Biomass is matter usually thought of as
If garbage can be converted to useful energy?
How biomass works is very simple.
Recycling biomass for fuel and other
uses cuts down on the need for "landfills"
What is the Biomass ?
Biomass is biological material derived from living, or recently living organisms.
In the context of biomass for energy this is often used to mean plant based
material, but biomass can equally apply to both animal and vegetable derived
Biomass comes in a million physical forms
However, it is composed typically of
Most biomass can be represented by
The carbon used to construct biomass is absorbed from the
atmosphere as carbon dioxide (CO2) by plant life, using energy
from the sun.
These processes have happened for as long as there have been
plants on Earth and is part of what is known as the carbon cycle.
Fossil fuels such as coal, oil and gas are also derived from
biological material, however material that absorbed CO2 from the
atmosphere many millions of years ago.
As fuels they offer high energy density, but making use of that
energy involves burning the fuel, with the oxidation of the carbon
to carbon dioxide and the hydrogen to water (vapor). Unless they
are captured and stored, these combustion products are usually
released to the atmosphere, returning carbon sequestered
millions of years ago and thus contributing to increased
The difference between the biomass and fossil fuel
The vital difference between biomass and fossil fuels is one of time
Biomass takes carbon out of the atmosphere while it is growing, and
returns it as it is burned. If it is managed on a sustainable basis,
biomass is harvested as part of a constantly replenished crop. This is
either during woodland or arboricultural management or coppicing or
as part of a continuous programmer of replanting with the new growth
taking up CO2 from the atmosphere at the same time as it is released by
combustion of the previous harvest.
This maintains a closed carbon cycle with no net increase in
atmospheric CO2 levels.
HOW WAS BIOMASS USED IN THE PAST?
Biomass was the first fuel mankind learned
to use for energy. Burning wood for
warmth and cooking and keeping wild
Some of the earliest power plants in
America were fueled by wood material
It was an abundant fuel in many parts of the
country where logging took place
It burned much cleaner than coal and it was
available before abundant oil and natural
gas was discovered
Many cultures used animal dung to burn,
and some are still doing this today
There are five basic categories of BIOMASS material:
•Virgin wood, from forestry, arboricultural activities or from wood
•Energy crops: high yield crops grown specifically for energy
• Agricultural residues: residues from agriculture harvesting or
•Food waste, from food and drink manufacture, preparation and
processing, and post-consumer waste
•Industrial waste and co-products from manufacturing and
CONVERSION OF BIOMASS WASTE INTO USEABLE FUEL
Exposing a solid fuel to high
temperatures and limited oxygen
Heating the biomass can produce
pyrolysis oil and phenol oil leaving
Bacteria, in an oxygen-starved
environment can produce methane.
Bio-material that is used to manufacture
Ethanol and Biodiesel by an anaerobic
biological process in which sugars are
converted to alcohol by the action of
micro-organisms, usually yeast.
Solid Fuel Combustion
Direct combustion of solid matter.
Biomass to Biogas
Biogas is produced by exposing
biomass to high temperatures and
Biogas energy can serve as a feedstock for
electricity generation or a building block
Heat is used to chemically
convert biomass to bio-oil.
Pyrolysis Oil, is easier to store and
transport than solid biomass material
and can be burned like petroleum to
Phenol Oil, a chemical used to
make wood adhesives, molded
plastics and foam insulation.
Wood adhesives are used to
glue together plywood and
other composite wood
Decomposition of organic matter by anaerobic bacteria in an oxygen-starved environment.
Heating Plant, Lior International
Dranco plant for anaerobic
digestion of biowaste
Ghent( Belgium )
Lemvig centralised biogas plant,
about 4 million m3/year of gas
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.
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
Eagar Biomass Plant, Springerville,
Peat is an accumulation of partially
decayed vegetable matter. Peat
forms in wetlands, bogs, moors,
mires and fens
Pure pyrolysis can be represented as...
CH1.4O0.6 0.4 C (charcoal) + C.6H1.4O.6
(pyrolysis oil and gas)
This requires an external heat source like the Bunsen
There’s a better way to make gas...
THE SIMPLE MATCH: Flaming
Pyrolysis, gasification and combustion are all visible in the
simple match. Please look CLOSELY
If you have lots of air passing over a small amount of wood, it
will burn completely to CO2 and H2O in “flaming combustion”,
as in the match
CH1.4O0.6 + 1.05 (O2 + 3.76N2)CO2 + .7H2O
If you have insufficient air passing through a mass of burning
wood, you have “flaming pyrolysis” producing CO and H2, the
basis of biomass gasification
THE KEYS TO BIOMASS THEMAL
GASIFICATION FUEL RATIO
It is necessary to have the correct air (or O2)/fuel ratio
to achieve complete gasification
With lower values of this ratio you have an excess of
charcoal and tar
With higher values you deplete charcoal and burn
We call the optimum ratio the “Sweet Spot” of
Controlling the “Sweet Spot”
The correct air/fuel ratio depends on many things:
Type of biomass
Air throughput rate
“Sweet Spot” control is the key to simple, clean
Greenhouse gases produced by burning
Extra costs of installing technology to process and
Expensive to collect, harvest and store raw materials
Large scale crop production will use vast areas of land
and water, representing major problems
• Biomass is very abundant. It can be found on every
square meter of the earth as seaweed, trees or dung.
• It is easy to convert to a high energy portable fuel
such as alcohol or gas.
• It is very low in sulphur reducing the production of
• Preservation of agricultural land that otherwise would
be sold for residential development or industrial use =
wide open spaces!!
Biomass production can often mean the restoration of
waste land (e.g. deforested areas).
• It may also use areas of unused agricultural land and
provide jobs in rural communities.
• Sustainable agricultural techniques for these crops
can restore and ensure soil stability and health along
with minimizing chemical residues and habitat
• Today 10,000 megawatts (MW) in total biopower capacity
• Use of waste from agricultural and timber industries. An
estimated 350 million tons of waste that goes to landfills could
be used for energy production.
• Methane is 20 times more potent than CO2. Capturing methane
from producers such as cows or rice fields and applying it for
fuel will significantly reduce this greenhouse gas.
• If it is produced on a renewable basis using biomass energy does
not result in a net carbon dioxide increase as plants absorb it
when they grow.
Biomass (Future) Advantages?
• Biomass can be used to produce solid, liquid, gaseous fuels
as well as electricity directly
• Fuel production technology is (largely) mature
• Combustion/conversion technology is immature
• Plants store energy at the rate of ~ 3000 EJ/yr, 2/3 on land
• Humans already manage around 1/2 of the usable land area
for food and fibre, and managed forests store ~ 600 EJ/yr.
Exa - 1018; Peta - 1015; Tera - 1012; Giga - 109; Mega - 106
1 TW = 31.54 EJ/year
Today there are opportunities to convert biomass resources into
liquid fuels, gaseous fuels and electricity to cater to
developmental needs of rural areas
Bioenergy produced locally can substitute fossil fuels and
reduce import burden and create employment in rural area
it requires coordinated efforts of scientists, and engineers to
overcome these limitations in order to translate this ‘high
potential’ technology to ‘high performing’ technology