Farm-based Biogas Technology and Automation

Transcription

1 Leibniz-Institute for Agriculturale Engineering Potsdam-Bornim e.v. Renewable Energy Asia 2009 German Day - May 21 Farm-based Biogas Technology and Automation Jörn Budde M. Heiermann, M. Plöchl Leibniz-Institute for Agricultural Engineering Department of Technology Assessment

2 Leibniz-Institute for Agriculturale Engineering Potsdam-Bornim e.v. Outline Biogas basics National framework Feedstock for biogas production Feeding technology Digesting technology Gas technology / processing / utilisation Measuring devices Control / Automation

3 biogas basics Biogas derived from anaerobic digestion of organic material composed of methane (50 to 70 %) carbon dioxide (30 to 50 %) sulfur hydrogen (20 to 2000 ppmv) ammonia, hydrogen, nitrogen (traces) universal renewable energy source electricity heat car fuel

4 biogas basics Anaerobic digestion 1. step 2. step 3. step 4. step Decomposition fermentation formation of formation of of macro molecules of decomposites methanogens biogas Carbon hydrate Lipids Proteins Sugars Fatty acids Amino acids Bases Carbonic acids Gases Alcohols Acetic acid or Hydrogen + Carbon dioxide Methane Carbon dioxide hydrolitic fermentative acetogenic methanogenic bacteria archea bacteria (acetotrophic or hydrogenotrophic)

5 biogas basics plant-site schematics

6 national framework Priority to the generation of electric energy from renewable energies and to purchase and transmission of this energy Secure fee for this energy sold paid by grid operators 20-year period, commissioned installations Nationwide consistent fee paid

7 national framework number of biogas-plants in Germany Quelle: Fachverband Biogas e.v. August 2008

8 feedstock for biogas production liquid manure, animal excrements organic residues of plant production animal feed organic wastes organic wastes from municipal collection kitchen waste waste from food industry energy crops cereals (grains and whole plant silages) maize (whole plant silage) sugar beet alfalfa (forage plant) grass (silage)

9 feeding technology Solid feedstock: by wheel loader delivered to an intermediate storage (e.g. a container) that is combined with a dosing feeder from there it is conveyd to digester by belt conveyor chain conveyor screw conveyor drag chain coneyor delivery piston or directly delivered to a mixing pit or the combination of both

10 feeding technology solid feedstock wheel loader and dosing feeder

11 feeding technology solid feedstock belt conveyor Quelle:

12 feeding technology solid feedstock screw conveyor

13 feeding technology solid feedstock delivery piston

14 feeding technology Liquid feedstock recirculate or slurry from stable (over an intermediate reservoir) by gravity (if arrangement/topography allows it) excentric screw-pump rotating piston-pump

15 feeding technology liquid feedstock excentric screw pump Quelle:

16 feeding technology liquid feedstock rotary piston pump Quelle: Vogelsang GmbH

17 feeding technology combination of mixing pit and pump Quelle: Vogelsang GmbH

18 digesting technology digesters possible is any gas-tight container: on surface (partially) subsurface usual in Germany are cylindrical steel tanks (horizontal or vertical) cylindrical concrete-steel tanks (normally vertical) rectangular concrete-steel basins hard-covered or membrane (foil) covered

19 digesting technology digester (schematic) Quelle:

20 digesting technology concrete-steel tank with insulation and steelhousing

21 digesting technology digesters also possible but not usual in Germany: fixed dome (Chinese type) floating cover (Indian type) tube digester

22 digesting technology digester: fixed dome (Chinese type) Quelle: adopted from Gunnerson and Stuckey, 1986

23 digesting technology digester: fixed dome (Chinese type)

24 digesting technology digester: floating cover (Indian type) Quelle: adopted from Gunnerson and Stuckey, 1986

25 digesting technology digester: tube digester

26 digesting technology digester: tube digester

27 digesting technology Mixing There are different types of mixers: propeller mixer paddle mixer ancre mixer gas pressure mixing

28 digesting technology mixer: propeller mixer Quelle:

29 digesting technology mixer: propeller mixer Quelle:

30 digesting technology mixer: paddle mixer

31 digesting technology mixer: paddle mixer Quelle:

32 digesting technology mixer: paddle mixer Quelle:

33 digesting technology mixer: gas pressure mixing Quelle: Biogas Praxis, Schulz, 1996

34 digesting technology heating internal heat exchanger wall or floor heater external heat exchanger e.g. pipe in pipe level control

35 gas technology gas transport gas measuring (quality/quantity) gas storage (integrated/external) integrated (membrane) gasholder telescoping gasholder dry-seal gasholder membrane gasholder safety installations safety valve emergency flare deflagration arrester

36 gas technology gas storage: integrated (membrane) gasholder

37 gas technology gas storage: telescoping gasholder Quelle: GNU-license

38 gas technology gas storage: dry-seal gasholder (piston) Quelle: GNU-license

39 gas technology gas storage: membrane gasholder Quelle: GNU-license

40 gas technology safety installations: safety valve

41 gas technology safety installations: deflagration arrester

42 gas technology safety installations: emergency flare

43 gas processing dehumidification condenser adsorption desulfurisation integrated (biological/chemical) external (biological/chemical) methane enrichment trace gas separation filtering

44 gas processing integrated desulfurisation

45 gas utilisation CHP Heat Fuel (automotive) Fuel (grid) Not state of the art yet, but promising future topics: Hybrid power plant BgtL (Biogas to Liquid) Biorefinery

46 gas processing Hybrid power plant (schematic)

47 measuring devices weight / estimated amount: solid feedstock volume/mass flow liquid feedstock biogas charging level solid feedstock (container / mixing pit) liquid feedstock (intermediate reservoir / mixing pit) slurry (digesters) gas holder (membrane)

48 measuring devices rotation speed mixer pumps temperature digesters heat exchangers (water / slurry) biogas (CHP) pressure gas pressure in digesters gas holder

49 control / automation handles the measured values due to the demanded conditions: temperature digester temperature: a heating device (heat exchanger and a water or slurry pump) is controled automatically due to demanded conditions (mesophilic/thermophilic) in digesters gas temperature: a gas cooler is controled by gas temperature to ensure condensing the vapor (dehumidification)

50 control / automation charging level membrane gas holder: controls the emergency flare mixing pit: controls the rotation speed (frequency) of the liquid feedstock pump and the frequency of the dosing feeder rotation speed mixers: controled by plant operator, so that the digester content is fully stirred pumps: owing to demanded volume/mass flow

51 control / automation rotation speed dosing feeder: owing to demanded feedstock/biogas per time volume/mass flow of liquid feedstock is controled by plant operator due to demanded feedstock/biogas per time pressure of integrated gas holder (membrane) controls the safety valve and the emergency flare

52 Leibniz-Institute for Agriculturale Engineering Potsdam-Bornim e.v. Thank you for your attention