Species use for the production - HelhaPHL2010-02


Dec 5, 2012 (5 years and 7 months ago)




and Biotechnologie

HELHa Agronomie



Temporary rapport

The production of algae coupled to anaerobic
digestion in a closed vessel system for bio

Group 2:

Anke Hauben

Marine D'Aulisa

Dorien Janssens

Jessica Leonard

Bjorn Tordoor

Aline Verbist

Selien Sanchez


B. Cornelis

O. Janssens



The 21st century is marked by one of its greatest challenges: environmental protection

energy production. Actually, during a lot of years, the relationship of ' environment' and ' energy'
was not friendly co
existents. The environment had suffered of the huge production of energy in
the context of our modern society. And the situation i
s going on! That is why the scientists have
begun to think about a way to combine the protection of the environment and the production of
energy. One of these ways is th
e biofuels.

What are bio fuels?


are solid, liquid or gas fuel refined in whole or in part from biomass ( that means plant
matter cultived or processed for use as biofuel). Unlike fossil fuel (from petroleum, coal...in
summary, natural resources) which are of limited availability, bio f
uels are not finite
resources.We can also add that biofuels respect the climate much more than fossil fuel.(Indeed, a
recent UK government publication declared that biofuels consumption has reduced emissions of
carbon dioxide « by 50
60% compared to fossil

fuels ».) That is an other significant reason to
produce them.

There is a diverse and long list of biofuels, but in recent years the ter
m « bio fuel » has come to

ethanol: an alcohol usually mixed with petrol.

diesel: either used on its own or in a mixture.

For their production, the resources we can use are for example: corn, soys, beans, palm oil...
(crops) but also wood ch
ips, straw, sewage...and algae.

Bio fuel from first and second generation

We can di
vide the bio fuels between the ones from the first

generation and the ones from the
second. These two dividings up are the well known because these bio fuels are put into
practice.Meanwhile, there is an other generation, the third, that is at the experime
ntal stage.

What means « first generation »? this production is characterised by mature commercial
markets and well understood technologies. But these bio fuels have many problems. Namely
not limited to:

they contribute to higher food price
s due to competition with food crops

they are expensive to produce

they are accelerating the deforestation

they do not meet their claimed environmental benefits because the biomass feedstock may
not always be produced sustainably

There are others disadvan
tages but we are not explining all of them in this article.

The second generation of biofuel aims to resolve the problems associated to the « first
generation ».

It is derived from lignocellulosic crops.Actually,plants are made from lignin and cellulose
second generation technology allows these two components of a plant to be split.After that, the
cellulose can be fermented into alcohol much in the same way as a first generation biofuel.

But this generation has also has her disadvantages.

To be completed


Bio fuel from the third


The last generation of bio fuels is the third generation. It is this generation that interesses this
article because it is the algae one.

Has to be completed

What are the advantages of algae biofuel?

Unlike to the biofuel produced with soya, corn,palm ,..(products of agriculture), algae is
not an aliment for humans, so its production does not deprive people of food. Moreover its
not compete with a
griculture food crops for land.

In the same way,algaes d
oes not dependant on a particular landscape or soil type in order
to grow ( we can even use abandoned land or land that is not suitable).

We do not need for huge land to cutlivate algae either. For instance: for the USA, only 3%
of the cultivating land of
the country would be necessary to produce all the biofuel for the

Sea water can be used for the culture and only a
small amount of it is required.

Another one of the important advantage is the time needed to cultivate

and harvest algae.
It is ve
quick.It is one of the fastest growing plant in the world.

The yields in this production is much higher than other productions type like soya or corn.
Algae contain much more energy per
unit of weight than other crops

About its impact in the environment
, biofuel from algae is non
toxic, highly biodegradable
and contains no sulfur.

Moreover,algae plants could sequester the CO2 and use it for their growth. It is a very
tant point for the environment.

Finally,the production of microalgae generates by
roducts that can be used for a lot of
things like for example food for animals.

=From Marine (references?)


Algae in general

(has to be finished)

There is two kind of algae on the earth: the macroalgae and the mircoalgae.
We are only
interested in the microalgae in this article.Indeed, it is the microalgae that are used for the
production of biofuel. What are the caracteristics of these algae?

The microalgae

Microalgae are , as the word says it, microscopics (~ 1 to 50 µm
). A big majority of microalgae
produces unique molecules like enzymes, antioxidants, fatty acids,....They are vegetable so they
are able to perform photosynthesis. That is why they are essential for the life on the earth.They
account for approximately hal
f of the production of the atmospheric oxygen and they grow using
the greenhouse gas carbon dioxide . Finally, microalgae are the basis of the food chain.

All this shows the important role of microalgae.

Species use for the production

There is a lot of microalgae species. Their exact number is unknown because there is so much of
them. It is said that only 10 percent of the species are identified.For the moment, the registered
species varies between 25 and 40 thousands.

All the different species are grouped in classes. Among all these species, only somes of them, for
the moment, are used for the microalgal biotechnology. The three mean ones are
chlorella, Dunaliella . The chlorella and the dunaliella a
re members of the chlorophyceae
class and the spirulina is a member of the cyanophyceae class.

A huge part of the algea are still untapped. That means that microalgae have an enormous

from Aline (references



Methane produced by anaerobic d
igestion of algal biomass.

What is anaerobic digestion?

(copy from http://www.oilgae.com/ref/glos/anaerobic_digester.html)

Anaerobic digestion is a process in which microorganisms break down biodegradable material
in the absence of oxygen. The process is w
idely used to treat wastewater sludges and organic
wastes because it provides volume and mass reduction of the input material.
As part of an
integrated waste management system, anaerobic digestion reduces the emission of landfill gas
into the atmosphere

Has to be rewritten

What is biomass?

(Copy from http://www.oilgae.com/ref/glos/algal_biomass.html)

Biomass, in ecology, is the mass of living biological organisms in a given area or ecosystem at a
given time. It can include microorganisms, plants or animal
s. Algal biomass is the amount of
algae in a water body at a given time.
Has to be rewritten

What is methane?

(copy from http://www.oilgae.com/algae/pro/met/met.html)

Methane is important for electrical generation by burning it as a fuel in a gas turbine or steam
boiler. Compared to other hydrocarbon fuels, burning methane produces less carbon dioxide for
each unit of heat released. At about 891 kJ/mol, methane's combus
tion heat is lower than any
other hydrocarbon; but a ratio with the molecular mass (16.0 g/mol) divided by the heat of
combustion (891 kJ/mol) shows that methane, being the simplest hydrocarbon, produces more
heat per mass unit than other complex hydrocarb
ons. In many cities, methane is piped into
homes for domestic heating and cooking purposes. In this context it is usually known as natural
gas, and is considered to have an

content of 39 megajoules per cubic meter, or 1,

per standard cubic foot.

Methane in the form of compressed natural gas is used as a vehicle
, and i
s claimed to be
more environmentally friendly than fossil fuels such as gasoline/petrol and diesel.
Has to be

The use of algal biomass

(copy from http://www.oilgae.com/algae/pro/met/met.html)

Theoretically, methane can be produced from any of the three constituents of

carbohydrates, proteins and fats. Closed algal bioreactors offer a promising alternative route for
biomass feedstock production for bio
e. Using these systems, micro
algae can be grown
in large amounts (150
300 tons per ha per year) using closed

systems (lower yields
are obtained with open pond systems). This quantity of biomass can theoretically

400,000 m of methane per ha per year.
Has to be rewritten



does the production process work?

(copy from

Methane Production by Anaerobic Digestion

This appears to be the most straight
forward method of producing methane from algae.

A process for obtaining methane from algae, involves the following successive stages:

treatment of the algae, capable of
producting a liquid suspension of fine solid particles,
said treatment being moreover capable of partially depolymerizing the solid algae matter,

Running the suspension through a fluidized bed containing granules on which enzymes
are immobilized which are capable of transforming the particles into sugar, said liquid
containing acidific bacteria capable of transforming said sugars into volatile fatty


Decantation of the suspension, so as to remove any solid particles that may remain, and to
extract a decanted liquid, and

Running the decanted liquid across a fixed bed containing methanogenic bacteria set onto
a support so as to cause the liquid

to release a gas mixture containing mainly methane.

Methane Production by Pyrolysis / Gasification

• One possibility for making methane from algae is the direct pyrolysis of microalgae. Wu et al.
(1999) report the direct pyrolysis of marine nanoplankt
on as a source of methane and oils with
Emiliania huxleyi, a widely distributed coccolithophorid species in world oceans with the
authors suggesting this as one of the most promising candidates for the production of biofuel.

• Methanation of syngas prod
uced from gasification of Algal Biomass is another route to
produce methane
rich syngas, sometimes also called synthetic natural gas.
Has to be rewritten

=from Bjorn


Biodiesel from microalgae oil

It is generally known that the use of petroleum sourced f
uels leads to the global warming of our
planet and that they are limited available. Before the petroleum fuels are exhausted it is
necessary to find solutions.

Biodiesel derived from oil crops is a potential renewable and carbon neutral alternative to
petroleum fuels. Unfortunately, they cannot realistically satisfy even a small fraction of the
existing demand for transport fuels.

The last few years there came a new course that can fix all that problems: the use of micro
Some species of algae ha
ve been claimed to be up to 20 times more productive per unit area than
oil palm, currently the most productive bio
(Chisti Y. 2007)

Other advantages of algae are that they don’t require arable land. They can grow everywhere,
even in the desert, so there is no competition with food crops for agricultural land. Many species
tolerate high nutr
ient wastewater from industrial sources, which may already contain the right
nutrients. These can be added to the algal growth media directly. This is cheaper and the
wastewater become clear. Another option is salt water, so competition for water will be l

Furthermore, the CO

released from industrial processes can be diverted through an algae
cultivation facility, so they can be used to grow the algae, there is no emission.
(Campbell N.M.

The byproducts like fats, su
gars and proteins could be recycled for animal feeds or even as
replacements for other petroleum products like ethanol.
(Alok J 2

Species used for the production of biodiesel

(has to be rewritten


, green algae, are the strain most favored by researchers. However, green algae
tend to produce starches instead of lipids and require nitrogen to grow.
They have the
advantage that they have very high growth rates at 30°C and at high light levels in aqueous

, diatom algae, are also favored by researchers. One drawback is that the diatom
algae require silicon to be present in the gr
owth medium. When algae are grown under nutrient
deficient conditions, the algae produce more oils per weight of algae, but the amount of algae
produced was reduced. Most algae are tolerant to temperature fluctuations, but diatoms have a
narrow temperature


Botrycococcus braunii

also known as pond scum or
green algae.

Researchers identified the most dramatic increases in the lipid content of the cultures during N
deficient conditions. Biochemical studies have also suggested that acetyl
CoA carboxylase
(ACCase), a biotin
containing enzyme that catalyzes

an early step in fatty acid biosynthesis, may
be involved in the control of this lipid accumulation process. Therefore, it may be possible to
enhance lipid production rates by increasing the activity of this enzyme via genetic



Methods of growing algae for biodiesel

Open ponds

The most natural method of growing algae for biodiesel
production is through

growing. Using open ponds,
algae can grow in hot, sunny areas so
they get maximum
production. This one is the least invasive of all the growing
techniques, but it has some drawbacks. Bad weather can stunt
algae growth, as can contamination from strains of bacteria or
other outside organisms. The water in which the algae

grow also
has to be kept between 20 and 30 degrees, which can be difficult
to maintain.
(Newman S. 2010)

Vertical growth/closed loop production

Vertical growth

or closed loop production

has been
developed to produce algae faster and more efficiently than open
pond growth. With vertical growing, algae are placed in clear
plastic bags, so they can be exposed to sunlight on two sides. The
bags are protected from th
e rain by a cover. The extra sun
exposure increases the productivity rate of the algae, which in
turn increases oil production. The algae are also protected from
(Newman S. 2010)

tank bioreactor

Other companies are constructing
tank bioreactors


help increase oil rates even further. Instead of growing algae
outside, indoor plants are built with large, round drums that
grow algae under ideal conditions. The algae are manipulated
into growing at maximum levels and can be harvested every
(Newman S. 2010)

Solar collectors, solar concentrators, or
fibre optics allow the sunlight to reach algal cells in the thin,
horizontal tubes or by directing light, through a
fibre optic
(Campbell N.M. 2008)

Closed bioreactor plants can also be
strategically placed near energy plants to capture excess carbon
dioxide that would otherwise pollute the air.
(Newman S. 2010)

Figure 3
(Oilgae 2010a)

: an open pond in Israel
(LaMonica M. 2008)

: vertical system of
hylene sleeves in
(Steger C. 2009)



Researchers are testing another variation of the closed
container or
pond process: fermentation. Algae are cultivated in stainless
steel tanks, similar to what you see in a brew pub, and fed sugar to
promote growth.

The benefit of this process is t
hat it allows the algae biodiesel to be
produced anywhere in the world. Therefore fermentation offers the
most control of all the methods. Each fermentation vat contains a
single species. Temperature, pressure, and other environmental
conditions can be min
utely controlled.
(Michael K. 2008)

The big
advantage is that it cost more and researchers are still trying to figure
out where to get enough sugar without creating problems.
(Newman S.

Ways to extract algae

(has to be rewritten)

Oil press

il press

is the simplest and most popular method. This one is similar to the concept of the
olive press. They just let the algae dry out and then extract the oil by pressing. It can extract up
to 75 percent of the oil from the algae being pressed.

the hex
ane solvent method

With the hexane solvent method you can extract up to 95 percent of oil from algae. This is a two
part process. First, the press squeezes out the oil. Then, leftover algae is mixed with hexane,
filtered and cleaned through distillation
so there's no chemical left in the oil.

the supercritical fluids method

supercritical fluids method

extracts up to 100 percent of the oil from algae. Carbon dioxide
acts as the supercritical fluid, when a substance is pressurized and heated to change

composition into a liquid as well as a gas. At this point, carbon dioxide is mixed with the algae.
When they're combined, the carbon dioxide turns the algae completely into oil. But the
additional equipment and work make this method a less popular opt
(Newman S. 2010)

The Ultrasonic
assisted extraction

In this process ultrasonic waves are being sent around the algae sending shock signals on to the
organisms. As a re
action to the wave they release oil substances into a solvent that can be easily
oil 2010)


(Stephen G. 2010)



Once the oil is extracted, we can make biodiesel from it. This happens in a process called

The fat or oil react with an alcohol, usually methanol or ethanol in the
presence of a catalyst such as potassium hydroxide or sodium hydroxide.
(Hess Scott M. 2010)

The end products of this reaction are hence biodiesel, sodium ethanolate and glycerol. To
separate this end
mixture ether and salt water are added en

mixed well. After sometime, the
entire mixture would have separated into two layers, with the bottom layer containing a mixture
of ether and
. This layer can also be separated.
(Oilgae 2010b)

Figure 5
(Chisti Y. 2007)

=from Dorien



Hydrogen is one of the most promising fuels for the future. The main advantage of hydrogen fuel
is that there is no emission of greenhousegases. The combustion of hydrogen gas produces only
water vapor, unlike fossil fuels, there will be no release of carb
on dioxide.

Another advantage is that hydrogen is almost inexhaustible. New hydrogen can be made from

The viability and future of H

depends entirely upon the development of efficient, large
and sustainable H2 production systems. Currently
, hydrogen is produced using non renewable
technologies such as steam reformation of natural gas, coal gasification and petroleum refining.

Process (has to be rewritten)

Photosystem II (PSII) drives the first stage of the process, by splitting H
O into
protons (H
electrons (e
), and O
. Normally, the photosynthetic light reactions and the Calvin cycle produce
carbohydrates that fuel mitochondrial respiration and cell growth. However, under anaerobic
conditions, mitochondrial oxidative phosphorylation
is largely inhibited. Under these conditions,
some organisms (e.g. Chlamydomonas reinhardtii) reroute the energy stored in carbohydrates
to a chloroplast hydrogenase (HydA, likely using a NAD(P)H
PQ e

transfer mechanism 4, to
facilitate ATP production via

photophosphorylation. Thus, H
ase essentially acts as a H

release valve by recombining H

and e

to produce H2 gas that is excreted from the cell 4.

therefore provides the basis for solar driven bio
hydrogen production. The
combustion o
f the evolved H

yields only H
O and thereby completes the clean energy cycle
defined by the equations below





+ 2e





+ 2e








O. + E

Modifications (has to be rewritten)

“In a laboratory there are low
density cultures and thin bottles so that light penetrates from all
sides. Because of this, the cells use all the light falling on them. But in a commercial bioreactor,
where dense algae cultures would be spread out in open p
onds under the sun, the top layers of
algae absorb all the sunlight but can only use a fraction of it.” Says Anastasios Melis, a plant

biology professor at the University of California, Berkeley.

The researcher have manipulated the genes th
at control the amount of chlorophyll in the algae’s
chloroplasts. So far, they have reduced this amount by half.

While regular green algae absorb most of the light falling on them (right), algae engineered to
have less chlorophyll let some light through (
left). When grown in large, open bioreactors in
dense cultures, the chlorophyll
deficient algae will let sunlight penetrate to the deeper algae
layers and thereby utilize sunlight more efficiently.


Project (has to be rewritten)

Energy companies of course think of significant algae plantations, but a group of Philadelphia
based (USA) creatives known as the 20/2 Collaborative have designed a unique concept that is
based on small
scale production of hydrogen. This plan mixes algae p
onds with floating balloons
to integrate fuel production and distribution into the local landscape and allows the renewable
fuel to be created and distributed from the same place.






=from Anke


The disadvantages and possible solutions. The future prospects and
companies involved in this evolution.

Disadvantages of bio
fuels produced by algae and possible solutions

As expected there are also disadvantages about bio
fuels produced by algae. The first and
obvious reason is that it is very expensive, because it’s a very new technology. There has to be a
lot of money for research and trying out different methods. Another

reason that makes the
harvest of algal biomasses relatively costly is the low biomass concentration in the microalgal
culture due to the limit of light penetration in combination with the small size of algal cells. Also
because it is very new it’s require
d to develop standardized protocols for cultivation and bio

Yusuf Christi, an New
Zeeland researcher, pointed out that to compete with other energy
sources the cost of growing microalgae for bio
fuel production must be drastically reduce
d. A
solution could be a high volume co
product strategy, this contains the
extracting of bioreactive
products from harvested algal biomass. Examples are carotenoïden, vitamins, polyunsaturated
fatty acids, … These can be used in pharmaceutical compounds,
health food and natural
pigments. A solution for the limit of light penetration has been found by
Anastasios Melis
, a

and microbial
biology professor at the University of C
alifornia. She produced a mutant
algae that makes a better use of sunlight than the normal algae. This is important for the
maximization of the production. The algae have less chlorophyll than others wherefore they
absorb less sunlight and more sunlight ca
n reach other algae. This process is still in progress and
so the new formed algae are not yet being used.

Another drawback is that the bio
fuel produced by algae is very unstable, not only does it
contain unstable chemical products also it has many polyunsaturated fatty acids which isn’t that
profitable. The produced bio
fuel has a lower performance also than
the bio
fuels produced by
for example rapeseed or soybean. Also there will have to be economically viable harvesting
technologies found for large scale algae production. Because now the focus lays with the
improvement of the algae itself and creating innov
ative harvesting technologies and not so much
with the economic side. This can be solved with genetic engineering, and several techniques are
currently being tested.







Companies involved

(has to be rewritten)


examples to discuss:


Chuo University and Japan’s Agriculture Ministry
the algaeus


Synthetic Genomics Inc. (SGI), a privately held company applying genomic
driven commercial
solutions to address a variety of global challenges including energy and the environment,
nnounced today a multi
year research and development agreement with ExxonMobil Research
and Engineering Company (EMRE) to develop next generation biofuels using photosynthetic

However, naturally
occurring algae do not carry out this process at the
efficiencies or rates
necessary for commercial
scale production of biofuels.

Using SGI's scientific expertise and proprietary tools and technologies in genomics,

synthetic genomics, and genome engineering as a platform, SGI and EMRE believe

that biology
can now be harnessed to produce sufficient quantities of biofuels.

Under the terms of the agreement, SGI will work in a systematic approach to find, optimize,
and/or engineer superior strains of algae, and to define and develop the best syst
ems for large
scale cultivation of algae and conversion of their products into useful biofuels. ExxonMobil's
engineering and scientific expertise will be utilized throughout the program, from the
development of systems to increase the scale of algae produc
tion through to the manufacturing
of finished fuels.

About ExxonMobil

ExxonMobil, the largest publicly traded international oil and gas company, uses technology and
innovation to help meet the world's growing energy needs.

About Synthetic Genomics Inc

SGI, a privately held company founded in 2005, is dedicated to developing and commercializing
driven solutions to address global energy and environment challenges. Advances in
synthetic genomics present limitless applications in a variety of pro
duct areas, including: energy,
chemicals and pharmaceuticals. The company's main research and business programs are
currently focused on the following major bioenergy areas



Toyota has made sustainable mobility and environmental leadership core principles of its
business strategy for future growth. As a fundamental part of this strategy, Toyota is pursuing a
broad range of technologies, each representing a step forward in impr
oving the environmental
impact of automobiles.



They now plan to team up with Chuo University and Japan’s Agriculture Ministry

to produce
algae biofuels from Pseudochoricystis. It’s been several years now since Denso, one of Toyota’s
suppliers, had been working on algae biofuels, hoping to sell their fuel as a substitute for
gasoline and diesel by 2020. Not totally, of course

nly 10 to 20 percent over the next 10 years.

Mitsubishi Chemical Corporation, the Microalgae Corporation and Kyoto Corporation had
previously been approached by the Agriculture Ministry about the project. By following several
pathways, Toyota is ensuring
that it would spread as many tentacles as possible in the unstable
times the car industry is living.


The algaeu

Fuel director Josh Tickell of the converted to plug
in Prius hybrid that he drove on a mix of
battery power and algae fuel blended with conventional gasoline. The Algaeus did less well on
the highway: 52 mpg, because of the lack of regenerative braking
that recharges the battery,
among other things.

The algae came from 22 acres of special ponds at Sapphire Energy's research and development
facility in New Mexico, where local strains of the microscopic plant grow in vats of saltwater
while being fed CO2
that would otherwise go into Coca
Cola and other fizzy drinks, according to
Tim Zenk, a spokesman for Sapphire.

The company claims that its algae produce at least 30 percent by weight of oil and they delivered
approximately five gallons of gasoline derive
d from their algal oil to prove it. Refined by
Syntroleum in Louisiana, the algae gasoline behaved no differently in the car, according to the
driving crew.

Of course, that's because the mix in the cylinder was roughly five percent algae
derived gasoline
and 95 percent 91
octane premium gasoline. And with the addition of a second battery pack in
the trunk, courtesy of Plug
In Conversions, the Algaeus could travel 25 miles on electricity alone
(after six hours of charging).

In the 10
day journey, the crew did not manage to get rid of the new car smell, but they did
manage to get some thumbs up

and break some speed limits

on the long trek. They also
proved that algae fuel doesn't smell too much like a neglected swimming pool,
although some of
the unrefined oil can be redolent of the ocean, Zenk says.


Sapphire Energy was founded with one mission in mind: to change the world by developing a
domestic, renewable source of energy that benefits the environment.

Sapphire Energy founders are led by entrepreneur and scientist J
ason Pyle, and bioengineer
Mike Mendez, backed by a team of the nation's leading researchers, scientists, and blue
investors in early
stage companies.

Sapphire has already developed breakthrough technology to
produce fungible, drop
in transportation


including 91 octane gasoline, 89 cetane diesel,
and jet fuel

all out of algae, sunlight, and carbon dioxide (CO2). Or, what we like to call Green

After two years of dedicated research and development, we developed an algae
based fuel that is

renewable, is produced in the United States, has a low carbon footprint, is price
competitive, and
fits seamlessly into our existing energy infrastructure.


In 2009, we participated in a test flight using algae
based jet fuel in a Boeing 737
engine aircraft. That same year, we provided the fuel for the world’s first cross
country tour of a
gasoline vehicle powered with a complete drop
in replacement fuel containing a mixture of
hydrocarbons refined directly from algae
based Green Crude.



Conclusion (not finished)

A lot of scientists and o
ther important people in this sector really believe that bio
fuel from
microalgae is a renewable bio
fuel with the potential to replace the petroleum transport fuels
without affecting the food supply.

=from Selien



Algae Oil Extraction
. 2010.

Ref Type: Online Source

Alok J.
'Oil from algae' promises climate friendly fuel
. 31

Ref Type: Online Source

Campbell N.M.
Biodiesel: Algae as a Renewable Source for Liquid Fuel
. Guelph Engineering
Journal . 2008.

Ref Type: Online Source

Chisti Y. Biodiesel from microalgae. ScienceDirect . 2007.

Ref Type: Online Source

Hess Scott M.
Fats and Biodiesel
. 2010.

Ref Type: Online Source

LaMonica M.
Joint venture to use coal emissions to grow algae for biofuels
. 20

Ref Type: Online Source

Michael K.
Fermentation or photosynthesis: The debate in algae fuel
. 28

Ref Type: Online Source

Newman S.
Growing Algae for Biodiesel Use
. 2010.

Ref Type: Online Source


ion, Glossary, Details

. 2010a.

Ref Type: Online Source

. 2010b.

Ref Type: Online Source


Steger C.
The Promise of Algae Biofuels

a new NRDC report
. 6

Ref Type: Online Source

Stephen G.
developing cheaper algae biofuels, brings jobs to Pennsylvania.


Ref Type: Online Source