Biogas is a renewable energy source that is produced by the breakdown of organic matter, such as food waste, agricultural waste, or sewage, in the absence of oxygen. The primary component of biogas is methane (CH4), which can be captured and used as fuel for heating, electricity generation, or even transportation.

However, biogas production can also result in methane emissions, both during the production process and during the use of biogas as a fuel. Methane emissions can occur during the anaerobic digestion process if the conditions are not optimal, or if the biogas is not properly captured and used. Methane emissions can also occur if the biogas is not burned efficiently or if there are leaks in the equipment used to distribute the biogas, methane can be released into the atmosphere.

There's an important difference between biogas and biomethane.  Biogas contains between 50 - 70% methane. To enable it to be used as part of the gas grid or used as a transport fuel - it requires purifying to 95% (biomethane), the same as the natural gas it is replacing.  This purification and upgrading process can produce emissions, as well as requiring energy to carry out, although the biogas itself can be used as a fuel source. 

To reduce methane emissions from biogas or biomethane, various measures can be taken such as:

  • Improving the efficiency of the anaerobic digestion process by optimizing the conditions under which organic matter is broken down.
  • Capturing and using biogas as a fuel, rather than releasing it into the atmosphere.
  • Using advanced monitoring and control technology to detect and repair leaks in biogas collection and distribution systems.
  • Using well-maintained and efficient equipment to burn biogas as a fuel.
  • Overall, biogas has the potential to be a low-emitting and renewable energy source when produced and used properly.

Biomethane emissions are a growing area of research for the SGI. Our most recent work suggests emissions from the Biogas supply chain are currently significantly underestimated.