Raw Biogas is a mixture of different gases produced of organic waste and consisting of mainly methane and carbon dioxide. Biogas may even have small amounts of hydrogen sulfide (H2S). Biogas is normally produced from raw materials such as agricultural waste, municipal waste, or food waste.
Biogas can be compressed for the removal of carbon dioxide and upgraded to higher amount of methane. Upgraded biogas can then be used as a fuel for vehicles or for generation of electricity. In the United Kingdom, for example, biogas is estimated to have the potential to replace around 17% of vehicle fuel in year 2024.
Biogas is a renewable resource because its “production-and-use” cycle is continuous, and it generates no net carbon dioxide. From a carbon perspective, as much carbon dioxide is absorbed from the atmosphere in the growth of the primary bio-resource as is released, when the material is ultimately converted to energy.
For the upgrade of raw biogas, SRM has developed a water-lubricated screw compressor where no oil is used for lubrication of bearings or for injection into the compression. This compressor is used in many biogas plants around the world.