Two stage bioethanol refining with multi litre stacked microbial fuel cell and microbial electrolysis cell

Area of Science:

• Bioenergy
• Electrochemistry
• Microbiology

Background:

• Traditional ethanol distilleries have limitations in energy vector production.
• Bioelectrochemical systems offer a promising alternative for sustainable fuel generation.

Purpose of the Study:

• To develop and evaluate a two-stage bioethanol refining process using microbial fuel cells (MFCs) and microbial electrolysis cells (MECs).
• To co-generate multiple energy vectors, including ethanol, electricity, and methane, from a single integrated system.

Main Methods:

• Utilized a 10L triple-stack microbial fuel cell (MFC) for ethanol and electricity co-generation.
• Employed a 33L microbial electrolysis cell (MEC) for methane production from fermentation waste.
• Investigated the effect of stack potential on ethanol productivity and glucose consumption in the MFC.

Main Results:

• Higher stack potentials in the MFC led to increased ethanol production and faster glucose consumption.
• Ethanol productivity under electrolytic conditions reached 96.3% of the theoretical maximum.
• Bioelectric methanisation in the MEC achieved 91% efficiency at room temperature with 1.5V applied voltage using nickel cathodes.

Conclusions:

• The two-stage bioethanol refining process using bioelectrochemical reactors significantly enhances the co-generation of multiple energy vectors.
• This integrated system surpasses the energy vector output of conventional ethanol distilleries.
• The study highlights the potential of MFCs and MECs for sustainable and efficient bioenergy production.