Selective butyric acid production from CO_(2)and its upgrade to butanol in microbial electrosynthesis cells  

作　　者：Meritxell Romans-Casas Laura Feliu-Paradeda Michele Tedesco Hubertus V.M.Hamelers Lluis Bañeras M.Dolors Balaguer SebastiàPuig Paolo Dessì 

机构地区：[1]Institute of the Environment,University of Girona.Campus Montilivi,Carrer Maria Aurélia Capmany 69,E-17003,Girona,Spain [2]Molecular Microbial Ecology Group,Institute of Aquatic Ecology,University of Girona,Maria Aurelia Capmany 40,17003,Girona,Spain [3]Wetsus,European Centre of Excellence for Sustainable Water Technology,Oostergoweg 9,8911,MA,Leeuwarden,the Netherlands

出　　处：《Environmental Science and Ecotechnology》2024年第1期119-127,共9页环境科学与生态技术（英文）

基　　金：This research was carried out in the project“PANGEA-Process intensificAtioN for bioelectroCO2 recyclinG into carbon-nEutrAl products)funded by the Spanish Ministry of Innovation and Science(ref.PID2021-126240OB-I00);PD is supported by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement,project ATMESPHERE,No 101029266;MR-C is grateful for the support of the Spanish Government(FPU20/01362);S.P.is a Serra Hunter Fellow(UdG-AG-575)and acknowledges the funding from the ICREA Academia award.LF-P is grateful for the Research Training grant from the Catalan Government(2021 FISDU 00132);LEQUIA and EcoAqua have been recognized by the Catalan Government(Ref 2021 SGR01352 and 2021 SGR01142).

摘　　要：Microbial electrosynthesis(MES)is a promising carbon utilization technology,but the low-value products(i.e.,acetate or methane)and the high electric power demand hinder its industrial adoption.In this study,electrically efficient MES cells with a low ohmic resistance of 15.7 mU m^(2)were operated galvanostatically in fed-batch mode,alternating periods of high CO_(2)and H2 availability.This promoted acetic acid and ethanol production,ultimately triggering selective(78%on a carbon basis)butyric acid production via chain elongation.An average production rate of 14.5 g m^(-2)d^(-1)was obtained at an applied current of 1.0 or 1.5 mA cm^(-2),being Megasphaera sp.the key chain elongating player.Inoculating a second cell with the catholyte containing the enriched community resulted in butyric acid production at the same rate as the previous cell,but the lag phase was reduced by 82%.Furthermore,interrupting the CO_(2)feeding and setting a constant pH2 of 1.7e1.8 atm in the cathode compartment triggered solventogenic butanol production at a pH below 4.8.The efficient cell design resulted in average cell voltages of 2.6e2.8 V and a remarkably low electric energy requirement of 34.6 kWhel kg1 of butyric acid produced,despite coulombic efficiencies being restricted to 45%due to the cross-over of O_(2)and H2 through the membrane.In conclusion,this study revealed the optimal operating conditions to achieve energy-efficient butyric acid production from CO_(2)and suggested a strategy to further upgrade it to valuable butanol.

关 键 词：BIOCATHODE Bioelectrochemical system Chain elongation Hydrogen partial pressure Megasphaera 

分 类 号：TM911.45[电气工程—电力电子与电力传动]