Advantages of our AD Process



1. Grit removal: Separation of heavy fragments and grit

Most materials treated by a digester contains grits, sand, gravel and other heavy particles, which has caused many expensive digester failures in the UK since 1980. The average rate of grit build up is around 7 to 12% per year.

In our patented process, the first stage is filled and emptied every 2 - 3 days, the heavy particles separate and precipitate to the bottom of the vessel and can be removed periodically.

No interruption of the digestion process is required!

2. Patented High Rate Process. 

In the first two process steps of the biogas production – hydrolysis and acidification – low pH values prevail. This has the biological acids which dissolve the molecular structures of celluloses and other such materials found in grass, straw and similar high fibre feedstocks. 

These are used by bacteria in the later process later to produce biogas.

3. Advanced Process Control.

Our process can control the biogas production down to a 50 minute period. This unique feature, developed for the use of bought in energy crops, can optimise energy production whilst preventing the waste of feedstock and biogas.  

4. Solid materials as input material for the biogas plant

Horse stable and farm yard manure (FYM) was one of the first input materials to be used in the our biogas plants. Solid manure is rarely used in conventional digesters as it causes problems regarding mixing, grit/sand/stones accumulation and solid layers.

Higher front end temperatures ensure pathogen, parasite, weed seed and odour control.
The use of high solids materials can lead to little or no excess liquid to deal with - a major advantage.
The process can deal with solid feedstock only, it is not dependent on farm animal slurry.

5. Solid Fuel

The dewatering process can also remove much of the nutrients from the fibre, making it suitable as a solid fuel similar in calorific value as turf or soft wood. The fuel can be used directly in a wood chip burner, made into briquettes/logs or into pellets.

6. Changes in Feedstock

The type of feedstock can be changed daily.
Changing input material is slow with one-stage biogas plants, the adjustment of input material over several weeks or even month is normal. 
Hydrolysis bacteria are very sturdy and tolerate disturbances of the process, such as a sudden change in the feedstock. This allows the biogas plant to react flexibly to the supply of available feedstocks. For example, single batches of grass and/or straw can be used at short notice.
 





Our two or three stage AD plant
• At least a 20% increase in biogas production can be expected

• Greater range of feedstocks including grass silage and straw
• Separation of heavy fragments, with reduced grit build up in the digester
• Faster throughput, lower retention times = smaller AD plant 
• The type of feedstock can be changed every day
• Pathogen, parasite, weed seed and odour control