Presentation

[Audio] Hello everyone. I am Andleeb Kiran and this is the " trends in bio-energy technology" course..

Chonnam National University. Content. Trends in Bioenergy Technology.

[Audio] The content is taken from these two manuscripts. They cover the topic of electricity generation by microorganisms. Electricity generation by microorganisms is a fascinating idea. Studies have greatly advanced our understanding of microbial electricity generation. Today we will see how a microbial fuel cell is assembled and works to generate electricity..

[Audio] Microbial fuel cells convert chemical energy stored in carbohydrates to electric energy using microorganisms. These fuel cells can be used to solve many problems such as organic waste management problems. If the waste is added to the cell, microbes will feed on it, oxidize the organic substance and turn it into electricity giving out a clean byproduct, water. Moreover, it is a biological energy source and doesn't release harmful gases into the environment. This way it can be a source of renewable and clean energy..

[Audio] Let's first see what is the general principle of the method. Every organism utilize the energy trapped in an electron-rich substance, carbohydrate. As a result of oxidation of this energy-rich substance, energy is liberated which is used by the living organism fo, which the living organism organisms, the process is more complex and involves many enzyme-catalyzed reactions. It involves successive oxidation-reduction changes and in this respect resembles an electrochemical process. In normal microbial catabolism, carbohydrates are initially broken in the absence of oxygen. Hence electrons are stored as intermediates and can be used to fuel the life processes. Ultimately oxygen acts as an " electron sink" and takes up all the electrons completing the reaction. This principle is used for microbial fuel cells. Here, a mediator is added to the solution, which takes the intermediate electrons to the cathode. Since the mediator becomes negatively charged after interaction with the anode, they act as negative charges moving around the cell, hence, producing electricity. The oxidizing (Positive) electrode acts as the electron sink. The oxidizing agent used is a simple oxidizing agent such as potassium ferricyanide. The current generated is detected by a microammeter..