Computational Fluid Dynamics of Catalytic Reactors

Today, the challenge in chemical and material synthesis is not only the development of new catalysts and supports to synthesize a desired product, but also the understanding of the interaction of the catalyst with the surrounding flow field. Computational Fluid Dynamics or CFD is the analysis of fluid flow, heat and mass transfer and chemical reactions by means of computer-based numerical simulations. CFD has matured into a powerful tool with a wide range of applications in industry and academia. From a reaction engineering perspective, main advantages are reduction of time and costs for reactor design and optimization, and the ability to study systems where experiments can hardly be performed, e.g., hazardous conditions or beyond normal operation limits. However, the simulation results will always remain a reflection of the uncertainty in the underlying models and physicochemical parameters so that in general a careful experimental validation is required. This chapter introduces the application of CFD simulations in heterogeneous catalysis. Catalytic reactors can be classified by the geometrical design of the catalyst material (e.g. monoliths, particles, pellets, washcoats). Approaches for modeling and numerical simulation of the various catalyst types are presented. Focus is put on the principal concepts for coupling the physical and chemical processes on different levels of details, and on illustrative applications. Models for surface reaction kinetics and turbulence are described and an overview on available numerical methods and computational tools is provided

Quo vadis multiscale modeling in reaction engineering? – A perspective

This work reports the results of a perspective workshop held in summer 2021 discussing the current status and future needs for multiscale modeling in reaction engineering. This research topic is one of the most challenging and likewise most interdisciplinary in the chemical engineering community, today. Although it is progressing fast in terms of methods development, it is only slowly applied by most reaction engineers. Therefore, this perspective is aimed to promote this field and facilitate research and a common understanding. It involves the following areas: (1) reactors and cells with surface changes focusing on Density Functional Theory and Monte-Carlo simulations; (2) hierarchically-based microkinetic analysis of heterogeneous catalytic processes including structure sensitivity, microkinetic mechanism development, and parameter estimation; (3) coupling first-principles kinetic models and CFD simulations of catalytic reactors covering chemistry acceleration strategies and surrogate models; and finally (4) catalyst-reactor-plant systems with details on linking CFD with plant simulations, respectively. It therefore highlights recent achievements, challenges, and future needs for fueling this urgent research topic in reaction engineering

Ex ante Dynamics of Real Effects of Monetary Policy: Theory and Evidence for Poland and Russia, 2001–2003

This paper proposes a new indicator of the expected real effects of an inflation-targeting monetary policy. This indicator can be derived from a simple two-dimensional vector autoregressive model of inflation and the output gap. A simulation experiment illustrates its rationale for timing monetary decisions, if the control of output is a secondary policy target. Applied for Poland, this might have contributed to a policy that would have reduced Polish inflation in 2003 and increased output growth in 2004. We also show how this indicator can be applied for RussiaComparative Economic Studies (2006) 48, 458–479. doi:10.1057/palgrave.ces.8100180