PERFORMANCE DATA FROM OPERATIONAL ANAEROBIC DIGESTION ENHANCEMENT SYSTEMS.
Froud, C.1 and Weber, R.2,
1CSO Technik Ltd, 2Biogest AG
(free)
Anaerobic digestion enhancement systems are in real danger of getting a bad name due to
some recent high profile problems with installed systems; however this paper reveals a more
positive picture which will bring delegates up to date with operational performance data and
experiences of mechanical anaerobic digestion enhancement systems from around the world.
At the time of writing there are 18 operational Crown mechanical sludge hydrolysis systems
primarily in Europe, the oldest of which was commissioned as early as 2002. The Crown
sludge disintegration system utilises mechanical forces to cause cavitation in surplus
activated sludge (SAS). Cavitation ruptures the cell structure releasing the otherwise locked in
resource for digestion enhancement or as a carbon source for biological treatment
enhancement. The paper details very positive performance data for improved biogas yields,
lower solids for disposal and reduced polymer consumption. The paper will also record
operational experience of the system including maintenance and operational costs and
supplementary benefits such as elimination of digester foaming caused by filamentous
bacteria.
Significant third party performance data will be discussed from the Rosedale plant project in
New Zealand which has been the subject of intense testing and scrutiny by North Shore City
Council. Wiesbaden Council provided performance data and operational experience of Crown
systems in both anaerobic digestion enhancement and carbon sourcing modes. Wiesbaden
were the first organisation to install Crown systems and have a wealth of valuable experience
regarding all aspects of owning, operating and deriving rapid paybacks from installed
equipment.
KEY WORDS
Crown, Digestion enhancement, Disintegration, Anaerobic digestion, Carbon source,
Hydrolysis, Cell lysis
