Experiences with a Farmstead Biogas Plant

Transcription

1 : Experiences with a Farmstead Biogas Plant Wiard Smidt Bohnenburg, Germany Local subsidies / RDA Zlatibor / Center for Development Leskovac Seite 1

2 Content: 1. Farm profile 2. Requirements to operate a biogas plant 3. Selection and construction of a biogas plant 4. Operation and malfunctions of the biogas plant Seite 2

3 Farm location The Farm is located in the Northwest of Germany Source: Google Maps 2015 Seite 3

4 East Frisia Coastal region: arable farms, tourism In the middle: intensive dairy farming Emden: Volkswagen factory (VW-Passat) Seite 4

5 Farm data: 250 ha agricultural land: 110 ha intensive grassland 30 ha corn 30 ha cereals 80 ha extensive grassland 230 dairy cows, 10,500 kg yield 200 female offspring 15 bulls for breeding 75 kw biogas plant 4 AK: plant manager, 2 employees, 1 trainee Seite 5

6 Seite 6

7 2. Why we built a farmstead biogas plant: 2012: Extension of the cowshed of 140 places to 260 places was planned, i.e. approved. Additional shed in which 120 cows can lay Silage plates Newly built manure tank 1500 m³ Manure biogas plants receive special funding. Big corn biogas plans are politically no longer supported. High compensation rates for electricity (25 Cent/ kw) => Thus, the new construction of the manure tank was waived (75,000 ), manure comes into the final storage of biogas plant Seite 7

8 And. : Many preconditions existed for an economic operation of a biogas plant. However, be careful: High building costs A lot of technology required => for a small amount of gas (i.e. electricity) Seite 8

9 Operational / structural conditions Sufficient animals, i.e. substrate is available 250 cows: ca m³ manure 120 cattle: ca m³ manure 700 t dung 200 t feed remains All cowsheds are fixed according to plan, there is no slatted floor All animals are lying on straw (ca. 80 ha straw p.a.) High milk yield => fresh, good substrate Power supply 20 kv is existing from the wind turbine. Foundations of the biogas plant are relatively unproblematic. (No ramming) Seite 9

10 Social environment: Dairy cattle production is under control to some extent Happy cows (good yield, low losses) Work effective cowsheds Father and wife can take over herd management for a certain period of time. Reliable and conscientious staff available. => It makes no sence to operate a biogas plant if the milk production is not running! Seite 10

11 Personal attitude: I am no technology freak Additional income without claiming the factor soil However, high capital commitment Substrate is available free of cost, no inflation 20 years guaranteed remuneration Digestion residue: Slightly higher fertilizer value Less fodder contamination, without straw residues No problems with spreading techniques, such as drag shoes, etc. Significantly reduced odour emission Heat for the house available free of charge Interesting workplace Seite 11

12 3. Selection of plant type:??? Seite 12

13 Most importantly: please, choose a simple technology! What can go wrong, will go wrong. Yes No Seite 13

14 Our plant: Implemented by Standard plant: 1100 m³ Fermenter (insulated, 2 lobed mixers) 2200 m³ final storage (roofed, 1 lobed mixer) Solids dispenser BHKW: gas engine Ca cheeper than high-tech Select large gas storage space: buffer at fodder fluctuations Select robust engine Seite 14

15 Plant construction :.from above Required pipelines: Biogas plant wing Red: manure pipeline Yellow 2: electricity (3x) Yellow 1: electricity, manure pump Blue: water Orange: heat pipeline Purple: Internet/telephone Seite 15

16 and from below do not build in the winter Seite 16

17 Approaching the cowshed Seite 17

18 4. Biogas Plant Operation Seite 18

19 All beginnings are difficult: Neu operation branch with new demands on the know-how Requires attention 24/7, same as with the cows However: if one 200 cows gets sick, you still have 199 healthy ones If one component of the biogas plant is defect, the whole plant stands still Communicate with plant manufacturer, with CHP manufacturer, with colleagues Seite 19

20 Feeding: Currently: ca. 15m³- 20m³ cattle manure, 2,4 t cattle dung Quantity and type are very different and difficult to quantify: Manure: absolute correlation with milk yield. If, for example, lower quality silage is fed, the gas is sinking faster than the milk yield. Manure: if manure is stored for more than 2 months, it has only 66 % of the gas yield, after 4 months only 50 %. Summer gap: cattle on pasture, cows are out grazing Gras silage: highly problematic: costs, mixer operation times, floating layers High level of chloride (cattle salt) damages the components Feeding of iron hydroxide (no iron chloride) in order to reduce sulphur content Seite 20

21 Fermenter biology: Indestructible: Like a Mercedes W d Always constant, huge buffer However: Better do not let in milking stand cleaning water No footbaths!!! Seite 21

22 Problems: The plant is running in the background Daily ca. 20 minutes for feeding and control When problems arise, they immediately become the center of everyones attention and takes up time of everyone at work Regard the biogas plant as a machine and not as a building Defects are very expensive: travel costs, skilled workers, spare parts, auto crane. Seite 22

23 Problems: Manure pump: Foreign bodies: stones, forks, claw logs destroy the wings => porched cutter => consciencious employees Solids dispenser: Solids block the auger: you will find everything again => consciencious employees Seite 23

24 CHP: Agitators: Defect spark plugs, defect relays, etc. Control and monitoring by best employee (boss?) => good customer service by CHP manufacturer Damages caused by foreign bodies (straw band) Or.. Seite 24

25 Problems caused by to strong storm The roof of the final storage after a severe storm. => Do not forget a good insurance Seite 25

26 Thank you for your attention! Seite 26