Relevance. There are many configurations of microfluidic chips that can be used to produce biofuel from various vegetable oils. Studies of this kind do not pay sufficient attention to the hydrodynamics of the interaction of reacting flows in micromixers and microreactors. Identifying the mechanisms and characteristics of droplet/slug formation of a dispersed medium as it moves through microchannels and controlling this process can help optimize ester production and maximize yield. Object. Converton of rapeseed oil into fatty acids methyl esters through the prism of the consequences of microfluidics of two-phase flow in a micromixer and microreactor. Aim. To identify and quantitatively characterize the hydrodynamic consequences of the interaction between flows of potassium hydroxide solution in methanol and rapeseed oil during microfluidic preparation of fatty acid esters using a chip with a configuration based on a T-shaped micro-mixer and a coil micro-reactor. Methods. The droplet microfluidics method for managing the flow of liquids through microchannels for transesterification of rapeseed oil, high-speed video recording to detect the effects of hydrodynamic interaction of immiscible liquids, additive manufacturing based on a digital model using Digital Light Processing technology to manufacture elements of a microfluidic system for transesterification. Results. As a result of analyzing experimental data on the flow of reactive liquid during vegetable oil transesterification, the boundaries of two-phase flow regimes (slug and Plateau–Rayleigh instability) and the effect of heating liquids to 55°C on these boundaries were identified when compared to the case without forced heating. Among the established flow regimes, the slug one is preferable, as it allows oil conversion to be controlled and characterized. Practical recommendations were formulated for optimizing ester production and maximizing their yield. It is shown how, through a rational analysis of the effect of the volumetric flow rates of the reacting liquids and their ratio on the hydrodynamic consequences, the nature of the two-phase flow, its quantitative parameters, and the associated conversion characteristics can be determined. The paper demonstrates an approach to controlling oil conversion intensification in a microreactor by introducing and tracking the ratio of the length of the slugs to the distance between adjacent slugs in the resulting flow and its dependence on the flow rate of the two-phase liquid. The closer this ratio is to 0, the more intense the conversion and the potentially higher the yield of fatty acid esters. It was established that the size of the slugs and the distance between them are significantly sensitive to the temperature of the interacting liquids due to the changing interfacial tension between them.

For citation: Zelentsov D.O., Piskunov M.V., Chobotova V.M., Khomutov N.A. Reactive fluid flow during vegetable oil transesterification using droplet microfluidics. Bulletin of the Tomsk Polytechnic University. Geo Assets Engineering, 2026, vol. 337, no. 6, pp. 133-144. https://doi.org/10.18799/24131830/2026/6/5306