Algae+Oil+as+Biofuel

=** Introduction **=

toc Algae are minuscule aquatic organisms that store energy that comes down in the suns rays as a natural oil [6]. Every strain of algae produces a different amount of oil, and it can be extracted through various cultivation methods and turned into [|biodiesel]. There are over 100,000 different species of algae that belong to two main groups: filamentous and phytoplankton [4][6]. Algae are the fastest growing plants in the world, making them a renewable source of natural oil. They are extremely versatile in terms of climate characteristics. The water that the algae uses does not have to be pure and the land it is produced on does not have to be fertile. Algae is composed of roughly 50% oil and the yield is anywhere from 7 to 31 times larger than the next highest oil producing crop: palm oil [5]. Palm oil is one of numerous organisms that scientists have found to produce oil comparable with algae oil. There is a strong interest in renewable, clean energy sources because we have began to face the negative effects of climate change caused by the carbon dioxide released into the atmosphere when we burn fossil fuels to power our everyday needs. A combination of algae oil’s biomass, [|hydro], [|wind] , [|solar] , [|geothermal] , and [|marine] energy sources seem are the most promising alternatives we have today, but algae oil is being further investigated so that it could possibly become our main source that takes the place of non-renewable sources.

**Growth Rate**
Algae are appeal to scientists as a potential source of energy because of its high growth rate. The organism only requires semicontinuous to continuos harvesting, so they need very little attention. Not much effort is needed to grow this organism [7]. Typically, open pond cultivation systems are used to maintain and control growth. Their photosynthesis is fueled by natural light. According to the [|U.S. Department of Energy], algae can produce up to 60 times more oil per acre than terrestrial crops [6].

**Water**
Algae are unique to other oil containing crops because of their ability to grow and flourish in any water conditions. Many species are able to grow in [|wastewater] and runoff, illustrating the organism's adaptability. Freshwater and saltwater are other options for the algae, but scientists believe that the algae benefit heavily from wastewater from agriculture. It contains various fertilizers providing the necessary nutrients for algae growth, such as nitrogen and phosphorus. Both of these elements are crucial for high growth rates in mass cultures [10].

**Growing Environments**
Algae are able to grow in almost every climate and elevation, making it a great candidate as a worldwide energy source. Less transportation would be needed to deliver the fossil fuels. Currently, the Middle east has 63% of the world’s global reserves and is the dominant supplier of [|petroleum] [5]. This forces countries to provide technical resources and energy pollution to import the oil from the Middle East. Algae’s worldwide growth possibilities could help reduce the emissions given off by current transportation methods. The commercialization of algae oil based biofuel could potentially help those in distant and hard to reach locations the energy they need to power their communities.

**Carbon Dioxide Utilization**
Unlike fossil fuels, algae intake carbon dioxide instead of outputting it. It is necessary for the [|photosynthesis] process that contributes to oil production. This characteristic of algae adds to its major benefits because it helps remove the [|carbon dioxide] pollution that we are already trying to reduce. It can be considered to be a “carbon-neutral fuel source” [6]. = =



**Harvesting** [[image:closed loop.jpg width="292" height="187" align="right" caption="Closed-Loop System"]]
Closed-Loop System is an algae growing system that is structured as a closed environment that is covered on top to protect the algae from outside organisms that could contaminate them. This type of system requires a pure carbon dioxide input that can be very expensive to maintain. [|Photobioreactors] are glass tubes that allow for sunlight and easy observation when the water is pumped through [13]. An Open Pond System is a system of algae growth pools that do not close off the algae from the surrounding climate. These ponds produce the most oil-rich algae. The algae are vulnerable to contamination from outside sources but are able to use natural carbon dioxide. The system allows algae to endure the local climate conditions which change the oil production rates in each strain. The oil-rich algae typically have slower growth rates due to the lack of focus on carbohydrate and protein production w hen making oil. There must be control over salinity, sterility, and nutrient concentration in the open ponds [3]. The most promising and economical cultivation method is turf scrubbing. [|Algal turf scrubbing] (ATS) is a practice used to removed nitrogen or phosphorus pollution from contaminated waters [3]. Algae turfs have a high growth rate in surface water such as these. Pulse induced turbulence provides mixing that aids growth rates when there is a lack of nutrients in the water [3]. Harvesting using an ATS system is done by draining the water, then scraping or vacuuming the algal biomass [3].

** Drying **
The algae must be dry before the extraction process begins. They can either be dried in the oven at 105 degrees Celcius or sun dried for 3 weeks [1].

**Extraction**
Mechanical extraction is performed using the press method. This is done by using either a [|manual ram press] or an engine driven screw press that uses pressure to squeeze the oil out of the organisms. This is the most practical extraction method. The ram presses extract roughly 60-65% of the oil, while the screw presses extract 68-80% of it [1]. Chemical extraction methods use solvents to remove the oil from the plant. The [|solvent method] is usually performed with hexane due to its affordability, but various solvents can be used [4]. When hexane is added during the pressing process, nearly 95% of the oil is extracted from the plant [13]. This method is only economical when more than 50 tons of biodiesel are being produced daily [1]. [|Soxhlet] [|extraction] is a method that uses an organic solvent to remove oil form algae by washing it repeatedly, expelling crude oil that needs to endure another chemical reaction to make it usable. [|Transesterification] is the process where a chemical catalyst and alcohol are added to the raw oil, inducing a reaction that makes a mix of glycerol and biodiesel [13]. [|Glycerol] is then removed, leaving behind usable biodiesel.

** Yield **
Algae can potentially produce up to 60 times for oil per acre than the plants that need arable land for growth can [6]. Each strain of algae has a different amount of oil, ranging from 5% to 50% of it’s dry weight [7]. The table below displays the oil contents of various microalgae. Scientists conclude that there is no specific strain that would be optimal for biodiesel production. [|Diatoms] and [|green algae] proved to be the most promising types of algae, both having high oil yields, high carbon dioxide intake rates, and high growth rates [5]. =** Current Energy Sources **=

The International Energy Agency claims that we will need 50% more energy in 2030 than we do today [1]. Between 2007 and 2035, over 12 million metric tons of carbon dioxide will be released into Earth’s atmosphere [1]. Although renewable energy use is projected to increase, fossil fuels will still be one of our main energy sources. = =

= Other Oil Producing Crops =

Non-edible oil sources are important worldwide because they can be grown in places not suitable for food crops [1]. Algae can grow using wastewater, so places without clean water would still be able to grow it. Vegetable oils and algae oils are highly viscous. The table below shows the oil amounts for common biodiesel sources.

[[image:type comparison table 4 importance.JPG width="209" height="187" align="right"]]
= Federally Illegal Sources =

The [|cannabis sativa] plant has also received some attention for its composition and similarity to algae because it is a non-edible resource that contains a lot of oil. Hemp seeds have an oil content ranging from 26% to 38% [8]. Cannabis based oil could reduce dependency on food crops for biodiesel production [11]. The plant produces high amounts of both biomass and oil, therefore it can create biodiesel and [|bioethanol]. It can be grown in wetlands not suitable for food crops. The production costs are very low and there is a high production rate without intensive care [8]. The marijuana plant is illegal in the United States, making experimentation more difficult and has limited our research and knowledge on it over the past few decades.

= **Industry** =

The transportation sector consumes 30% of the world’s energy. 97.6% of the transportation sector’s fossil fuel use is oil [1]. Currently, petroleum is the most efficient energy type used in the aviation industry. The only way to change this is by creating new technology or upgrading what we have now [2]. The aviation industry is interested in diversifying its energy sources by integrating renewable ones. The petroleum economy is constantly fluctuating, making operating costs high and unpredictable. The world’s energy consumption rate in 2010 was 5,220,000 barrels per day which is almost triple the 1,837,000 barrels per day used in 1980 [2].

= **Conclusion** =

Excessive and universal use of fossil fuels has input tons of carbon dioxide emissions into the Earth’s atmosphere. Scientists have been searching for the perfect oil producing organism to be transformed into commercial use biodiesel. Algae is a promising source of oil because it is renewable, tough, and has a high growth rate. Due to the production costs and biomass quantity, algae hasn’t been one of the top renewable energy competitors. Algae’s properties make it unique and a great option when looking in a global scope. Unlike sunlight and wind, algae is found in every climate and can grow under an extremely wide range of conditions. The biofuel is non-toxic and biodegradable because it contains no sulfur [13]. Algae is a fuel source that can help both society and the environment. Algae helps our ecosystem by removing phosphorus, nitrogen, and other contaminants from wastewater [13]. It also would not produce the excessive carbon emissions that fossil fuels do while still providing us the power we need to supply the world.

= **References** =

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