Problems at the biogas plant. Henrik Bangsø Nielsen Biogasforum, seminar, 29/

Transcription

1 1 Problems at the biogas plant Henrik Bangsø Nielsen Biogasforum, seminar, 29/11-25

2 2 Outline Strategy and objectives Data obtained from Danish biogas plants On going experiments Future experiments Comments from the audience

3 3 Danish centralized biogas plants Lemvig biogas plant Animal manure Alternative biomass: Biogas production Temperature Reactor capacity HRT Post storage 362 t/day 75 t/day 51,6 m 3 /m 3 53 o C 76 m 3 18 days 18 o C/ 3d (Biogasforum) (Al Seadi, 2)

4 4 Strategies and objectives 21 status * : 1,5% of the production is lost via imbalances and technical problems, but what about suboptimal performances? The project mainly focuses on the microbiology of the process Research along with practical real life experiences A B Visits at biogas plants Data collection C Experiments and results that can be 1) directly related and used by specific plants and 2) can be published * Planenergi, Midtjylland 21: Årsager til hæmning af biogasprocessen

5 5 The biogas process Biological polymers Carbohydrates, lipids, proteins Mono- and oligomers Hydrolytic extracellular enzymes Fermentative bacteria VFA, Lactate, Alcohols H 2, CO 2 H 2 -consuming methanogens Syntrophic bacteria Acetate oxidizing bacteria Homoacetogenic bacteria Acetate Aceticlastic methanogens CH 4, H 2 O CH 4, H 2 O

6 6 Visits at biogas plants Main conclusions: No problems Pre-storage tanks are not useful Substrate composition is unknown Substrate degradation characteristics is unknown Inadequate surveillance, especially with regard to VFA

7 7 Process breakdown Blåbjerg LCFA-inhibition,,5 1, 1,5 2, 2, date methane (m3/m3 reactor vol.)

8 8 Process breakdown 2,5 m3/(m3 reactor vol.) 2 1,5 1, Date

9 9 Process breakdown 2,5 m3/(m3 reactor vol.) 2 1,5 1,5 Ammonia inhibition from pigmanure og mucosa Date Biogas production

10 1 Suboptimal reactor performance 2,5 m3/(m3 reactor vol.) 2 1,5 1, Date Biogas production

11 11 Suboptimal reactor performance 2,5 12 m3/(m3 reactor vol.) 2 1,5 1, tons Date Biogas production Total fedt

12 12 Suboptimal reactor performance 2,5 12 m3/(m3 reactor vol.) 2 1,5 1, Fedt tons Date Biogas production Total fedt Daka fedt Fra 1/11-4 sker der et skifte fra kogt madaffald til Daka-fedtaffald.

13 13 Suboptimal reactor performance/breakdown Case story: Whey replaced with blood from pigs at the 1. of September 25 Slow inhibition of biogas production observed in the beginning of October m3/(m3 reactor vol.) 4 3,5 3 2,5 2 1,5 1,5 Biogas production 6-okt-5 13-okt-5 2-okt-5 27-okt-5 3-nov- 5 1-nov nov nov- 5 Biogas production constituted only 4% of normal production at the 8. November 8 date VFA Propionate extremely high m M nov-5 14-nov-5 date 19-nov-5 24-nov-5 Acetat Propionate Isobut. Butyrate Isoval. Valerate

14 14 Suboptimal reactor performance/breakdown Reasons for inhibition: Combination of increasing ph and increasing ammonia concentration Increase in ammonia concentration was related to the feeding with pig blood Increase in ph was caused by the increase in ammonia and omission of whey from the feedstock Construction of the plant forced the operator to add further amounts of blood even after the imbalance had occurred Inadequate measurement of VFA NH3 NH3 / total ammonia Total ammonia, NH3 and ph 4,5 9, 4, 3,5 8,8 3, 2,5 8,6 2, 1,5 8,4 1, 8,2,5, 8, 6-okt 13-okt 2-okt 27-okt 3-nov 1-nov 17-nov 24-nov 1% 9% 8% 7% 6% 5% 4% 3% 2% 1% % date Free ammonia fraction at different temp ph ph (Figure by Hinrich Hartmann)

15 15 Studsgaard biogas plant 3,5 3 methane (m3/m3 reactor vol.) 2,5 2 1,5 1, date

16 16 Suboptimal conditions 3,5 daily 1 per. Mov. Avg. (daily) 2 per. Mov. Avg. (daily) 3, methane (m3/m3 reactor vol.) 2,5 2, 1,5 1,,5, date Foaming starts april Foaming ends march 25

17 17 Suboptimal conditions methane (m3/m3 reactor vol.) 3,5 3, 2,5 2, 1,5 1,,5, y = -,1x + 7, methane (m3/m3 reactor vol.) 3,5 3, y = -,9x + 36,725 2,5 2, 1,5 1,,5,

18 18 Sinding-ørre biogas plant 3,5 daily 1 per. Mov. Avg. (daily) 2 per. Mov. Avg. (daily) methane (m3/m3 reactor vol.) 3, 2,5 2, 1,5 1,,5, date

19 19 On going experiments related to full-scale experiences Screening of various wastes in batch experiments Toxicity Biogas potential Waste index Tests of the most inhibitory compounds in reactor experiments Effect on microbial activity Effect on microbial composition (DNA extraction and TGGE) Maximum loading rate Identification of suitable parameters for indication of process imbalances (VFA, Methane.)

20 2 Screening of various wastes in batch experiments with regard to toxicity and biogas potential Lipids Meat and bone meal Mixture methane production (ml/gvs) gvs/l methane production (ml/gvs) gvs/l time (days) 14 time (days) methane production (ml/gvs) gvs/l methane production (ml/gvs) g/lvs time (days) time (days)

21 21 Waste index. Examples Waste type Blood from pigs Blood from pigs Shrimp sludge Shrimp sludge Meat and Bone meal Meat and Bone meal 1% Fat, DAO Flotations fedt, pigs Bakery (mainly fat) Flotationsfedt, pigs Flotationsfedt, pigs Limfedt (fat) Food waste (fat) Flotationsfedt, chickens Temperature 37 o C 55 o C 37 o C 55 o C 37 o C 55 o C 55 o C 55 o C 55 o C 55 o C 55 o C 55 o C 55 o C 55 o C Inhibition level g VS/l = kg VS/t,5-1, <,5 1,-5,,5-1, 1,-5,,5-2, <1,,5-1, 5,-1, 5,-1, 5,-1, 5,-1, >1, >1,

22 22 Effect of MBM pulses Inadequate process surveillance 1,4 5 gvs/l 5 gvs/l 5 gvs/l 1,2 methane yield (ml/gvs) 1,,8,6,4,2, time (days)

23 23 Effect of MBM pulses VFA dynamics Acetate Propionate Isobutyrate Butyrate Valerate Isovalerate VFA (mm) time (days) 1 VFA (mm) time (days)

24 24 Future experiments related to full-scale experiences Recovery of reactors following process imbalances: Dilution Re-inoculation Continued feeding with waste Feeding with manure only No feeding at all Foaming in biogas plants Microbial phenomenon? Physical phenomenon?

25 25 Conclusions

26 26 Acknowledgements Thanks to Henard Meer de Soto and Elena Pueyo Abad for sharing their results Thanks to Hector Garcia and Prasad L. Kaparaju for their technical assistance The work is supported by Energistyrelsens Energiforsknings-program (EFP-25) Thank you for your attention!!!!