2025-11-182025-11-18https://repositorio.uandes.cl/handle/uandes/53968<p>The microbial valorization of CO<sub>2</sub> requires the development of novel bioreactor configurations capable of ensuring a cost-effective gas-liquid mass transfer. This study presents the design, characterization and performance evaluation of a novel Airlift Taylor Flow Reactor (ATFR), which integrates the gas-induced liquid recirculation of airlift systems, with the high gas-liquid mass transfer potential of Taylor flow in multicapillary systems. The liquid recirculation flow in the downcomer was quantified using a colour tracer method, and the volumetric oxygen mass transfer coefficient (k<sub>L</sub>a) was determined via the sulphite oxidation method, both with and without forced recirculation. The results showed that the implementation of forced mechanical recirculation via a centrifugal pump negatively impacted the total liquid recirculation and k<sub>L</sub>a. A maximum k<sub>L</sub>a of 891 ± 23 h<sup>−1</sup> was achieved at a gas flow rate of 60 L min<sup>−1</sup>, representing a 75 % increase compared to the same condition with external forced liquid recirculation. The autotrophic growth of Cupriavidus necator showed a direct correlation with k<sub>L</sub>a, with a 171 % increase in maximum cell concentration and a 67 % increase in the specific growth rate when k<sub>L</sub>a increased from 183 to 364 h<sup>−1</sup>. These findings highlight the potential of the ATFR as a promising platform for gas-liquid mass transfer-limited processes, particularly in systems bioconverting poorly soluble gases such as H<sub>2</sub>, CH<sub>4</sub>, CO and O<sub>2</sub>.</p>info:eu-repo/semantics/openAccessAirlift Taylor Flow bioreactors as a novel platform to enhance H<sub>2</sub>-assisted CO<sub>2</sub> bioconversion processesArticle