arrieta Andrés Adolfo Arrieta Carlos, 2016;Saxena et al, 2013;Yepes & Amell, 2013) Combustibles líquidos (Padilla et al, 2017b) Combustibles sólidos (Rojas et al, 2012) Tabla 9S. Investigaciones relacionadas con la combustión realizadas por investigadores colombianos Descripción Referencia Relación con características de Colombia: altura sobre el nivel del mar (presión atmosférica), humedad y composición química de combustibles en aplicaciones relacionadas con aplicaciones industriales de la combustión (Andrés A.…”

Section: Koreaunclassified

Hacia una estructura de investigación y educación para la prevención de accidentes por incendios y explosiones en Colombianción de accidentes por incendios y explosiones en Colombia

Molina

López

Escobar

et al. 2021

Rev. Acad. Colomb. Cienc. Ex. Fis. Nat.

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Se analizó la situación actual de la investigación y la educación en incendios y explosiones en Colombia desde un enfoque de ciencia e ingeniería y se hicieron recomendaciones sobre los campos que deben desarrollarse para crear una estructura investigativa y educativa que respalde los esfuerzos por prevenirlos. Dado el riesgo de incendios y explosiones, la mayoría de los países han propiciado la creación de centros de investigación y educación orientados al desarrollo científico en esta área. En Colombia tal infraestructura tiene un desarrollo apenas incipiente. La revisión de aspectos importantes en incendios y explosiones como el análisis estadístico, la caracterización fisicoquímica de sustancias inflamables, la cinética química, la combustión, la simulación, la radiación térmica, los fenómenos de pirólisis, el smouldering, la formación de hollín y de humo, la caracterización experimental, la evaluación de riesgos, la educación y otros aspectos específicos de las explosiones evidenció que en Colombia existe un buen desarrollo en la aplicación de la combustión y la pirólisis con fines comerciales, pero sin énfasis en incendios y explosiones. En las demás áreas existen antecedentes de investigación específicamente relacionados con este campo que deben reforzarse. Se recomienda la creación de programas curriculares de posgrado en ciencia y tecnología en esta área, así como el aumento de la capacidad experimental para la caracterización de sustancias inflamables, el fortalecimiento de la investigación en ciencias básicas y el desarrollo de habilidades de computación y simulación.

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“…As presented in Section 2.1, five sets of experimental data at different O 2 oncentrations were used to plot ln βG(α) T−T 0 against 1/T (Equation (11)), and then 5 × 41 sets of E values were obtained. Furthermore, 5 × 41 sets of E values were also calculated by using Equation (13). At each O 2 oncentration, 41 pairs of E values from the two above-mentioned algorithms were compared for finding the closet E values.…”

Section: Numbermentioning

confidence: 99%

“…In the studies of the coal network model by Fletcher et al [10], Shurtz et al [11], and Niksaa et al [12], multiple chemical and empirical parameters were prerequisites. In addition, due to the heterogeneous characteristics of coal constituents, the carbon-oxygen reaction kinetics in char combustion, for example, are believed to be influenced by ash, maceral group properties of coal, particle size, diffusion phenomena, and flame temperature [13], which indeed impact the complexity of network models. Thus, developing a global kinetic model with the proper mathematical form is a reasonable approach for modelling practical combustion and reproducing the major features of kinetic data.…”

Section: Introductionmentioning

confidence: 99%

A Novel Method of Kinetic Analysis and Its Application to Pulverized Coal Combustion under Different Oxygen Concentrations

et al. 2018

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Currently, many efforts have been made to improve the approach to build kinetic models. Based on mathematical algorithms, a novel method (named DIM method) of kinetic analysis was introduced in detail. A formula combining differential and integral was deduced and applied to the determination of the mechanism function f (α). Subsequently, multivariable linear regression was conducted to simultaneously obtain the apparent activation energy E, pre-exponential factor A, and oxygen concentration exponent n. In the application of pulverized coal combustion under different oxygen concentrations (3%, 5%, 10%, 15%, and 21%), E, A, and n were calculated as 258,164 J/mol, 6.660 × 10 17 s −1 , and 3.326, respectively, and the mechanism function f (α) was determined as the Avrami-Erofeev equation. A validation was performed under a 7% oxygen concentration, which shows that the DIM method has a higher accuracy. This work can provide a reference for the study of kinetic analysis.

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A new char combustion kinetic model – Part 2: Empirical validation

Cited by 11 publications

References 40 publications

A theoretical study of three gas-phase reactions involving the production or loss of methane cations

A theoretical study of three gas-phase reactions involving the production or loss of methane cations

Hacia una estructura de investigación y educación para la prevención de accidentes por incendios y explosiones en Colombianción de accidentes por incendios y explosiones en Colombia

A Novel Method of Kinetic Analysis and Its Application to Pulverized Coal Combustion under Different Oxygen Concentrations

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