RE technology options:

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RE technology options

• Hydroelectric ?
• Solar ?
• Wind ?
• Geothermal
• Marine (Wave and Tidal)
• Biofuels (Biomass ?, Bioethanol and Biodiesel)

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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???

http//renewables.morris.umn.edu/biomass/faq/
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Conversion of Biomass into Useable Fuel

• Solid Fuel Combustion
• Gasification
• Pyrolysis
• Hydrolysis / Fermentation / Digestion

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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.

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Conversion of Biomass into Useable Fuel
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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.
http//renewables.morris.umn.edu/biomass/faq/
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Biomass gasification for electricity generation
http//stlenergy.org/?attachment_id461
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Biomass gasification for electricity generation
http//gasifiers.bioenergylists.org/beloniocfrh
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Typical product composition from a gasifier
http//www3.ul.ie/childsp/CinA/Issue58/TOC14_Futu
reA.htm
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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).
http//www.ars.usda.gov/Main/docs.htm?docid19898
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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.
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Fast Pyrolysis
http//www.avellobioenergy.com/en/technology/fast_
pyrolysis/
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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 500C - high heating rates - rapid
cooling of the pyrolysis vapors after biochar has
been sufficiently removed.
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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 gt 1 kg/L, much greater
than that of biomass feedstocks, making it more
cost effective to transport than biomass.
http//www.ars.usda.gov/Main/docs.htm?docid19898
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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 soils ability to retain water,
nutrients and agricultural chemicals, preventing
water contamination and soil erosion.
http//www.ars.usda.gov/Main/docs.htm?docid19898
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http//eng.marmore.com.tr/marmore-pyrolysis-system
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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.
http//www.ars.usda.gov/Main/docs.htm?docid19898
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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.
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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.
http//www.ars.usda.gov/Main/docs.htm?docid19898
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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.

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Biomass cycle
How biomass reduces global warming?
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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

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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 socio-economic benefits to meet the
  needs of societies
• - Legal, institutional and economic framework for
  conservation and sustainable management

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Environmental constraints

• Different biomass resources have different
  sustainability considerations
• Waste products
• By-products
• Forestry products
• Dedicated cropping

No sustainability constraints
Multi sustainability constraints
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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
• Waste

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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

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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 bird species damage sensitive wetland habitats increase abundance/diversity ground flora farmland bird species and invertebrates 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
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Management recommendations for SRC
Do Benefits use mixed species biodiversi
ty, landscape incorporate headlands, rides open
spaces biodiversity, landscape locate to
minimise transport reduce CO2 coppice
cyclically biodiversity, landscape limit use
of fertiliser, herbicides pesticides biodiversi
ty, water quality
Dont 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
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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 non-native species

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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
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Management recommendations for SRF
Do Benefits 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
Dont 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
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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

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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 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
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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 reduced risk of windblow disturbing remains
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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

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The Biomass Availability in Sri Lanka
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Land Availability for Dendro Plantations
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Projects undertaken in Sri Lanka
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