Biogas: Converting Waste to Energy
October 3, 2017
As stated by EESI [Environmental and Energy Study Institute]
Biogas is produced after organic materials (plant and animal products) are broken down by bacteria in an oxygen-free environment, a process called anaerobic digestion. Biogas systems use anaerobic digestion to recycle these organic materials, turning them into biogas, which contains both energy (gas), and valuable soil products (liquids and solids).
According to Environmental and Energy Study Institute, biogas is mixture of gases that are composed primarily of:
50‐70% Methane Natural Gas
30‐40% Carbon Dioxide
Biogas is reliable, efficient, and safe, over 50% of homes are heated with natural gas. The gases methane, hydrogen, and carbon monoxide can be combusted or oxidized with oxygen. This energy release allows biogas to be used as a fuel; it can be used for any heating purpose, such as cooking. It can also be used in a gas engine to convert the energy in the gas into electricity and heat.
Biogas can be compressed after the removal of carbon dioxide, the same way as natural gas is compressed to CNG, and used to power motor vehicles. Additionally, it can be cleaned and upgraded to natural gas standards, when it becomes bio-methane.
Biogas is considered to be a renewable resource because its production-and-use cycle is continuous, and it generates no net carbon dioxide. As the organic material grows, it is converted and used. It then regrows in a continually repeating cycle. From a carbon perspective, as much carbon dioxide is absorbed from the atmosphere in the growth of the primary bio-resource as is released, when the material is ultimately converted to energy.
Author: Sara Tanigawa
Editor: Jessie Stolark