Human Exploitation of the Anaerobic Digestion Process
As mentioned, the various advantages of AD have resulted in wide-spread attempts to harness the process while addressing all of the potential concerns. World-wide efforts at small- to very large-scale systems dealing with very dilute to very dry residues have resulted in a broad range of system configurations, a few of which may be seen here. The various configurations have varying applicability.
Again, a digester may most usefully be seen as an extension of the intestines of large animals. Given a gas-tight container, a reasonable digester feed with adequate water for anaerobic conditions to develop, and some anaerobic microbe-containing starter, anaerobic digestion will occur! If the gas has nowhere to go, it will very likely burst the seams of nearly any container. It is largely efforts to increase the speed of digestion, generally in larger systems, that result in increased efforts and concern about system control}.