Numerical Simulation of Catalytic Reactors by Molecular-Based Models
Investigations in the field of high-temperature catalysis often reveal complex interactions of heterogeneous, homogeneous, and radical chemistry coupled with mass and heat transfer. The fundamental aspects as well as several applications of high-temperatu
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Abstract Investigations in the field of high-temperature catalysis often reveal complex interactions of heterogeneous, homogeneous, and radical chemistry coupled with mass and heat transfer. The fundamental aspects as well as several applications of high-temperature catalysis are covered in the light of these interactions. Benefits of molecular-based numerical simulations are discussed. Furthermore, this chapter looks at challenges associated with parameter estimation.
1 Background Understanding and optimization of heterogeneously catalyzed reactive systems require the knowledge of the physical and chemical processes on a molecular level. In particular, at short contact times and high temperatures, at which reactions occur on the catalyst and in the gas-phase, the interactions of transport and chemistry become important. High-temperature catalysis is not a new concept; the Oswald process for the NO production by oxidation of ammonia over noble metal gauzes at temperatures above 1,000ıC and residence times of less than a micro second has been technically applied for decades; total oxidation of hydrogen and methane (catalytic combustion) over platinum catalysts were even used before Berzelius proposed the term “catalysis.” Recently, however, high-temperature catalysis has been extensively discussed again, in particular in the light of the synthesis of basic chemicals and hydrogen, and high-temperature fuel cells.
O. Deutschmann S. Tischer () Institute for Chemical Technology and Polymer Chemistry, Karlsruhe Institute of Technology, Engesserstr. 20, 76128 Karlsruhe, Germany e-mail: [email protected]; [email protected] H.G. Bock et al. (eds.), Model Based Parameter Estimation, Contributions in Mathematical and Computational Sciences 4, DOI 10.1007/978-3-642-30367-8 11, © Springer-Verlag Berlin Heidelberg 2013
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Catalytic partial oxidation (CPOX) of natural gas over noble metal catalysts at short contact times offers a promising route for the production of synthesis gas [1, 2], olefins [3, 4], and hydrogen. For instance, synthesis gas, also catalytically produced by steam and autothermal reforming, is needed in (gas-to-liquids) plants for synthetic fuels, which are currently under development. CPOX of gasoline, diesel, or alcohols to synthesis gas or hydrogen may soon play a significant role in mobile applications for reduction of pollutant emissions and auxiliary power units. For any fuel other than hydrogen, catalytic reactions are likely to occur in the anode of a solid oxide fuel cell (SOFC) leading to a complex chemical composition at the anode–electrolyte interface [5]. Primarily the products of the electrochemical reactions, H2 O and CO2 , drive the catalytic chemistry in the anode. For the application of hydrocarbon and alcohol containing fuels, the understanding of the catalytic kinetics is vital for the precise prediction of fuel utilization and performance [6]. Coupling of the thermo catalytic reactions with the electrochemical processes and mass and heat
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