Bio-energy (also known as biomass energy) comes from the processing of organic materials such as wood, agricultural crops, or organic waste like animal manures or municipal wastewater sludge. Since it comes from a wide range of organic matter that can be quickly replenished, bio-energy is classified as a renewable resource. With much less impact on the environment than the burning of fossil fuels, bio-energy can help reduce Canadian greenhouse gas emissions and help make the move toward greater environmental sustainability.
One of the most interesting applications of bio-energy is the conversion of animal waste or raw wastewater into biogas. This process of creating energy is particularly valuable to the farming industry, which can turn animal waste into fuel.
The process of creating bio-energy from animal waste is called anaerobic digestion. It begins at the barn or cow house where the animal by-products are collected and put into an anaerobic reactor. The reactor is brought to a temperature of 35 degrees Celsius that starts a bacterial fermentation process. This process can take 10 days to several weeks to complete. Once the fermentation process is finished and the organic matter is properly decomposed, it produces a biogas comprised of approximately 35-40% carbon dioxide and 60-65% methane. With such a high concentration of methane, the biogas can be effectively used for heating and electrical generation.
The process of capturing methane gas for energy use goes beyond the farmyard. Bio-energy is also being applied to landfills that emit methane as garbage decomposes, and in wastewater treatment plants. Methane gas is a large contributor to greenhouse emissions, so by capturing and repurposing it, we reduce its exposure to the atmosphere. The bio-energy process converts the methane gas into carbon dioxide, thus reducing its environmental impact. Bio-energy systems capitalize on the inherent "flaring" process and use the excess heat to power steam turbines for electrical generation. By recovering the methane gas, it becomes an efficient source of energy.
If you want more information on bio-energy, please visit Natural Resources Canada.