What is the typical gas composition in a well-run anaerobic digester?

In a well-run anaerobic digester, the typical gas composition consists of 65-75% methane and 25-35% carbon dioxide. This range reflects the ideal fermentation conditions used to break down organic material in the absence of oxygen, leading to the production of biogas. Methane is the primary product, formed as a result of the metabolic processes of methanogenic microorganisms that thrive in anaerobic environments.

The production of methane is crucial because it serves as a valuable renewable energy source when captured from the digester. The carbon dioxide present is a byproduct of the anaerobic digestion process and also indicates the effective microbial activity within the system.

This composition highlights the efficiency of the digestion process under optimal conditions. If the methane production were significantly lower, as seen in the incorrect options, it would indicate inefficiencies or issues within the digester. Therefore, recognizing the correct range of gas composition helps operators evaluate the performance of the anaerobic digestion process and ensures proper management for maximizing methane production.