1. On farm small scale biogas
Jon Hovland
Chief scientist
Technology forum, HSN

2. This is a team effort!
Rune Bakke has been the central person in this work since 1995.
I worked in Norsk Hydro when this started as a project in
There has been several Ph.D., M.Sc, B.Sc covering different aspects of the technology so we could get to where we are today.

3. Explicitly stating that manure should be used to produce biogas
Is it realistic to make biogas from manure at typical Norwegian farms, given that they are small in European context?
The Government presented a strategy for increased biogas production in 2014.
Explicitly stating that manure should be used to produce biogas
Previously a target of treating 30% of the manure had been put forward

4. Central vs on-farm Some places central treatment is the best option
The best example is Greve Biogas
Localisation very important
Many farms are located too far away from central plants
Max distance 15 – 40 km depending on a number of factors, cost of transportation is limiting – not GHG.

5. Capital expenditure is the key
Typical farms in Norway cannot invest more than approximately 1 million NOK
Otherwise it will be a loss
Typical “traditional” biogas plants offered in the market has a CAPEX above 3 mill NOK
How can a plant be designed and built for 1 mill NOK?

6. Reactor type is the key CSTR reactors are the typical construction
High rate reactors must be used
Small size make it possible to do prefabrication in an industrial setting
On site construction is costly and must be avoided
Upward flow sludge blanket
Anaerobic baffle reactor

8. Granules from high rate reactor
Norske Skog Saugbrugs (UASB)
ABR pilot reactor on pig manure

9. The advantage of the High Rate reactor
Bergland, W.H., Dinamarca, C., Toradzadegan, M., Nordgård A.S.R., Bakke I., Bakke, R., High Rate Manure Supernatant Digestion. Water Research.
CSTR
In a CSTR the solids retention time is equal to the hydraulic retention time.
In a high rate reactor SRT >> HRT

10. Why high rate reactor with long SRT?
In the conversion of organic material to CH4 and CO2 there is very little energy available for the microorganisms to use for growth
Very slow growth – generation time more than 20 days, for some much more 60 – 100 days
In a CSTR with hydraulic retention time of 30 days, the microorganism are washed out!

11. Telemark reactor delivered at site

12. Biogas to boiler
Heat
Reaktor
Heat exchanger

14. SCADA using Labview