ALGAE FUEL
ABSTRACT:
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Algae fuel is an alternative to fossil
fuel and uses algae as
its source of natural deposits. Several companies and government agencies are
funding efforts to reduce capital and operating costs and make algae fuel
production commercially viable. The
production of biofuels from algae does not reduce atmospheric carbon dioxide
(CO2), because any CO2 taken
out of the atmosphere by the algae is returned when the biofuels are burned.
They do however potentially reduce the introduction of new CO2 by displacing fossil hydrocarbon
fuels.
High oil prices, competing demands between foods and other biofuel
sources, and the world food
crisis, have ignited interest in algacultur (farming algae) for making vegetableoil,biodiesel, bioethanol, biogasoline, biomethanol, biobutanol and other biofuels, using land that is not suitable for agriculture. Among
algal fuels' attractive characteristics: they do not affect fresh water resources, can
be produced using ocean and wastewater, and are biodegradable and relatively harmless to the environment if spilled. Algae cost more per unit mass (as of
2010, food grade algae costs ~$5000/tonne), due to high capital and operating
costs, yet can theoretically yield between 10 and 100 times more energy per
unit area than other second-generation
Biofuel crops. One biofuels company has claimed that
algae can produce more oil in an area the size of a two car garage than a
football field of soybeans, because almost the entire algal organism can use
sunlight to produce lipids, or oil. The United
States Department of Energy estimates
that if algae fuel replaced all the petroleum fuel in the United States, it
would require 15,000 square miles (39,000 km2) which is only
0.42% of the U.S. map. This is less than 1⁄7 the
area of corn harvested
in the United States in 2000.However, these claims remain unrealized,
commercially. Algae fuel can reach price parity with oil in 2017 if granted
production tax credits, according to the head of the Algal Biomass Organization.
FACTORS:
Dry mass factor is the percentage of dry biomass in relation to the fresh
biomass; e.g. if the dry mass factor is 5%, one would need 20 kg of wet
algae (algae in the media) to get 1 kg of dry algae cells. Lipid content is the percentage
of oil in relation to the dry biomass needed to get it, i.e. if the algae lipid
content is 40%, one would need 2.5 kg of dry algae to get 1 kg of
oil.
FUELS:
The veg oil algae product can then be
harvested and converted into biodiesel or green-colored crude oil. The algae’s carbohydrate content can be fermented into bioethanol and biobutanol
BIODIESEL:
Currently
most research into efficient algal-oil production is being done in the private
sector, but predictions from small scale production experiments bear out that
using algae to producebiodiesel may
be the only viable method by which to produce enough automotive fuel to replace
current world diesel usage.
Microalgae
have much faster growth rates than terrestrial crops. The per unit area yield
of oil from algae is estimated to be from between 5,000 to 20,000 US gallons
per acre per year (4,700 to 18,000 m3/km2·a).
Studies show that some species of algae can
produce up to 60% of their dry weight in the form of oil. Because the cells
grow in aqueous suspension, where they have more efficient access to water, CO2 and dissolved nutrients, microalgae
are capable of producing large amounts of biomass and usable oil in either high
rate algal ponds or photobioreactors. This oil can then be turned into biodiesel which could be sold for use in
automobiles.
BIOBUTANOL:
Butanol fuel
Butanol can be made from algae or diatoms using
only a solar powered biorefinery.
This fuel has an energy density 10%
less than gasoline,
and greater than that of either ethanol ormethanol.
In most gasoline engines, butanol can be used in place of gasoline with no
modifications. In several tests, butanol consumption is similar to that of
gasoline, and when blended with gasoline, provides better performance and
corrosion resistance than that of ethanol or E85. The
green waste left over from the algae oil extraction can be used to produce butane.
BIOGASOLINE:
Biogasoline is
gasoline produced from biomass such as algae. Like
traditionally produced gasoline, it contains between 6 (hexane) and 12 (dodecane)
carbon atoms per molecule and can be used in internal-combustion engines.
METHANE:
Methane a form
of natural gas can be produced from algae in various methods, namely Gasification, Pyrolysis and Anaerobic Digestion. In Gasification and
Pyrolysis methods methane is extracted under high temperature and pressure.
Anaerobic Digestion[21] is a straight forward method involves
in decomposition of algae in to simple components then transforming it in to fatty acids using microbes like acidific bacteria followed by
removing any solid particles and finally adding methanogenic bacteria to release a gas mixture
containing methane.
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ETHANOL:
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The Algenol system which is being commercialized
by BioFields in Puerto Libertad, Sonora, Mexico
utilizes seawater and industrial exhaust to produce ethanol.
SVO:
The algal-oil feedstock that is used to produce biodiesel
can also be used for fuel directly as "Straight Vegetable Oil", (SVO). The
benefit of using the oil in this manner is that it doesn't require the
additional energy needed for transesterification, (processing the oil with an
alcohol and a catalyst to produce biodiesel). The drawback is that it does
require modifications to a normal diesel engine. Transesterified biodiesel can be run in an unmodified modern
diesel engine, provided the engine is designed to use ultra-low sulfur diesel, which, as of 2006,
is the new diesel fuel standard in the United States.
HYDROCRACKING
TO TRADITIONAL TRANSPORT FUELS:
Main
article: Vegetable oil refining Vegetable
oil can be used as feedstock for an oil refinery where
methods like hydrocracking or hydrogenation can
be used to transform the vegetable oil into standard fuels like gasolineand diesel.
JET
FUEL:
Aviation biofuel
rising jet fuel prices are putting severe
pressure on airline companies, creating
an incentive for algal jet fuel research. The International Air Transport Association,
for example, supports research, development and deployment of algal fuels.
IATA’s goal is for its members to be using 10% alternative fuels by 2017.
ALGAE
CULTIVATION:
Algae can produce up to 300 times more oil per acre than
conventional crops, such as grapeseed, palms, soybeans, or jatropha. As
Algae has a harvesting cycle of 1–10 days, it permits several harvests in a
very short time frame, a differing strategy to yearly crops (Chisti 2007).
Algae can also be grown on land that is not suitable for other established
crops, for instance, arid land, land with excessively saline soil, and
drought-stricken land. This minimizes the issue of taking away pieces of land
from the cultivation of food crops (Schenk et al. 2008). Algae can grow 20 to
30 times faster than food crops.
PHOTOBIOREACTORS:
Most companies pursuing algae as a source of biofuels are
pumping nutrient-laden water
through plastic tubes (called "bioreactors"
) that are exposed to sunlight (and so called photo
bioreactors or PBR ).Running
a PBR is more difficult than an open pond, and more costly.
Algae can also grow on marginal lands, such as in desert areas where the groundwater is saline,
rather than utilize fresh water. A cost-effective cultivation system (i.e.,
type of photobioreactor) that is best suited to that strain. There is also a
need to provide concentrated
CO2 to increase the rate of
production.
CLOSED
LOOP SYSTEM:
Another obstacle preventing widespread mass production of
algae for biofuel production has been the equipment and structures needed to
begin growing algae in large quantities. Maximum use of existing agriculture
processes and hardware is the goal.
In a closed system (not exposed to open air) there is not
the problem of contamination by other organisms blown in by the air. Algae
farming for biofuels will have to be done as part of cogeneration,
where it can make use of waste heat, and help soak up pollution.
OPEN
POND:
Open-pond systems for the most part have been given up
for the cultivation of algae with high-oil content.[35] Many believe that a major flaw of the Aquatic Species Program was the decision to focus their
efforts exclusively on open-ponds; this makes the entire effort dependent upon
the hardiness of the strain chosen, requiring it to be unnecessarily resilient
in order to withstand wide swings in temperature and pH, and competition from
invasive algae and bacteria. Open systems using a monoculture are also
vulnerable to viral infection. Algal species with lower oil content, not having
to divert their energies away from growth, have an easier time in the harsher
conditions of an open system.
ALGAE TYPES:
Research
into algae for the mass-production of oil is mainly focused on microalgae;
organisms capable of photosynthesis that are less than 0.4 mm in diameter,
including the diatomsand cyanobacteria;
as opposed to macroalgae, such as seaweed. The
preference towards microalgae is due largely to its less complex structure,
fast growth rate, and high oil content (for some species). The following
species listed are currently being studied for their suitability as a mass-oil
producing crop, across various locations worldwide
SPECIFIC
RESEARCH:
Companies such as Sapphire Energy are using genetic
engineering and chemically induced mutations to produce algae suitable for use
as a crop. Some commercial interests into large scale algal-cultivation systems
are looking to tie in to existing infrastructures, such as cement factories, coal power plants, or sewage treatment
facilities. This approach changes wastes into resources to provide the raw
materials, CO2 and nutrients, for the system.
NUTRIENTS:
Algal nutrient solutions: Nutrients like nitrogen (N), phosphorus (P), and potassium (K), are important for plant growth
and are essential parts of fertilizer. Silica and iron, as well as
several trace elements, may also be considered important marine nutrients as
the lack of one can limit the growth of, or productivity in, an area.
CARBONDOXIDE:
The Glenturret Distillery in Perthshire,
UK – home to The
Famous Grouse Whisky –
percolate CO2 made during the whisky distillation
through a microalgae bioreactor. Each tonne of microalgae absorbs two tonnes of
CO2. Scottish Bioenergy, who runs the project, sells the microalgae as high
value, protein-rich food for fisheries. In the future, they will use the algae
residues to produce renewable energy through anaerobic digestion.
WASTE WATER:
Wastewater treatment facility
A possible nutrient source is waste water from the treatment of sewage,
agricultural, or flood plain run-off, all currently major pollutants and health
risks. However, this waste water cannot feed algae directly and must first be
processed by bacteria, through anaerobic digestion. If waste water is not
processed before it reaches the algae, it will contaminate the algae in the
reactor, and at the very least, kill much of the desired algae strain. In biogas facilities, organic waste is often
converted to a mixture of carbon dioxide, methane, and
organic fertilizer. Organic fertilizer that comes out of the digester is liquid, and nearly suitable for
algae growth, but it must first be cleaned and sterilized.
The utilization of wastewater and ocean water instead of
freshwater is strongly advocated due to the continuing depletion of freshwater resources.
However, heavy metals, trace metals, and other contaminants in wastewater can
decrease the ability of cells to produce lipids biosynthetically and also
impact various other workings in the machinery of cells. The same is true for
ocean water, but the contaminants are found in different concentrations. INVESTMENT AND ECONOMIC VIABILITY:
There is always uncertainty about the success of new
products and investors have to consider carefully the proper energy sources in
which to invest. A drop in fossil fuel oil prices might make consumers and
therefore investors lose interest in renewable energy. AlgaePro Systems found
in its talks with investors that while one wants at least 5 times the returns
on their investment, others would only be willing to invest in a profitable
operation over the long term. Additional concerns consider the potential
environmental impact of Algal fuel development, as well as secondary impacts on
wildlife such as bears and fish.
ALGAE FUEL BY COUNTRY:
EUROPE:
Universities in the United
Kingdom which are working on
producing oil from algae include: University of Glasgow, Cambridge University
UNITED
STATES:
The Aquatic Species Program, launched in 1978,
was a research program funded by the United States Department of Energy (DoE) which was tasked with investigating
the use of algae for the production of energy.
REFERENCE:
From Wikipedia,
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