(16c) Quantifying the Impact of Catalyst Architecture on Yield and Activity Lifetime through Mesoscale Modeling and Simulation

Authors: 
Ciesielski, P. N., National Renewable Energy Laboratory
Pecha, B., NREL
Dagle, R. A., Pacific Northwest National Laboratory
Mukarakate, C., National Renewable Energy Laboratory
Effective heterogeneous catalytic processes require precise coordination of physiochemical phenomena that occur over orders of magnitude in length and time scales. The majority of computational studies of such systems focus on the extrema: detailed investigations of reaction energetics and mechanisms at the atomic scale; or process-scale simulations of catalytic reactor systems. However, many important processes occur at intermediate scales wherein transport of reactants and products within catalyst particles are tightly coupled to the rates of desirable and undesirable chemical reactions. Tunable catalyst design parameters such as particle size, shape, and porosity can have a large impact in the effective yield, selectivity, and activity lifetime delivered by a catalyst in given reactor system. We have been working to develop “mesoscale” modeling approaches to understand and quantify these effects and thereby provide actionable recommendations to catalyst designers. In this presentation, I will overview two examples of mesoscale simulations in catalytic systems used for the transformation of bio-derived intermediates. First, I will present a study of catalytic fast pyrolysis wherein ex-situ vapor-phase upgrading of pyrolysis vapors is performed using a zeolite catalyst. Next, I will describe packed-bed catalyst system that utilizes a structured mesoporous silica support (SBA16) to convert ethanol to butadiene. In both cases I will present methods to develop suitable hierarchical transport models coupled to chemical reaction kinetics and provide insight for improving the performance of the system based on modification of architectural features of the catalyst particles.