Fixed‐bed gas–solid catalytic reactors

Fixed-bed reactors are a core technology in chemical engineering, which appear in a number of well-established processes or in new configurations with superior thermal and functional integration. Over the past decades, the theory associated with the modeling of these units has grown substantially. In this chapter, a review of the main transport and reaction phenomena occurring in a packed bed is provided. The commonly used models for design and simulation of packed beds are obtained from a sufficiently generic set of conservation equations, assuming dominance of dispersion and interphase transfer compared to the other processes present in the reactor. The analysis becomes complete with approximate solutions for the effectiveness factor at the particle level. This represents a methodology for consistent model hierarchization and selection, determination of equivalent formulations, and improvement of simplified descriptions.