A small amount of compressed biogas, regularly introduced into the process tank, keeps the biomass in suspension. This maintains a gentle mixing action and achieves greater contact of the waste with the digesting microbes.

The biogas that is produced powers a specially designed internal combustion engine or gas turbine, generating electricity. It can also be used for heat production in a steam-generating boiler, or to
power a refrigeration system. By-product heat can be captured to benefit other processes on the operator's site.