Theoretical optimization of bed packing arrangement in cascade Dual-Catalyst system with side reactions.

• A theoretical model was developed for optimizing spatial arrangement of reactor-scale cascade dual-catalyst system. • Defined a new descriptor (Delta Switch) to spatially quantify the contributions of optimal dual-catalyst distribution. • The effect of side reaction from each catalyst on the optimized arrangement were isolated and analyzed by variation of Delta Switch value. • A simplified and practicable arrangement optimization framework was built based on patterns of Delta Switch value and isolated side-reaction analysis. The performance of cascade dual-catalyst systems is highly related to the catalysts spatial arrangement within the bed layers. However, optimization tools for the cascade dual-catalyst layer arrangements are still in need of development. In this study, an optimization framework based on genetic algorithms (GA) and artificial neural networks (ANN) is developed for optimization while explore effects of side reaction on optimized arrangement. Further, a new descriptor as known as delta switch (DS) is introduced. Isolated analysis of the effects of the two types of side reactions shows that the solely side reaction on S0 results in a repeated S0-S1-S0 structure, while the introduce of side reactions on S1 disrupts this structural regularity and reduces the optimal length of the bed layer. Based on DS patterns, a simplified cascade dual-catalysts spatial optimization framework (≤3 layers) is employed, achieving ≥ 95 % performance of original GA. [ABSTRACT FROM AUTHOR]