Algae as a Biofuel

GEOGRAPHY 3900
Fall 2012
Final Paper
By Samantha Allen
Bioengineering Algae for Biofuels:
The Green Gold

















With the growing concern for climate change around the world and with
recent occurrences such as Super Storm Sandy on the American east coast,
the conversation is starting to turn to what we can do to prevent or even
reverse the impacts of climate change. Although there are many viable
options that can help reduce greenhouse gases and possible reverse
anthropogenic climate change, one option that seems most practical is
bioengineering algae to use for biofuels to replace fossil fuels. Algae
can offer other benefits as well, such as water purifying to economic
security, all of which can be related to fossil fuels consumption. When
algae becomes a more salient issue to the American public and technological
advances help innovate the bio-fuel industry, it will be an adopted
standard source of fuel throughout the world.
Algae is a 3rd generation biofuel, which means it can create fuel
that is made out of biomass and that can replace feed stock; it is also a
renewable resource. A technical definition would be "[a]lgae as feedstock
for biofuels, the definition include all unicellular and simple multi-
cellular Microorganisms" (Jasvinder). There are three generations, the
first being made from feedstock such as corn and sugarcane. This generation
requires land and a certain climate, as well as produces more CO2. The
second generation biofuels are made from lignin cellulose, like switch
grass, which are the cell walls of wood. Lignin cellulose has no
nutritional value to the human body. This generation is also limited on
where it can be grown and has little technological development. The third
generation makes biofuels from algae, bacteria and fungi. This generation
only relies on sunlight and CO2 to produce fuel. As you can see in figure
1, an alga has the highest potential of creating biofuel with using limited
amount of space. It can produce up to 50 times more per acre. It is
already more efficient than the other generations, yet there are always new
technologies that allow more information to be gained from continuous
research and one day these potentials will grow exponentially.
Algae have several ways that it can be made into biofuels. The OMEGA
project by NASA AMES Research Center is growing algae in a closed culture
system. "The OMEGA system is designed to grow freshwater algae in municipal
wastewater using NASA's photo-bioreactors, which are flexible plastic tubes
that float in seawater." (Nguyen). Algae requires a lot of water to grow,
"approximately 16 trillion gallons of water would be needed to make 60
billion gallons of biodiesel per year, the diesel demand in the U.S"
(NREL). This doesn't have to be fresh water, whereas hydraulic fracturing
requires 5 to 8 million gallons per well. Algae can grow in wastewater and
clean it at the same time. According to the National Renewable Energy
Laboratory for a 50/50 production rate, which is "10,000 gallons an acre
per year", would require" 6 billion acres and use 16 trillion gallons of
water per year" (NREL). There are plenty of water sources that are
noncompeting for this growth. The use of forward osmosis can use this
wastewater to produce fresh clean drinking water. Osmosis allows water
molecules to pass through the cell walls and because they are semi-
permeable no particles or minerals can pass through thereby filtering the
water. The material left behind is used up when the algae creates C6H12O6
sugar and 6O2 oxygen. With this idea of being able to clean wastewater,
many ideas can be formed about the multiuse of algae. With the industrial
production of livestock, there is nutrient waste run off that ends up in
watersheds and eventually the ocean. This nutrient waste, or algae blooms,
creates dead zones in the hydrosphere. Growing algae in these areas and
filtering the water through closed cultured systems could possibly help
this problem for the reason that algae feeds off nutrient waste. This can
be done by using forward osmosis, which is "the natural diffusion of water
through a semi-permeable membrane from a solution of a lower concentration
to a solution with a higher concentration. The semi-permeable membrane acts
as a barrier that allows small molecules such as water to pass through
while blocking larger molecules like salts, sugars, starches, proteins,
viruses, bacteria and parasites." (Howard G. Levine, Ph.D, NASA). As seen
in Figure 2, wastewater can be used in growing the algae while also
cleaning the water using the suns energy and forward osmosis.
One of the major issues of climate change is the carbon that is being
emitted into the atmosphere, at an alarming rate. Since the 1800s we have
raise the CO2 content in the atmosphere from 280 parts per million (ppm) to
today where it's on an exponential climb at 390ppm. Algae are plants that
conduct photosynthesis, which means that it needs CO2 to survive just like
humans need oxygen. With technological advance, a very efficient way of
growing algae has come to the front of this new innovation. As seen in
Figure 3, this Gas Exchange Column removes oxygen from the algae growing
area and pumps in CO2 to help the algae grow. This is great news
considering "[t]hese algae are the fastest growing planets in the
world."(Jonathan Trent, NASA). They consume about "1.8 kg of carbon dioxide
(CO2) per 1 kg of algae."(Chisti).
Algae can be grown in a number of ways. As mentioned before the
OMEGA system is a closed cultured system. A closed cultured system can be
something like a photobioreactors (PBRs) "which are flexible plastic tubes
that" can float in any water source or be placed directly over power plant
smoke stacks to capture carbon immediately (Nguyen). These tubes allow
sunlight in and can pump CO2 into the water. This also allows algae to
able to be grown anywhere. There is no concern for the elements because
the photobioreactor provides a stable environment for the algae to grow at
its most efficient level. There are open systems, as well, such as ponds
that the algae could be grown directly in. Again these could be place
strategically around carbon emitters such as coal-fired plants. Open
systems can also use photobioreactors but these are tank that are exposed
to weather and they are shaped in a way that allows the algae to be mixed.
A stir runs along the pond bioreactor like Jacuzzi jets to add and mix more
CO2 into the water
There are many uses for algae; however the main benefit would be the
biofuels. Algae are capable of creating algae fuel, Biological hydrogen
production, biohydrogen, biodiesel, ethanol fuel, butanol fuel,
and vegetable fats and oils. "One of the biggest advantages of biodiesel
compared to many other alternative transportation fuels is that it can be
used in existing diesel engines without modification, and its suitability
for blending in at any ratio with petroleum diesel"(Jasvinder). This allows
our current infrastructure to still function without any major expenditure
such as producing new vehicles. One of the main ways these are produced
is through fermentation. After the algae have grown to a substantial size,
the biomass is taken and put into light deprived containers that "initiate
and promote the decay of the biomass" (Bush et al.). This process can take
anywhere from a few days until a week. The US patent states that sensors
could be fitted to determine that rate of decay of the chambers and allow
them to know when the biomass is ready to be separated. Ethanol is then
separated from the fermentation process.
How efficient is an alga growing, harvesting, and processing cycle at
producing into biofuels? Figure 4 explains a breakdown of carbon emissions
based on the fuel source. Producing ethanol from corn creates 81 to 85
kilograms (kg) of CO2 per mega joule (MG) of energy produced. That means
if one barrel of ethanol is created, you are producing an average of
486,506 kg of GHG emissions. On average the United States consumes "19.2
million barrels per day in 2010"which is 21% of all global use" (EIA). So
if one barrel of oil produces almost 500,000 kg of emissions that's about
9.3 x10^12 kg of emission a year. Algae can reduce these emissions by not
only using less energy, but by consuming those GHGs. Algae reduces
emissions by 1,072,658 kg per barrel.

There are many uses to algae as I have explained in this paper. There
is a lot of potential good that can come from the production of algae.
There are already many companies working on producing algae for fuel such
as "BP in a joint project with Martek, Chevron with Solazyme, ExxonMobil
with an investment of $600 million in Synthetic Genomics, Indian Oil,
India's largest company, a joint project with PetroAlgae, and Shell in a
joint project with Cellana" (Freedenthal). If more money and time was put
into this bio -engineering technique, it could become very popular and
replace conventional fuels. Since algae have a consumption rate of GHG
emissions that is higher than what it produces, this is a viable option to
stop the rate of CO2 levels from rising. With the growing concern for
climate change all over the world, science has to try and find ways to
alleviate fears, and at the same time invent new ways for dealing with
anthropogenic climate change. Algae biofuels, along with the other benefits
of algae, are the best source for replacing fossil fuel consumption




Bibliography
1. Bush, R. A. et al. Process for the production of ethanol from algae.
U.S Patent 7135308. November 14, 2006.

2. Jasvinder Singh, Sai Gu. Commercialization potential of microalgae for
biofuels production. Renewable and Sustainable Energy Reviews,
Volume 14, Issue 9, December 2010, Pages 2596–2610

3. Dragone, Giuliano. Fernandes, Bruno Daniel. Vicente, A.A. Teixeria,
J.A. Third generation biofuels from microalgae. Formatex: Badajoz.
2010


4. Freedenthal, Carol. Liquid Fuels from Algae Shows Many Advantages.
Pipeline and Gas Journal [Online] 2010, Vol 237, No1.

5. Nguyen, Huong. NASA Showcases Innovative Method To Grow Algae-Based
Biofuels. NASA. [Online] April 17, 2012.
http://www.nasa.gov/centers/ames/news/features/2012/omega_algae_feature
.html (access November 14, 2012)
6. Maddi, Balakrishna. 2011. Comparative study of pyrolysis of algal
biomass from natural lake blooms with lignocellulosic biomass.
Bioresource Technology 102, no. 23:11018-11026.
7. Y. Chisti, Biodiesel from microalgae. Biotechnol Adv, 25 (3) (2007),
pp. 294–306


8. Kurki, Al, Amanda Hill and Mike Morris, Biodiesel: The Sustainability
Dimensions, National Sustainable Agricultural Service, 2006,
IP281
9. U.S. Energy Information Administration. Annual Energy Outlook 2012.
June 2012. Release Number DOE/EIA-0383(2012).






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Figure 1 shows the amount of gallons per acre per year

Figure2 The OMEGA System by NASA showing forward osmosis

Figure 3 OMEGA Gas Exchange Columns

Figure 4 shows the different fuel sources to produce biofuels and how
efficient they are in reference to reduce CO2 emission and land use.