Anaerobic Digestion (AD)
Anaerobic Digestion (AD) is the fermentation of energy rich biodegradable materials such as food waste and specially grown energy crops to produce a methane rich biogas. The fermentation process is carried out in closed tanks and can be a simple single stage process typical of on-farm AD systems to more elaborate two or three stage processes for faster and more efficient production of biogas.
The biogas is then either cleaned and dried and used to power gas engines or it can be upgraded and directly injected into the gas mains for distribution.
Powering gas engines locally and exporting electricity will probably be the solution of choice for smaller AD systems as biogas upgrading is more complicated and expensive but makes more of the energy available via the gas grid.
SES works with partners that supply both low technology single stage systems suited to on-farm applications as well as larger, state-of-the-art, high efficiency multi-stage digesters.