Embed Size (px)
Citation preview
© Fraunhofer IGB
Germany – Indonesia Forum on „Biomass and Biogas“
11. October 2016
Barbara Waelkens, Fraunhofer IGB - Stuttgart
Biogas production from organic waste –
technologies, performance and development
© Fraunhofer IGB
CONTENT
Overview Biogas Production and Use
Biogas in Europe
Project Examples
© Fraunhofer IGB
Overview:
Anaerobic digestion process scheme
Biogas use
(CH4 + CO2)
Sludge/Waste
Reduce the mass of
organic material
Decrease organic
material disposal cost
Produce and use
biogas
Improve digestate
quality
© Fraunhofer IGB
Overview:
Material sources for the production of biogas
Semi-Solids
Organic municipal solid
waste
Industrial organic solid
residue
Agriculture waste
Energy crops
Liquids
Municipal wastewater and
sludge
Industrial wastewater
Liquid waste from palm oil
production
© Fraunhofer IGB
Overview:
Biogas – production and quality by substrate
Biogas Production Methane Content CO2 content
Material Source lgas/kgVS [%] [%]
Carbohydrates 700 – 830 50 – 55 45 – 50
Proteins 700 – 900 70 – 75 25 – 30
Fats 1000 – 1400 68 – 73 27 – 32
Organic MSW 350 – 500 55 – 68 32 – 45
Energy Crops 500 – 700 50 – 62 38 – 50
(Source: Weiland, 2003)
© Fraunhofer IGB
Uses:
Combustion
thermal energy
Cogeneration
Electric and thermal energy
Substitute of natural gas
Vehicle fuel
Grid injection
Fuel cells
CO2 can be used in industry
Advantages:
Biogas can be produced
continuously
Biogas can be stored
Biomethane can substitute natural
gas directly
Reduction of NOx, CO, CO2, VOCs,
Particulates and Noise Emissions
Important: NEVER USE BIOGAS
WITHOUT TREATMENT
Overview:
Biogas uses and advantages
© Fraunhofer IGB
Biogas in Europe:
Germany – Cogeneration
Biogas plants in Germany are
descentralized and have an
installed capacity of 4,1 GW
In 1999 the average capacity of a
plant was 60 kWel
The average plant capacity in
2014 was of about 440 kWel
Total electricity production in
2014 was 29 TWh
© Fraunhofer IGB
Biogas in Europe:
Germany – Biomethane
Newer trend: Biomethane
production
as vehicle fuel
feed to the grid
© Fraunhofer IGB
Biogas in Europe:
Biogas Production and Treatment Plants in Sweden
© Fraunhofer IGB
Biogas in Europe:
Biogas as Vehicle Fuel – from Sweden do Switzerland
Bus moved on Biomethane
in Malmö, Sweden
Bus moved on Biomethane
in Bern, Switzerland
© Fraunhofer IGB
PROJECT EXAMPLES
MASS REDUCTION AND ELECTRICITY
Edenkoben
Sludge reamoval and biogas
production for electricity and heat
generation at the Wastewater
Treatment Plant in Edenkoben
Leonberg
Municipal solid waste reduction
and biogas production for
electricity and heat generation at
the MSW treatment plant in
Leonberg
© Fraunhofer IGB
Project Example - Edenkoben:
WWTP as energy consumer
In Germany around 94 % of
the population is connected to
a WWTP
Total of roughly 10.000
municipal WWTPs
Total electricity consumption is
around 4.400 GWh per year
WWTPs represent about 20 %
of the municipal electricity
demand, and are the biggest
electricity consumers of a
municipality
© Fraunhofer IGB
Project Example - Edenkoben:
Potential to reduce electricity consumption
In Germany, anaerobic sludge stabilization used to be financially viable only
for cities with more than 50.000 people equivalents.
New technologies and higher electricity prices changed the scenario. The
lower limit for a financially viable anaerobic sludge stabilization is currently at
10.000 people equivalents.
Gretzchel et al.
© Fraunhofer IGB
Project Example - Edenkoben:
WWTP as energy consumer
WWTP Edenkoben was build in the mid 80‘ies with Aerobic sludge
stabilization
The WWTP is influenced by the wine production and receives variable loads
throughout the year.
The load varies between 7.000 and 120.000 people equivalent every year.
Aiming to become an „energy neutral“ WWTP several measures were taken.
Shift from aerobic to anaerobic sludge stabilization.
Construction of a two stage high load digester.
© Fraunhofer IGB
Project Example - Edenkoben:
Average load of Chemical Oxygen Demand
1.000
2.000
3.000
4.000
5.000
6.000
7.000
8.000
9.000
10.000
1 2 3 4 5 6 7 8 9 10 11 12
Mittlere
CS
B-Z
ula
uffra
cht
in k
g/d
Monat
2013 2011 2012 2014
© Fraunhofer IGB
Project Example - Edenkoben:
Overview Wastewater Treatment Plant with high load
digester
© Fraunhofer IGB
Project Example - Edenkoben:
Current operational parameters
Inicial inoculation 5.1.2016
Active digester volume 2 x 430 m3
Sludge feed 40 - 120 m3/d
Total solids at reactor inflow TS =
4,5 % to 5 %
Specific Biogas production currently
1,9 m3/(m3*d)
Installed capacity: 2x50 kWel
Electricity production:
1200 - 2400 kWh/d
Energy Neutrality: up to 66 % of
total demand is covered by biogas
© Fraunhofer IGB
Project Example - Leonberg:
organic Municipal Solid Waste
© Fraunhofer IGB
Project Example - Leonberg:
organic Municipal Solid Waste
Organic municipal solid waste is collected separately from other waste types.
Often the urban organic MSW is treated in composting plants
This requires energy input
Can cause odor problems
Leonberg introduced an anaerobic treatment step to produce electricity and
heat
The produced biogas is used in a cogeneration plant
The solid and liquid waste from the anaerobic digestion is sent to a
composting plant.
The Project resulted in better energy efficiency and higher waste reduction
© Fraunhofer IGB
Project Example - Leonberg:
organic Municipal Solid Waste
Digester volume: 2400 m3
Hydraulic Retention Time: 21d
Operating Temperature: 48 – 55°C
Treated Waste: 35.000 Mg/year
Waste Reduction: 10.000 Mg/year
Gas Storage: 2400 m3
Cogeneration units: 3
Electricity Production: 8,2 GWhel/year
Heat Production: 6,0 GWhtherm/year
Source: Abfallwirtschaft Landkreis Böblingen
© Fraunhofer IGB
Project Example - Leonberg:
organic Municipal Solid Waste
© Fraunhofer IGB
PROJECT EXAMPLES
BIOGAS AS VEHICLE FUEL
Franca
Biogas from anaerobic digestion is flared on a WWTP in Brazil
Electricity in Brazil comes largely from hydropower
Most of light oil is imported
To demonstrate the potential of biogas a project was started to clean the
biogas to biomethane and use it as vehicle fuel
© Fraunhofer IGB
Project Example – Franca, Brazil:
Biomethane as Vehicle Fuel
The current project will capture the biogas
produced at the 3 digesters of the WWTP and
upgrade it to methane. This bio-methane will
then be used as vehicle fuel
WWTP for 315.000 PE
(current load 215.000 PE)
The Wastewater treatment plant in Franca
produces over 2.800 Nm3/day of biogas
(1.680 Nm3 CH4/day)
1 Nm3 of methane is equivalent to around
1 l of gasoline, thus 1.680 l gasoline/day
It is enough fuel for the whole vehicle fleet
© Fraunhofer IGB
Project Example – Franca, Brazil:
Biomethane as Vehicle Fuel
© Fraunhofer IGB
Project Example – Franca, Brazil:
Biogas Upgrading through Pressure Swing Adsorption
Source: Carbotech
modified
© Fraunhofer IGB
Project Example – Franca, Brazil:
Biomethane as Vehicle Fuel – Biogas Upgrading
Biomethane is compressed and stored at 250 bar
The biomethane is now available as vehicle fuel
© Fraunhofer IGB
Conclusions
Biogas production and use presents several advantages, from waste
reduction to variable forms of energy production
Several technology options are available
Project examples show possible alternatives for biogas and
biomethane use
Business models need to fit the local demand
A big change can start with a small project
© Fraunhofer IGB
Fraunhofer IGB
Environmental Biotechnology and Bioprocess Engineering
Development, optimization and process evaluation in
the fields:
Wastewater and sludge treatment
Organic waste treatment
Nutrient recovery
Energy availability and use (Biogas, Biomethane)
Algae technology
© Fraunhofer IGB
Overview:
The four steps of anaerobic microbial digestion
Source: Mudrack (modified)
© Fraunhofer IGB
Biogas in Europe:
Biogas as Vehicle Fuel – County of Zeeland (NL)
County of Zeeland has chosen
biogas Buses
43 Buses running since 2007
CO2 Neutral
Better Air quality
Less noise
© Fraunhofer IGB
Beschreibung des Prozesses – Dritte Stufe:
Zur Entfernung von
Kohlenstoffdioxid wird das
getrocknete und vom
Schwefelwasserstoff befreite
Biogas einer Druckwechsel-
adsorption PSA zugeführt. Dort
wird das CO2 an einem
Kohlenstoffmolekularsieb
adsorbiert, so dass im Ausgang
der PSA ein Gas entsteht, das
sehr reich an Methan ist –
Biomethan.
Quelle: Carbotech modifiziert
© Fraunhofer IGB
Aerober und anaerober Stoffwechsel
Quelle: Köppke
© Fraunhofer IGB
Substitute of natural gas
To increase energy density CH4
and CO2 should be separated.
Common technologies are:
Pressure Swing Adsorption,
Scrubbing, Pressure Scrubbing,
Amine Scrubbing, Membrane
separation.
Overview:
Treatment Steps Biogas
Biogas
(CH4 + CO2)
Biogas
Treatment
CH4 CO2
© Fraunhofer IGB
Overview:
Basic Biogas Treatment
Combustion and Cogeneration
Biogas should be dry and free of
H2S to guarantee long operation
time of the burner or engine
Particulates: Grit filter
Humidity: Cooling of the Biogas
Hydrogen Sulfide: Active Carbon
Filter
Siloxanes: Active Carbon Filter
© Fraunhofer IGB
Overview:
Advanced Biogas to Biomethane Technologies
Pressure Swing Adsorption: CO2
is adsorbed on the internal surface
of active charcoal or zeolithes under
pressure conditions of up to 10 bar.
Scrubbing: CO2 is absorbed in a
liquid under atmospheric or
pressure conditions (up to 10 bar).
Common liquids are water, glycols
and amines.
Membrane Technologies: Some
gases are held back by membranes
while others permeate. In the gas
industry high pressures are applied.
