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1 Biogas from waste Lennart Mårtensson PhD, Associate Professor Section for Aquatic Biology and Chemistry Presentation Kathmandu University 8 April 2010
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Biogas from wasteLennart Mårtensson
PhD, Associate ProfessorSection for Aquatic Biology and Chemistry
Presentation Kathmandu University 8 April 2010
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Kristianstad University College
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Where is Kristianstad?
Kristianstad is situated in the southern part of Sweden, Skåne.
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Kristianstad town
• Founded in 1614 by the Danish king Christian IV
• Became a part of the Swedish kingdom in 1658
• Kristianstad and its surroundings has 75 000
inhabitants with 28 000 in the town centre
• Shops, banks, services, a theatre, museums and
entertainment, all within easy walking distance
• Famous for “Absolut” Company
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Kristianstad University College
History of Campus
• Built in 1923 as an Infantry Regiment
• Rebuilt, reopened in 1995 as a modern University campus
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Today
• Around 9000 Students
• 2 Departments
•School of Health and Society
•School of Teacher Education
• Unit of professional development
• Science Park
• Student Union
• Administration
• Library, Gym, Media centre, Computer Halls, Restaurant, café
Kristianstad University
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Section for Aquatic Biology and Chemistry
Research about water related issues:Waterfowls, fate of pharmaceuticals, microbiology,sanitation, landfill leachate etc
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What is biogas
• Biogas is a methane rich flammable gas that results from the decomposition of organic waste material.
• Biogas Energy is the use of Biogas to produce heat or power
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WHERE DOES BIOGAS COME FROM?Vegetation - When vegetation
decomposes, it gives off methane gas
Farm and ranch animals -cattle, chickens, pigs produce manure.
When manure decomposes, it also gives off methane gas
Sewage – The treatment of human waste in anaerobic digesters produces methane
Landfills -Garbage produces methane as it decomposes
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VEGETATION - WETLANDS AND PONDSCaused by rotting vegetationEscaping methane rich gas goes into he atmosphere.More hazardous than CO2 as a greenhouse gasCan Ignite spontaneouslyOne common occurrence is swampgas
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CONVERSION OF ORGANIC WASTE INTO BIOGASUncontrolled anaerobic digestion• Wetlands and Ponds• Landfills
Controlled anaerobic digestion• Sewage Treatment Plants• Cattle Manure Digesters
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Microbiological growth
From -5 till 80˚CLimitations depends of how the
microorganism handles cold or heatClassification depends on temperature
Organisms can be• Psycrophiles (<20˚C)• Mesophiles (10 - 40˚C)• Termophiles (>45˚C)• Superthermophiles (>80˚C)
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Decomposition of organics
Polymeric substrateProteins Carbohydrates Lipids
Polymeric substrateProteins Carbohydrates Lipids
NH4+NH4
+
Amino acidsSugar
Amino acidsSugar
Organic acidsAlcohols
Organic acidsAlcohols
Hydrogen gasCarbon dioxideHydrogen gas
Carbon dioxideAcetic acidAcetic acid
Methane gasMethane gas
HydrolyseHydrolyse
Acid productionAcid production
Acetic acid prodAcetic acid prod
Methane prodMethane prod
Fermentingbacteria
Fermentingbacteria
Acetogenicbacteria
Acetogenicbacteria
Metanogenicbacteria
Metanogenicbacteria
Fermentingbacteria
Fermentingbacteria
Fatty acidsFatty acids
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Properties of Methane
• Molecular Formula: CH4
• Heating value: 2350 Jg-1
• Solubility in water: 17 mg/L• Ratio of O2:CH4 req.
for combustion: 2
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Landfill Gas - generation phases
I II III IV V
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40
60
80
100
Cellulose
Methane
CO2
Volatile fatty acids
N2
O2
H2
N2
vol-%
O2
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Gas Composition - Major Gases
• Methane (45 - 60 % by volume)• Carbon Dioxide (40 - 60 % by volume)• Nitrogen (2 - 5 % by volume)• Oxygen (0.1 - 1.0 % by volume)• Ammonia (0.1 - 1.0 % by volume)• Hydrogen (0 - 0.2% by volume)
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Significance of Landfill Gas
• Potential energy recovery of methane• Methane is a potent greenhouse gas• Explosive danger • Health hazards associated with trace
gases• Odor nuisance
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Gas Composition - Trace Gases (less than 0.6 % by volume)
• Odor causing compounds• Aromatic hydrocarbons• Chlorinated solvents• Aliphatic hydrocarbons• Alcohols• Polyaromatic hydrocarbons
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Green Community
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Material for digestion
• Agricultural related waste and crops– Manure– Rest products
• Waste– Waste from househoulds and restaurants– Park and garden waste– Sewage sludge– Organic industrial waste
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Organic waste, composition:
• Polysaccarides (cellulose, starch, hemicellulose)
• Lipids• Proteins• Lignin• Minerals mm (phosphorous, metalls)
Contaminants: heavy metals, pesticides, insecticids
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Decomposition of organics
Polymeric substrateProteins Carbohydrates Lipids
Polymeric substrateProteins Carbohydrates Lipids
NH4+NH4
+
Amino acidsSugar
Amino acidsSugar
Organic acidsAlcohols
Organic acidsAlcohols
Hydrogen gasCarbon dioxideHydrogen gas
Carbon dioxideAcetic acidAcetic acid
Methane gasMethane gas
HydrolyseHydrolyse
Acid productionAcid production
Acetic acid prodAcetic acid prod
Methane prodMethane prod
Fermentingbacteria
Fermentingbacteria
Acetogenicbacteria
Acetogenicbacteria
Metanogenicbacteria
Metanogenicbacteria
Fermentingbacteria
Fermentingbacteria
Fatty acidsFatty acids
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Biochemical Methane Potential
Sample Methane Yield, m3/kg VS
Mixed MSW 0.186 - 0.222
Mixed Yard Waste 0.143
Office Paper 0.369
Newsprint 0.084
Magazine 0.203
Food Board 0.343
Milk Carton 0.318
Wax Paper 0.341* From Owens, J.M. and D.P. Chynoweth
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Biogas in Kristianstad
Produced at three locations:• The landfill - (about 15 000 MWh) is used for
incineration in the district heating plant• The waste water treatment plant - used partly
for internal heating production (4 000 MWh) and partly 3 000 MWh) as vehicle fuel
• The biogas plant for waste- (ca 40 000 MWh) used for district heating (50 %) and as vehicle fuel (50%).
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Digestion
Biological degradation of organic material to biogas under anaerobic conditions
Biogas plant in Kristianstad primarily for waste from food industry co-digested with manure and houshold waste
Total of 72 000 tonnes/year of biological wasteOf these 5 000 tonnes organic household waste
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Factors affecting the digestion• Distribution of gases in liquid and gaseous
phases• Temperature• Distribution of gases in liquid and gaseous
phases• Water content• Carbon nitrogen ratio (Optimum C/N ratio 25-30)• pH and buffering system• Chemical substances (inhibitors)• The structure of the material
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Digestion system
Temperature• Mesophile digestion
Temperature; 30 -40˚C
optimum ca 35 - 37˚C• Termophil digestion
Temperature; 50 -60˚C
optimum ca 55˚C
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Biogasproduction depends of the composition
m3 gas/kg metan CO2
• Carbon hydrate 0.79 50% 50%• Fat 1.25 70% 30%• Protein 0.70 80% 20%
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Inhibitors-Compounds that negatively affects the biogas production• Ammonia• Sodium• Heavy metals• Fatty acids• Oil products• Sulphur coumpounds
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The Biogasconcept
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Benefits of centralised biogas production
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Biogas in Europe
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Gas Cleanup
• Particulate removal• Condensate removal• Trace compound removal• Upgrading to natural gas quality
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Gas Cleanup
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Upgrading plant in Kristianstad
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Electric Power GenerationAdvantages:
• Large market of stable, continuous demand• Easy access to wide energy distribution
network• Low pollutant emissions• Practical for a large range of landfill sizes• Wide variety of viable technologies
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Generator
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Biogas for vehicles
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Vehicular Fuel
Advantages:• Potential large market of stable,
continuous, long-term demand• Low pollutant emissions• Simplified modular processing system
design• Low area requirements• by-product CO2 has market value?
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Gas vehicles
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Bi-fuel system
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Vehicle fuels in EUTransport Growth
Passengers, Goods, GDP 1990-2002
100
105
110
115
120
125
130
135
1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002
1990
=100
Passengers (1) (pkm)
Goods (2) (tkm)
GDP (at constant 1995 prices)
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Vehicle fuels in EUGreen house effect and transports
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Vehicle fuels in EUEU - Bio fuel directives & Target 2020
Fuels for vehicles 202010 % naturalgas (25 mill. cars)
8 % biofuels5 % hydrogen
2 % biofuels 20055,75 % biofuels 2010
High security of energy supply
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Light duty vehicles Heavy duty vehicles
Short to middlelong term
CNG/BiogasEthanolFT-diesel (0-100 %)Low blending (< 10 % ethanol)Hybrides
CNG/BiogasFT-diesel (0-100 %)
Low blending(< 5 % FAME, fatty acid
methyl ester )Hybrides
Long term
2nd generationHydrogenSynth. Biomethane
2nd generationDMESynth. Biomethane
Vehicle fuels in EUVehicle fuels and strategies
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Why biogas?
Sustainable system for waste
treatment
One step towards hydrogen
technology
Less impact of the environment and the health
Domestic fuel High security of energy supply
No contribution to the green house effect
Wide range of biomass
feedstocks
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Biogas potential
Digestion technology•Biomass - waste, energy crops•Small to medium scale
Digestion technology•Biomass - waste, energy crops•Small to medium scale
Technology of today
Very big biomass potential from
Cities Agriculture Forests
Hydrogasification•Biomass from waste, wood•Large scale
Hydrogasification•Biomass from waste, wood•Large scale
Up coming technology
Hydrogasification•Biomass from waste, wood•Large scale
Hydrogasification•Biomass from waste, wood•Large scale
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Natural gas compared to Biogas
Very low impacts environment and health
Are used for industry, electricity/heat generation and for vehicles
Methane - fossil origin ne – renewable energy
Exist in every part of the wo duced all over the world
Metha
rld Is pro
Big biomass potential
re to oil CO2
Bigger reserves than oil
20-25 % less CO2 compa neutral
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Synergism biogas - natural gas
-
Biogasplant Up grading
Natural gas
•Possibility to produce domestic renewable fuel for vehicles
•Biogas can be up graded and mixed with natural gas
•Biogas can be distributed in the natural gas grid
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Biogas up grading and injection in the natural gas grid
Up grading equipment purifies the biogas up to 97-98% methane
Report: IEA Bioenergy, Task 24
Better distribution of biogasAdditional product for the LPG companies
Biogas can be distributed as “green gas”similar to “green electricity”
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Emissions
•Nitrogen oxides (NOx) – 50-70% less comp.diesel
•Hydrocarbon (NMHC) – 90% less comp. petrol
•Particles –90% less comp. diesel
•Less or no greenhouse gases
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Strategy for biogas and hydrogen as fuel for vehicles
Big potential of biomass
Efficient biogas production and up grading
Injection into natural gas grid
Co operation with hydrogen
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Vehicle fuels in Sweden
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Total transportfuel consumption
5,75 %
Ethanol 5 %Low blending
FAME 5 %Low blending
Biogas
Fuel strategy in Sweden 2010
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Comparison: biogas and ethanol productionfrom energy crops
1 kg wheat 3,12 kWh biogas
1 kg wheat 2,25 kWh ethanol
39 %moreenergy
Ratio: Fuelproduction/Energy input Ethanol 1,38
Biogas 2,5
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Costs for biogas production in Sweden
Process ~ € / kWh ~ € 1 l petrol eq.
Sewage Treatment
0,034 0,30
Slaughter house waste
0,045 0,39
Energy Crop Gas
0,049 0,43
Petrol price in Sweden € 1,22/lBiogas price 20 –40 % lower
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Biogas in Sweden
State fundingsfor production & infrastructure
No tax on renewable fuelsLow tax on CNG for vehicle
More than 50 refuelling stations for CBG/CNG
6000 bi-fuel cars, buses and heavy duty trucks
30 biogas production plants.
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Biogas and natural gas co-operation
45 % biogas and 55 % LPG reduce CO2 with 55 % Compared to petrol
0
100
200
300
1995
1996
1997
1998
1999
2000
2001
2002
2003
(progn
os) 20
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BiogasNaturgas(G
Wh )
Mix of biogas and natural gas for vehicles in Sweden
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Göteborg (4)
Trollhättan
Falkenberg
Helsingborg
MalmöLund Eslöv
Kalmar
Linköping
Stockholm (4)
Uppsala
Gas filling stations
= filling stations (European highways) under construction 2005
1999
Göteborg (6) +2
TrollhättanLilla EdetLerum
Partille
Mölndal
HalmstadFalkenberg
Gnosjö
Gislaved
Helsingborg (2)
Malmö (3) +1Lund
Eslöv +1Kristianstad +1
Kalmar
Skövde
Laholm
Linköping (3) +1
Stockholm (4) + 2
Jönköping
Västerås
EskilstunaKatrineholm
Uppsala
Norrköping +1
Red = stations under construction 2005
Kungälv
Mjölby
Nyköping
Arlanda
Stenungsund
Borås
Örebro
E
ÅstorpÄngelholm
MotalaÅtvidaberg
2005
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Trollhättan
Borås
Lilla Edet
Göteborg
Vänersborg
Ulricehamn
Skövde
Laholm
Helsingborg
Malmö
Kristianstad
Eslöv
Kalmar
Jönköping
Linköping
Norrköping
Katrineholm
Stockholm
Uppsala
Eskilstuna
Production of biogas for vehicles
Västerås
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Biogas Use in Nepal
90% biogas is used for cooking
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Biogas plant at KU
Big potentialFor future projects
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Small biogas plant at hotel
Used for cookingFood waste as substrate
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Kathmandu Valley
• 500 tonnes/day• Ca 70 % is organic material• This can utilized for biogas
production- full scale plant?• Less amount of solid waste• Biogas can be used as
vehicle fuel?• Collection of landill gas?
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What are the potential for biogas production in Nepal?
Used for cooking?As vehicle fuel?Large or small scale?
In Kathmandu valley?In rural areas?
