Microbial fuel cell – used in direct conversion of lignocellulosic waste to energy

“The Research project on Microbial fuel cell – used in direct conversion of lignocellulosic waste to energy” (MFC project) is a national research project bringing together 3 research groups to study bacterial production of electricity from waste streams.

 
Energy generation from renewable materials and waste treatment are two challenges in the request for a sustainable society. These challenges can be solved at the same time by usage of a microbial fuel cell. A microbial fuel cell (MFC) is an elegant technology because it directly generates electricity during waste treatment which is based on microbial metabolism of organic acids and sugars. The electricity produced by a MFC is in this project optimized. Phenolic compounds originating from lignin in agricultural waste products such as straw is used as mediating components in the MFC since these can act as electron shuttles.

The MFC project will particularly focus on three issues: 
  • Construct a small scale MFC with a reference electrode whereby one can determine the energy losses from fuel oxidation, ohmic resistance in the solution, and the overvoltage of the air electrode.
  • Demonstrate the function of a MFC with xylose and hemicellulose as fuel energy and oxygen as electron acceptor.
  • Test the possibility of using MFC to treat real lignocellulosic hydrolysate like hydrothermal treated wheat straw. Schematic of microbial fuel cell setup
    Schematic diagram of the setup and operation of a microbial fuel cell. Carbohydrates are oxidized anaerobically by bacteria in the anode chamber. The generated electrons and protons pass via the external wire and proton exchange membrane, respectively, to the cathode electrode where oxygen serves as electron acceptor to form water and closes the circuit for electricity generation.

Background:
Energy generation from energy crop and agricultural waste like manure are key challenges in the request for sustainable agriculture. During the last 25 year a lot of focus has been on bioethanol and biogas from these feedstocks due to the needs for replacing gasoline. In both bioethanol and biogas production sugars are needed, however less than 50% of the sugars are converted into bioethanol and biogas since also CO2 is produced in equal amounts. Furthermore, a costly purification is needed, before these products can be used for transportation or for production of electricity. These problems can potentially be solved with microbial fuel cells.
Participants: The MFC project involves research groups from Biosystems Division and Fuel Cell and Solid State Chemistry Division at Risø DTU and the Bioenergy group at DTU Environment.

Role:
Risø leads the project and is responsible for pretreatment of straw biomass to make the fuel for the MFC. Furthermore the electrochemical studies are performed at Risø.

Resources:
The MFC project is funded by Danish Agency for Science and Innovation.

Duration:
The MFC project is funded to run from 2006 through 2009.

Employees involved:
Anne Belinda Thomsen (head), Anders Thygesen (post doc), Finn Willy Poulsen (electrochemistry), Tomas Fernqvist (analysis) and Ingelis Larsen (analysis).

 

Page updated  by   08.10.2010