Generating energy through burning, vaporising, or fermenting biomass such as leftover plant material, vegetable waste, and manure are tried and tested methods. A new shoot on this branch of energy production is the microbial fuel cell, which is capable of directly generating energy from substances such as waste water. At the present time, this has only been done in the lab, but the first results and applications of this new technology show tremendous potential.
If an electrode is placed in waste water, bacteria automatically begin to grow on it. These bacteria are capable of transforming the organic compounds present in the water into electricity. This process purifies the waste water, which in and of itself is a useful application. But researchers who are working with each other as part of the Microbial Fuel Cell project , are more interested in generating electricity.
A liquid or gaseous organic derived fuel of vegetal or animal origin like black liquor, palm oil, bioethanol, landfill gas or biogas coming from the anaerobic digestion processes (i.e. treating pig manure, poultry litter, sewage sludge, etc.) is combusted in a burner to generate steam in an appropriate boiler. The steam is directly sent to a turbine/generator unit to produce electricity, then passed through a condenser to convert it into water again.
Anaerobic digestion is typically applied in sewage sludge treatment due to its advantages over aerobic systems, such as lower energy consumption, smaller amounts of solids generated, lower nutrient requirement and potential energy recovery from the produced biogas. Sewage sludge is stabilized during anaerobic digestion by converting most organic matter into biogas
