Algae fuel , algal biofuel , or algal oil is an alternative to liquid fossil fuels that uses algae as its source of energy-rich oils. Also, algae fuels are an alternative to commonly known biofuel sources, such as corn and sugarcane.   Several companies and government agencies are funding efforts to reduce capital and operating costs and make algae fuel production commercially viable.  Like fossil fuel, algae fuel releases CO 2 when burnt, but unlike fossil fuel, algae fuel and other biofuels only release CO 2recently removed from the atmosphere via photosynthesis as the algae or plant grew. The energy crisis and the world food crisis -have ignited interest in algaculture (farming algae) for making biodiesel and other biofuels using Unsuitable land for agriculture. Among algal fuels’ attractive characteristics are That They Can be grown with minimal impact is fresh water resources,   Can Be Produced using saline and wastewater ,-have a high flash points ,  and are biodegradable and Relatively harmless to the environment if spilled.  Algae cost more per unit mass than other second-generation biofuel crops due to high capital and operating costs,  but is claimed to yield between 10 and 100 times more fuel per unit area.  The United States Department of Energy estimates that if it were algae fueled in the United States, it would require 15,000 square miles (39,000 km 2 ), which is only 0.42% of the US map,  or about half of the land area of Maine . This is less than 1 / 7 the area of corn harvested in the United States in 2000. 
According to the head of the Algal Biomass Organization, the price of oil can be increased by 2018 if granted production tax credits .  HOWEVER, in 2013, Exxon Mobil Chairman and CEO Rex Tillerson Said That after-committing notary C. up to $ 600 million over 10 years on development in a joint venture with J. Craig Venter ‘s Synthetic Genomics in 2009, Exxon pulled back after- Four years (and $ 100 million) when it is realized that algae fuel is “probably more” than 25 years away from commercial viability.  On the other hand, Solazyme ,  Sapphire Energy , and Algenol ,  among others, and 2015, respectively. By 2017, most efforts had been abandoned or changed to other applications, with only a few remaining. 
In 1942 Harder and Von Witsch were the first to propose that microalgae be grown as a source of lipids for food or fuel.   Following World War II, research began in the US,    Germany,  Japan,  England,  and Israel  on culturing techniques and engineering systems for growing microalgae on large scales, particularly species in the genus Chlorella . Meanwhile, HG Aach showed that Chlorella pyrenoidosa could be induced through nitrogen starvation to accumulate as much as 70% of its dry weight as lipids. Since the need for alternative transportation fuel had subsided after World War II, research at this time focused on the culturing of food sources, in some cases, for wastewater treatment. 
Interest in the application of biofuels was rekindled during the oil embargo and oil price surges of the 1970s, leading the US Department of Energy to initiate the Aquatic Species Program in 1978.  The Aquatic Species Program spent $ 25 million over 18 years with the goal of developing liquid transportation fuel from algae that would be competitive with petroleum-derived fuels. The research program focuses on the cultivation of microalgae in open air ponds, which systems are low in cost and vulnerable to environmental disturbances like temperature swings and biological invasions. 3,000 algal strains were collected from the world and screened for desirable properties such as high productivity, lipid content, and thermal tolerance, and the most promising strains were included in the SERI microalgae collection at the Solar Energy Research Institute (SERI) in Golden, Colorado and used for further research.  Among the program’s most significant findings were that rapid growth and high lipid production were “mutually exclusive”, since the latter required high nutrients and the latter required low nutrients. The final report suggests that genetic engineering may be necessary to overcome these strains of algal strains, and that the ideal species may vary with place and season.  Although it was widely demonstrated that large-scale production of fuel for fuel was feasible, the program failed to provide a competitive advantage in the 1990s. Even in the best case scenario, it would be estimated that it would be $ 59-186 per barrel,  while petroleum cost less than $ 20 per barrel in 1995.  Therefore, under budget pressure in 1996, the Aquatic Species Program was abandoned. 
Other contributions to algal biofuels algal cultures. For example, in the 1990s Japan’s Research Institute for Innovative Technology for the Earth (RITE) implemented a research program with the goal of developing systems using CO
2 using microalgae.  ALTHOUGH the goal Was not energy production Several studies produced by RITE Demonstrated That Could Be algae grown using flue gas from power plants have a CO
2 source,  an important development for algal biofuel research. Other work focuses on harvesting hydrogen gas, methane, or ethanol from algae, as well as nutritional supplements and pharmaceutical compounds, has also helped to inform biofuel production from algae. 
Following the disbanding of the Aquatic Species Program in 1996, there was a relative lull in algal biofuel research. Still, various projects have been funded by the Department of Energy , Department of Defense , National Science Foundation , Department of Agriculture , National Laboratories , state funding, and private funding, as well as other countries.  More recently, rising prices in the 2000s spurred a revival of interest in algal biofuels and US federal funding has increased,  numerous research projects are being funded in Australia, New Zealand, Europe, the Middle East, and other parts of the world, and a wave of private companies has entered the field  (see Companies ). In November 2012, Solazyme and Propel Fuels made the first retail sales of algae-derived fuel,  and in March 2013 Sapphire Energy began commercial sales of algal biofuel to Tesoro . 
Algal oil is used as a source of fatty acid supplementation in food products, as it contains mono- and polyunsaturated fats , in particular EPA and DHA .  Its DHA content is roughly equivalent to that of salmon based fish oil.  
Algae can be converted into various types of fuels, depending on the technique and the part of the cells used. The lipid , or oily part of the algae biomass can be extracted and converted into biodiesel by a process similar to that used for any other vegetable oil, or converted into a “drop-in” replacements for petroleum-based fuels. Alternatively gold Following lipid extraction, the carbohydrate glad of algae can be fermented into bioethanol or fuel butanol . 
Biodiesel is a diesel fuel derived from animal or plant lipids (oils and fats). Studies have shown that some species of algae can produce 60% or more of their dry weight in the form of oil.      Because the cells grow in aqueous suspension, Where They Have More efficient access to water, CO
2 and Dissolved nutrients, microalgae are able OF PRODUCING wide water equivalent of biomass and usable oil in high algal gold ponds or photobioreactors . This oil can then be turned into biodiesel which could be used for automobiles. Regional production of microalgae and processing into biofuels will provide economic benefits to rural communities.
They can not produce structural proteins such as cellulose for leaves, stems, or roots, and because they can be grown in a rich nutritional medium, microalgae can have faster growth rates than terrestrial crops. Also, they can convert to a much larger fraction of their biomass than conventional oil, eg 60% versus 2-3% for soybeans.  The yield of oil is estimated to be from 58,700 to 136,900 L / ha / year, depending on lipid content, which is 10 to 23 times as high as the next highest yielding crop, oil palm, at 5,950 L / ha / year. 
The US Department of Energy’s Aquatic Species Program , 1978-1996, focused on biodiesel from microalgae. The final report suggests that biodiesel could be the only viable method of production.  If algae-derived biodiesel were to replace the global production of 1.1bn tons of 57.3 million hectares would be required, which would be highly favored compared to other biofuels. 
Butanol can be made from algae or diatoms using a solar powered biorefinery . This fuel has an energy density 10% less than gasoline, and greater than that of either ethanol or methanol . 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 can be used to produce butanol. In addition, it has been shown that macroalgae (seaweeds) can be fermented by Clostridia genus bacteria to butanol and other solvents. 
Biogasoline is gasoline produced from biomass . 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 ,  the main constituent of natural gas can be produced from various methods, namely gasification , pyrolysis and anaerobic digestion . In gasification and pyrolysis methods methane is extracted under high temperature and pressure. Anaerobic digestion  is a straightforward method involved in decomposition of algae into single components then transforming it into fatty acids using microbes like acidogenic bacteria followed by methanogenicto the mixture with methane. A number of studies have shown that biomass from microalgae can be converted into biogas via anaerobic digestion.      Therefore, in order to improve the energy balance of microalgae cultivation operations, it has been proposed to recover the energy contained in biomass via anaerobic digestion to methane for electricity . 
The Algenol System, which is being commercialized by BioFields in Puerto Libertad , Sonora , Mexico utilizes seawater and industrial exhaust to produce ethanol. Porphyridium cruentum has also been shown to be suitable for ethanol production due to its ability to accumulate large amounts of carbohydrates. 
Algae can be used to produce ‘ green diesel ‘ (Also Known As diesel renewable, hydrotreating vegetable oil  or hydrogen-derived renewable diesel)  through a hydrotreating refinery processes That breaks molecules down into go short hydrocarbon chains used in diesel engines .   It has the same chemical properties as petroleum-based diesel  it does not require new engines, pipelines or infrastructure to distribute and use. It has yet to be produced at a cost that is competitive with petroleum . While hydrotreating is currently the most common pathway to produce fuel-like hydrocarbons via decarboxylation / decarbonylation, there is an alternative process offering a number of important advantages over hydrotreating. In this regard, the work of Crocker et al.  and Lercher et al.  is particularly noteworthy. For oil refining, research is underway for catalytic conversion of renewable fuels by decarboxylation . As the oxygen is present in crude oil at low levels, of the order of 0.5%, deoxygenation in petroleum refining is not of much concern, and no catalysts are specifically formulated for oxygenates hydrotreating. Hence, one of the critical technical challenges to make the hydrodeoxygenation of the process economically feasible is related to the research and development of effective catalysts.  
Rising jet fuel prices are putting a strain on airline companies,  creating an incentive for algal jet fuel research. The International Air Transport Association, for example, research, development and deployment of algal fuels. IATA’s goal is for its members to be using 10% alternative fuels by 2017. 
Trials have been conducted by Air New Zealand ,  Lufthansa , and Virgin Airlines . 
In February 2010, the Defense Advanced Research Projects Agency announced that the US military is about to start large-scale oil production from algal ponds into jet fuel. After extraction at a cost of $ 2 a gallon, the oil will be refined at less than $ 3 a gallon. A larger-scale refining operation, producing 50 million gallons a year, is expected to go into production in 2013, with the possibility of lowering costs than fuel-based fossil fuels. The projects, run by the companies SAIC and General Atomics , are expected to produce 1,000 gallons of oil per acre per year from algal ponds. 
Research into algae for the mass-production of oil Focuses Mainly we microalgae (organisms able of photosynthesis That are less than 0.4 mm in diameter, Including the diatoms and cyanobacteria ) as Opposed to macroalgae, Such As seaweed . The preference for microalgae has been reduced to a small complex structure, fast growth rates, and high oil content (for some species). However, some research is being done using seaweeds for biofuels, probably due to the high availability of this resource.  
As of 2012, various manufacturers have been investigating the following species for their suitability as a mass oil-producers:   
- Botryococcus braunii
- Dunaliella tertiolecta
- Pleurochrysis carterae (also called CCMP647). 
- Sargassum , with 10 times the output volume of Gracilaria . 
The amount of each strain of algae produces varies widely. Note the following microalgae and their various oil yields:
- Ankistrodesmus TR-87: 28-40% dry weight
- Botryococcus braunii : 29-75% dw
- Chlorella sp .: 29% dw
- Chlorella protothecoides (autotrophic / heterothrophic): 15-55% dw
- Crypthecodinium cohnii : 20% dw
- Cyclotella DI- 35: 42% dw
- Dunaliella tertiolecta : 36-42% dw
- Hantzschia DI-160: 66% dw
- Nannochloris : 31 (6-63)% dw
- Nannochloropsis : 46 (31-68)% dw
- Neochloris oleoabundans : 35-54% dw
- Nitzschia TR-114: 28-50% dw
- Phaeodactylum tricornutum : 31% dw
- Scenedesmus TR-84: 45% dw
- Schizochytrium 50-77% dw 
- Stichococcus : 33 (9-59)% dw
- Tetraselmis suecica : 15-32% dw
- Thalassiosira pseudonana : (21-31)% dw
In addition, due to ict high growth-rate, Ulva  has-been Investigated as a fuel for use in the SOFT cycle , (SOFT stands for Solar Oxygen Fuel Turbine), a power-generation closed-cycle system suitable for use in arid, subtropical regions. 
Other species used include Clostridium saccharoperbutylacetonicum,  Sargassum, Glacilaria, Prymnesium parvum, and Euglena gracilis 
Nutrients and growth inputs
Light is what algae primarily needs for growth and is the most limiting factor. Many companies are investing in developing systems and technologies for providing artificial light. One of them is OriginOil that has developed a Helix BioReactorTM that features a rotating vertical shaft with low-energy lights arranged in a helix pattern.  Water temperature also influences the metabolic and reproductive rates of algae. Although most often grow at low temperature when the water temperature gets lower, the biomass of algal communities can get larger due to the lack of grazing organisms.  The modest increases in water velocity can also affect rates of growth and the rate of nutrient uptake. 
Other than light and water, phosphorus, nitrogen, and certain micronutrients are also useful and essential in growing algae. Nitrogen and phosphorus are the most important nutrients required for algal productivity, but other nutrients such as carbon and silica are additionally required.  Of the nutrients required, phosphorus is one of the most essential ones as it is used in numerous metabolic processes. The microalgae D. tertiolecta was analyzed to see which nutrient affects its growth most. The concentrations of phosphorus (P), iron (Fe), cobalt (Co), zinc (Zn), manganese (Mn) and molybdenum (Mo), magnesium (Mg), calcium (Ca), silicon (Si) and sulfur ( S) concentrations were measured daily using inductively coupled plasma (ICP) analysis. Among all these elements being measured, phosphorus resulted in the most dramatic decrease, with a reduction of 84% over the course of culture.  This result indicates that phosphorus, in the form of phosphate, is required in all cases by all organisms for metabolism.
There are two enrichment media that have been extensively used to grow most species of algae: Walne medium and Guillard’s F / 2 medium.  These commercially available nutrient solutions can be prepared for all the nutrients required to grow algae. However, due to their complexity in the process of generation and high cost, they are not used for large-scale culture operations.  Therefore, enrichment media used for mass production of algae contains only the most important nutrients with agriculture-grade fertilizers rather than laboratory-grade fertilizers. 
Algae grow much faster than food crops, and can produce more than a few crops such as rapeseed, palms, soybeans, gold jatropha .  As a harvests have a harvesting cycle of 1-10 days, their cultivation permits several times in a very short time-frame, a strategy differing from that associated with annual crops.  In addition, algae can be grown on land for terrestrial crops, including arid land and land with excessively saline soil, minimizing competition with agriculture.  Most research on algae cultivation has been focused on growing algae in clean but expensive photobioreactors , or in open ponds, which are likely to maintain but prone to contamination.
The lack of equipment and structures needed to begin growing algae in large quantities has inhibited widespread mass production of algae for biofuel production. Maximum use of existing agriculture and hardware is the goal. 
Closed systems avoid the problem of contamination by other organisms blown in by the air. The problem for a closed system is finding a cheap source of sterile CO
2 . Several experimenters found the CO
2 from a smokestack works for growing algae.   For reasons of economy, some experts think that farming is more likely to result in pollution , where it can be used for waste heat and soak up pollution.  
Most companies pursuing algae as a source of biofuels pump nutrient -rich water through plastic or borosilicate glass tubes (called ” bioreactors “) that are exposed to sunlight (and so-called photobioreactors or PBR).
Running a PBR is more difficult than using an open pond, and costlier, but can provide a higher level of control and productivity.  In addition, a photobioreactor can be integrated into a closed loop cogeneration system much more easily than other methods.
Open-pond systems for the most part of the cultivation of algae with high oil content.  Many [ who? ] believe that a major flaw of the Aquatic Species Programwas the decision to focus their efforts exclusively on open-ponds; This method makes the whole effort dependent on the hardness of the pH, and it is necessary to reduce the pH of the pH and to invade the environment. Open systems using a monoculture are also vulnerable to viral infection. The energy that a high-pressure oil is in the production of proteins or carbohydrates, resulting in less hardy, or having a slower growth rate. Algal species with a lower oil content, not having to divert their energies away from growth, can be grown more effectively in the harsher conditions of an open system. 
Some open sewage-ponds trial production has taken place in Marlborough , New Zealand. 
The algal turf scrubber (ATS) is a system designed primarily for cleaning nutrients and pollutants out of water using algal turfs. ATS mimics the algal turfs of a natural coral reef by taking in nutrient rich water of waste streams or natural water sources, and pulsing it over a sloped surface.  This surface is coated with a plastic membrane or a screen, which naturally displaces algal spores to settle and colonizes the surface. Once in a lifetime, it can be harvested every 5-15 days,  and can produce 18 metric tons of algal biomass per hectare per year. In contrast to other methods, which focuses primarily on high yielding species of algae, this method focuses on naturally occurring polycultures of algae. As such, the lipid content of the product is generally lower, which makes it more suitable for a fermented fuel product, such as ethanol, methane, or butanol.  Conversely, the harvested algae could be treated with a hydrothermal liquefaction process, which would make possible biodiesel, gasoline, and jet fuel production. 
There are three major advantages of ATS over other systems. The first advantage is in the form of higher productivity over open systems.  The second is lower operating and fuel production costs. The third is the elimination of contamination from the reliance on the naturally occurring algae species. The projected costs for energy production in ATS system are $ 0.75 / kg, compared to a photobioreactor which would cost $ 3.50 / kg.  Furthermore, the fact that the primary purpose of ATS is removing nutrients and pollutants is to demonstrate that nutrient removal can be used to reduce nutrient deficiencies. removal as the primary function, with biofuel production as an added benefit.
After harvesting the algae, the biomass is typically processed into a series of steps, which can differ based on the species and desired product; This is an active area of research  and is the bottleneck of this technology: the cost of extraction is higher than those obtained. One of the solutions is to use filter feeders to “eat” them. Improved animals can provide both foods and fuels. An alternative method to extract the algae is to grow the algae with specific types of fungi. This causes bio-flocculation of the algae which allows for easier extraction. 
Often, the algae is dehydrated, and then such a hexane is used to extract energy-rich compounds like triglycerides from the dried material.  Then, the extracted compounds can be processed using standard industrial procedures. For example, the extracted triglycerides are reacted with methanol to create biodiesel via transesterification .  The unique composition of fatty acids in the presence of selected species and the resultant selection of algal species for feedstock. 
An alternative approach called hydrothermal liquefaction used in continuous processes that subjects high temperatures and pressures to 350 ° C (662 ° F) and 3,000 pounds per square inch (21,000 kPa).   
Products include crude oil, which can be further refined into aviation fuel, gasoline, or diesel fuel using one or many upgrading processes.  The test process converted between 50 and 70 percent of the algae’s carbon into fuel. Other outputs include clean water, fuel gas and nutrients such as nitrogen, phosphorus, and potassium. 
Nutrients like nitrogen (N), phosphorus (P), and potassium (K) are important for plant growth and essential parts of fertilizer. Silica and iron, as well as several trace elements, may also be considered important nutrients in the lack of growth, or productivity in, an area. 
2 through algal cultivation systems can significantly increase productivity and yield (up to a saturation point). Typically, about 1.8 tons of CO
2 will be used per tonne of algal biomass (dry) produced, though this varies with algae species.  The Glenturret Distillery in Perthshire , UK – home to the Famous Grouse Whiskey – percolate CO
2 made during the whiskey distillation through a microalgae bioreactor. Each ton of microalgae absorbs two tons of CO
2 . Scottish Bioenergy, who run the project, sell 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 . 
Nitrogen is a valuable substrate that can be used in algal growth. Various sources of nitrogen can be used as a nutrient for algae, with varying capacities. Nitrate was found to be the preferred source of nitrogen, in view of amount of biomass grown. The results are comparable, making it an alternative economy for a large scale source of algebra.  Despite the clear increase in growth compared to a nitrogen-less medium, it has been shown that alterations in nitrogen levels affect lipid content within the algal cells. In one study hydrogen deprivation for 72 hours caused by the total fatty acid content (on a per cell basis) to increase by 2.4-fold. 65% of the total fatty acids were esterified to triacylglycerides, when compared to the original culture, indicating that the algal cells of novo synthesis of fatty acids. It is vital for the lipid content, while maintaining adequate cell division times.
A possible nutrient source is the water of the treatment of sewage, agricultural, or flood plain run-off, all the major pollutants and health risks. However, this waste water can not feed directly and must be treated by bacteria, through anaerobic digestion . It is likely that the contaminant will be contaminated in the reactor, and it will kill most 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 almost suitable for algae growth, but it must first be cleaned and sterilized. 
The use of wastewater and ocean water is strongly advocated for freshwater resources. However, heavy metals, trace metals, and other contaminants in wastewater can decrease the ability of cells to produce lipids and other biosynthetic effects. The same is true for ocean water, but the contaminants are found in different concentrations. Thus, agricultural-grade fertilizer is the preferred source of nutrients, but heavy metals are again a problem, especially for strains of algae that are susceptible to these metals. In open pond systems the strains of algae that can deal with high concentrations of heavy metals could prevent these organisms from infesting these systems. In some instances it has been shown that strains of algae can remove over 90% of nickel and zinc from industrial wastewater in relatively short periods of time. 
In comparison with terrestrial-based biofuel crops, such as corn or soybeans, microalgae production results in a much less significant land footprint due to the higher oil productivity of the microalgae than all other oil crops. Algae can also be grown on marginal lands for use in low-value crops, and can be used for agricultural purposes.   Algae can also grow on the surface of the ocean in bags or floating screens.  Thus microalgae could provide a source of clean energy with little impact on the provisioning of adequate food and water or the conservation of biodiversity. Algae cultivation also requires no external subsidies of insecticides or herbicides, removing any risk of generating associated pesticide waste streams. In addition, algal biofuels are much less toxic, and degrade far more readily than petroleum-based fuels.    However, due to the flammable nature of any fuel fuel, there is potential for some environmental hazards if ignited or spilled, as may occur in a pipeline. This hazard is reduced compared to fossil fuels, due to the ability to algal biofuels. Therefore, algal biofuels should be treated in a similar manner to petroleum fuels in transport and use, with sufficient safety measures in place at all times.
Fossil fuels with renewable energy sources, such as biofuels, have the capability of reducing CO
2 emissions by up to 80%.  An algae-based system could capture 80% of the CO
2 emitted from a power plant when sunlight is available. Although this CO
2 would later be released into the atmosphere when the fuel is burned, this CO
2 would have entered the atmosphere regardless.  The potential for total reduction CO
2 emissions therefore in the prevention of CO
2from fossil fuels. Furthermore, the production and combustion of algal biofuels does not produce any sulfur oxides or nitrous oxides, and produces a reduced amount of carbon monoxide, unburned hydrocarbons, and reduced emission of other harmful pollutants.  Since terrestrial plant sources of biofuel production are simply one of the following:
Microalgae production also includes the ability to use saline waste or waste CO
2 streams as an energy source. This opens a new strategy to produce biofuel in conjunction with waste water treatment, while being able to produce clean water byproduct.  When used in a microalgal bioreactor, harvested microalgae will capture significant quantities of organic compounds and heavy metals contaminants absorbed from wastewater streams that would otherwise be directly discharged into surface and ground-water.  Moreover, this process also allows the recovery of phosphorus from waste, which is an essential goal in the nature of the past 50 years. Another possibility is the use of algae production systems to clean up non-point source pollution, in a system known as an algal turf scrubber (ATS). This method has been demonstrated to be more effective and more efficient, and it is capable of processing up to 110 million liters of water per day. ATS can also be used for treating point source pollution, such as the waste water mentioned above, or in treating livestock effluent.   
Nearly all research in algal biofuels has focused on single species, or monocultures, of microalgae. However, the ecological theory and empirical studies have shown that plant and algae polycultures, ie groups of multiple species, tend to produce larger yields than monocultures.     Experiments have also shown that more aquatic microbial communities tend to be more stable through time than less diverse communities.    Recent studies found that polycultures of microalgae produced significantly higher lipid yields than monocultures.  Polycultures also tend to be more resistant to pest and disease outbreaks, as well as by other plants or algae.  Thus culturing microalgae in polyculture can not only increase yields and stability of biofuel yields, but also reduce the environmental impact of an algal biofuel industry. 
There is clearly a need for sustainable biofuel production, but a specific biofuel will be used. Therefore, research is focusing on the cost of algal biofuel production to the point where it can compete with conventional petroleum.   The output of Several products from algae has-been MENTIONED [ weasel words ] as the MOST significant factor for making algae produce economically viable. Other factors are improving energy efficiency (currently 3%, but 5 to 7% is theoretically achievable  ) and making the oil extraction from the algae easier. 
In a 2007 report  has been derived from the estimation of the cost of a viable alternative to petroleum diesel:
- C (algal oil) = 25.9 × 10 -3 C (petroleum)
where: C (algal oil) is the price of microalgal oil in dollars per gallon and C (petroleum) is the price of crude oil in dollars per barrel. This equation assumes that algal oil has roughly 80% of the caloric energy value of crude petroleum. 
With current technology available, it is estimated that the cost of producing microalgal biomass is $ 2.95 / kg for photobioreactors and $ 3.80 / kg for open-ponds. These estimates assume that carbon dioxide is available at no cost.  The annual biomass production capacity was increased to 10,000 tons, the cost of production per kilogram reduced to roughly $ 0.47 and $ 0.60, respectively. Assuming that the biomass contains 30% oil by weight, the cost of biomass for the oil supply would be approximately $ 1.40 ($ 5.30 / gal) and $ 1.81 ($ 6.85 / gal) for photobioreactors and raceways, respectively. Oil recovered from the low cost biomass produced in photobioreactors is estimated to cost $ 2.80 / L, assuming the recovery process 50% to the cost of the final recovered oil. If existing algae projects can achieve biodiesel production targets of less than $ 1 per gallon, the United States can achieve its goal of replacing up to 20% of fuels by 2020 by using environmentally and economically sustainable fuels from algae production. 
Such technical problems, such as harvesting, are being successfully addressed by the industry, the high upfront-of-the-world-of-biofuels facilities are seen by many as a major obstacle to the success of this technology. Only few studies on the economic viability are publicly available, and are often in the public domain. Dmitrov  reviewed the GreenFuel’s photobioreactor and estimated that it would only be competitive at an annual price of $ 800 per barrel. A study by Alabi et al. reviewed by photobioreactors, photobioreactors and anaerobic fermenters to make biofuels from algae and found that photobioreactors are too expensive to make biofuels. Raceways might be cost-effective in warm climates with very low labor costs, and can become cost-effective afterwards to significant process improvements. The group found that capital cost, labor cost and operational costs (fertilizer, electricity, etc.) by themselves are too high for the biofuels to be cost-competitive with conventional fuels. Similar results,    suggesting that unless new, cheaper ways of harnessing algae for biofuels production are found, their great technical potential may never become economically accessible. Recently, Rodrigo E. Teixeira demonstrated a process for harvesting and extracting raw materials for biofuel and chemical production that requires a fraction of the energy of current methods, while extracting all cell constituents.
Use of Byproducts
Many of the byproducts produced in the processing of microalgae can be used in various applications, many of which have a longer history of production than algal biofuel. Some of the products used in the production of biofuel include natural dyes and pigments, antioxidants, and other high-value bio-active compounds.    These chemicals and excess biomass have been used in other industries. For example, the dyes and oils have found a place in cosmetics, commonly as thickening and water-binding agents.  Discoveries within the pharmaceutical industry include antibiotics and antifungals derived from microalgae, which have been growing in popularity over the past few decades. Par exempleSpirulina contains numerous polyunsaturated fats (Omega 3 and 6), amino acids, and vitamins,  which may be beneficial, such as beta-carotene and chlorophyll. 
Ease of growth
One of the main advantages that using microalgae as the feedstock when compared to  Algae may be grown in a state that would not be considered suitable for the growth of the regularly used crops.  In addition to this, wastewater would normally be shown to be very effective in growing algae.  Because of this, it may be grown without a priorization that would otherwise be used for production of food crops, and the best resources can be reserved for normal crop production. Microalgae also requires less resources to grow and is needed, allowing the growth and cultivation of algae to be a very passive process. 
Impact on food
Many traditional feedstocks for biodiesel, such as corn and palm, are also used as feeds for livestock on farms, as well as a valuable source of food for humans. Because of this, both of them resulting in increased costs for both food and fuel production. Using algae as a source of biodiesel can alleviate this problem in a number of ways. First, algae is not used as a primary food source for humans, it could be used for fuel and there would be little impact in the food industry. Second, many of the waste-product extracts produced during the processing of algae for biofuel can be used as a sufficient animal feed. This is an effective way to minimize waste and a much cheaper alternative to the traditional corn- grain-based feeds. 
Minimization of waste
Growing algae as a source of biofuel has also been shown to have many environmental benefits, and has presented itself as a more environmentally friendly alternative to current biofuels. For one, it is able to utilize run-off, water contaminated with fertilizers and other nutrients that are a by-product of farming, and its primary source of water and nutrients.  Because of this, it prevents water from mixing with lakes and rivers. In addition to this, the ammonia, nitrates, and phosphates that would normally render the water unsafe actually serve as excellent nutrients for the algae, meaning that fewer resources are needed to grow the algae. Many algae species used in biodiesel production are excellent bio-fixers, meaning they are able to remove carbon dioxide from the atmosphere to use as a form of energy for themselves. Because of this, they have found a way to treat GHG emissions. 
Algae biodiesel is still a fairly new technology. Despite the fact that it has been researched for 30 years, it has been in the mid-1990s, mainly due to a lack of funding and a relatively low petroleum cost.  For the next few years algae biofuels saw little attention; it was not until the peak of the early 2000s that it eventually had a revitalization in the search for alternative fuel sources. While the technology exists to harvest and convert to a source of biodiesel, it still has not been implemented. Further research is needed to make the production of biofuels more efficient, and it is currently being held back by lobbyists in support of alternative biofuels, like those produced from corn and grain.  In 2013, Exxon Mobil Chairman and CEO Rex Tillerson Said That after-Originally committing to spending up to $ 600 million one development in a joint venture with J. Craig Venter ‘s Synthetic Genomics , algae is “probably further” than “25 years away “from commercial viability,although Solazyme  and Sapphire Energy  have already begun small-scale sales in 2012 and 2013, respectively. By 2017, most efforts had been abandoned or changed to other applications, with only a few remaining. 
The biodiesel produced from the processing of microalgae differs from other forms of biodiesel in the content of polyunsaturated fats.  Polyunsaturated fats are known for their ability to retain fluidity at lower temperatures. While this may seem like an advantage in the production of cold temperatures in the winter, the polyunsaturated fats result in lower stability. 
The National Renewable Energy Laboratory (NREL) is the US Department of Energy’s primary national laboratory for renewable energy and energy efficiency research and development. This program is involved in the production of renewable energies and energy efficiency. One of its most currents is the biomass program which is involved in biomass characterization, biochemical and thermochemical conversion technologies in conjunction with biomass process engineering and analysis. The program aims at producing energy efficient, cost-effective and environmentally friendly technologies that support rural economies, reduce the nations dependency in oil and improve air quality. 
At the Woods Hole Oceanographic Institution and the Harbor Branch Oceanographic Institution the wastewater of domestic and industrial sources contain rich organic compounds that are being used to accelerate the growth of algae.  The Department of Biological and Agricultural Engineering at University of Georgia is exploring microalgal biomass production using industrial wastewater.  Algaewheel , based in Indianapolis , Indiana, presented a proposal to build a facility in Cedar Lake, Indiana that uses municipal wastewater treatment , using the sludge byproductto produce biofuel.   A similar approach is being followed by Algae Systems , a company based in Daphne, Alabama. 
Sapphire Energy (San Diego) has been producing green crude from algae.
Solazyme ( South San Francisco, California ) has produced a fuel suitable for powering jet aircraft from Algae. 
The Marine Research station in Ketch Harbor, Nova Scotia , has been involved in growing algae for 50 years. The National Research Council (Canada) (NRC) and National Byproducts Program have provided $ 5 million to fund this project. The aim of the program has been to build a 50,000-liter pilot farm at the Ketch Harbor facility. The station has been involved in the assessment of algae for biofuel and is involved in investigating the use of species in North America. NRC has joined forces with the United States Department of Energy, the National Renewable Energy Laboratory in Colorado, and Sandia National Laboratories in New Mexico. 
University of Manchester , University of Sheffield , University of Glasgow , University of Brighton , University of Cambridge , University College London , Imperial College London , Cranfield University and Newcastle University . In Spain, it is also being researched by the CSIC ‘s Instituto de Bioquímica Vegetal y Fotosíntesis (Microalgae Biotechnology Group, Seville ). 
The European Algae Biomass Association (EABA) is the European association for both research and industry in the field of algae technologies, currently with 79 members. The association is headquartered in Florence, Italy. The general objective of the EABA is to promote mutual interchange and cooperation in the field of biomass production and use, including biofuels uses and other uses. It aims at creating, developing and maintaining solidarity and links between its members and at defending their interests at European and international level. It is a catalyst for fostering synergies among scientists, industrialists and decision makers to promote the development of research, technology and industrial capacity in the field of Algae.
CMCL innovations and the University of Cambridge are carrying out a detailed design study of a C-FAST  (Carbon negative Fuels derived from Algal and Solar Technologies) plant. The main objective is to design a demonstration of the production of hydrocarbon fuels (including diesel and gasoline) as sustainable carbon-negative energy and raw materials for the chemical commodity industry. This project will report in June 2013.
Ukraine plans to produce biofuel using a special type of algae. 
The European Commission’s Algae Cluster Project, funded through the Seventh Framework Program , is a biofuel-based, biofuel-based project. The projects are BIOFAT, All-Gas and InteSusAl. 
Various types of hydrolysis, hydrothermal liquefaction, gasification and pyrolysis, for the application of an integrated algal biorefinery. 
Reliance Industries in collaboration with Algenol , USA commissioned a pilot project to produce algal bio-oil in the year 2014.  Spirulina, which is an alga rich in protein content commercially grown in India. Algae is used in India for Treating the sewage in open / natural oxidation ponds This Reduces the Biological Oxygen Demand (BOD) of the sewage and aussi Provides algal biomass qui peut être converted to fuel. 
The Algae Biomass Organization (ABO)  is a non-profit organization whose mission is “to promote the development of viable commercial markets for renewable and sustainable commodities derived from algae”.
The National Algae Association (NAA) is a non-profit organization of algae researchers, algae production companies and the investment community who share the goal of commercializing algae as an alternative feedstock for the biofuels markets. The NAA gives its members a forum for the success of various technologies.
Pond Biofuels Inc.  in Ontario, Canada has a functioning pilot plant where it is grown directly from smokestack emissions from a cement plant, and dried using waste heat.  In May 2013, Pond Biofuels announced a partnership with the National Research Council of Canada and Canadian Natural Resources Limited to construct a demonstration-scale algal biorefinery at an oil sands site near Bonnyville, Alberta. 
Ocean Nutrition Canada in Halifax, Nova Scotia, Canada has found a new strain of algae that is capable of producing 60% of the production of biofuels. 
VG Energy, a subsidiary of Viral Genetics Incorporated, claims to have discovered a new method of increasing algal lipid production by disrupting the metabolic pathways that would otherwise divert photosynthetic energy towards carbohydrate production. Using these techniques, the company states that lipid production could be increased several-fold, potentially making algal biofuels cost-competitive with existing fossil fuels.
Algae production from the warm water discharge of a nuclear power plant has been piloted by Patrick C. Kangas at Peach Bottom Nuclear Power Station, owned by Exelon Corporation. This process takes advantage of the relatively high temperature water to sustain algae growth even during winter months.
Companies such as Sapphire Energy and Bio Solar Cells are using genetic engineering to make algae fuel production more efficient. According to Klein Lankhorst of Bio Solar Cells, genetic engineering could vastly improve algae fuel efficiency as algae can be modified to only build short carbon chains instead of long chains of carbohydrates. Sapphire Energy also uses chemically induced mutations to produce algae suitable for use as a crop.
Some business interests into wide-scale algal-cultivation systems are looking to tie into existing infrastructure, Such As cement factories,  coal power plants or sewage treatment facilities. This approach wastes into resources to exchange Provide the raw materials, CO
2 and nutrients, for the system. 
A feasibility study using marine microalgae in a photobioreactor is being done by the International Research Consortium on Continental Margins at the Jacobs University Bremen . 
The Department of Environmental Science at the University of Manila University in the Philippines , is working on producing biofuel from a local species of algae. 
Genetic engineering has been used to increase lipid production or growth rates. Current research in genetic engineering includes the introduction or removal of enzymes . In 2007 Oswald et al. Introduced a monoterpene synthase from sweet basil into Saccharomyces cerevisiae , a strain of yeast .  This particular monoterpene synthase causes the de novo synthesis of large amounts of geraniol , while also secreting it into the medium. Geraniol is a primary component in rose oil , palmarosa oil , and citronella oilit is a viable source of triacylglycerides for biodiesel production. 
The enzyme ADP-glucose pyrophosphorylase is vital in starch production, but has no connection to lipid synthesis. Removal of this enzyme resulted in mutant sta6, which showed increased lipid content. After 18 hours of growth in nitrogen deficiency medium the sta6 mutants had on average 17 ng triacylglycerides / 1000 cells, compared to 10 ng / 1000 cells in WT cells. This increase in lipid production has been attributed to the reallocation of intracellular resources, as it has been diverted from starch production. 
In 2013 researchers used a “knock-down” of fat-reducing enzymes (multifunctional lipase / phospholipase / acyltransferase) to increase lipids (oils) without compromising growth. The study also introduced an efficient screening process. Antisense-expressing knockdown strains 1A6 and 1B1 contained 2.4- and 3.3-fold higher lipid content during exponential growth, and 4.1- and 3.2-fold higher lipid content after 40 h of silicon starvation.  
Numerous Funding programs have been created with Renewable Energy. In Canada, the ecoAgriculture biofuels capital initiative (ecoABC) provides $ 25 million per project to assist farmers in constructing and expanding renewable fuel production facilities. The program has $ 186 million set aside for these projects. The sustainable development (SDTC) program has also applied $ 500 million over 8 years to assist with the construction of next-generation renewable fuels. In addition, over the last 2 years $ 10 million has been made available for renewable fuel research and analysis 
In Europe, the Seventh Framework Program (FP7) is the main instrument for funding research. Similarly, the NER 300 is an unofficial, independent portal dedicated to renewable energy and grid integration projects. Another program includes the Horizon 2020 program which will start 1 January, and will bring together the framework and other programs EC Innovation and Research Funding 
The American NBB ‘s Feedstock Development program is Addressing Production of algae on the horizon to expand available material for biodiesel in a sustainable Manner. 
Numerous policies have been put in place since the 1975 oil crisis in order to promote the use of Renewable Fuels in the United States, Canada and Europe. In Canada, these included the implementation of excise tax exempting propane and natural gas, which was extended to ethanol from biomass and methanol in 1992. The federal government is also proposing its renewable fuels strategy. New Brunswick, New Brunswick, New Brunswick, New Brunswick, New Brunswick, New Brunswick. These mandates were quickly followed by the Canadian provinces:
BC introduced a 5% ethanol and 5% renewable diesel requirement which was effective by January 2010. It also introduced a low carbon fuel requirement for 2012 to 2020.
Alberta introduced a 5% ethanol and 2% renewable diesel requirement implemented April 2011. The province also introduced a minimum 25% GHG emission reduction requirement for qualifying renewable fuels.
Saskatchewan implemented a 2% renewable diesel requirement in 2009. 
In 2006, the Canadian Federal Government announced its commitment to using its power to encourage the biofuel industry. Section three of the 2006 alternative fuels act stated that when it is economically feasible to do so-75% per cent of all federal motor vehicles. 
The National Research Council of Canada has established Algal Carbon Conversion as one of its flagship programs.  As part of this program, the NRC made an announcement in May 2013 that they are partnering with Canadian Natural Resources Limited and Pond Biofuels to construct a demonstration-scale algal biorefinery near Bonnyville, Alberta. 
$ 2.84 trillion in the United States. This is more than just a part of the biofuel industry. The leaders of the G20 in Pittsburgh have agreed that “inefficient fossil fuel subsidies encourage wasteful consumption, reduce our energy security, and reduce the impact of climate change. If this commitment is followed through and removed, a fair market in which biofuels can be created. In 2010, the US House of Representatives passed a lawsuit to provide biofuels with biofuels in federal tax credits. The algae-based renewable energy promotion act (HR 4168) has been implemented to give a $ 1.01 per gallon production tax credit and a 50% bonus for biofuel plant property. The US Government also introduced the Domestic Fuel Act for the Enhancement of the National Security Act implemented in 2011. This policy is an amendment to the Federal Property and Administrative Services Act of 1949 and the Federal Defense Provisions in the United States of America. Defense (DOD) multiyear contract may be entered into the box of the purchase of advanced biofuel. Federal and DOD programs are usually limited to a 5-year period This legislation is an amendment to the National Defense Act for the Protection of National Defense Act. (DOD) multiyear contract may be entered into the box of the purchase of advanced biofuel. Federal and DOD programs are usually limited to a 5-year period This legislation is an amendment to the National Defense Act for the Protection of National Defense Act. (DOD) multiyear contract may be entered into the box of the purchase of advanced biofuel. Federal and DOD programs are usually limited to a 5-year period
The European Union (EU) has responded by quadrupling the credits for second-generation biofuels which has been established as an amendment to the Biofuels and Fuel Quality Directives 
With algal biofuel being a relatively new alternative to petroleum products, it leaves many opportunities for drastic advances in all aspects of technology. Producing algae biofuel is not yet a cost-effective replacement for gasoline, but alterations to current methodologies can change this. The two most common targets for advancements are the growth medium (open pond vs. photobioreactor) and methods to remove the intracellular components of the algae. Below are companies that are currently innovating algal biofuel technologies.
Founded in 2006, Algenol Biofuels is a global, industrial biotechnology company that is marketing its patented algae technology for ethanol production and other fuels. Based in Southwest Florida, Algenol’s patented technology enables the production of the most important fuels oven (ethanol, gasoline, jet, and diesel fuel) using proprietary algae, sunlight, carbon dioxide and saltwater for around $ 1.27 per gallon and at production levels of 8,000 total gallons of liquid fuel per acre per year. Algenol’s technology produces high yields and lowers the cost of photobioreactors and proprietary downstream techniques for low-cost fuel production using carbon dioxide from industrial sources. The company was originally intended to be produced commercially by the Florida Governor Rick Scott signed in a bill in 2013 eliminating the state’s mandate of a minimum of 10% ethanol in commercial gasoline. This caused Algenol CEO Paul Woods to scrap a plan for a US $ 500 million plant to produce commercial amounts of algae biofuels and pursued other job sites. Currently, Algenol is a partner of the US Department of Energy’s Bioenergy Technologies Office, and is responsible for the development of the Florida-based fuel distributor. 
Blue Marble Production
Blue Marble Production is a Seattle-based company that is dedicated to removing algae from algae-infested water. This in turn cleans up the environment and allows this company to produce biofuel. Rather than just focusing on the mass production of algae, this company focuses on what to do with the byproducts. This company recycles almost 100% of its water through reverse osmosis, saving about 26,000 gallons of water every month. This water is then pumped back into their system. The gas produced as a byproduct of algae will be brought into being by a photobioreactor system that holds multiple strains of algae. Whatever gas remains is then made into pyrolysis oil by thermochemical processes. Food flavoring, food flavoring, food flavoring,
Solazyme is one of a handful of companies which is supported by such companies as Chevron. Additionally, this company is also backed by Imperium Renewables, Blue Crest Capital Finance, and The Roda Group. Solazyme has developed a way to use up to 80% of dry algae as oil.  This process requires the growth of a dark fermentation vessel and the growth of carbon substrates within their growth media. The effect is the production of triglycerides that are almost identical to vegetable oil. Solazyme’s production method is produced to produce more or less algae grown photosynthetically or made to produce ethanol. Oil refineries can then take this algal oil and turn it into biodiesel, renewable diesel or jet fuels.
Part of Solazyme’s testing, in collaboration with Maersk Line and the US Navy, placed 30 tons of Soladiesel (RD) algae fuel at the 98,000-ton, 300-meter Maersk Kalmar container ship. This fuel was used at the end of a week-long trip from Bremerhaven, Germany to Pipavav, India in Dec 2011. In Jul 2012, The US Navy used 700,000 gallons of HRD76 biodiesel in three ships of the USS Nimitz “Green Strike Group” during the 2012 RIMPAC exercise in Hawaii. The Nimitz also used 200,000 gallons of HRJ5 biofuel jet. The 50/50 biofuel blends were provided by Solazyme and Dynamic Fuels.   
Sapphire Energy is a leader in the algal biofuel industry backed by the Wellcome Trust, Bill Gates’ Cascade Investment, Monsanto, and other large donors.  After experimenting with production of various fuels beginning in 2007, the company now focuses on producing what it calls “green crude” from algae in open raceway ponds. After receiving more than $ 100 million in federal funds in 2012, Sapphire built the first commercial demonstration in New Mexico and has continuously produced biofuel since completion of the facility in that year.  In 2013, Sapphire began sales of algal biofuel to Tesoro , making it one of the first companies, along with Solazyme, to sell algae fuel on the market. 
Diversified Technologies Inc.
Diversified Technologies Inc. has created a patent pending pre-treatment option to reduce costs of oil extraction from algae. This technology, called Pulsed Electric Field (PEF) technology, is a low cost, low energy process that uses high voltage electric pulses to a slurry of algae. The electric pulses enable the algal cell walls to be ruptured easily, increasing the availability of all the contents (Lipids, proteins and carbohydrates). This alternative method to intracellular extraction has shown the possibility of being integrated into high-yielding structures. The Pulse Electric Field subjects the algae to short, intense bursts of electromagnetic radiation in a treatment chamber, electroporating the cell walls. The formation of holes in the cell wall PEF technology only requires 1-10 microsecond pulses, enabling a high-throughput approach to algal extraction.
Preliminary calculations showed that PEF technology would be used for $ 0.10 per gallon of algae derived biofuel produced. In comparison, conventional dry and solvent-based extractions account for $ 1.75 per gallon. This inconsistency between costs can be attributed to the fact that it accounts for 75% of the extraction process.  Although a relatively new technology, PEF has been successfully used in both food and water treatment. 
Origin Oils Inc.
Origin Oils Inc. has been researching a revolutionary method called the Helix Bioreactor,  altering the common closed-loop growth system. This system utilizes low energy lights in a helical pattern, enabling each algal cell to obtain the required amount of light.  Sunlight can only penetrate algal cells, making light on the limit in open-pond algae farms. Each lighting element in the bioreactor is specifically altered to emit specific wavelengths of light, as a full spectrum of light is not beneficial to algae growth. In fact, ultraviolet irradiation is actually detrimental as it inhibits photosynthesis, photoreduction, and the 520 nm light-dark absorbance changes of algae. 
This bioreactor also addresses another key issue in algal cell growth; introducing CO 2 and nutrients to the algae without disrupting or over-aerating the algae. Origin Oils Inc. fights this issues through the creation of their Quantum Fracturing technology. This process takes the CO 2 and other nutrients, breaks them up and delivers them to the micron sized bubbles to the algae. This allows the nutrients to be delivered at a much lower level, maintaining the integrity of the cells. 
Providence is a Belgian microalgae that also operates in the United States. The company has been working on a new type of reactor (using flat plates) which reduces the cost of algae cultivation. At AlgaePARC similar research is being conducted using 4 growing systems (1 open pond system and 3 types of closed systems). According to René Wijffels the current systems do not yet allow to be competitively produced. However using new (closed) systems, it would be possible to reduce costs by 10X, up to a price of 0.4 € per kg of algae.  Currently, Proviron is primarily concerned with alternative uses of algae cultures, such as environmentally-conscious plastics, esterification processes, and de-icing processes. 
Genifuel Corporation has licensed the high temperature / pressure fuel extraction process and has been working with the team at the lab since 2008. The company is looking for a solution for the future.  Combined hydrothermal hydrothermal liquefaction with catalytic hydrothermal gasification in reactor running at 350 Celsius (662 Fahrenheit) and pressure of 3000 PSI. 
Qeshm Microalgae Biorefinery Co. (QMAB)
QMAB is an Iran-based biofuels company operating solely on the island of Iranian island of Qeshm in the Strait of Hormuz. QMAB’s original pilot has been operating since 2009, and has a 25,000 Liter capacity.  In 2014, QMAB released BAYA Biofuel, a biofuel deriving from the algae Nannochloropsis, and has since determined that its unique strain is up to 68% lipids by dry weight volume.  Production of nutraceutical products and the production of biofuel. The product of their microalgae culture is crude oil, which can be broken down into the same kinds of fuels and chemical compounds.