Transcript Slide 1

RE technology options:
- Hydroelectric 
- Solar 
- Wind 
- Geothermal
- Marine (Wave and Tidal)
- Biofuels (Biomass , Bioethanol and Biodiesel)
Prof. R. Shanthini
02 Feb 2013
What is biomass?
Biomass consists of organic matter which typically comes
from recently living organisms.
The majority of biomass resources are composed of plant
material or derived from plant material.
These sources are regenerated constantly by plant growth.
Therefore, biomass is a sustainable energy source.
Examples???
Prof. R. Shanthini
02 Feb 2013
http://renewables.morris.umn.edu/biomass/faq/
Conversion of Biomass into Useable Fuel:
• Solid Fuel Combustion
• Gasification
• Pyrolysis
• Hydrolysis / Fermentation / Digestion
Prof. R. Shanthini
02 Feb 2013
What is Solid Fuel Combustion?
Direct combustion of solid matter where the biomass is fed
into a furnace where it is burned.
The heat is used to boil water and the energy in the steam is
used to turn turbines and generators.
Prof. R. Shanthini
02 Feb 2013
Conversion of Biomass into Useable Fuel:
Prof. R. Shanthini
02 Feb 2013
What is Gasification?
- It is the partial burning of biomass (at high temperatures
and limited oxygen) to create specific gases, generally
referred to as "Producer Gas" (or "Synthesis Gas"), which is
similar to natural gas.
Prof. R. Shanthini
02 Feb 2013
http://renewables.morris.umn.edu/biomass/faq/
Biomass gasification for electricity generation
Prof. R. Shanthini
02 Feb 2013
http://stlenergy.org/?attachment_id=461
Biomass gasification for electricity generation
Prof. R. Shanthini
02 Feb 2013
http://gasifiers.bioenergylists.org/beloniocfrh
Typical product composition from a gasifier :
Prof. R. Shanthini
02 Feb 2013
http://www3.ul.ie/~childsp/CinA/Issue58/TOC14_FutureA.htm
What is Pyrolysis?
Pyrolysis is the heating of an organic material (such as
biomass) in the absence of oxygen.
Because no oxygen is present the material does not
combust but the chemical compounds (i.e. cellulose,
hemicellulose and lignin) that make up that material
thermally decompose into combustible gases and
charcoal.
Most of these combustible gases can be condensed into
a combustible liquid, called pyrolysis oil (bio-oil), though
there are some permanent gases (CO2, CO, H2, light
hydrocarbons).
Prof. R. Shanthini
02 Feb 2013
http://www.ars.usda.gov/Main/docs.htm?docid=19898
What is Fast Pyrolysis?
Fast pyrolysis is the rapid thermal decomposition of
carbonaceous organic matter in the absence of oxygen.
This process occurs at low pressure, moderate temperatures
and in a very short amount of time.
Fast pyrolysis produces three products: biochar, pyrolysis oil
and non-condensable gases.
Prof. R. Shanthini
02 Feb 2013
Fast Pyrolysis
Prof. R. Shanthini
02 Feb 2013
http://www.avellobioenergy.com/en/technology/fast_pyrolysis/
Fast Pyrolysis
Yields are dependent on many factors including process
conditions (reactor temperature, pressure, residence time)
and feedstock composition.
Optimal biomass processing conditions include:
- reaction temperatures near 500°C
- high heating rates
- rapid cooling of the pyrolysis vapors after biochar has
been sufficiently removed.
Prof. R. Shanthini
02 Feb 2013
Pyrolysis Oil
Pyrolysis Oil (or Bio-oil) is a dense complex mixture of
organic compounds.
It has a fuel value that is generally 50 – 70% that of
petroleum bases fuels and can be used as boiler fuel or
upgraded to renewable transportation fuels.
It density is > 1 kg/L, much greater than that of biomass
feedstocks, making it more cost effective to transport than
biomass.
Prof. R. Shanthini
02 Feb 2013
http://www.ars.usda.gov/Main/docs.htm?docid=19898
Bio-char
Bio-char produced can be used on the farm as an
excellent soil amender that can sequester carbon.
Bio-char is highly absorbent and therefore increases the
soil’s ability to retain water, nutrients and agricultural
chemicals, preventing water contamination and soil
erosion.
Prof. R. Shanthini
02 Feb 2013
http://www.ars.usda.gov/Main/docs.htm?docid=19898
Prof. R. Shanthini
02 Feb 2013
http://eng.marmore.com.tr/marmore-pyrolysis-system
Phenol oil
It is a potential product of pyrolysis.
It is used to make wood adhesives, molded plastics and
foam insulation. Wood adhesives are used to glue together
plywood and other composite wood products.
Prof. R. Shanthini
02 Feb 2013
http://www.ars.usda.gov/Main/docs.htm?docid=19898
What is Hydrolysis/fermentation?
Biomass can be converted directly into liquid fuels—
biofuels— for our transportation needs (cars, trucks, buses,
airplanes, and trains).
The two most common types of bio-fuels are ethanol and
bio-diesel.
Ethanol is an alcohol, created by hydrolysis and fermentation
of biomass high in carbohydrates.
Bio-diesel is made by combining alcohol with vegetable oil,
animal fat or other recycled cooking greases (no
fermentation is involved here).
Details on bioethanol and biodiesel
are provided separately.
Prof. R. Shanthini
02 Feb 2013
What is Digestion?
Decomposition of organic matter by anaerobic bacteria in an
oxygen-starved environment can produce methane.
Anaerobic digesters compost (or “digest”) organic waste in a
machine that limits access to oxygen, encouraging the
generation of methane and carbon dioxide by microbes in the
waste.
This digester gas is then burned as fuel to make electricity.
Prof. R. Shanthini
02 Feb 2013
http://www.ars.usda.gov/Main/docs.htm?docid=19898
Economic Sustainability of Biomass
Production
The development of bio-energy markets can have
many positive economic benefits including:
- creating markets for biomass wastes,
- improving the economic viability of thinning and
harvesting operations
- promoting new crops to farmers, especially on
marginal or unused agricultural
- creating employment in biomass production,
harvesting, transport and conversion to useful energy
- providing a saleable energy product.
Prof. R. Shanthini
02 Feb 2013
How biomass reduces global warming?
Biomass cycle
Prof. R. Shanthini
02 Feb 2013
Life Cycle Analysis
This analysis examines power generation from the following
processes:
Two fossil fuel based technologies:
- coal-fired power production
- natural gas combined-cycle (NGCC)
Two biomass technologies:
- biomass-fired integrated gasification combined
cycle (IGCC) system using a biomass energy crop,
- direct-fired biomass power plant using biomass
residue
Prof. R. Shanthini
02 Feb 2013
Prof. R. Shanthini
02 Feb 2013
Prof. R. Shanthini
02 Feb 2013
Prof. R. Shanthini
02 Feb 2013
List of Sustainability Indicators:
- Conservation of biological diversity
- Maintenance of productive capacity of forest ecosystems
- Maintenance of forest ecosystem health and vitality
- Conservation and maintenance of soil and water resources
- Maintenance of forest contribution to global carbon cycles
- Maintenance and enhancement of long-term multiple socioeconomic benefits to meet the needs of societies
- Legal, institutional and economic framework for conservation
and sustainable management
Prof. R. Shanthini
02 Feb 2013
Environmental constraints
Different biomass resources have different
sustainability considerations:
No sustainability
constraints
– Waste products
– By-products
– Forestry products
– Dedicated cropping
Multi sustainability
constraints
Prof. R. Shanthini
02 Feb 2013
What are the environmental impacts of bio-energy?
Range of impacts both positive and negative that
arise from use of bio-energy
Focus on:
Wood based fuels:
• short rotation coppice (SRC)
• short rotation forestry (SRF)
• forest residues and low grade timber
Not covering…..
Perennial grass crops;
Conventional annual crops;
Prof. R. Shanthini
Waste
02 Feb 2013
What is short rotation coppice (SRC)?
• Densely planted, high yielding varieties of either willow or
poplar
• Harvested on average every 2-5 years
• Expected lifespan of 15-25 years (corresponding to around
6 harvests)
• Shoots usually harvested during the winter as chips, short
billets or as whole stems
• Yields from SRC at first harvest range from 7-12 tonnes dry
weight/ha/yr
Prof. R. Shanthini
02 Feb 2013
What are the environmental impacts of SRC?
Threats
Opportunities
Landscape
 change in landscape
character
 obscure landscape
features
 add structural diversity
 restore and reinstate boundary
features
Biodiversity
 displace open farmland
 increase abundance/diversity
bird species
ground flora farmland bird
 damage sensitive wetland
species and invertebrates
habitats
 provide habitat for small
mammals
 buffer woodlands and vulnerable
habitats
Water
 high water requirements
 improve water quality
 tackle nitrate pollution problems
 treat wastewater
Soil
 soil compaction
 reduce soil erosion and
sedimentation problems
Archaeology
 damage archaeological
sites and deposits
Prof. R. Shanthini
02 Feb 2013
Management recommendations for SRC
Do:
Benefits:
use mixed species
biodiversity, landscape
incorporate headlands, rides & open spaces
biodiversity, landscape
locate to minimise transport
reduce CO2
coppice cyclically
biodiversity, landscape
limit use of fertiliser, herbicides & pesticides
biodiversity, water quality
Don’t:
Impacts:
establish large monoculture blocks
biodiversity, landscape
replace land of high value for biodiversity
biodiversity
plant in low rainfall areas or on waterlogged soils
biodiversity
block recreational access
well-being
plant on sites of archaeological interest
heritage
Prof. R. Shanthini
02 Feb 2013
What is short rotation forestry (SRF)?
• Cultivation of fast-growing trees that reach their
economically optimum size between 8-20 years old
• When felled - replaced by new planting or
regenerate from stumps as coppice
• Varieties may include native species such as alder,
ash, birch, poplar, sycamore (cultivars), and nonnative species
Prof. R. Shanthini
02 Feb 2013
What are the environmental impacts of SRF?
Threats
Opportunities
Landscape
 non native species - impact
on landscape character
 inappropriate in some open
landscapes
 creation of new native
broadleaved woodland
 expansion of existing woodland
Biodiversity
 trees with dense canopies –
discourage ground feeding
birds
 displace birds adapted to
open habitats
 increase biodiversity if native
species used
 understorey vegetation can
provide habitat for invertebrate
and mammal species
 increase abundance/diversity
woodland birds
Water
 non-native species- high
water requirements
 lower inputs required – reduce
nitrate pollution
Soil
 soil compaction during
harvesting
 stabilising impact - reduce soil
erosion
Archaeology
 root growth - damage
archaeological sites and
deposits
Prof. R. Shanthini
02 Feb 2013
Management recommendationsBenefits:
for SRF
Do:
incorporate 10-20% of open space
biodiversity, landscape
leave some areas to mature to old age
biodiversity
maximise diversity of woodland structure
biodiversity, landscape
harvest cyclically
biodiversity, landscape
use UK Woodland Assurance Standard
biodiversity, water quality
Don’t:
Impacts:
plant in sensitive open landscapes
biodiversity, landscape
use non-native species
biodiversity
use exceptionally heavy equipment
soil structure, water
harvest forests on high carbon soils
release CO2
plant on sites of archaeological interest
heritage
Prof. R. Shanthini
02 Feb 2013
What are forest residues and low grade timber
(LGT)?
• Forest residues - harvesting residues (i.e. lop and top or
brash) and small round wood (i.e. small stems of no
commercial value)
• Low grade timber - poor quality final crop and wood from
unmanaged coppice
Demand for wood fuel for bio energy has the potential to
create an economic rationale for the re-introduction of
traditional sustainable woodland management
Prof. R. Shanthini
02 Feb 2013
What are the environmental impact of forest
residues and LGT?
Threats
Opportunities
Landscape
 visual impact of new
access tracks
 perception of rapid
changes to landscape
 diversification of age structure of
woodlands (reduce storm damage)
 restoration of historic coppiced
landscapes
Biodiversity
 depletion of nutrients
 deprivation of food and
habitat for small fungi
and bats etc
•
•
•
•
•
•
•
Prof. R. Shanthini
02 Feb 2013
diversification of woodland structure
increase in edge and ride habitats
increase in ground flora by reduction
in shadiness
thinning or felling of Plantations on
Ancient Woodland Sites (PAWS)
restoration of neglected coppice
woodlands
removal of invasive scrub and trees
removal of rhododendron and other
invasive species from open habitats
What are the environmental impact of forest
residues and LGT?
Threats
Opportunities
Water
 increased runoff and
impaired water quality
 increased sedimentation
of water courses
Soil
 damage to woodland soils
 increased susceptibility to
soil erosion after
harvesting
 counter 20th century increase
in nitrogen and potassium
levels in soils
 establishment ground cover
– reduce soil erosion
Archaeology
 heavy machinery and
creation of woodland
tracks - damage to
archaeological sites
•
Prof. R. Shanthini
02 Feb 2013
reduced risk of windblow
disturbing remains
THE BIOMASS ENERGY SECTOR IN SRI LANKA
• In developing countries, biomass fuel supplies
approximately 35% of total primary energy, most of which is
used traditionally for domestic cooking and space heating.
• Traditional biomass accounts for nearly 52% of the
primary energy supplied in Sri Lanka.
• Nearly 76% of our population still depend on fuel wood
and other forms of biomass for their household cooking
Prof. R. Shanthini
02 Feb 2013
The Biomass Availability in Sri Lanka
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02 Feb 2013
Land Availability for Dendro Plantations
Prof. R. Shanthini
02 Feb 2013
Projects undertaken in Sri Lanka
Prof. R. Shanthini
02 Feb 2013
Prof. R. Shanthini
02 Feb 2013