Biomass by Akash Kewal

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Biomass
A profitable Energy Resource
Presented by: Akash Kewal Ram
(AREVA T&D Pakistan Pvt. Ltd.)
23rd
multi-topic International Symposium 2008
March 29, 2008
IEEEP, Karachi Centre

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Contents
 What is biomass??
 The difference b/w biomass & fossil fuel
 How biomass works
 Biomass helps in reducing global warming
 A neutral source of energy
 Source of biomass
 Some of the most efficient residues
 Various processes to obtain energy
 Ways to produce transportation biofuels
 Generating energy from biomass
 Efficiency of biomass
 Advantages & Disadvantages

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 A renewable energy par excellence, is the oldest
sources, of power used by humans.
 Is still the basic energy source for some 1.6 billion
humans who do not have access to electricity.
 Biomass include: dead trees, tree branches, yard
clippings, left-over crops, wood chips, bark & sawdust
from lumber mills, grasses and manure.
 can be used to produce electricity, heat or fuel for
transportation.
 has a calorific value, roughly equivalent to one-third of
that of fossil fuels.
 Biomass is relatively evenly distributed over the surface
of the globe
Biomass:

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 Renewable over much shorter periods, ranging from a
few decades for forestry biomass to a few months for
energy crops.
 When burned, the chemical energy in biomass is
released as heat
 Each MW of power produced by a biomass power plant
means a reduction in CO2 emission of around 3000 to
5000 metric tons.
 can be converted to other usable forms of energy like
methane gas or transportation fuels like ethanol and
biodiesel.
 Biomass fuels provide about 3 percent of the energy
used in the United States.
Biomass:……………..cont

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 millions of families cook, heat and light their homes by
burning biomass materials.
 The use of biomass in distributed generation is
considered one of the best ways to meet targets for
renewable energy without compromising supply
reliability.
Biomass:……………..cont

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 Biomass is carbon based and is composed of a mixture
of organic molecules containing hydrogen, usually
including atoms of oxygen, often nitrogen and also small
quantities of other atoms, including alkali, alkaline earth
and heavy metals.
 These metals are often found in functional molecules
such as the porphyries which include chlorophyll which
contains magnesium.
Chemical Composition:

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 The vital difference between biomass and fossil
fuels is one of time scale.
 Biomass takes carbon out of the atmosphere
while it is growing, and returns it as it is
burned.
 biomass maintains a closed carbon cycle with
no net increase in atmospheric CO2
levels.
The difference b/w biomass & fossil fuel

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 Virgin wood, from forestry, arboricultural
activities or from wood processing
 Energy crops: high yield crops grown
specifically for energy applications
 Agricultural residues: residues from agriculture
harvesting or processing
 Food waste, from food and drink manufacture,
preparation and processing, and post-consumer
waste
 Industrial waste and co-products from
manufacturing and industrial processes.
Categories of biomass materials

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 Biomass is fed into a furnace where it is burned. The
heat is used to boil water in the boiler, and the energy in
the steam is used to turn turbines and generators.
 Biomass can also be tapped right at the landfill with
burning waster products. When garbage decomposes, it
gives off methane gas. Pipelines are put into the landfills
and the methane gas can be collected. It is then used in
power plants to make electricity.
 Also used to produce ethanol, a liquid alcohol fuel.
Ethanol can be used in special types of cars that are
made for using alcohol fuel instead of gasoline.
 The alcohol can also be combined with gasoline. This
reduces our dependence on oil
How biomass works:

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Sources of biomass:
 Wood chips / waste
 Nut shells
 Sewage sludge
 Olive pips
 Bone meal
 Leather waste
 Animal litter
 Coal
 Tyres
 Sugar Cane Bagasse
 Oil sludge/waste
 Energy crops
 Oil seed rape husks
 Rice and Corn husks
 Packaging Waste
 Chicken Waste, etc.

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Some of the most efficient residues
1. BAGASSE:
 bagasse, the sugarcane fiber that remains after the juice
has been extracted in sugar factories and distilleries, is
the king of biomass.
 Bagasse leads wood as the preferred biofuel for
generating electricity.
 Each year approximately 1.2 billion metric tons of
sugarcane are harvested worldwide, yielding around 350
million metric tons of bagasse.
 If existing installations were modernized, bagasse could
produce much more electrical power, estimated at
around 50,000 MW for power plants operating primarily
on this fuel.

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Some of the most efficient residues
2. RICE HUSKS OR CHAFF:
 The grain of the rice is separated from its envelope or
husk before it is consumed.
 Rice husks represent approximately 20% o the weight of
the rice.
 Other than its utilization as a biofuel, there is no other
process for eliminating this waste, which accumulates in
heaps around rice mills.
 World produces around 600 million metric tons of rice
per year, approximately 120 million metric tons of rice
chaff is left unused annually.
 the total approx. 15000 MW of electricity could be
generated from above qty.

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Some of the most efficient residues
3. WOOD:
 wood has traditionally been the major source of primary
energy used by humans.
 today, the source of wood based biofuel is the waste
produced by forestry operations (twigs, bark, sawdust,
etc.)
 Wood is one of the biomass which has largest caloric
value.

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S.no Description Kcal/kg kWh/kg
1 Bagasse 2,272 2.64
2 Rice husk 3,150 3.66
3 Sunflower husk 4,155 4.83
4 Cotton stalk 3,900 4.53
5 Can trash 2,880 3.35
6 Wood chips 4,490 5.22
7 Palm shell 4,390 5.10
8 Chilly stalk 3,850 4.48
Comparison of kcal/kg & kWh/gm of some of
the residues

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 Biomass contains stored energy from the sun. Plants
absorb the sun's energy in a process called
photosynthesis. The chemical energy in plants gets
passed on to animals and people that eat them.
 Or we can say: Plants use and store carbon dioxide
(CO2) when they grow. CO2 stored in the plant is
released when the plant material is burned or decays.
By replanting the crops, the new plants can use the
CO2 produced by the burned plants. So using
biomass and replanting helps close the carbon
dioxide cycle.
 It is also a renewable energy because plants to make
biomass can be grown over and over
A neutral source of energy

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Biofuels for transportation
 Green fuels produced from organic material can be
used, either totally or partially, in the place of
petroleum-based fuels.
 Burning biofuels in vehicles lowers the greenhouse
emission (GCG) produced by road transportation,
which generates 24% of all planetary CO2 emissions.
 biofuels lowers the demand for oil, and energy costs
in consequences.
 Biofuels open up a avenue for using agricultural
products, helping to regulate market prices, for
primary agricultural commodities, and also create
jobs in rural areas.

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Ways to produce transportation biofuels
 [1] Ethanol (bioethanol) is extracted by distilling
plants which a high sugar content (sugar beet,
sugarcane) or high starch content (wheat, potatoes,
corn, etc.). ethyl alcohol is obtained by fermentation
of the sugar or starch.

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Ways to produce transportation biofuels
 [2] Easters are produced by the reaction of methanol
or ethanol with vegetable oils (sunflower, soyabean,
etc.) and are added to diesel fuel.

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Generating energy from biomass
• Generating energy from biomass is also called as
conversion of biomass.
 Various processes are employed to obtain energy
from biomass. Three of them are:
1. COMBUSTION:
 biomass is used as fuel to heat water to obtain high-
pressure steam. The steam is fed to a turbine linked
to an alternator, which produces electricity.
 The low-pressure stream given off by the turbine may
be used to supply heat to district heating networks as
well as in various industrial processes: sugarcane
distillation, paper-making, esterification, etc.
 when waste energy is also made use of in a power
plant, this is called cogeneration.

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Generating energy from biomass
2. Gasification (Anaerobic digestion):
 Gasification is a partial oxidation process
whereby a carbon source such as coal, natural
gas or biomass, is broken down into carbon
monoxide (CO) and hydrogen (H2
), plus carbon
dioxide (CO2
) and possibly hydrocarbon molecules
such as methane (CH4
).
Applications:
 Heating water in central heating, district heating
or process heating applications
 Steam for electricity generation or motive force
 As part of systems producing electricity or motive
force
 Transport using an internal combustion engine.
 Types of gasification: Low temperature & high
temperature gasification

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Generating energy from biomass
3. Pyrolysis :
 Pyrolysis is the precursor to gasification, and
takes place as part of both gasification and
combustion. It consists of thermal decomposition
in the absence of oxygen. It is essentially based
on a long established process, being the basis of
charcoal burning.
Applications:
 Biomass energy densification for transport or
storage
 Co-firing for heat or power
 Feedstock for gasification.

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Generating energy from biomass

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Generating energy from biomass

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Biomass a Profitable Energy
 The wide use of biomass may significantly contribute
to developing rural areas, as opposed to urban areas,
because it will create sustainable activities that make
use of unexplored agricultural resources and also
provide access to electricity in isolated areas where
the power supply is not always reliable.
 Producing energy using biomass also allows for
diversifying sources of income in the agricultural
sector, where competition is fierce.
 The traditional income generated by the production of
electrical power will contribute to ensuring greater
economic stability for agricultural producers.

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BIOMASS A PROFITABLE ENERGY……..cont.
1. In industrialized countries
 When biomass materials are not the byproducts of an
existing industry (bagassse produced by sugar
factories, sawdust by forestry operations), using
them as biofuel results in an increase in prices;
 the cost of collecting the dead wood and branches
from felled trees in forests and transforming then into
wood pellets is Euro 40 to Euro 50 per metric ton,
whereas the cost of sawmill waste is Euro 20 / metric
ton.
 In these countries, subsides are needed to make
biomass a competitive energy. However, in contrast
to other sources, biomass has a low environmental
and social impact, which lower its cost over the long
term.

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BIOMASS A PROFITABLE ENERGY……..cont.
2. In developing countries
 Biomass power plant investment and operating costs
are lower in developing countries.
 In Thailand, the installation of a 15 MW capacity
power plant costs around Euro 1250 / kW, in
comparison to Euro 2500 / kW in Europe.
 Biomass is more profitable energy because power
plants in developing countries benefit from carbon
credits.
 It is a viable solution for electrifying rural areas that
are not effectively connected to power grid.

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Efficiency of biomass
 The electrical efficiency rating of transforming
biomass into electrical energy is around 30% for 10 to
20 MW capacity plants.
 This efficiency rating is representative of the latest
technologies for solid biofuels used in plants of this
size.
 In comparison, top-ranked plants producing 500 MW
and more with combined cycle gas turbines can only
attain an electrical efficiency rating of 57%.
 Regarding fossil fuels, the efficiency rating of the
biggest coal-fired plants, with an output close to 1000
MW, does not exceed 45%.

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Advantages & Disadvantages:
1. Advantages:
 Theoretically inexhaustible fuel source.
 there is minimal environmental impact
 Alcohols and other fuels produced by biomass are
efficient, viable, and relatively clean-burning
 Available throughout the world
2. Disadvantages:
 Could contribute a great deal to global warming and
particulate pollution if directly burned
 Still an expensive source, both in terms of producing
the biomass and converting it to alcohols
 On a small scale there is most likely a net loss of
energy--energy must be put in to grow the plant mass

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Biomass power plant at Satyamaharshi (India)
>> 7.5MW Power Plant (Built by AREVA)

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