Bioenergy and Climate Change Mitigation:
Options and Opportunities
Dr. P. Abdul Salam
Associate Professor – Energy
Thematic Leader - Low Carbon, and
Sustainable Production and Consumption Technologies and Management
Asian Institute of Technology
International Symposium on Renewable Energy & Energy Efficiency Initiatives:
Policies, Technologies and Sustainability
3-5 June, 2015, Bhutan
Presentation Outline
 Background
 Biomass Energy Conversion Routes
(Technical options)
 Emerging Biomass Technologies
 Mitigation Potential of Bioenergy
 Bioenergy and Sustainable Development
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Background
 Biomass refers to all materials constituting and
originating from plants and animals.
 Biomass accounts for about 10% ( 50 EJ/yr) of
global energy use at present.
 In developing countries biomass:
– provides basic energy requirements for cooking
and heating of rural households.
– accounts for 20-90% of the total energy
consumption.
 By 2050, bioenergy contribution could be in the
range of 100 to 300 EJ.
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Background
• Biomass is a renewable source
• Its application as a fuel does not result in net
CO2 emission,
– i.e. CO2 released during the conversion of biomass =
CO2 absorbed by the biomass from the atmosphere
during the process of photosynthesis.
• Thus, unlike fossil based fuels, Biomass is a CO2
neutral energy source.
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CO2 Emission Mitigation
• World CO2 emission is around 30 GtCO2. It is estimated that
it would be 34 and 42 GtCO2 in 2020 and 2035,
respectively.
• Presently CO2 concentration in atmosphere is about 400
ppm. This is about 2/3rd of the total GHG emissions.
• Emission at current rate would exceed 600 ppm level by
the end of 2050 and 750 ppm by the end of the century.
This means a rise of 40C in mean temperature of earth.
• The maximum allowable range of change should be within
20C which is equivalent to less than 450 ppm.
• To stabilize at 450 ppm CO2 concentration, we need to
mitigate 5-10 GtCO2/yr excluding natural sequestration of
CO2 by Ocean (7.4 GtCO2) and forest (5.5 GtCO2).
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Options for CO2 Emission Mitigation
 Energy conservation
 Efficiency improvement to reduce
consumption of fossil fuel
 Renewable energy to substitute fossil fuel
 Carbon capture and storage
 Carbon capture and storage cum Biomass
usage
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Advantages of Biomass
• Biomass is a renewable resource and is readily
available
• Adds secondary value to agricultural crops
• Biomass can be converted to several forms of
energy
• Growing biomass crops produce oxygen and use
carbon dioxide
• The use of waste materials reduces waste in
landfills
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Disadvantages of Biomass
• Low bulk density, high moisture content, Low
calorific value.
• Energy comes mainly from plants which must be
harvested.
• Land used to grow biomass materials is needed
for other uses.
• Biomass crops can deplete soil of nutrients.
• Burning plants releases carbon dioxide.
• Bi-products of biomass contain less energy per
litre than gasoline.
• Research needed to make more cost efficient.
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Biomass Energy Conversion Routes (Technical Options)
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Example: Paths to several energy products from algae
(Pires, Alvim-Ferraz, Martins, & Simões, 2012)
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Improvement of Biomass Conversion Systems
Biopower efficiency:
1) Traditional (Steam turbine) systems
Old design: ~20%
Advanced designs: ~ 33%
2) Emerging Options
Cofiring: ~36%
BIGCC: ~ 40%
Stove Efficiency:
1) Traditional stoves: 8-15%
2) Improved stoves: 20-30%
3) Advanced (gasifier stoves): ~ 35%
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Emerging Biomass Technologies
Exciting developments are taking place in bioenergy: Heat
BIGCC
Gasifier
Gas
conditioner
Combined
cycle
Power
Cellulosic ethanol
Algal biofuel
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Example: Microalgae - A Solution for CO2
Capture and Usage
• One ton of algae biomass requires about 1.8 tonne of CO2
• This implies that out of 10 billion tCO2 that the power plants
emit, we can get about 5.5 billion tons of algae biomass.
• The right strains of algae have about 30% of oil by weight. Thus,
5.5 billion tons of algae will result in about 1.65 billion tons of
oil.
• The total world consumption of oil is about 4.2 billion tons of
oil every year.
• Thus, theoretically, algae grown using power plant flue gas
have the potential to produce about 40% of total oil
consumption.
A Comprehensive Guide for Algae-based Carbon Capture
Source: http://www.oilgae.com/ref/report/co2_capture/co2_capture.html
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Emerging Biomass Technologies
Fuels
Biorefineries
Biomass
Biorefinery
Chemicals
Advanced (gasifier) stoves
Biogas –Fuel cell system
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Global biopower installed capacity (GW)
100
Annual growth rates: 4%-27%
Overall Growth (2004-2013): 125%
90
80
70
60
50
40
30
20
10
0
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
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Global biofuel production
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Global wood pellet production
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7000
World RE use for electricity by type in the 450 Scenario, TWh
6000
5000
4000
3000
2000
1000
0
20112035
Bioenergy
20112035
20112035
Hydro
Wind
20112035
PV
20112035
20112035
CSP
Geothermal
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Mitigation Potential of Bioenergy
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Source: IPCC 92007
Bioenergy and Sustainable Development
• Relations between bio-energy and sustainable
development are varied and complex:
Pros:
 improved energy security
 economic gains
 rural development
 reduced GHG emissions
Cons:
 expansion of agricultural frontier
 deforestation & monocropping
 water pollution
 food security problems
 poor labor conditions
 unfair distribution of benefits
Positive impacts and trade-offs vary depending on the type of
energy crop, cultivation method, conversion technology and
area under consideration
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Energy Park at AIT
Thank You
For more information, please contact:
Dr. P. Abdul Salam ([email protected])
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