Grass/Cattle Manure as feedstock for AD plants

Transcription

1 Grass/Cattle Manure as feedstock for AD plants Dublin, Ireland, October 24 th, 2017 Michael Köttner International Biogas and Bioenergy Centre of competence, IBBK

2 International Biogas and Bioenergy Centre of Competence IBBK Know-How transfer (international workshops, conferences, study tours, training) Technical support especially with dry digestion, lagoon technology, small scale installations Contacts to experts in planning, design and construction Contacts to specialized companies Networking with members in different regions nationally and internationally Origin in Organic Biogas Dublin, Ireland, October 24 th, 2017 Page 2

3 Content 1. Status of agricultural biogas production in industrial agriculture in Europe 2. Feasible Digester Technology Options for Grass/Manure Biogas Production 3. Economic success factors for Grass/Manure Biogas Projects 4. Feedstock in Grass/Manure Biogas Plants 5. Feeding Technology in Grass/Manure Biogas Plants 6. Conclusions Dublin, Ireland, October 24 th, 2017 Page 3

4 1. Status of agricultural biogas production in industrial agriculture in Europe Dublin, Ireland, October 24 th, 2017 Page 4

5 Biogas plants in Germany Dublin, Ireland, October 24 th, 2017 Page 5

6 Increase of biogas plants with energy crops 6746 biogas plants In 8 years with Energy crops Dublin, Ireland, October 24 th, 2017 Page 6

7 What is the reason for this strong growth? Creation of sufficient to generous feed-in tariffs and unlimited priority feed-in of RE-power Focus on Energy Crops in EEG 2004 & 2009 (2012) Dublin, Ireland, October 24 th, 2017 Page 7

8 Why Energy Crops? Higher specific gas yield than slurry Agricultural technology known and available from dairy farming Less dependency from the waste market Growing energy crops on set-aside land did not seem to interfere with normal crop farming at the beginning of the 2000s plus Energy crop farming and biogas production provided an additional source of income for farms leading to reduced dependency from agricultural price cycles At first no discussion of food versus fuel Dublin, Ireland, October 24 th, 2017 Page 8

9 Primary energy production of biogas in the EU (ktoe) Source: Eurobserver 2012 Dublin, Ireland, October 24 th, 2017 Page 9

10 2. Feasible Digester Technology Options for Grass/Manure Biogas Production Dublin, Ireland, October 24 th, 2017 Page 10

11 Batch dry fermentation for manure and grass Garage type digesters Inoculation of substrates and percolation with process water Additional aerobic pretreatment Solid mater immersion process with flexible cover (agriculture) Erep, CH. Aria-Biogas, FR. Wolferstetter, DE Simultaneous wet-dry digestion (agricultural substrates and biowaste) Agrargeräte Langenau, DE. Renergon, CH Dublin, Ireland, October 24 th, 2017 Page 11

12 CSTR System Steel Tank with Hydrolysis Dublin, Ireland, October 24 th, 2017 Page 12

13 CSTR Control system with Hydrolysis Dublin, Ireland, October 24 th, 2017 Page 13

14 Sauter Irrigation System for Solids Fermentation Dublin, Ireland, October 24 th, 2017 Page 14

15 Sauter Irrigation System for Solids Fermentation Dublin, Ireland, October 24 th, 2017 Page 15

16 D&K DIY System for building owner construction Dublin, Ireland, October 24 th, 2017 Page 16

17 D&K DIY System for building owner construction Dublin, Ireland, October 24 th, 2017 Page 17

18 3. Economic success factors for Grass/Manure Biogas Projects Dublin, Ireland, October 24 th, 2017 Page 18

19 Investment costs for Biogas Plants 2014: for 75 kw more than 10,000 /kw Dublin, Ireland, October 24 th, 2017 Page 19

20 Investment costs for Biogas Plants Investkosten Invest. costs spez. Specific Kosten costs kw GM 500 kw GM PF 500 kw GM 2F 500 kw GM 1F 370 kw GM PF 370 kw GM 250 kw ZS PF 250 kw ZS 190 kw GM 180 kw ZS 110 kw ZS 100 kw GM 60 kw GM 40 kw ZS 740 kw GM PF Dublin, Ireland, October 24 th, 2017 Page 20

21 rel. investment fraction Investment costs for Biogas Plants 120% 100% 80% 60% 40% 20% Others Excavation work Clamp silo Building Grid connection Construction Analytics Gas utilisation Gas technology Manure technology Control systems Feed-in system Storage tank Secondary digester Digester Mixing pit Planning & Design 0% 30 kw 65 kw 100 kw 180 kw 250 kw 500 kw Dublin, Ireland, October 24 th, 2017 Page 21

22 Operating Costs Depreciation costs Interest charge (related to 1/2 of investment costs) Maintenance & repair of biogas plant Maintenance CHP Insurance Labour costs Costs for input substrates Costs for land spreading digestate Dublin, Ireland, October 24 th, 2017 Page 22

23 4. Feedstock in Grass/Manure Biogas Plants Dublin, Ireland, October 24 th, 2017 Page 23

24 Use of Grass and Grass residues as Energy Crops massebezogen energiebezogen 7% 12% 2% 2%1% 2% 1% 7% 7% 2% 0% 1% 0% Maissilage Grassilage Getreide-GPS Getreide (Getreidekorn) 11% Zwischenfrüchte Landschaftspflegematerial Zuckerrübe 73% According to mass 12% and 1% of grass was used in 2014 in the mix. According to energy 11 % and 0, % came from energy grass and landscape grass respectively 72% sonstige NawaRo n = 651 Source: DBFZ, 2015 Dublin, Ireland, October 24 th, 2017 Page 24

25 Gas yields from different substrates Cow manure, liquid (9% DM) Pig manure, liquid (7% DM) Chicken manure (15%DM) Turkey manure (20% DM) Vegetable residues (10% DM) spec. gas yield m³ / t substrate Grass silage (25% DM) Corn silage (30% DM) Left over food (20% DM) Cereal straw (85 % DM) Grease separator (5 / 50 % DM) Colza cake (15% fat) Left over bread (90 % DM) Wheat whole grain (85% DM) Dublin, Ireland, October 24 th, 2017 Page 25

26 Typical grass/manure substrate mix daily feed-ration 6000 kg/day FM kg/day ots kg/day liquid-manure grain manure Clover/grass Dublin, Ireland, October 24 th, 2017 Page 26

27 Biomass supply, Trade agreements, Prices for Grass Substrates High commodity and transport prices on the conventional market (Maize, Grain) Market for grass substrates takes place locally with grass residues and sub products Prefer own cheap and available substrates Restrictions to origin of substrates Use of substrates within the farms own nutrient cycle Dublin, Ireland, October 24 th, 2017 Page 27

28 Grass/Manure Cheap substrates, but difficult to digest Low energy in the feed mix High ammonia levels in the digester Problems with earth in the substrate High in structure and tendency to form swimming crusts Source: Dublin, Ireland, October 24 th, 2017 Page 28

29 Operation, Maintenance and Repair Solid feed in systems have a high wear and tear Pumps and stirrers come second place Digester has to be opened and cleaned more Machinery and personal costs are higher Source: Dublin, Ireland, October 24 th, 2017 Page 29

30 5. Feeding Technology in Grass/Manure Biogas Plants Dublin, Ireland, October 24 th, 2017 Page 30

31 Reception pit for liquids Typically applied at waste and slurry digestion plants Sometimes for maceration and mixing prior to pre-storage tank Sometimes as bunker prior to contaminants removal Dublin, Ireland, October 24 th, 2017 Page 31

32 Solid feeding systems Developed to feed solid material directly into the digester Always a combination of buffer volume with removal system and conveyor system for the solids Rather used in agricultural AD plants Typical feedstock: dung, energy crops, vegetables Dublin, Ireland, October 24 th, 2017 Page 32

33 Dublin, Ireland, October 24 th, 2017 Page 33

34 Feeding systems Conveyors Most often screws are used Sometimes conveyor belts in combination with screws Extremely high wear and tear If pistons or press screws are used feedstock will be highly compressed danger of sedimentation Material selection is crucial with energy crops and organic waste stainless steel (AISI 316) Limited to 12 m length / height Dublin, Ireland, October 24 th, 2017 Page 34

35 Feeding systems Hopper feed pumps Used for mixing solids with liquid alternative to traditional mixing pit Suitable for any type of wet digester Solids are not compressed fine dosing & quick degradation Sensitive towards stones and contaminants Requires buffer for solids Challenge is the level control of solids Dublin, Ireland, October 24 th, 2017 Page 35

36 Feeding systems Chute Rather simple feeding system used in combination with lagoon digesters Very simple system No moving parts, little wear and tear compared with other systems Must reach under liquid level CH4 emissions Dublin, Ireland, October 24 th, 2017 Page 36

37 6. Conclusions Dublin, Ireland, October 24 th, 2017 Page 37

38 What are the bottlenecks for biogas from grass residues? Suitable technology is not available or too expensive Difficult logistics for small amounts of grass residues Problems with the waste and compensation laws Low energy, high nitrogen and high structure content High energy substrates are used for animal feeding Higher investment and operation costs Dublin, Ireland, October 24 th, 2017 Page 38

39 What can politics do for Biogas production from grass residues? Recognition of triple emission reduction effect Special compensation for Biogas from grass residues Active awareness campaigns for Biogas from grass residues Research in non food crops for soil improvement Every left over grassland is a potential biogas producer Promotion of nutrient recycling and resource saving Dublin, Ireland, October 24 th, 2017 Page 39

40 Thank you for your attention! Michael Köttner International Biogas and Bioenergy Centre of competence, IBBK