High Acetic Acid Production Rate Obtained by Microbial Electrosynthesis from Carbon Dioxide

Abstract

High product specificity and production rate are regarded as key success parameters for large-scale applicability of a (bio)chemical reaction technology. Here, we report a significant performance enhancement in acetate formation from CO2, reaching comparable productivity levels as in industrial fermentation processes (volumetric production rate and product yield). A biocathode current density of -102 ± 1 A m(-2) and an acetic acid production rate of 685 ± 30 (g m(-2) day(-1)) have been achieved in this study. High recoveries of 94 ± 2% of the CO2 supplied as the sole carbon source and 100 ± 4% of electrons into the final product (acetic acid) were achieved after development of a mature biofilm, reaching an elevated product titer of up to 11 g L(-1). This high product specificity is remarkable for mixed microbial cultures, which would make the product downstream processing easier and the technology more attractive. This performance enhancement was enabled through the combination of a well-acclimatized and enriched microbial culture (very fast start-up after culture transfer), coupled with the use of a newly synthesized electrode material, EPD-3D. The throwing power of the electrophoretic deposition technique, a method suitable for large-scale production, was harnessed to form multiwalled carbon nanotube coatings onto reticulated vitreous carbon to generate a hierarchical porous structure.

Bio-Electrochemical process for Metal and Sulfur Recovery from Acid Mine Drainage

“…However, the most remarkable shift of the reductive wave onset was attained with the electroactive inoculum, almost 0.2 V higher than the reactors with non-electroactive inoculum. This reductive wave shift is consistent with CVs obtained from BESs with live biocathodes producing hydrogen, acetate and methane (Jourdin et al 2015a;Marshall et al 2012). Accordingly, a much higher cathodic current of about -1.2 A m -2 was achieved at acclimated inoculum remained at -0.07 A m -2 at the same potential and pH.…”

“…The cathode potential was decreased to -1.1 V vs. SHE after 55 days of operation in order to increase the SRR. This potentiostatic start-up has been successful in enriching an autotrophic cathodic biofilm for nitrate reduction (Gregoire et al 2014) and carbon dioxide reduction (Jourdin et al 2015a). …”

“…In autotrophic microbial electrosynthesis, (Jourdin et al 2015a) showed that H 2 -mediated electron transfer drives the process of CO 2 reduction to acetate and suggested that biologically-driven Cu deposition on the electrode surface was responsible for the observed increase in hydrogen evolution. Another recent study by Yates et al 2014 suggested instead that enhanced hydrogen production resulted from cell debris, with living cells not required.…”

“…Carbon electrode materials are a key parameter that affects biofilm attachment and selective microbial retention. Several three-dimensional carbon electrodes have been proposed in order to increase microbial-surface interaction due to their high conductivity, good chemical stability and smooth surface (Jourdin et al 2015a;Jourdin et al 2016a;Marshall et al 2012;Virdis et al 2011). Although some research has been carried out on carbonbased surface as electron material for autotrophic sulfate removal (Su et al 2012;Coma et al 2013;Luo et al 2014;Teng et al 2016;Blázquez et al 2016), no single study exists which described autotrophic sulfate reduction using three-dimensional coating multiwalled carbon nanotubes on reticulated vitreous carbon (MWCNT-RVC) as the electrode material.…”

The Effect of Membrane Type on the Performance of Microbial Electrosynthesis Cells for Methane Production

“…Therefore, investigations into optimal microbial communities along with interspecies interactions have also gained attention in recent years. [16][17][18][19][20][21][22][23][24][25] The practical application of microbial electrosynthesis still requires a deeper understanding of how reactor design may fundamentally impact performance and overall microbial composition. In most cases, a microbial electrosynthesis reactor is a dual-chambered system composed of an anode electrode, a cathode electrode and a separator.…”