BiomassA sustainable source

of energy

BY PRANAV MUNDADA

Contents

What is biomass?Categories Of Biomass MaterialsBiomass better than fossil fuels

A neutral source of energySource of biomass

Some of the most efficient residuesHow biomass works

Turning biomass into electricityGenerating energy from biomass

Ways to produce transportation biofuelsEfficiency of biomass

Biomass a Profitable EnergyAdvantages & Disadvantages

Power Plants in India

Biomass is biological material from living or

recently living organisms; As an energy source, biomass can either be

used directly, or converted into other

energy products.Biomass is carbon,

hydrogen and oxygen based. Biomass energy is derived from five distinct energy sources: garbage,

wood, waste, landfill gases and alcohol fuels.

Biomass is the oldest source of energy

Categories of biomass materials

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.

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 unlike fossil fuels.

Biomass better than fossil fuel

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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Sources of

Biomass

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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.

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:

Pipes filled with water are heated to make

steam

Inside a biomass steam boiler

Fire heats the

water

Boiler

Steam Turbine

Biomass

High Heat

Boiler

SteamSteam spins the turbine

blades

Turning Biomass into

Electricity

Rotating magnets create

electricity

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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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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).

Types of gasification: Low temperature & high temperature gasification.

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.

Generating energy from biomass

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.

PYROLYSIS

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Generating energy from biomass

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 (GHG) 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.

Biofuels for transportation

Ways to produce transportation biofuels

[1] Ethanol (bioethanol) is extracted by distilling plants with 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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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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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.

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 40-50 Euros (2500-3500 Rupees) per metric ton, whereas the cost of sawmill waste is 20 Euros (1500 Rupees)/ 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.

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 1250 Euros (90000 Rupees) / kW, in comparison to 2500 Euros (180000 Rupees) / 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.

BIOMASS A PROFITABLE ENERGY……..cont.

Tree Plantations

Seedlings(2

months)

Saplings (1 year)

3 years

7 years

Cutting Sorting

LoadingHauling

Chipping

Saw mill

Harvested LogsSaw dust

from sawmill

Wood chips from forestry

waste

Paper Mill Biomass

power and heat plant

Bringing it all together…with no waste!

Electricity and Steam are used by the Paper Mill

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.

Advantages & Disadvantages:

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.

Advantages & Disadvantages:

Malavalli, Karnataka Samalkot Mill, Andhra Pradesh

Akaltara, Chhattisgarh Satyamaharshi, Andhra Pradesh

Thoothukkudi,Tamil Nadu

Biomass Power Plants In India

Thank You