Anaerobic digestion wastewater treatment creates the opportunity for waste management as well as renewable energy.

What is Anaerobic Digestion?

Anaerobic digestion is a sequence of processes where bacteria break down biological material in the absence of oxygen. In industrial processes, such as wastewater treatment, anaerobic digesters can be used to help manage waste as well as create renewable energy.

What is Digester Gas?

Digester gas (typically 65% methane and 35% carbon dioxide) is produced when organic matter, such as raw sewage, decomposes in the absence of oxygen.

Anaerobic Digestion Wastewater Treatment

Digester gas, which is created during the anaerobic digestion wastewater treatment process, can be converted to renewable energy. Modern wastewater treatment plant processes incorporate digester gas flow measurement systems for the plant’s process performance and control, as well as monitoring cogeneration processes.

In the wastewater process, after the suspended particles have been consumed by bacteria, the solid matter is subsequently removed before it enters a secondary process where digesters break down the waste and digester gas (methane and carbon dioxide) is created. Digester gas can be converted to renewable energy to fuel onsite boilers and flare the excess. Other systems can use the gas to generate electricity, sell the energy to local industries, or even create fuel for natural gas-fuelled vehicles.

The anaerobic digester gas is dirty, wet and contains contaminants that can collect within the piping. A thermal mass flow meter has no moving parts making it an optimum choice for this application. Most wastewater digester gas applications function at low pressure and thermal flow meters have no pressure drop. The SAGE Meter has an extremely low-end sensitivity which is needed to handle the very low flow typical of digester gas.  Throughout this process, gas mass flow meters are used to optimize the process and comply with the EPA regulations.

EPA and Greenhouse Gas Reduction

Sage Thermal Mass Flow Meters are ideal for monitoring the digester gas flow rate of the WWTP digesters to improve overall system balance and operation, as well as to measure the flow rate of gas for co-generation systems, to measure the amount of excess gas being stored, and to monitor flare gas to comply with environmental regulations and/or to report on greenhouse gas (GHG) reduction credits.