How algae can be used to produce biofuel

Lesson 6
Content Section - How Algae can be used to produce Biofuel.
From lesson 5 you have discovered that there
are many uses for algae. You also have
discovered that algae can be used to produce
biofuels.
Biofuels are fuels that are made from biomass.
Biomass is material from living or recently
living organisms. Some common examples of
biomass are algae, grass and wood. Biomass
can be used to make biofuels. There are three
common types of transport biofuels in Europe;
bioethanol, biodiesel and biogas. Bioethanol
is mixed with petrol, biodiesel is mixed with
diesel and biogas (methane) can be used to fuel
specially adapted vehicles. These three types
of biofuel can be produced from algae.
Biofuel
All Biofuels are made from biomass. These
biofuels can all be produced from algae.
In this section you will learn how all three
different biofuels are made using algae.
Biodiesel
Biodiesel can be made from oils within the
algae. As we learned in a previous lesson, microalgae contains oil within its cell. This oil can be
used to make biodiesel. There are
different varieties of microalgae which contain
oil. The scientists that make the biodiesel
try to identify the species of microalgae that
have the most oil within their cells and also the
microalgae that grows best within its environment. Some microalgae have lots of oil, but are
very fragile and so will not grow well at large
scales. Once grown, the oil is removed from the
microalgae using chemicals or by squeezing oil
out of the cells using scientific equipment. Then
the oil is used as an ingredient in biodiesel.
This oil is changed chemically from plant oil to
biodiesel. The finished product can be used on
its own as pure biodiesel but is normally mixed
with ordinary diesel and used directly in cars.
There is biodiesel in most mineral diesel on sale
in Europe but it makes up less than 5% unless
otherwise noted.
BioMara gratefully acknowledges the following funders:
A project supported by the
European Union’s INTERREG
IVA Programme managed by the
Special EU Programmes Body.
Lesson Six. Page
103
Bioethanol
Bioethanol is used in petrol. Ethanol is
better known as alcohol. The word “bioethanol”
means ethanol that can be made from biomass
mainly for transport use.
Macroalgae can be used to make bioethanol.
Macroalgae that contain a high amount of sugar
are used in the production of bioethanol. The
macroalgae are cut and treated to free up the
sugars within the algae. These sugars decompose to a simple sugar called “glucose”. The
macroalgae is now a “feedstock” for the next
step.
survive and the anaerobic digestion to produce
gas the environment must be correct. The
environment consists of no oxygen (air),
correct temperature and acidity.The anaerobic
digestion results in the production of methane gas and carbon dioxide (C02). They can be
produced in a 50:50 ratio but normally there is
a little more methane than biogas. The biogas
can then be burned directly in an engine or
a cooker or upgraded for use in car engines
or for generating electricity, The remaining
sludge in the anaerobic digester can be used as
a fertiliser.
Yeast is then added to the process. During this
time there is a chemical reaction produced by
the yeast called “fermentation”. Fermentation
is when the yeast uses glucose and produces
ethanol and other components. The ethanol is
then separated from the other components by
heating it up until it boils and then cooling the
vapours. This is called distillation. The bioethanol undergoes a further filtering process to
remove water so it can then be used as an
ingredient with petrol.
Advantages of using algae as biofuel
Biofuels have many advantages as sources of
renewable energy. Algae occur naturally, grow
quickly and produce oxygen by photosynthesis. Macroalgae don’t grow on land and so do
not compete with land based plants which are
normally used for food. Therefore macroalgal
biofuels have little effect on farms or food
supplies.
Biogas
Biogas is produced naturally from the breakdown of organic material. The main
constitutent in biogas is methane gas. Macroalgae can form biogas because of its high sugar
content. It is washed, mashed up and treated
and then becomes the “feedstock”. The
feedstock then enters big tanks. At this stage
special micro-organisms called “anaerobes”
are added when conditions are correct. These
micro-organisms are special
because they live and work without oxygen.
They use the feedstock for their food and
there are a series of chemical reactions which
happen in this environment called “Anaerobic
Digestion”. When the feedstock undergoes
anaerobic digestion by the micro-organisms
they produce methane gas.
Anaerobic Digestion literally means eating
without oxygen. For the micro-organisms to
Biofuels reduce air pollution. They are
described as “carbon neutral”. This means that
carbon dioxide is used by algae and plants from
the atmosphere during photosynthesis to make
their own food but the same amount of carbon
dioxide is also returned to the atmosphere
when used as a biofuel. This means that additional carbon dioxide is not being added to the
atmosphere that is not ‘fixed’ again in the near
future in macroalgae again.
As we know that burning fossil fuels such as
petrol or coal increase pollution and increases
carbon dioxide. Carbon dioxide is a greenhouse
gas and governments throughout the world
would like us to reduce the amount of greenhouses gases and pollution. Using biofuels could
help to reduce the amount carbon dioxide in
the atmosphere.
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104
Lesson 6: How to use algae as biofuel.
Brief Summary
Aim: The aim of this lesson is to show how algae can be used as biofuel and briefly
illustrate the 3 different methods of production of biogas, biodiesel and bioethanol.
Biofuels - are made from biomass. Biomass is material from living or recently living organisms. Examples of biomass are grass, wood and algae. Both macroalgae and microalgae
are
involved in the production of biofuel. The word biofuel means fuel that is made from
biomass. Biofuel is a term used to describe biodiesel, bioethanol which is used in petrol
and methane gas which is found in biogas.
Biodiesel - Microalgae are involved in the production of biodiesel. Microalgae are chosen
for the production of biofuel based on their oil content. The oil inside the microalgae is
removed from algae by chemical means or either squeezed out. The oil is collected and
changed chemically and is then used as an ingredient in biodiesel.
Bioethanol – Bioethanol is an ingredient used in the production of petrol. Macroalgae
that contain a lot of sugar are chosen. Macroalgae are cut, mashed and treated.
The macroalgae now appear as sludge and is called feedstock.
Other micro-organisms called Yeast are added at this stage. Yeast uses the feedstock
as food and breaks down the feedstock into ethanol and other components. This process
is called fermentation. Ethanol is separated from the other components and then the
ethanol is used in petrol.
Biogas – Methane is the main ingredient in the production of biogas. Methane gas can be
produced by using macroalgae. The macroalgae must have a high sugar content.
Macroalgae are cut and mashed. Micro-organisms convert the natural sugars in
macroalgae into glucose. The macroalgae now appear as sludge and is called feedstock.
The feedstock will go into a big tank and special micro-organisms called anaerobes are
added. These micro-organisms are special because they don’t need oxygen to survive.
They work without oxygen(air). They also need an environment that has the correct
temperature and acidity. When conditions are correct the special micro-organisms
perform a series of reactions called anaerobic digestion.
Within this environment methane and other gases are produced. The methane gas is
separated and used as biogas.
Biofuel is better for the environment because biomass is easily accessible. Biomass includes grass and algae which absorbs carbon dioxide during photosynthesis. The biomass
is then used to make biofuel.
Lesson Six. Page
105
Learning Outcomes:
►► Describe how algae is used for energy and transport.
►► Explain the three procedures of producing biodiesel, bioethanol and biogas.
►► Explain why it is better to use biofuel than ordinary diesel, gas or petrol.
Introduction:
Recall from Lesson 5 that one of the uses of algae is for fuel.
Explain biomass.
Explain how natural resources such as algae can be used for biofuel production.
Describe briefly that there are three different methods for producing biofuels
by simply explaining concepts such as Fermentation and Anaerobic Digestion. Use
visual aids if neccesary.
Activity:
Activity 1. - Explanation by movement about how biofuel (Biodiesel, bioethanol
and biogas) is produced.
Final Activity:
►► Teacher revises the main learning points.
►► Teacher may ask pupils to complete Activity 2- Steps to produce Biogas,
Steps to produce Bioethanol and Steps to produce Biodiesel.
►► Ask class how algae benefits the environment.
Vocabulary: fermentation, anaerobic digestion, glucose, yeast and biomass.
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106
Steps to produce Biodiesel.
Microalgae
Oil
Biodiesel
1. Microalgae cells are specially grown and selected
for their oil content. They contain oil inside their
cells.
2. The oil is taken out of the microalgae by the use
of chemicals. The oil may also be squeezed out of
the microalgae cells by scientific equipment.
3. The oil is then changed chemically
so it can be used as biodiesel.
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107
Steps to produce Bioethanol.
1. Macroalgae is chosen because it has a high sugar
content.
Macroalgae
2. The macroalgae is cut up and treated.
It appears like sludge and it is now called feedstock.
Feedstock
Yeast
Tank
Separation
3. Micro-organisms called
Yeast are added to the feedstock mixture in a big tank.
The feedstock is changed by
the yeast to ethanol and other
components. This process is
called fermentation.
Fermentation
Bioethanol
4. The ethanol is separated from
the other components and filtered.
The bioethanol can now be used with
petrol.
Lesson Six. Page
108
Steps to produce Biogas
Macroalgae
Feedstock
Anerobic Digestion
Biogas
1. Biogas can be made using macroalgae. The
macroalgae chosen must contain a high amount of
sugars.
2. The macroalgae is then washed and cut up.
Micro-organisms help to decompose the macroalgae.
The substance is now called feedstock.
3. The next step is called Anaerobic Digestion.
It takes place in big tanks. Special micro-organisms
are added. These micro-organisms are called
anaerobes and can breakdown the macroalgae without oxygen.
They need their environment to be warm, acidic and
must contain no oxygen (air).The mixture undergoes
a series of reactions thanks to the micro-organisms.
Methane gas is produced at the end of this process.
4. Methane gas is the main ingredient of biogas
which can be used as fuel.
Lesson Six. Page
109
Curriculum Links
Scotland
Curriculum for Excellence
Level 1
Literacy and English
Listening and talking
finding and using
information
Writing, processes,
creating texts
Sciences
Planet Earth
energy sources and
sustainability
Expressive arts
Drama
Literacy and English
Listening and talking
Writing,
creating text
Science
Planet Earth
Expressive Arts
Drama
As I listen or watch, I can identify and discuss the
purpose, key words and main ideas of the text and use this
information for a specific purpose. LIT 1-04a
I can convey information, describe events or processes,
share my opinions or persuade my reader in different
ways. LIT 1-28a / LIT 1-29a
I am aware of different types of energy around me and
can show their importance to everyday life and my survival.
SCN 1-04a
I enjoy creating, choosing and accepting roles, using
movement, expression and voice. EXA 1-12a
Level 2
As I listen or watch, I can identify and discuss the purpose, main ideas and supporting detail contained within the
text, and use this information for different purposes.
LIT 2-04a
I can convey information, describe events, explain processes or combine ideas in different ways. LIT 2-28a
Through exploring non-renewable energy sources, I can
describe how they are used in Scotland today and express
an informed view on the implications for their future use.
SCN 2-04b
I can create, adapt and sustain different roles, experimenting with movement, expression and voice and using
theatre arts technology.
EXA 2-12a
Skills: Comprehend, move, question and describe.
Lesson Six. Page
110
Ireland
National Council of Curriculum and Assessment (NCCA)
First Class, Second Class
English
Oral Language, developing
cognitive abilities through oral
language
Give a description, recount a narrative or describe a
process and answer questions about it.
Writing, developing cognitive
abilities through language
Write a simple sentence and add words to it to extend its
meaning.
Social Environmental and
Scientific Education (SESE)
Science
Environmental awareness and
care, caring for my locality
Realise that there is both an individual and a community
responsibility for taking care of the environment.
Drama
Drama to explore feelings,
knowledge and ideas, leading
to understandings, reflecting
on drama
Experience, through drama, the relationships between the
story, theme and life experience.
Third Class, Fourth Class and Fifth Class
English
Writing, developing cognitive
abilities through language
Reading, receptiveness to
language
Social Environmental and Scientific Education (SESE)
Science
Environmental awareness and
care, caring for my locality
Drama
Drama to explore feelings,
knowledge and ideas, leading
to understandings, reflecting
on drama
Read a story and write it in his/her own words.
Understand the relationship between text and illustration.
Become aware of the importance of the Earth’s renewable
and non-renewable resources.
Learn through drama, the relationship between the story,
theme and life experience.
Skills: Drama, observe, read and comprehend.
Lesson Six. Page
111
Northern Ireland
Council for Curriculum Examination and Assessment (CCEA)
Key Stage 1
Language and Literacy
Talking and listening
Reading
Writing
The World Around Us
Change over time
The Arts
Drama
Listen to, interpret and retell, with some supporting detail
a range of oral and written texts.
Explore opinions and give reasons based on what they have
read.
Spell correctly a range of familiar, important and regularly
occurring words.
Positive change and how we have a responsibility to make
an active contribution.
Develop their understanding of the world by engaging in a
range of creative and imaginative role situations.
Key Stage 2
Language and Literacy
Talking and listening
Describe and talk about real and imaginary situations.
Reading
Represent their understanding of texts in a range of ways,
including visual, oral and dramatic. Writing
Express thoughts, feelings and opinions in imaginative and
factual writing.
The World Around Us
Change over time
The Arts
Drama
The effects of positive and negative changes globally and
how we contribute to some of these changes.
Develop their understanding of the world by engaging in a
range of creative and imaginative role play situations.
Skills: Question, drama, comprehend and working together.
Lesson Six. Page
112
Activity Section –
Activity 1-Explanation by movement about how biofuel (Biodiesel, bioethanol and
biogas) is produced.
This activity will explain how bioethanol, biodiesel, and biogas is produced by the
movement of pupils. It will take place in the classroom or in an open space. Pupils will represent each stage of the process. They will represent micro-organisms, sugar, glucose,
yeast, macroalgae, other components, oil and other ingredients involved in the production
of biofuels. The pupils should also be provided with labels (and some images) to name the
group which they represent. They must work together and provide the answers at all
stages.
The teacher will follow the diagrams of bioethanol, biodiesel and biogas production from
that which are supplied in the materials on page 107, 108 and 109.
The teacher may use the images provided on page 117, 119 and 121. The teacher can cut
the individual images and stick them up on the board as the class explains the production
process of each fuel. There are a few images that are not included so the pupils must use
their imagination.
The teacher may chose to explain either “production of biodiesel” or “production of
biogas” or “production of bioethanol”. Read the instructions before completing the
activity.
Production of Biodiesel
Choose 3 groups of pupils.
Choose a big group representing “microalgae”, choose a smaller group respresenting “oil”
and another group representing “other ingredients in biodiesel”
Label each group. (3 stages )
1. Teacher asks pupils about first stage of biodiesel production.
There is oil within the cell of the microalgae.
Choose the “microalgae” group and the “oil” group.
Place pupils representing microalgae around pupils representing oil within microalgae.
Teacher will use the image of microalgae on page 117 to explain the first stage of diagram
on board.
2. Teacher asks pupils to describe next stage.
The oil within the microalgae is removed by chemicals or either squeezed by machines to
release the oil.
The pupils representing the oil within the microalgae will move onto stage 2.
Teacher will use the image of the oil provided to explain this stage on the board.
3. Teacher will ask pupils to describe the next stage.
The oil from microalgae is changed chemically and then it mixes with other ingredients to
form biodiesel.
The group representing oil within microalgae will move onto stage 3 and they will join the
group representing “other ingredients in biodiesel”.
Lesson Six. Page 113
Teacher will use the image of the biodiesel pump at this stage on the board.
Production of Bioethanol
Pupils must be divided into 1 large group representing “macroalgae”. The “macroalgae”
group changes to “ethanol”, “other components” as they go along the production process.
2 smaller groups representing “Yeast”, “other ingredients in petrol”
Label each group. (4 stages)
1. Teacher will ask pupils to describe the first stage.
Macroalgae is choosen for its high sugar content.
Choose a large group to represent “macroalgae”.
Teacher will use the image of macroalgae at this stage on the board.
2. Teacher will ask pupils to describe the next stage.
The macroalgae is cut and washed and turns into sludge. The sludge-like material is now
called feedstock.
Pupils representing “macroalgae” group from stage 1 move onto stage 2.
Explain to the pupils that the macroalgae are washed, cut and mashed up. The “macroalgae” group is now labelled “feedstock”.
Teacher will use the image of feedstock to explain what happens at this stage. Place the
image on the board.
3. Teacher will ask pupils to describe the next stage.
The feedstock is placed in a tank and micro-organisms called Yeast are added. Yeast
breaks down the feedstock and produces ethanol and other components. This process is
called Fermentation. As the ethanol concentration increases the yeast micro-organisms
die.
Pupils representing the “feedstock” move to stage 3. A group of pupils are chosen to
represent “Yeast” micro-organisms. They are labelled and enter stage 3.
The “yeast” changes the “feedstock” group into “ethanol” and “other components”.
Take some of the pupils from the “feedstock” group and label them as “ethanol” and take
other pupils from the “feedstock” group and label them as “other components”.
The “yeast” micro-organisms eventually die as there is too much ethanol produced. The
pupils representing the yeast group lie on the floor respresenting death .
Teacher will use the images of Yeast, Tank and Fermentation to explain this stage. Put
all images on the the board.
4. Teacher will ask pupils to describe the next stage.
Ethanol is separated from other components. Ethanol is cleaned to become pure ethanol.
The bioethanol (which is ethanol made from biomass) becomes an important ingredient in
petrol.
The pupils representing “ethanol” are separated from “other components”. The pupils
representing “ethanol” move onto to stage 4.
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114
Choose another group of pupils representing “other ingredients in petrol”.
Mix the pupils representing “ethanol” with the pupils representing “other ingredients in
petrol” together.
Teacher will use the seperation and bioethanol images to explain this concept. Place these
images on the board.
Production of Biogas
Pupils must be divided into 1 large group representing “macroaglae”. The group
representing “macroalgae” will change throughout the production process and will be
labelled “sugars”, “glucose”, “feedstock”, “methane gas”, “fertilizer”..
3 smaller groups representing “micro-organisms”, “micro-organisms who work without
oxygen” and “other ingredients in biogas”
Label each group. (4 stages)
1. Teacher will ask pupils to describe the first stage.
The macroalgae that is chosen must be high in sugar content.
Choose a group of pupils representing “macroalgae”.
Teacher will the image of macroalgae and place it on the board.
2. Teacher will ask pupils to describe the next stage
Macroalgae is washed, cut and mashed. Micro-organisms help to break down the sugar
content into simple sugars called glucose. The environment changes, this due to
moisture content, acidity and temperature change cause micro-organisms to then die. The
macroalgae over time turn into sludge and this is called feedstock.
Move pupils representing “macroalgae” to stage 2.
Choose some pupils within this group to represent sugars. Label them “sugars”. Get the
sugar group to hold hands. Introduce a new group and label them as
“micro-organisms”. The “micro-organisms” group will unlock the hands of the sugar group.
This represents the micro-organisms breaking the sugar into simple sugars called
glucose. Label the sugar group as “glucose”.
The “glucose” group and the remaining “macroalgae” pupils all become one group and will
be labelled as “feedstock”
The group representing “micro-organisms” will lie on the floor as the micro-organisms will
die due to the environmental conditions.
Teacher will use the image of feedstock to explain this stage. Place the image on the
board.
3. Teacher will ask pupils to describe the next stage
All of the feedstock will enter big tanks called anaerobic digesters where the
environment and temperature is controlled. In this environment there is no oxygen.
Special micro-organisms are added. This environment is ideal for producing methane gas.
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Pupils representing the “feedstock” all enter the tanks at stage 3.
Choose a group of pupils who represents special micro-organisms who can work without
oxygen. Label them as “microorganisms who work without oxygen”.
Mix the groups labelled “microorganism who can work without oxygen” and the “feedstock” together.
Teacher will use the image of Anaerobic Digester to explain this stage. Place the image
on the board.
4. Teacher will ask pupils to describe the next stage.
In the Anaerobic Digester a number of chemical reactions take place. The
micro-organisms that work without oxygen use the feedstock as food and break them
down. Over time methane gas and other gases are produced. The remaining feedstock
are converted to fertilizer. Fertilizer will help grass to grow. The micro-organisms will
die as there is too much gas produced.
Move both groups to the stage 4.
This will include the group labelled “feedstock”and “microorganisms who work without
oxygen”.
Get the “micro-organisms who work without oxygen” to separate from the “feedstock”
representing the fact that the micro-organisms use the feedstock as food.
Take some members of the “feedstock” group and label them as “methane gas”. Some of
the micro-organisms die off at the end of the process. The group representing
“microorganisms who work without oxygen” lie down on the floor to represent that they
are now dead.
The “methane gas” group separate from the feedstock. The rest of the “feedstock”
group are then labelled “fertilizer”.
Choose another group and label them “other ingredients used in biogas”. Mix the
“methane gas” group with the group labelled “other ingredients used in biogas”. This
group now becomes “biogas” as the main ingredient in biogas is methane gas.
Methane gas is the main gas used in biogas. Biogas is a type of biofuel.
Teacher will use the image of biogas to explain this stage. Place the image on the board.
the diagram on the board.
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Lesson Six. Page
117
Microalgae
Oil
Biodiesel/ Biogas
Macroalgae
Tank
Lesson Six. Page
119
Feedstock
Fermentation
Yeast
Lesson Six. Page
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Bioethanol
Anaerobic Digestion
Activity 2 – Steps to produce Biodiesel.
Name
1.
Microalgae
2.
Oil
3.
Biodiesel
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Activity 2 – Steps to produce Bioethanol.
Name
1.
Macroalgae
2.
Feedstock
3.
Yeast
Fermentation
Tank
4.
Seperation
Bioethanol
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Activity 2 – Steps to produce Biogas.
Name
1.
Macroalgae
2.
Feedstock
3.
Anaerobic Digestion
4.
Biogas
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Activity 3 - What am I?
Name
I am a fuel that can be used in cars or to generate heat in houses or generate electricity.
The main component involved is methane and carbon dioxide. What am I?
My name is used to describe a group of environmentally friendly fuels. I can be described
as a renewable fuel where my raw products can be grown naturally and can be used for
other purposes. I am not a fossil fuel. What am I?
I am a fuel. I am produced by microalgae resulting in oil production. I can be blended
with other normal fuel. What am I?
I am a fuel. I use micro-organisms called yeast to breakdown the feedstock and
produce ethanol. What am I?
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Questions
1.
What is the one common name for biodiesel, biogas and bioethanol produced by
algae?
2.
Name some examples of biomass?
3.
How is oil taken out of microalgae?
4.
What is the name of the substance when sugars are broken down (decomposed)?
5.
What is the name of the micro-organisms involved in fermentation?
6.
What do you call the micro-organisms that do not require oxygen?
7.
What is the name of the main gas in biogas?
8.
When the process of biogas production is finished, how can the leftover feedstock
be used?
9.
Apart from fuel, what are the other uses of biogas?
10.
Where is biogas made?
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Answers
Activity 2
Steps to produce Biodiesel
1. Microalgae cells are specially grown and selected for their oil content.
2. The oil is taken out of the microalgae by the use of chemicals. The oil may also be
squeezed out of the microalgae cells.
3. The oil is then changed chemically so it can be used as biodiesel.
Steps to produce Bioethanol
1. Macroalgae is chosen because it has a high sugar content such as
Laminaria digitata (Oarweed) or Saccharina latissima (Sea belt).
2. The macroalgae is cut up and treated.
It appears like sludge and the substance is now called feedstock.
3. Micro-organisms called yeast are added to the mixture in a big tank. The feedstock is
changed by the yeast to ethanol and other components. This process is called
fermentation.
4. The ethanol is seperated from the other components and filtered. This can now be
used with petrol.
Steps to produce Biogas
1. Biogas can be made using macroalgae. The algae chosen must contain a high amount of
sugars.
2. The macroalgae is then washed and cut up. Micro-organisms help to decompose the
macroalgae. They help to break down the sugars. This makes it easier to produce biogas.
The substance is now called feedstock.
3. The next step is called Anerobic Digestion.
It takes place in big tanks. Special micro-organisms are added. They can breakdown the
macroalgae at this stage without oxygen. They need their environment to be warm, acidic
and free from oxygen(air). The mixture undergoes a series of reactions thanks to the
special micro-organisms called anaerobes. Methane gas is produced at the end of this
process.
4. Methane gas is the main ingredient of biogas which can be used as fuel.
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Activity 3 - What am I?
I am a fuel that can be used in cars or to generate heat in houses or generate electricity.
The main component involved is methane and carbon dioxide. What am I?
Answer: Biogas.
My name is used to describe a group of environmentally friendly fuels. I can be described
as a renewable fuel where my raw products can be grown naturally and can be used for
other purposes. I am not a fossil fuel. What am I?
Answer: Biofuel.
I am a fuel. I am produced by microalgae resulting in oil production. I can be blended
with other normal fuel. What am I?
Answer: Biodiesel.
I am a fuel. I use micro-organisms called yeast to breakdown the feedstock and can
produce ethanol. What am I?
Answer: Bioethanol.
Questions
1. What is the one common name for biodiesel, biogas and bioethanol produced by algae?
Answer: Biofuels are known as biodiesel, biogas and bioethanol.
2. Name some examples of biomass?
Answer: Grass, algae, and wood.
3. How is oil taken out of microalgae?
Answer: Oil can be squeezed out of microalgae by using special machines or chemicals.
4. What is the name of the substance when sugars are broken down
(decomposed)?
Answer: Glucose.
5. What is the name of the micro-organisms involved in fermentation?
Answer: Yeast.
6. What do you call the micro-organisms that do not require oxygen?
Answer: Anaerobic micro-organisms are called “anaerobes.
7. What is the name of the main gas in biogas?
Answer: Methane gas.
8. When the process of biogas production is finished, how can the leftover feedstock be
used?
Answer: It can be used as fertilizer.
9. Apart from fuel, what are the other uses of biogas?
Answer: Heating and electricity.
10. Where is biogas made?
Answer: In big tanks called Anaerobic Digesters.
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