Anaerobic Degradation of Pure Glycerol for Electricity Generation using a MFC: The Effect of Substrate Concentration

Abstract

Alternative glycerol treatment and valorization, could be a promising solution, contributing to the biodiesel production economy. Thus, the potential of electricity generation from pure glycerol, using a two-chamber microbial fuel cell (MFC), was evaluated. The effect of glycerol concentration in a range of 0.5-5.2 g COD L -1 on MFC performance was examined. In order to achieve a stable MFC performance and a high power density, special attention was paid during the acclimation phase of the anaerobic consortium, which was performed using glucose, instead of glycerol, as substrate. The best performance of the cell was observed at a glycerol concentration of 3.2 g COD L -1 . At this concentration, the Coulombic efficiency (CE) was 34.1 %, the chemical oxygen demand (COD) removal efficiency was approximately 99 % and the maximum power density was 65.4 mW m -2 . Further increase of glycerol concentration to 5.2 g COD L -1 did not enhance the MFC performance, since the power density remained at 63.4 mW m -2 , while the CE and the COD removal efficiency decreased to 22.1 and 81 %, respectively. The experimental results showed that glycerol is a suitable and promising substrate for power generation, using a simple two-chamber MFC and that acclimation of anaerobic sludge using glucose as substrate, is a suitable procedure for securing a stable MFC performance, even at high glycerol concentrations.

Performance Modelling of the Bioelectrochemical Glycerol Oxidation by a Co‐Culture of Geobacter Sulfurreducens and Raoultella Electrica

“…These values are in the same range as the CE of 23.08 % determined for a glycerol‐fed pure culture of Bacillus subtilis BBK006 or the CEs of 14–27 % for undefined mixed cultures . However, some undefined mixed cultures achieved even higher CEs of up to 35 % . Electron losses were described before to be the result of the production of metabolites that do not contribute to current production .…”

“…However, it has already been demonstrated that crude glycerol can also be used for bioelectrochemical processes . The utilization of glycerol was solely achieved with complex, mostly undefined microbial communities derived from wastewater plants and soil . During these processes coulombic efficiencies (CE) between 20 % and 50 % were achieved .…”

“…The utilization of glycerol was solely achieved with complex, mostly undefined microbial communities derived from wastewater plants and soil . During these processes coulombic efficiencies (CE) between 20 % and 50 % were achieved . However, electrochemically active biofilms from wastewater or other undefined sources require enrichment prior use.…”

“…However, electrochemically active biofilms from wastewater or other undefined sources require enrichment prior use. The electroactive and glycerol consuming microorganisms usually need several weeks to accumulate at the anode or alternatively to produce mediators in the planktonic phase that finally lead to low initial CEs . In order to increase cell concentrations at the anode, biofilms enriched on the electrode surface are usually scraped off and transferred to new MFCs .…”

Influence of Sludge Age on the Performance of a Cyclically Fed Microbial Fuel Cell Using Glycerol from Biodiesel

“…Tremouli et al. studied the effect of the glycerol concentration in a H‐type MFC separated by a Nafion ® 117, observing an optimum glycerol concentration corresponding to 3.2 kg COD (chemical oxygen demand) m −3 . Pannell et al.…”