Principle & How it works
Biomass, also known as biofuels or bioenergy, is
obtained from organic matter, either directly from
plants or indirectly from industrial, commercial,
domestic or agricultural products. The use of biomass is
generally classed as a ‘carbon-neutral’ process because
the carbon dioxide released during the generation of
energy is balanced by that absorbed by plants during
Biomass falls into the following groups, dependent
resources, dedicated energy crops and multi-functional
crops. Dependent resources are the co-products and waste
generated from agricultural, industrial and commercial
processes. This includes forest products, waste wood,
straw, slurry, animal litter and industrial and
municipal wastes (such as food processing wastes).
Dedicated energy crops are short-rotation crops, such as
coppice, miscanthus, willow and poplar, which are grown
specifically to generate biomass fuel. Multi-functional
crops are crops that can be used to create different
types of energy. For example, wheat can be used to
create fuel (including bioethanol and biodiesel), while
straw can be used to generate electricity.
Biomass can be converted into heat and electricity in a
number of ways. Depending on its source, these processes
include burning, pyrolysis (the decomposition or
transformation of a compound caused by heat),
gasification (the conversion of solid biomass into a
gaseous fuel), anaerobic digestion (the decomposition of
an organic biodegradable material by bacterial action in
the absence of air, and in warm, moist conditions) or
Biogas is generated from concentrations of sewage or
manure. These are usually in the form of slurry
comprising mostly water (almost 95 per cent). The slurry
is fed into a digester, either continuously or in
batches. Digestion takes from about 10 days up to
several weeks, at a temperature of 35°C.
Landfill gas arises from waste deposited underground in
landfill sites. Biodegradable organic waste decomposes
anaerobically to produce a gas that is roughly an even
mixture of carbon dioxide and methane. The methane
content gives it the potential as a fuel, which can then
be used to generate electricity or to provide process
Fermentation occurs when anaerobic digestion converts
sugars into ethanol with the use of micro-organisms,
usually yeast. Bioethanol can be used as a transport
fuel by mixing it with petrol or using it directly in a
modified combustion engine. Sugar cane or beet is the
most efficient source but potatoes, corn, wheat and
barley can also be used.
- Biomass, considered renewable, works with
a range of technologies.
- Biomass as a fuel source can be stored,
transported and used where and when needed.
- Alcohols and other biofuels are efficient,
viable, and relatively clean-burning as the
emissions associated with oil and coal are not
- Growing biomass crops can lead to carbon
dioxide absorption in the atmosphere and oxygen
- Biomass offers opportunities to re-use
waste such as crop residues and sewage.
- Unfortunately, there has been some evidence that
growing corps for energy leads to rising prices for
- Increased use of wood for energy generation
leads to rising prices for woods and wood products.
This adversely affects the poorer segments of
- The process also requires large areas of
land which leads to decreasing supply of land for
competing food crops.
- If biomass is directly burned, this could
contribute a great deal to global warming.
- It is still an expensive source, both in
terms of producing the biomass and converting it to
- The environmental impacts include
deforestation if trees are uncontrollably felled
which leads to soil erosion. In extreme cases,
natural disasters become more frequent.
- The process consumes a great deal of
energy because energy must be put in to grow the
plant mass and into collecting, drying and
transporting the residues to power plants.
Therefore, on a small scale there is most likely a
net loss of energy.
Where it's working (Syria, Abroad)
A large proportion of Syrian populations live in rural
areas and a considerable number of these people continue
to use biomass in the form of animal and agricultural
wastes for their energy needs such as lighting, heating,
hot water production and cooking. The quantity of
biomass used in the domestic sector has decreased over
the last twenty years with the spread of oil and gas
stoves and electrification. Other combustion of biomass
for energy includes heat generated from burning olive
leaves which is used for heating greenhouses and poultry
farms, or drying tobacco.
The Damascus city wastewater is collected in a water
treatment plant linked to a 2 MW generation plant.
In addition to direct combustion of biomass there is the
following use of biomass in Syria: Two biogas plants
(20m3 and 100 m3) owned by the Ministry of Agriculture
for cow waste at Gouta, near Damascus; Two biogas plants
(12 m3 and 35 m3) in Ezraa village, Daraa. The daily
output of the larger unit is 8 m3; Two biogas plants of
12 m3 in Der Alfradese, Hama.
Future Development & integration
In industrialised countries, the main biomass processes
utilized in the future are expected to be the direct
combustion of residues and wastes for electricity
generation, bio-ethanol and biodiesel as liquid fuels,
and combined heat and power production from energy
crops. In the short to medium term, biomass waste and
residues are expected to dominate biomass supply, to be
substituted by energy crops in the longer term. The
future of biomass electricity generation lies in biomass
integrated gasification/gas turbine technology, which
offers high energy conversion efficiencies and will be
further developed to run on biomass produced fuels.
Local Factors & Conditions
Agriculture in Syria is the primary sector having the
one of the highest percentage of contribution to GDP.
The popular crops raised include wheat and barley,
cotton, olives, sugar beet, tobacco and fruits. All
these crops can be used as multi-functional crops for
Syria’s wastewater treatment plants and landfills are
potential resources for biogas and landfill gas.
Wastewater from the main cities equals 1,154,000 m3 per
day with 85 % of the contribution from five cities,
Damascus, Aleppo, Homs, Hama and Lattakia. On a national
scale, waste amounts to between 3.6 and 4.1 million
tonnes/year. The proportion of organic waste which
decomposes to methane in landfills is about 60 %.
Landfills currently passively vent the methane gas into
the atmosphere. There are projects in progress to
collect and flare this gas so that the harmful emissions
are reduced from methane to carbon dioxide. But an even
better option is to generate electricity from methane.
Homs is the only city which collects the gas but it
still does not generate electricity from it. The cities
of Aleppo, Damascus, Homs and Hama present good
prospects for waste-to-energy plants in Syria.