Able to be delivered to fully ABP compliant standards, the BEKON^® anaerobic digestion process presents a unique approach to the problems associated with processing high solids content material such as household waste through a process that traditional requires a saturated homogenous feedstock.  The systems presents a proven means of treating co- collected kitchen and garden wastes without any damage to the process.

Perfectly suited to the contamination to be expected from households, the system cannot be damaged by physical contamination unlike systems which rely on maceration and pumping to process the waste.  A side benefit is that by not shredding down to very small particle sizes, the contamination (plastic bags, foil, large lumps of wood, etc) remains in large pieces and is therefore far easier to screen out – leaving an extremely clean and marketable product.

> Play The BEKON Waste Cooking Animation

BEKON^® anaerobic digestion is:

• A dry digestion system – capable of as much as 50% dry solids content
• A batch process for more robust, cost effective digestion; and
• Employs mesophilic digestion for a more stable process

BEKON installations can be delivered to integrate with existing waste management infrastructure (materials recovery facilities, composting sites, etc) or can be delivered as a turnkey project.  For a mesophilic system, animal by-products (ABP) compliance is achieved through meeting time and temperature requirements for composting during the back-end maturation and curing phase.

The key benefits of the system are:

• Able to process co-collected kitchen and garden wastes
• Modular design for incremental capacity increases (2,500 tpa per digester)
• Minimal maintenance, robust technology, low machine-technical costs
• Few moving parts, low wear and tear
• Low energy consumption (uses only 4% of gross energy output)
• High gas yields and superior gas quality
• Use of simple machinery to operate the system (front-end loaders, etc)
• Highly robust to foreign materials (e.g. plastics, foils, logs, sand, etc.)
• No macerating or pumping of substrate – easier product clean-up
• Minimal liquor production (<4% total input comes out as process effluent)
  
  

The dry/ batch nature of the BEKON system allows exploitation of renewable energy sources that have remained essentially unused in the past. This is because solid material can be mixed into the biomass, whereas traditional wet fermentation processing makes only minimum use of solids and can be particularly prone to physical and chemical contamination.

HOW IT WORKS
The BEKON process utilises standard sized box digesters with a hermetically sealed, automated front door.  New material is seeded with methanogens from the previous load and is loaded into the digester.  There are no internal moving parts.  Once inside, the door is closed and sealed.  Liquor in the waste is allowed to drain into the floor and is stored in a percolate buffer tank.  It is then recirculated to the digesters by means of spray bars and dispersers. 

Depending on the gas yield from the material, residence times can be between 28 and 40 days – during which time gas is extracted from the head space in the digesters and also from the percolate buffer tank and can be combusted in any standard CHP engine.

Due to the simple nature of the system and minimal moving parts, parasitic energy consumption is extremely low (only 4% of total energy produced – of which 3% is heat used to warm the digesters).  This leaves a considerable amount of energy available for export to either commercial users or the grid.

Once the gas yield has peaked and begins to diminish, the material is removed, some is returned to the digester to be mixed with new incoming material, while the rest is matured for between 2 and 6 weeks to produce high quality compost.  At this stage Animal By-Products compliance can be achieved by reaching 600^oC for 2 days, twice.

Further technical information can be found on the downloads page.