Rakičan, 2007 BIOGAS FOR FARMING, ENERGY CONVERSION AND ENVIRONMENT PROTECTION Kestutis NAVICKAS Department of Agroenergetics Lithuanian University of Agriculture 29 Novembra 2007, Rakičan
Rakičan, 2007
BIOGAS FOR FARMING, ENERGY CONVERSION AND ENVIRONMENT PROTECTION
Kestutis NAVICKAS
Department of AgroenergeticsLithuanian University of Agriculture
29 Novembra 2007, Rakičan
Rakičan, 2007
INSPIRATIONS FOR BIOGAS
Political - Kyoto protocol, EU and national legislations
Environmental – reduction of organic and biological
pollution
Veterinary – treatment of animal by-products not
intended for human consumption
Energy – replacement of fossils to local resources
Recovery – production of new products from wastes
Agricultural – waste treatment, fertilizers
Social – labor market and regional development
Rakičan, 2007
100 120 139 159 186274
370450
617
8501050
1600
1800
2000
2400
2800
3500
0
500
1000
1500
2000
2500
3000
3500
Nu
mb
er
of
pla
nts
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
P. Weiland, 2007
Development of biogas industry in Germany
Rakičan, 2007
Process design
Technology flows and elements
Substrate
collection and holding
pretreatment - separation, cutting, mixing, sanitation
loading and removal
digestate storage and utilization
Process
mixing
heating
Biogas
collection and holding
conversion
Rakičan, 2007
Process parameters
Temperature
Psychrophilic (10oC - 25oC)
Mesophilic (25oC - 45oC)
Thermophilic (55oC - 60oC)
Hydraulic retention time HRT
(the average time the substrate remain in a digester)
HRT = Vl / Sd (Vl – liquid volume, Sd – daily flow)
Cattle manure - 12 – 18 days
Pig manure - 10 – 15 days
Organic loading rate OLR
(organic material fed daily per m3 of digester volume)
Cattle manure - 2.5 –3.5 kg VS/ m3 day
Pig manure - 3.0 –3.5 kg VS/ m3 day
Rakičan, 2007
Process indicators
SUBSTRATE
• Composition (TS, VS, Proteins, Fats and Carbohydrates)
• pH level (about 7.0)
• Rate of C:N
• Biogas yield potential (m3/kg substrate or m3/kg TS)
BIOGAS
• Biogas rate (m3/m3 of digester volume per day)
• Biogas composition and energy potential
OTHER
• Energy efficiency or biogas utilization factors
• BOD and COD in feed and removal or VS in feed and removal
• Pay back
Rakičan, 2007
Biogas yields from different biomass
25
30
35
35
55
80
80
350
400 800
75
110
200
0 100 200 300 400 500 600 700 800
Biogas yield, m3/t
Pig manure
Cattle manure
Poultry manure
Fruit and vegetables
Dairy waste
Distilary waste
Sewage waste
Vegetable oil
Fatty wastes
Used fats
Mangel
Grasses
Maize
Rakičan, 2007
0
50
100
150
200
250
300
350
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
Weeks
Su
bst
rate
, t
0
2
4
6
8
10
12
Bio
gas,
103
. m
3
manure industrial waste biogas per week
Influence on biogas production of the industrial substrate
Rakičan, 2007
Composition of Biogas
Component Dimension Content
CH4 % 55 - 80
CO2 % 15 - 45
H2S mg/m3 0 - 5000
NH3 mg/m3 0 - 450
Humidity - Saturated
Caloric value MJ/m3 20 - 25
Caloric value kWh/m3 5,5 – 8,0
Rakičan, 2007
Biogas useBIOGAS
Boiler Cogenerator Fuel cell Storage
Conversion Compression
Electricity Heat Electricity Heat Liquid fuelHeat
Separation of sulphur, dust and moisture
Upgrading
Rakičan, 2007
Cogeneration
Bio
mass
en
ergy p
ote
nti
al
100%
Gas
engine
Mechanical energy 35,4
%
Th
erm
al
en
ergy 6
1.7
Effluent gas
36,1%
Liquid
cooler
26,6 %
Effluen
t gas c
ooler
Effluent gas
25.8%
Losses of heat transmission
2,9%
Heat exchanger
of liquid cooler
Heat
exchanger
of effluent
gas
Power
generator
35,4%
Heat energy
57.3 %
Electrical energy
33,9 %
21.9% Losses
8.8%
0.3%3.5%
0.6%
2.9%
1.5%
10,3%
Rakičan, 2007
Pig Farm Biogas Plant, Lithuania
60 m3 pig manure / day + Industrial wastes: ~ 3 t / day
Digester: 3 x 300 m3 horizontal steel digesters
Biogas production: 1200 - 2500 m3/d
Co-generation: 1 x 75 kW and 1 x 110 kW
2 x 300 kW gas burners
Rakičan, 2007
Pig Farm Biogas Plant, Lithuania 2
90 m3 pig manure / day + Industrial wastes: ~ 10 t / day
1 x 2000 m3 vertical steel digester
Biogas production: 3000 - 3500 m3/d
Co-generation: 4 x 150 kWel
Rakičan, 2007
Potential problems of anaerobic digestion
Waste management create traffic movements for wastecollecting and digestate transporting to the land. Accidentsof waste transporters can cause pollution of environment.The potential noise can be given from deliveries, pumps,compressors, mixers etc.There may also be some risk of fire and explosion, althoughno greater than with systems using natural gasEmployers of people working in biogas plants must assessthe risk from exposure of the gases, pathogens in thefeedstocks and to control that riskTransportation of animal by-products creates some risksfor health and risk of animal disease transmission betweenfarms.
Rakičan, 2007
Benefits for environment
Mitigation atmospheric methane concentrationsreduces impacts on global climate change
Treatment of wastes reduces water, airpollution, odors and destroys pathogens
Application of digestate fulfils the phosphorusrequirements of the crops and completes thenitrogen requirements from mineral fertiliser.
Displacement of fossil fuels reduces CO2
emissions
Rakičan, 2007
Farming benefits
Diversification of farming activities;
Reliable energy production and utilisation;
Additional earnings from waste treatment, production of energy and fertilisers, selling of green certificates;
Improvement of the mechanical and nutrition properties of manure;
Rakičan, 2007
Thank you for attention!Kestutis NAVICKASDepartment of Agroenergetics
Lithuanian University of AgricultureStudentu 11, LT-53361,Akademija, Kaunas distr.LITHUANIA
E-mail [email protected]. + 370 68 78 68 26Fax. + 370 37 75 22 71