„batch process“?
TRANSCRIPT
Dipl. Agrar-Biologe Michael Köttner
Internationales Biogas und Bioenergie Kompetenzzentrum IBBK
BIOGAS
Plant Oil
Wood Gas
Liquid & Solid Manure and Digestate treatment
Decentralized Wastewater Management
... German Association, created in 2001
... promotes the sustainable generation and use of energy made out of biomass.
... Fields of Work
GERBIO ...
Activities of GERBIO related to Biogas technology
Know-How transfer (international workshops, study tours, training)
Support of small scale installations
Contacts to experts in planning, design and construction
Contacts to specialized companies
Networking with members in different regions nationally and internationally
Biogas Production in Europe
Landfill
Klärschlamm
ktoe
Quelle: EurObserv'ER, May 2007
Success of Biogas Technology in Germany
139 159 186 274 370 450617
8501.050
1.3001.600
1.7502.050
2.680
3.5003.711
3.891
4.984
5065
182256
333390
650
1.100
1.271
1.377
1.893
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0
1.000
2.000
3.000
4.000
5.000
6.000
Anzahl Biogasanlagen
installierte elektrische Leistung [MW]
Agricultural Subproducts15,4%
Animal waste
23,9%
Organic industrial waste-
1,7%
Sewage sludge
3,8%
Landfills
5,1%Organic household
waste
2,3%Energy crops
46,2%
landscaping
1,6%
In total: 24 Bln m³ Biogas: 50 Mio. MWh electricity and 72 Mio. MWh heat
Quelle: P. Weiland FAL BS
Feedstock for Biogas Production in Germany
utilisation of
biogenous
material
material material /
energeticenergetic
80-90 % 10-15 % ???
composting
/direct utilisationdigestion incineration
ca.1.000 composting plants
11.2 Mio. capacity / a
ca. 85 anaerobic digestion plants
1.7 Mio. capacity / *a?
*= incl. CO digestion
Utilisation of Biowaste
Energy maize – bio-waste
Gas yield: 1 ha energy maize
(45 t FM) = ca. 70 t bio-waste
Collected Bio-waste quantity in Germany:
ca. 4 Mio. t bio-waste
Corresponding gas yield of:
= ca. 2,6 Mio. t energy maize
= ca. 55.000 ha energy maize
Biowaste versus Energy Crops
Components of a biogas plant with CHP unit
Feststoffeintrag
Kondensat-abscheider
Rührkessel-reaktor Endlager
Vorgrube
Heizöltanks
N a h - (Fe rn -) W ä rm e n e tz
Pufferspeicher
Spitzenlast-Kessel
Heat buffer storage
Peak heat supply
District heating
Mixing pit
Solid feeder
End storageMixed
reactor
Reception of biowastes=> closed chamber with
odour treatment
Preparation=>Chopping and
sorting of disturbing materials
Fermentationwith post treatment
Biogas
liquid fertilizercompost
(post composting)
hygienising, separation
Example Process chain for the digestion of biowaste
Pulper
Biogas from Food Waste and Agricultural Slurry
Comparison: Wet vs. Dry Fermentation
More problematicNot problematic (batch process)Hygienic aspects
Liquid substrateSolid substrate/ compostingRequ. technology
Depending on managementDepending on managementEmissions
LowerHigherEnergy density
higher (effort for homogenisation)lower (percolate pump)Process energy
Affects complete digesterAffects only batch (1 module)Disturbances
complex, multi-stage continuous
operation
Modular, batch operationPlant
Foaming, sinking layer, swimming
layer
Percolate distribution system
(sieves, sprinkler heads)
Disturbances
HomogenisationPercolate circulation technology,
flooding, pre-mixing
Technology
pumpable (max. 13 % TS)digestable (max 50 % TS)Substrate
Wet fermentation (Continuous)Dry fermentation (Batch)Criteria
Biowaste Treatment Technologies
1. Continuous processes
1.1 Digestion Channel (test plant, conceptuous stage)
Wire mesh box system (Thailand, GTZ), Swimming crust percolation (ATZ-
EVUS)
1.2 DRANCO-process (Belgium)
Vertical cylinder, thorough crushing of organic wastes, mixing with already
digested matter, vertical passage from top to bottom through cylinder
1.3 Kompogas process (Switzernland)
Horizontal digester, requires thorough crushing of organic wastes, max 25% DM
Biowaste fermentation – process overview
Biowaste Treatment Technologies
1. Continuous processes
1.4 ATF – process (pilot plant University of Applied Science Hamburg)
Vertical cylinder, requires thorough crushing and mixing, percolation of process
water, substrate removal with push floor, 20 – 45% DM, Substrate: organic
household waste
1.5 Anacom-process (test plant: Tänikon, Switzerland)
Vertical cylinder, single-stage process, feeding via „Maulwurfsystem“,
Substratee: solid manure, grass silage, percolation of process water
Biowaste fermentation – process overview
Biowaste Treatment Technologies
1. Discontinuous processes (new developments, trials)
2.1 Garage type digester
Mixing of substrates and percolation of process water (Biocell,
Schiedermeyer, Bekon, do-it-yourself)
2.2 Simultanous wet-dry digestion
(Loock, Germany)
2.3 Solid matter immersion process
(Switzerland, France)
2.4 Plastic tube reactor
Pilot plants (Budissa AG, Triesdorf – both Germany)
Biowaste fermentation – process overview
Biowaste Treatment Technologies
1. Discontinuous processes (new developments, trials)
2.5 „3A“-process
(Prof. Steffens, Germany)
2.6 Proprietary development with flexible membrane cover
2.7 Digestion of percolation liquid
(Denmark, UK)
Biowaste fermentation – process overview
Biowaste Treatment Technologies
What‘sa„batchprocess“?
Advantage of batch processes:
no pre-mixing of solid with liquid matter, no stirring,
no pumping
processing of substrates with high DM-contents
Compared to:
„semi-continuous“operation(wetdigestion)
= continuous feeding and removal of small
quantities of substrate
during digestion substrate is neither added nor
removed from the digester
Batch Biowaste Digestion
Gas tight, hydraulically operated gates
Gates open upwards
inflatable ring seal
between concrete and
gate
(BEKON, 2002)
Batch Biowaste Digestion
Modular constructed digesters
BAL Biogas-Anlagenbau Langenau GmbH dry fermentation plant
Batch Biowaste Digestion
Sophisticated safety concepts required
Avoiding of explosive methane-air-mix (ex-proof
design and operation)
Gas/ air evacuation during removal and filling
photoelectric barrier, visual control
Flare
Computer-controlled operation
percolation circuit
heating system
measurement of gas quality
CHP unit
Batch Biowaste Digestion
(Linke, 2000)
Gas production rate of the dry fermentation of biowaste mixed
with 50% digestate (innoculum) at 35 °C
Batch Biowaste Digestion
Success factors for biowaste dry digestion systems
Substrates need to be suitable for dry digestion (stackable)
Thorough pre-mixing of input substrates is essential
Active bacteria have to be transported to the fresh substrate (in contrast to
wet digestion where fesh biomass is transported to active bacteria)
Digestion process has to support the development of appropriate bacteria
Applied technology has to suit local conditions
Plant size has to be designed according to available amounts of input
substrates
Modular design concept allows future enlargement of biogas plant
Batch Biowaste Digestion
Elimination of pathogens in batch biowaste digestion
(Ten Brummeler, 2000)
Pathogen/ bacteria Property Inocculate( cfu / g )
In substrate after 21 d
(cfu days /g)
Reduction in %
Enterobacteriaceae human and animal
pathogenic bacteria
(fecal contamination)
1.6 X 107
1.2 X 103
>99.99
Salmonella typhimurium 1.4 X 107
<3 >99.99
Pseudomonas solanacearum
Plant pathogenic
bacteria
(affects potatoes)
Infected potatoes
tissue
(+/- 50 units total )
<1 >99.99
Fusarium oxysporum 8.4 X 104biowaste <1 >99.99
human and animal
pathogenic bacteria
(intestinal infection)
Plant pathogenic
fungi
(affects roots)
Dry digestion with percolation
(BEKON, 2002)
flare
percolate tank
biogas
Cogeneration unit
heating Stacked biomass
Gas tight
gate
Spray nozzles for percolation liquid
Drainage for
percolate
Concrete digester with wall & floor heating
Batch Biowaste Digestion
Bekon Energy Technologies GmbH & Co.KG
• 15 plants with Bekon System in operation in Germany, Switzerland
and Italy
• The standard module has 4 digesters
• The fermentation process: 21 day
Batch Biowaste Digestion
BIOFerm GmbH
• 30 biogas plants in Germany
• Biggest plant: 8 digesters and a capacity of 750kWe
• Substrate is fermented during four weeks
Batch Biowaste Digestion
Eggersmann Anlagenbau GmbH & Co.KG
• 5 plants in Germany, all running on organic municipal waste
• The standard module has 8 digesters
• 21 day for fermentation process
Batch Biowaste Digestion
Strabag Umweltanlagen GmbH (formerly Linde-
KCA Umweltanlagen GmbH)
• About 20 dry fermentation plants in operation
• The dry digester built as a horizontally arranged, special-concrete, very
sturdy compartment.
Continuous Biowaste Digestion
Axpo Kompogas AG
• The volume of each digester is 1300m³
• Retention time in the fermenter is about 14 to 20 days
Continuous Biowaste Digestion
Organic Waste Systems (DRANCO)
MIXER
PUMP
WASTE < 40 mm
STEAMRESIDUE
TO POST-TREATMENT
BIOGASBIOGAS UTILIZATION
DRANCO
FERMENTER
• First plant built in1984; almost 20 full scale plants and 7
demonstration plants
• Vertical digestion, material drops vertically by gravitational force
Continuous Biowaste Digestion
Gesellschaft zur Verwertung organischer Abfälle (GvoA
mbh & Co.KG)
460 kWe, Input: 48.000 t/a
1-mechanical part of the MBT
2- digester and gas storage
3- loading point for separated
secondary fuel
4- rotting piles
5- Regenerative Thermal
Oxidizer (RTO)
Waste: up to 120.000 tons per year
Continuous Biowaste Digestion
Continuous Biowaste Digestion
Continuous Biowaste Digestion