Experimental and Theoretical Dataset on Decreasing Gas Holdup with Increasing Gas Flux in Millimetre–Micrometre Dual-Sized Bubble Columns

This dataset focuses on the response characteristics of the system gas holdup and the interaction mechanism between dual-size bubbles within a bubble tower reactor in a coalescence and suppression system. It conducts a systematic quantitative comparative analysis between dual-size and single-size systems, centred on characterising gas-liquid contact and transfer capabilities under conditions where micrometre-scale and millimetre-scale bubbles coexist. Results indicate micron-scale bubbles dominate the contribution to system gas holdup. Furthermore, when millimetre-scale bubbles are progressively introduced into a fixed microbubble system, the system gas holdup exhibits a non-monotonic variation pattern. To explain these evolutionary characteristics, this study proposes a coupled model within the drift flux framework. The decline in gas holdup during the intermediate phase is attributed to increased rise velocities of micron-sized bubbles caused by interactions between dual-sized bubbles, thereby altering their residence and accumulation levels. Based on these observed patterns and the proposed model interpretation, this dataset provides mechanistic rationale and empirical support for optimising bubble tower operating parameters and structural design. It is particularly applicable to scenarios requiring high gas flux and enhanced gas-liquid mass transfer, such as wastewater oxidation, 1,4-butanediol synthesis, and electrolytic hydrogen production.