RT Journal Article T1 Isobutyric and n-butyric acid production from H2 and CO2 by Clostridium luticellarii in a hollow fiber membrane biofilm reactor: Reactor operation and process modelling A1 Mariën, Quinten A1 Flores Alsina, Xavier A1 Aslam, Umair A1 Gernaey, Krist V. A1 Regueira López, Alberte A1 Ganigué, Ramon K1 Carbon capture and utilization K1 Gas fermentation K1 Simulation K1 Hydrogen K1 Carbon dioxide AB Clostridium luticellarii is an acetogen uniquely capable of producing acetic, n-butyric and isobutyric acid from H2 and CO2. Since n-butyric and isobutyric acid are currently produced from petrochemically derived propylene, establishing a direct production route from CO2 and H2 could greatly improve their sustainability as platform chemicals while simultaneously capturing carbon. Here, we demonstrate for the first time the production of these acids from H2 and CO2 by C. luticellarii in a continuously operated hollow fiber membrane biofilm reactor (HFMBR). The HFMBR was operated for 80 days while gradually increasing the H2:CO2 ratio from 2.5 to 5.0. Concentrations of acetic, n-butyric and isobutyric acid of respectively 8.93 ± 0.22 g L−1, 1.56 ± 0.04 g L−1 and 1.51 ± 0.06 g L−1 were achieved at a dilution rate of 0.25 d−1. Subsequently, a holistic process model was developed to gain deeper insights into the performance of the system and how to optimize its operation. The model described the autotrophic production of the acids, as well as mass transfer of H2 and CO2 through the membrane, biofilm diffusion and convective movement of particulates, and biofilm growth and detachment. Calibration against experimental data confirmed the model accuracy in reflecting the production dynamics (NRMSE of products < 0.1). Scenario analyses highlighted the importance of biofilm thickness control to minimize pH gradients and revealed that increased membrane surface area and optimized dilution rates are critical in enhancing volumetric production rates and steering product selectivity. Overall, these combined experimental results and model-generated insights can inform future optimization of HFMBRs for the production of added-value products from H2 and CO2. PB Elsevier YR 2024 FD 2024-09-01 LK http://hdl.handle.net/10347/34752 UL http://hdl.handle.net/10347/34752 LA eng NO Chemical Engineering Journal Volume 495 , 1 September 2024, 153216 NO QM is supported by the Research Foundation of Flanders (Fonds Wetenschappelijk Onderzoek Vlaanderen, FWO) [grant number 1SC5722N] and the Special Research Fund of Ghent University [BOF23/CDV/085]. QM acknowledges additional support by the Research Foundation of Flanders through a travel grant [V439823N]. A.R. acknowledges the support of the Xunta de Galicia through a postdoctoral fellowship [ED481B-2021-012]. A.R. belongs to a Galician Competitive Research Group [GRC ED431C 2021/37], cofounded by ERDF (EU). UA is supported by overseas scholarship Higher Education Commission (HEC), Pakistan at Ghent University [1(2)/HRD/OSS-III/2022/HEC/409]. RG is supported by the Special Research Fund of Ghent University [BOF19/STA/044]. DS Minerva RD 27 abr 2026