Renewable Energy from Biomass
and Biofuel
Biomass
Biomass is the general term for natural or organic
fuel source. Biomass is produced from organic materials
derived from recently living plant organisms or from metabolic
by-products such as organic or food waste products.
The principle behind biomass is that as a tree grows
it absorbs carbon dioxide which it stores in its woody tissue and
when the wood is burned, the same amount of carbon dioxide is
released back into the atmosphere making the process what is known
as carbon neutral.
Biomass fuels falls into two main categories:
Woody biomass
- includes forest products, untreated wood products, and energy
crops. When burned, the chemical energy in biomass is released as
heat. If you have a fireplace at home, the wood you burn is a
biomass fuel. Wood waste or garbage can be burned to produce steam
for making electricity or to provide heat to industries and homes.
For small scale biomass systems, the application of biomass fuels
like woody chips, wood pellets and logs are used in domestic boilers
and stoves.
Non woody biomass
- includes animal waste, industrial and biodegradable municipal
products from food processing and high energy crops for example:
rape, sugar cane and maize.
You can use biomass to heat your home through:
Stand alone stoves which provide space heating for a
room. These can be fuelled by logs or wood pellets. Stoves can
provide a significant amount of heat (between 6-12KW) and with some
systems, it is possible to attach a back boiler for hot water
heating and central heating through radiators.
Biomass boilers are connected to central heating and
hot water systems and can provide heating for an entire property.
These are suitable for pellets, logs or chips and are
generally larger than 15 kW.
There are many types of domestic boilers available,
they include:
Log stoves/boilers which burn logs directly
Wood chip boilers which burn wood chips
Pellet stoves/boilers burn wood pellets
Multi-fuel stoves can burn a range of solid fuel
types
Ceramic stoves burn wood products and store heat in
thermally massive ceramic tiles for release throughout the day
Many boilers have dual fire for both wood chips and
pellets.
Wood pellets are a
homogeneous fuel with high energy density; the boilers can be
simpler and cheaper. Requirements for storage are smaller than for
logs and heating comfort is equal to oil fired boilers.
What to consider before committing to a biomass
boiler:
Storage space - Storage space is needed for supply of
wood pellets, wood chips or logs and it must be easily accessible to
the boiler.
Is there a local supplier for your supplies of wood
chippings, pellets and logs.
Is your flue specifically designed for use with
appliances that use wood as a fuel. Flues that don’t meet these
requirements can be fitted with a lining tube.
Compliance with any regulations from your local
authority in regards to biomass system installation for example,
safety and building regulations and smokeless zones. Most biomass
fuels are smokeless and so do comply with the Clean Air Act.
The costs of using a using a biomass system consists
both of the cost of the boiler and the running cost of the fuel. The
cost for boilers varies depending on the type and size of system you
choose. Running fuel costs generally depend on the accessibility and
nearness of your fuel supplier.
Biomass is a good alternative energy source over
fossil fuel. It is renewable and it’s generally commonly available.
Biofuels
Biofuel is any fuel
derived from biomass. Biofuel is a renewable energy source.
Agriculturally
produced biomass fuels such as biodiesel and ethanol can be burned
in internal combustion engines such as cars or boilers.
Biofuels can help
reduce carbon emissions, greenhouse gas build up and dependence on
fossil fuels. Biofuels are commonly used to power vehicles and
cooking stoves.
Types of Biofuels are:
Vegetable
oils
Biodiesel
Ethanol
Biofuel can be
considered as carbon neutral as the energy produced by biofuels does
not contribute to any increase of carbon into the atmosphere. The
reason is the plants used to produce the biofuel have removed CO2
from the atmosphere during growth whereas fossil fuel release carbon
which had been stored beneath the surface for millions of years back
into the air. |