Microbial electrosynthesis
Encyclopedia
Microbial electrosynthesis is a form of microbial electrocatalysis in which electrons are supplied to living microorganisms via a cathode
in an electrochemical cell by applying an electric current
. The electrons are then used by the microorganisms to reduce carbon dioxide
to yield industrially relevant products. The electric current would ideally be produced by a renewable source of power.
This process is the opposite to that employed in a microbial fuel cell
, in which microorganisms transfer electrons from the oxidation of compounds to an anode to generate an electric current.
Comparison to microbial electrolysis cell
Microbial electrosynthesis is related to microbial electrolysis cells (MEC). Both use the interactions of microorganisms with a cathode to reduce chemical compounds, but differ in the source of power for this process. In microbial
electrosynthesis electrons are supplied solely by the external electrical power source. In MECs, and electrical power source is used to augment the electrical potential produced by the microorganisms consuming a source of chemical energy such as acetic acid
. The combined potential provided by the power source and the microorganisms is then sufficient to for example reduce hydrogen ion
s to molecular hydrogen
.
Cathode
A cathode is an electrode through which electric current flows out of a polarized electrical device. Mnemonic: CCD .Cathode polarity is not always negative...
in an electrochemical cell by applying an electric current
Electric current
Electric current is a flow of electric charge through a medium.This charge is typically carried by moving electrons in a conductor such as wire...
. The electrons are then used by the microorganisms to reduce carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
to yield industrially relevant products. The electric current would ideally be produced by a renewable source of power.
This process is the opposite to that employed in a microbial fuel cell
Microbial fuel cell
A microbial fuel cell or biological fuel cell is a bio-electrochemical system that drives a current by mimicking bacterial interactions found in nature....
, in which microorganisms transfer electrons from the oxidation of compounds to an anode to generate an electric current.
Comparison to microbial electrolysis cellMicrobial electrolysis cellA microbial electrolysis cell is a technology related to Microbial fuel cells . Whilst MFC's produce an electric current from the microbial decomposition of organic compounds, MEC's partially reverse the process to generate hydrogen or methane from organic material by applying an electric current...
s
Microbial electrosynthesis is related to microbial electrolysis cells (MEC). Both use the interactions of microorganisms with a cathode to reduce chemical compounds, but differ in the source of power for this process. In microbialelectrosynthesis electrons are supplied solely by the external electrical power source. In MECs, and electrical power source is used to augment the electrical potential produced by the microorganisms consuming a source of chemical energy such as acetic acid
Acetic acid
Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...
. The combined potential provided by the power source and the microorganisms is then sufficient to for example reduce hydrogen ion
Hydrogen ion
Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes.Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions....
s to molecular hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
.
Applications
Microbial electrosynthesis may be used to produce fuel from carbon dioxide using electrical energy generated by either traditional power stations or renewable electricity generation. It may also be used to produce speciality chemicals such as drug precursors through microbially assisted electrocatalysis.See also
- Glossary of fuel cell termsGlossary of fuel cell termsThe Glossary of fuel cell terms lists the definitions of many terms used within the fuel cell industry. The terms in this fuel cell glossary may be used by fuel cell industry associations, in education material and fuel cell codes and standards to name but a few. –...
- ElectrohydrogenesisElectrohydrogenesisElectrohydrogenesis or biocatalyzed electrolysis is the name given to a process for generating hydrogen gas from organic matter being decomposed by bacteria. This process uses a modified fuel cell to contain the organic matter and water...
- ElectromethanogenesisElectromethanogenesisElectromethanogenesis is a form of electrofuel production where methane is produced by direct biological conversion from electrical current and carbon dioxide. The reduction process is carried out in a microbial electrolysis cell...
- Microbial fuel cellMicrobial fuel cellA microbial fuel cell or biological fuel cell is a bio-electrochemical system that drives a current by mimicking bacterial interactions found in nature....