Bioelectrochemical Systems
  and Engineering
Research Group

Enzymatic Fuel Cells  Bioelectrochemical Systems Biosensors   Nanomaterials

Bioelectrochemical Systems (BES)

Bioelectrochemical Systems are integrated systems
combining wastewater treatment with energy generation and resource recovery

Microbial Fuel Cells (MFCs)
represent an emerging technology that could eventually become an important renewable energy source. Power in a microbial fuel cell is generated when bacteria donate electrons to an insoluble anode, these electrons travel through an external circuit, and then go onto reduce oxygen at a cathode, producing water. The circuit is completed by the migration of protons from the anode to the cathode through a proton exchange membrane. MFC’s are being developed for the treatment of domestic wastewater, as BOD biosensors, as power sources for remote devices, and for bioremediation applications.
An important limitation with respect to MFC development is in the use of precious metal catalysts, such as Pt, for oxygen reduction at the cathode. Biocathodes are a suitable alternative to these abiotic catalysts as they are both cheap and sustainable. Through microbial metabolism, they work by oxidising spent mediators or directly accepting electrons from plain electrodes.

Microbial Electrolysis Cells (MECs)
Microbial electrolysis cell (MEC) is a device that utilizes electron from anodic oxidation metabolisms in cathode to produce hydrogen. At normal condition, proton reduction at cathode is thermodynamically unfavourable. Therefore, electricity is applied with the use of platinum catalyst to lower the cathode potential. Then after, enriched microbial consortia in cathode can replace platinum as catalyst. The consortia are dominated by sulfate-reducing bacteria of genus Desulfovibrion which conserve energy through an anaerobic electron transport mechanism.

Resource Recovery from Waste using Bioelectrochemical Systems
Production and recovery of energy and industrial materials from novel biological sources reduces our dependency on the Earth's finite mineral petrochemical resources and helps the UK economy to become a low carbon economy. Recovering energy and valuable resources such as metals from waste materials is an attractive but challenging prospect. The valuable materials are usually present in wastes at very low levels and present as a highly complex mixture. This makes it very difficult to concentrate and purify them in an economically sustainable manner.
In recent years there have been exciting advances in our understanding of ways in which microorganisms can extract the energy locked up in the organic compounds found in wastewater and in the process generate electricity by MFCs. In theory MFC can be configured such that, rather than conversion of oxygen to water at the cathode they could convert metal ions to metals or drive the synthesis of valuable chemicals. It is our aim to develop such systems that use energy harvested from wastewater to recover metals from metal-containing waste streams and for the synthesis of valuable chemicals, ultimately from CO2.
This project will bring together experts from academia and industry to devise ways in which this can be achieved and will form the foundation of a research programme where scientists working on fundamental research and those with the skills to translate laboratory science to industrial processes will work together to develop sustainable processes for the production of valuable resources from waste.

Convert Carbon Dioxide into Valuable Chemicals
The conventional Carbon capture and storage (CCS) in some way provides effective means for emission reductions but high investment costs, possibilities for leakage and increased public resistance and energy costs demanding for alternative methods.
The electrocatalytic reduction of CO2 to liquid fuels, chemical feedstock and valuable chemicals has attracted growing interest in CO2 capture and utilisation (CCU) in the past several years. The electrochemical processes offer good reaction selectivity and reduced cost because of possibility of direct control of electrode surface free energy through electrode potential. However, due to extreme stableness of CO2 molecule, the overpotential for CO2 electrochemical reduction is high. The energy required for the process could be intensive, current efficiency could be low and the yield of the desired product could be low.
From our research on Microbial fuel cells (MFCs), it is clear that MFC can largely reduce the energy demand in the wastewater treatment process and clean the organic carbon simultaneously.
The ultimate goal is to develop low cost and low energy consumption bioelectrochemical system (BES) to convert CO2 into high valued products, such as liquid fuels, chemicals, amino acids or alkenes. For this project, the aim is to conduct preliminary study on converting CO2 into small organic molecules, such as methanol and formic acid by electrochemical synthesis.





Last updated in December 2016