Desenvolvimento e validação do modelo de reação global para hidrocarbonetos gasosos e hidrogênio / Development and validation of the global reaction model for gaseous hydrocarbons and hydrogen

In view of the constant search for new sources of renewable energy, the particulate agro-industrial waste reuse emerges as an advantageous alternative. However, despite the advantages of using the biomass as an energy source, there is still strong resistance as the large-scale replacement of petroleum products due to the lack of scientifically proven efficient conversion technologies. In this context, the pyrolysis is presented as one of the most widely used thermal decomposition processes. The knowledge of aspects of chemical kinetics, thermodynamics these will, heat and mass transfer, are so important, since influence the quality of the product. This paper presents a kinetic study of slow pyrolysis of coffee grounds waste from dynamic thermogravimetric experiments (TG), using different powder catalysts. The primary thermal decomposition was described by the one-step reaction model, which considers a single global reaction. The kinetic parameters were estimated using nonlinear regression and the differential evolution method. The coffee ground waste was dried at 105°C for 24 hours. The sample in nature was analyzed at different heating rates, being 10, 15, 20, 30 and 50 K/min. In the catalytic pyrolysis, about 5% (w/w) of catalyst were added to the sample, at a heating rate of 30 K/min. The results show that the one-step model does not accurately represent the data of weight loss (TG) and its derivative (DTG), but can do an estimative of the activation energy reaction, and can show the differences caused by the catalysts. Although no one can say anything about the products formed with the addition of the catalyst, it would be necessary to micro-pyrolysis analysis, we can say the influence of the catalyst in the samples, based on the data obtained in thermogravimetric tests.

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The Algorithm for Automatic Construction of a Global Reaction Model

49th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition ◽

10.2514/6.2011-512 ◽

2011 ◽

Author(s):

Anton Zizin ◽

Nadja Slavinskaya ◽

U. Riedel ◽

M. Aigner

Keyword(s):

Reaction Model ◽

Automatic Construction ◽

Global Reaction

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Numerical Simulation of Natural Gas Combustion Process Using a One-Step and a Two-Step Reaction

Energy Conversion ◽

10.1115/imece2002-39312 ◽

2002 ◽

Cited By ~ 2

Author(s):

Angela O. Nieckele ◽

Moˆnica F. Naccache ◽

Marcos S. P. Gomes ◽

Joa˜o N. E. Carneiro ◽

Andre´ Augusto Isnard ◽

...

Keyword(s):

Experimental Data ◽

Natural Gas ◽

Combustion Process ◽

Chemical Species ◽

Reaction Model ◽

Gas Combustion ◽

First Case ◽

Natural Gas Combustion ◽

Cylindrical Furnace ◽

Global Reaction

The work evaluates the combustion of natural gas in a cylindrical furnace. The Generalized Finite Rate Reaction Model was selected for predicting the reactions. Two situations were considered. In the first case the combustion of the fuel was predicted by a single global reaction, and in the second case a two-step reaction was considered for predicting the combustion process. The conservation equations of mass, momentum, energy and chemical species were solved by the finite volume procedure, with the commercial software FLUENT. The turbulent flow was modeled by employing the two differential equation κ–ε model. The solutions obtained with the two reaction models, for the temperature and species concentration fields, were compared among them and against experimental data available in the literature. It was observed that the two-step reaction model represents better the physical phenomena, showing a better agreement with the experimental data.

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Fast computation of multi-scale combustion systems

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2011.0026 ◽

2011 ◽

Vol 369 (1945) ◽

pp. 2396-2404 ◽

Cited By ~ 2

Author(s):

Eliodoro Chiavazzo ◽

Pietro Asinari ◽

Filippo Visconti

Keyword(s):

Flow Simulation ◽

Reaction Model ◽

Ideal Gas ◽

Reactive Flow ◽

The Novel ◽

Homogeneous Ideal ◽

Multi Scale ◽

Combustion Systems ◽

Global Reaction ◽

Missing Variables

In the present work, we illustrate the process of constructing a simplified model for complex multi-scale combustion systems. To this end, reduced models of homogeneous ideal gas mixtures of methane and air are first obtained by the novel relaxation redistribution method, and thereafter used for the extraction of all the missing variables in a reactive flow simulation with a global reaction model.

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Experimental Validation of a Global Reaction Model for a Range of Gasolines and Kerosenes under HCCI Conditions

10.4271/2011-24-0024 ◽

2011 ◽

Author(s):

Annelies Vandersickel ◽

Yuri Wright ◽

Konstantinos Boulouchos ◽

Sebastian Beck ◽

Michael Bargende

Keyword(s):

Experimental Validation ◽

Reaction Model ◽

Global Reaction

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Numerical Simulation of Hydrogen Combustion: Global Reaction Model and Validation

Frontiers in Energy Research ◽

10.3389/fenrg.2017.00031 ◽

2017 ◽

Vol 5 ◽

Author(s):

Yun Zhang ◽

Yinhe Liu

Keyword(s):

Numerical Simulation ◽

Reaction Model ◽

Hydrogen Combustion ◽

Global Reaction

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A global reaction model for oh* chemiluminescence applied to a laminar flat-flame burner

Combustion Science and Technology ◽

10.1080/713713115 ◽

2003 ◽

Vol 175 (10) ◽

pp. 1859-1891 ◽

Cited By ~ 35

Author(s):

L. C. Haber ◽

U. Vandsburger

Keyword(s):

Reaction Model ◽

Flat Flame ◽

Flame Burner ◽

Global Reaction

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Diesel Engine Simulations and Experiments: Fuel Variability Effects on Ignition

Volume 8A: Heat Transfer and Thermal Engineering ◽

10.1115/imece2014-37336 ◽

2014 ◽

Author(s):

Mingdi Huang ◽

Sandeep Gowdagiri ◽

Xander M. Cesari ◽

Matthew A. Oehlschlaeger

Keyword(s):

Diesel Engine ◽

Cfd Simulation ◽

Cetane Number ◽

Engine Performance ◽

Reaction Model ◽

Compression Ignition ◽

Ignition Timing ◽

Cfd Simulations ◽

Compression Ignition Engines ◽

Global Reaction

The chemical composition and properties of fuels used in compression-ignition engines can influence engine performance significantly. Consequently, the modeling of fuel chemistry within computational fluid dynamics (CFD) simulations of diesel and other compression ignition engines is important. Modern detailed chemical mechanisms may provide predictive modeling of fuel chemistry; however, they are generally far too computationally expensive for use in CFD. We present simulations of diesel engine combustion, focusing on the prediction of ignition, using the CONVERGE CFD software package. A CFD simulation framework with models for turbulence and spray breakup and atomization is presented with a reduced global reaction model to describe fuel oxidation and ignition. The global reaction model incorporates a single parameter, the derived cetane number (DCN), to describe fuel reactivity variability. CFD simulations are compared to experiments carried out in a single-cylinder diesel engine for compositionally diverse conventional and alternative diesel and jet fuels. Model-experiment comparisons show general agreement for ignition timing and the influence of fuel variability on ignition timing. In addition, the sensitivity of CFD predictions on the chemistry, turbulence, and spray models is illustrated.

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