2. I. Where is biogas used:I. Where is biogas used:
Biogas has been used all over theBiogas has been used all over the
world.world.
It is primarily used by farmers and inIt is primarily used by farmers and in
rural areas to reduce costs of citiesrural areas to reduce costs of cities
powering stationspowering stations
Becoming more popular in higherBecoming more popular in higher
populated areas.populated areas.
3. II. What is the raw materialII. What is the raw material
for producing biogasfor producing biogas??
Biodegradable Waste Materials:Biodegradable Waste Materials:
Poultry ManurePoultry Manure
Human ManureHuman Manure
Poultry Offal (the blood, guts and gore)Poultry Offal (the blood, guts and gore)
Commercial Food Waste StreamsCommercial Food Waste Streams
Onions, green beans, potatoes, cookingOnions, green beans, potatoes, cooking
oils, cheese wastes, eggs and grainoils, cheese wastes, eggs and grain
5. III. What are the technologicalIII. What are the technological
limitations of the resource?limitations of the resource?
Supply of raw material: variation of theSupply of raw material: variation of the
capacity and the qualitycapacity and the quality
Processing technology: Relatively slowProcessing technology: Relatively slow
process and limited productivity. Could notprocess and limited productivity. Could not
be treated as usual production processbe treated as usual production process
(automation, etc.)(automation, etc.)
Require future research to improve theRequire future research to improve the
technology, that can substitute thetechnology, that can substitute the
conventional fuel.conventional fuel.
6. Biochemical Process: Anaerobic Digestion
Biological degradation of organic volatile solids in theBiological degradation of organic volatile solids in the
absence of oxygen:absence of oxygen:
1. Hydrolysis1. Hydrolysis
2. Fermentation2. Fermentation
3. Acetogenesis3. Acetogenesis
4. Methanogenesis4. Methanogenesis
Products of anaerobic digestion include water,Products of anaerobic digestion include water,
undigested volatile solids, inert materials and biogasundigested volatile solids, inert materials and biogas
IV. Biogas Production
7. 4.1. Anaerobic Digestion Process (1)4.1. Anaerobic Digestion Process (1)
the raw organic residue (raw sewage, manure and other suchthe raw organic residue (raw sewage, manure and other such
resources) that is required in this process is converted to itresources) that is required in this process is converted to it
usable energy state by bacteria breaking down methaneusable energy state by bacteria breaking down methane andand
releasing COreleasing CO22, which is the energy source sought after in this, which is the energy source sought after in this
conversion.conversion. Since it is a cycling of carbon so it isn’t actuallySince it is a cycling of carbon so it isn’t actually
released into the atmosphere.released into the atmosphere.
happens though a series of chemical breakdownhappens though a series of chemical breakdown (see chart on(see chart on
next slide)next slide)
required bacteria in this process, the raw material must berequired bacteria in this process, the raw material must be
belowbelow a temperaturea temperature ofof 6060°°cc oror 140140°°FF . This helps the material. This helps the material
to be broken downto be broken down
process is also naturally occurring as well.process is also naturally occurring as well.
15. V.V. Use of Biogas.Use of Biogas.
In the Past:In the Past:
it is believed that a form of this gas wasit is believed that a form of this gas was
usedused by the Babylonians to heat water.by the Babylonians to heat water.
By 1850 the concept of biogas was startingBy 1850 the concept of biogas was starting
to become better understood and in sewageto become better understood and in sewage
processing plant was built to create biogas,processing plant was built to create biogas,
and this energy was used to illuminateand this energy was used to illuminate
streetlights.streetlights.
16. Present and Future UsePresent and Future Use
Biogas has been used for many purposes, itBiogas has been used for many purposes, it
best to used for direct use such as heatingbest to used for direct use such as heating
and cooking.and cooking.
It can be used as the fuel for vehicleIt can be used as the fuel for vehicle
engines, with higher efficiency and lessengines, with higher efficiency and less
pollutants than using gasoline fuel.pollutants than using gasoline fuel.
It may also be used to produce electricityIt may also be used to produce electricity
using gas turbine or engine, with less thanusing gas turbine or engine, with less than
30% of the energy of the biogas converted30% of the energy of the biogas converted
to electricityto electricity..
17. VI. How do the production,VI. How do the production,
transportation and use of biogastransportation and use of biogas
affect the environment:affect the environment:
cleanest and least toxic in the world. machinery required tocleanest and least toxic in the world. machinery required to
heat the raw materials is non-polluting, and it is a completelyheat the raw materials is non-polluting, and it is a completely
natural processnatural process
Also through manufacturing biogas landfills and sewageAlso through manufacturing biogas landfills and sewage
systems become smaller and the process creates an odourlesssystems become smaller and the process creates an odourless
gas, and a high nutrient fertilizergas, and a high nutrient fertilizer
in a way the production of this form of gas is better for thein a way the production of this form of gas is better for the
environment than not producing it.environment than not producing it.
transportation of biogas is done through trucks similar totransportation of biogas is done through trucks similar to
those that transport any other gas.those that transport any other gas.
clean burning and completely natural so it has noclean burning and completely natural so it has no
adverse effects on the environment. It also reduces theadverse effects on the environment. It also reduces the
amount of methane and carbon dioxide released into theamount of methane and carbon dioxide released into the
environment.environment.
18. Pros and ConsPros and Cons
ProsPros
RenewableRenewable
High nutrient fertilizer producedHigh nutrient fertilizer produced
in excess.in excess.
Environment friendly.Environment friendly.
Reduces methane and carbonReduces methane and carbon
dioxide release into the air.dioxide release into the air.
Cheap to produce.Cheap to produce.
Many different uses.Many different uses.
Reduces landfill sites, sewageReduces landfill sites, sewage
drainage, and farm manure.drainage, and farm manure.
Clean/ quiet fuel for cars andClean/ quiet fuel for cars and
trucks.trucks.
ConsCons
Reduced powerReduced power
from vehicles.from vehicles.
Extra time requiredExtra time required
to produce into produce in
comparison to othercomparison to other
energy resources.energy resources.
