Biogas is created by breaking down organic matter in an anaerobic environment in absence of light. In the process, microorganisms break down the material into its basic components, producing methane – also described as fermentation or digestion. Biogas plants utilise a wide range of organic materials as feedstock, such as animal waste, energy crops, municipal waste, organic food industry waste and sewage sludge.

The main components of biogas are methane (CH4) and carbon dioxide (CO2). The gas can be combusted and utilised as fuel in a CHP gas engine such as Shengdong’s biogas generator sets.  The generated electricity can be exported to the public grid or used on-site, whilst the captured heat power from the CHP generator set is typically used for process heating.

Biogas production is driven by three main factors: (i) generation of combined heat and power (CHP), (ii) improved safety and  (iii) environment protection from release of methane.

Biogas is also often described according to the feedstock used for its production
  • Agricultural biogas: energy crops (maize, wheat, rye, grass) and organic waste (manure and slurry)
  • Sewage and landfill gas: organic waste
  • Distillery biogas: by-products of the alcohol distillation process, derived from wheat, rye, maize, molasses, grain, etc
Biogas is also known as sewage gas, marsh gas, landfill gas and methane gas
Calorific value (CV) of biogas is 25-32 MJ/m3
Biogas typical composition:
  • 50-75% Methane (CH4)
  • 25-45% Carbon dioxide (CO2)
  • 2-7% Water (H20)
  • < 2% Oxygen (O2)
  • < 2% Nitrogen (N2)
  • < 1% Ammonia (NH3)
  • < 1% Hydrogen sulphide (H2S)