The hydrodynamic behavior of bale packing was tested in a catalytic distillation column. Models and empirical equations for predicting pressure drop and dynamic liquid holdup were proposed and compared with experimental results. The examination of residence time distribution (RTD) relied on the pulse method and a conductivity meter which deduced the axial Péclet number, axial dispersion coefficient, and dynamic liquid holdup. The relations of dynamic liquid holdup obtained from gravimetric draining experiments and RTD studies were discussed with static and total liquid holdup. Potential impacts of the liquid distributor and conductivity cell were also assessed. The results prove that models and empirical equations fit well and are reliable in design and scale‐up.

A recently designed packing sheet Winpak was assembled with catalysts in a modular catalytic structured packing (MCSP) column. A combined mesoscale−microscale methodology was used to analyze and determine the pressure drop mechanism in the MCSP. The proposed methodology differentiates the pressure drop into six different principles, which was determined and compared using computational fluid dynamics (CFD). The three major causes are gas flow confluence and diffluence through the packing windows, the sudden change in the effective gas channel area and the wall effect. Inspired by constructal theory, the height of packing sheets loaded with catalysts was reduced, which resulted in a less abrupt gas channel contraction and expansion at the packing layer junction and more favorable for the undisturbed gas flow. The optimized overall pressure drop was reconstructed in Fluent and was validated by both dry and irrigated packing experiments. Furthermore, irrigated packing experiments were also conducted. Result comparisons reveal that the proposed optimization method is reliable and accurate. This methodology is shown to be significant in the optimization of Winpak-based MCSP. INTRODUCTIONProcess intensification is a critical method for achieving energy conservation and emissions reduction. Resource consumption and pollution can be reduced and high efficiency, sustainability and flexibility can be achieved. The combination of different unit operations is a logical method to approach process intensification. For instance, a distillation column can be integrated with a reactor, which is known as a catalytic distillation column. Catalytic distillation packing plays a significant role in a catalytic distillation column. Its structure, amount and installation method affect the pressure drop, liquid holdup and mass transfer. The most frequently used packing type is modular catalytic structured packing (MCSP), such as bale packing, 1,2 Katapak 3,4 and Multipak. 5,6 In general, catalytic distillation processes that produce esters, 7 acetal 8 and gasoline additive 9 use one or more prereactors before the catalytic distillation column, which ensures that the conversion rate of reactants in the prereactor(s) is at least 80%. Therefore, because of the good selectivity of the catalyst (e.g., MTBE, 10 TAME, 11 ethyl acetate 12 ), the catalytic distillation column is limited by the flux capacity rather than by the reaction.The primary structure of an MCSP is built from conventional corrugated sheets or sheets with flutes, embossments, perforations, grooves, lances, etc. In this case, the flux capacity of an MCSP is dependent on the geometry and arrangement of the corrugated sheet: the lower the packing layer pressure drop, the larger the column flux capacity. Researchers have analyzed the effects of packing on the pressure drop through the column. From the perspective of packing performance under specific operating conditions, Olujić1 3 proposed the Delft overall performance model, which predicted the hydraulic and separation perform...