Is it possible to start-up a biogas plant from manure in only 4 months?

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1 Is it possible to start-up a biogas plant from manure in only 4 months? Nordic Biogas Conference Erik Nordell Tekniska verken i Linköping AB, Sweden in co-operation with Greve Biogass AS, Tønsberg, Norway.

2 Tekniska verken i Linköping AB 19 years experience of full scale biogas production (since jan 1997) 110 GWh/y of bio-methane 100 % renewable vehicle fuel produced using organic material Local production of biogas (Tekniska verken): Linköping Partnerships in several locations Operates its own filling stations in the counties of Östergötland and Södermanland (Svensk Biogas): 11 filling stations and 3 bus depots >160 busses in three cities, 25 garbage trucks >3 000 cars (public and private)

3 The plant started in late 2015 and is located in Tønsberg, Norway It s owned by Greve Biogass AS and operated by Lindum AS Tekniska Verken has been in a co-operation with Greve Biogass during the whole project TV s R&D Biogas involved to achieve a secure and rapid start-up of the plant based on the local conditions

4 Den magiske fabrikken - plant design Main substrates: Food waste tons/y (eq ton slurry) Manure (cow) tons/y Manure (pigs) tons/y 2 digesters working in parallel (each 6000 m 3 ) Pre-treatment of food waste Upgrading the biogas to bio-methane with water scrubbing technique Capacity to upgrade 65 GWh/y

5 The typical way to start-up a new biogas plant 1 st alternative: 1. Collect digestate from a nearby biogas plant (preferably with similar substrate) 2. Start feeding the digesters slowly and increase the organic loading rate Cons: Requires a lot of digestate (!), in this case tons 2 nd alternative: 1. Fill the digesters with digestate (approx. 10%) and water (90%) 2. Start feeding the digesters slowly Cons: the first tons of digestate will be useless as fertilizer due to the dilution and low alkalinity

6 Fine, but there was one problem the nearest co-digestion plant was located in Oslo appr. (100 km one-way from Tønsberg) which will require 400 transports of digestate (realistic? No!) However, there is a lot of cow manure in the neighborhood.

7 Cow rumen / manure Complex organic matter (Proteins, fat, polysaccharides etc.) Hydrolysis Monosacharides (Amino acids, sugars, peptides etc.) Acidogenesis Intermediate products (Alcohols, fatty acids etc.) Acetogenesis Substrate for the cow Homoacetogenesis H 2 + CO 2 Acetate Hydrogenotrophic methanogenesis SAO CH 4 + CO 2 Acetoclastic methanogenesis The methanogens are present but supressed in the rumen

8 The start-up plan 1. Start with a small amount of digestate (25%) Also Introduce trace elements (chock-dosing) 2. Start feeding rapid with fresh cow-manure (75%) to fill the digesters Continuously dosing trace elements to promote methanogens grow and iron to precipitate sulfides 3. Increase the organic loading with food waste and cow-/pig manure Full organic loading rate within 4 months from starting filling the digesters with digestate

9 Prior to start-up we simulated the plan in lab-scale conditions = Greve Biogass (Grenland og Vestfold Biogass) Tekniska verken i Linköping AB

10 The setup in lab CSTR fed once a day in lab-scale No heating or stirring until digesters was 50% filled Fresh digestate and fresh cowmanure from Tönsberg and Oslo Head-space exposed to oxygen Kemira BDP-startup and BDP-86X to precipitate sulfides and promote optimal conditions for the methanogens

11 The start-up in lab

12 Accumulated amount (ton) Cumulative substrate flow (lab/plan) Cow manure Pig manure Other manure Food waste Sum Time (days)

13 Specific methane production (Nm 3 CH 4 /kg VS) Organic loading rate (kg VS/m 3 d) 800 Specific methane production (lab) Greve biogass RK1 Greve biogass RK2 Organic loading rate RK1 Organic loading rate RK Time (days)

14 Gas production (m 3 /h) Gas production up scaled to full-scale conditions Förväntat ExpectedRågas prod. RK1 RK1 Förväntat ExpectedRågas prod. RK2 RK Time (days)

15 Gas production (m 3 /h) Lab results up-scaled to full-scale conditions Rågas Gas prod. RK1 m3/h RK1 Rågas Gas prod. RK2 m3/h RK1 Förväntat ExpectedRågas prod. RK1 RK1 Förväntat ExpectedRågas prod. RK2 RK2 Total Gas Rågas prod. m3/h RK1+RK Stable production at approx m3/h Corresponding to 65 GWh/y Time (days)

16 Alkalinitet (mg HCO3- eqv./l) ph Process stability Harry Alk Potter Alk Harry ph Potter ph 9, , , , , , Time (days) 6,0

17 Process stability

18 So what about full-scale? Start-up was very successful and the filling of the digester was faster than expected The digestate was slightly warmer than simulated in lab No peak in VFA in the start-up Status now: Robust and stable process operating at approx. 80% of max. capacity Den magiske fabrikken has been approved to be the national biogas pilot plant in Norway a true success!

19 Conclusion It s was possible to reach a stable operation at the goal of 3.7 kg VS/m 3 within 4 months from start-up Inoculation with cow manure is an suitable method The plan was applied in full-scale with great success the plant is currently producing approx GWh/y

20 Thank you - any questions?