49 research outputs found
A Catalytic Reaction Mechanism for Methane Partial Oxidation at Short Contact Times, Reforming, and Combustion, and for Oxygenate Decomposition and Oxidation on Platinum
Hierarchical multiscale model-based design of experiments, catalysts, and reactors for fuel processing
Abstract In this paper a hierarchical multiscale simulation framework is outlined and experimental data injection into this framework is discussed. Specifically, we discuss multiscale model-based design of experiments to optimize the chemical information content of a detailed reaction mechanism in order to improve the fidelity and accuracy of reaction models. Extension of this framework to product (catalyst) design is briefly touched upon. Furthermore, we illustrate the use of such detailed and reduced kinetic models in reactor optimization as an example toward more conventional process design. It is proposed that hierarchical multiscale modeling offers a systematic framework for identification of the important scale(s) and model(s) where one should focus research efforts on. The ammonia decomposition on ruthenium to produce hydrogen and the water-gas shift reactions on platinum for converting syngas to hydrogen serve as illustrative fuel processing examples of various topics. The former is used to illustrate hierarchical multiscale model development and model-based parameter estimation as well as product engineering. The latter is employed to demonstrate model reduction and process optimization. Finally, opportunities for process design and control in portable microchemical devices (lab-on-a chip) for power generation are discussed
From Density Functional Theory to Microchemical Device Homogenization: Model Prediction of Hydrogen Production For Portable Fuel Cells
SO<sub><i>x</i></sub> Oxidation Kinetics on Pt(111) and Pd(111): First-Principles Computations Meet Microkinetic Modeling
This work examines the complex nature
of SO<sub><i>x</i></sub> (<i>x</i> = 0–4)
interaction and oxidation on Pt(111) and Pd(111) surfaces using density
functional theory (DFT) calculations coupled with microkinetic modeling.
Thermodynamic and kinetic analyses suggest similar adsorption and
oxidation behaviors for SO<sub><i>x</i></sub> species on
both metal surfaces, although the observed greater tendency of Pd
to undergo sulfating is borne out by the present results. Selected
quantities computed using DFT, when used in a previously developed
microkinetic model, are shown to predict SO<sub>2</sub> conversion
as a function of temperature in excellent agreement with available
experimental data