Biogas is a renewable energy source produced from the breakdown of organic matter by bacteria in anaerobic digesters. It is composed primarily of methane and carbon dioxide. Biogas can be produced from various organic wastes and used to generate electricity, heat homes, fuel vehicles or cook food. Large commercial biogas plants process thousands of cubic meters of waste materials like manure and food scraps, while smaller household digesters are also common.

1. REPRESENTED BY-
HARSHITA SINGH
CIVIL ENGINEER

2. INTRODUCTION
Biogas typically refers to a mixture of gases produced
by the breakdown of organic matter in the absence of
oxygen.
 Biogas can be produced from regionally available raw
materials such as recycled waste.
 It is a renewable energy source and in many cases
exerts a very small carbon footprint.
Biogas can be compressed, the same way natural gas
is compressed to CNG, and used to power
motor vehicles.

3. Typical composition of biogas
Compound Molecular formula %
Methane CH4 50–75
Carbon dioxide CO2 25–50
Nitrogen N2 0–10
Hydrogen H2 0–1
Hydrogen sulphide H2S 0–3
Oxygen O2 0–0

4. ‘GOOD’ or ‘BAD’?
Sort these FUELS from BEST to WORST. There’s no right
answer so think about why you’ve chosen that order.
Methane
Coal
The North Wind
A cowpat
A banana skin
A tree
Sunshine
A waterfall
Your legs
Uranium
GOOD
BAD

5. What is biogas?
• A mixture of methane
and carbon dioxide
CH4
CO2 • Methane or ‘swamp gas’,
produced naturally in
swampy ponds
What is this?

6. What is it used for?
• Biogas is a fuel used as an
energy source for light, heat
or movement
?

7. Biogas is produced by the breakdown of
organic waste by bacteria without oxygen
(anaerobic digestion or fermentation).
How is it made?
Leftover food from houses,
shops, restaurants and
factories
Cow, sheep and
chicken manure Sewage
Leftover meat
and blood from
abattoirs
Leftover straw
and crops from
farming
What types of organic waste
could be turned in biogas?

8. Biogas is made by fermenting organic waste in a
biogas digester.
Digesters vary from small household
systems…
How is it made?

9. Holsworthy Biogas Plant, Devon
….to large commercial plants of several thousand cubic metres

10. CREATE A SENTENCE USING THE
KEYWORDS TO COMPARE THE TWO
CASE STUDIES
KEYWORDS
Electricity generators at Holsworthy
Katakwa’s biogas stove
environmental
electricity
methane manure
biogas
Anaerobic
digestion
greenhouse
gases
organic waste pollution

11. Biogas production in rural
Germany
Biogas is practically produced as landfill gas (LFG) or
digested gas.
A biogas plant is the name often given to an anaerobic
digester that treats farm wastes or energy crops.
 It can be produced using anaerobic digesters.
These plants can be fed with energy crops such as maize
silage or biodegradable wastes including sewage sludge
and food waste.
 During the process, an air-tight tank transforms biomass
waste into methane, producing renewable energy that can
be used for heating, electricity, and many other operations
that use an internal combustion engine, such as
GEJenbacher or Caterpillar gas engines.

12. Applications
Biogas can be used for electricity production on
sewage works, in a CHP gas engine, where the waste
heat from the engine is conveniently used for heating
the digester; cooking; space heating; water heating;
and process heating.
 If compressed, it can replace compressed natural gas
for use in vehicles, where it can fuel an
internal combustion engine or fuel cells and is a much
more effective displacer of carbon dioxide than the
normal use in on-site CHP plants.

13. Biogas in transport
If concentrated and compressed, it can be used in
vehicle transportation.
Compressed biogas is becoming widely used in
Sweden, Switzerland, and Germany.
In 1974, a British documentary film titled Sweet as a
Nut detailed the biogas production process from pig
manure and showed how it fueled a custom-adapted
combustion engine.
In 2007, an estimated 12,000 vehicles were being
fueled with upgraded biogas worldwide, mostly in
Europe.

14. CONCLUSION
Biogas typically refers to a mixture of gases produced
by the breakdown of organic matter in the absence of
oxygen.
 Biogas can be produced from regionally available raw
materials such as recycled waste.
It is a renewable energy source and in many cases
exerts a very small carbon footprint.
The gases methane, hydrogen, and carbon monoxide
(CO) can be combusted or oxidized with oxygen.