Typically, an anaerobic digester will produce about what percentage by volume of carbon dioxide (CO2)?

Anaerobic digesters are designed to break down organic matter in an oxygen-free environment, leading to the production of biogas, which primarily consists of methane and carbon dioxide. In the typical operation of an anaerobic digester, carbon dioxide usually makes up a significant portion of the biogas produced. The volume of carbon dioxide generated can vary based on factors such as the composition of the feedstock, operating temperature, and retention time, but it commonly falls within the range of 30% to 35% by volume. This range reflects a balance where the methane concentration is higher than in other processes, illustrating the efficiency of anaerobic digestion in converting organic materials into energy-rich biogas while still producing a notable percentage of carbon dioxide as a byproduct.

The other choices provided do not align with the typical composition of biogas produced by anaerobic digesters. Percentages lower than 30% would underestimate the volume of carbon dioxide produced, while percentages approaching 50% or higher would suggest an imbalance and would likely indicate inefficiencies or specific conditions that don't align with standard operations of an anaerobic digester.