When organic waste is disposed in a landfill it decomposes naturally and produces a significant amount of methane – a greenhouse gas with 21 times the global warming potential of carbon dioxide. Landfills are a major source of human-related methane in the United States, accounting for more than 20 percent of all methane emissions. By diverting Anaheim’s food and organic waste from the landfill and sending it through a digestion process at the Anaheim Sustainability Center, methane will be captured and used to generate renewable energy.
Anaerobic digestion is a commonly used process whereby microorganisms break down organic material in the absence of oxygen. The resources recovered from anaerobic digestion are (1) biogas, a product similar to natural gas used to make renewable energy; and (2) a solid byproduct called digestate, which contains nutrients and can be used as a soil amendment or fertilizer. Organic material is biodegradable and comes from either a plant or an animal. Commercial food waste will be the primary source of organic material that will be processed at the Anaheim Sustainability Center.
Below is an illustration which shows the process that will occur at the Anaheim Sustainability Center.
How will the project reduce greenhouse gas emissions?
Food waste and organic material that is diverted to the Anaheim Sustainability Center will decompose in a controlled environment. The methane produced will be captured and used to generate renewable energy and produce fertilizer.
After the organic materials are converted into renewable energy, what remains?
A solid byproduct known as digestate remains, which is hauled away. Off-site processing transforms the nutrient-rich digestate into a valuable soil amendment.