Algae fuel, also called algal fuel, oilgae, algaeoleum or third generation biofuel , is a biofuel from algae. Compared with second generation biofuels, algae are high-yield high-cost (30 times more energy per acre than terrestrial crops) feedstocks to produce biofuels. Since the whole organism uses sunlight to produce lipids, or oil, algae can produce more oil in an area the size of a two-car garage than an entire football field of soybeans.
Though there are many factors to overcome for algae to be a wide-spread source of energy, several positive factors can already be considered. Algal fuels do not impact fresh water resources, and can use ocean and wastewater. The cost of various algae species is typically between US$5–10 per kg dry weight, with research actively looking to reduce capital and operating costs and make algae oil production commercially viable.
With the record oil price increases since 2003, competing demands between foods and other biofuel sources and the world food crisis, there is much interest in algaculture (farming algae) for making vegetable oil, biodiesel, bioethanol, biogasoline, biomethanol, biobutanol and other biofuels.
The production of biofuels to replace oil and natural gas is in active development, focusing on the use of cheap organic matter (usually cellulose, agricultural and sewage waste) in the efficient production of liquid and gas biofuels which yield high net energy gain. One advantage of many biofuels over most other fuel types is that they are biodegradable, and so relatively harmless to the environment if spilled.
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 (40,000 square kilometers), which is a few thousand square miles larger than Maryland, or 1.3 Belgiums. This is less than 1/7th the area of corn harvested in the United States in 2000.
The Aquatic Species Program launched in 1978. The U.S. research program, funded by the U.S. DoE, was tasked with investigating the use of algae for the production of energy. The program initially focused efforts on the production of hydrogen, however, shifted primary research to studying oil production in 1982. From 1982 through its culmination, the majority of the program research was focused on the production of transportation fuels, notably biodiesel, from algae. In 1995, as part of the over-all efforts to lower budget demands, the DoE decided to end the program. Research stopped in 1996 and staff began compiling their research for publication. In July of 1998, the DoE published the report "A Look Back at the U.S. Department of Energy's Aquatic Species Program: Biodiesel from Algae"
In 2008, Time Magazine voted Isaac Berzin one of the world's most influential for 2008 for his ability to turn a dream of an oil-free future into a reality through GreenFuel, founded in Boston in 2001.
Lipid factor is the percentage of vegoil in relation with the algae cells needed to get it, i.e. if the algae lipid factor is 40%, one would need 2.5 kg of algae cells to get 1 kg of oil.
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 gallons per acre, per year (4.6 to 18.4 l/m2 per year); this is 7 to 30 times greater than the next best crop, Chinese tallow (699 gallons).
Algae can also grow on marginal lands, such as in desert areas where the groundwater is saline.
The difficulties in efficient biodiesel production from algae lie in finding an algal strain with a high lipid content and fast growth rate that isn't too difficult to harvest, and a cost-effective cultivation system (i.e., type of photobioreactor) that is best suited to that strain.
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. Diversified Energy Corporation have avoided this problem by taking a different approach, and growing the algae in thin walled polyethylene tubing called Algae Biotape, similar to conventional drip irrigation tubing, which can be incorporated into a normal agricultural environment.
Open-pond systems for the most part have been given up for the cultivation of algae with high-oil content. 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. The energy that a high-oil strain invests into the production of oil is energy that is not invested into the production of proteins or carbohydrates, usually resulting in the species being less hardy, or having a slower growth rate. Algal species with a lower oil content, not having to divert their energies away from growth, have an easier time in the harsher conditions of an open system.
Some open sewage ponds trial production has been done in Marlborough, New Zealand.
In a closed system (not exposed to open air) there is not 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 carbon dioxide (CO2). Several experimenters have found the CO2 from a smokestack works well for growing algae. To be economical, some experts think that algae farming for biofuels will have to be done next to power plants, where they can also help soak up the pollution.
A feasibility study using marine microalgae in a photobioreactor is being done by The International Research Consortium on Continental Margins at the International University Bremen
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 diatoms and cyanobacteria; as opposed to macroalgae, e.g. seaweed. However, some research is being done into using seaweeds for biofuels, probably due to the high availability of this resource. This preference towards microalgae is due largely to its less complex structure, fast growth rate, and high oil content (for some species). Some commercial interests into large scale algal-cultivation systems are looking to tie in to existing infrastructures, such as coal power plants or sewage treatment facilities. This approach not only provides the raw materials for the system, such as CO2 and nutrients; but it changes those wastes into resources.
NBB’s Feedstock Development program is addressing production of algae on the horizon to expand available material for biodiesel in a sustainable manner .
Butanol can be made from algae or diatoms using only a solar powered biorefinery. This fuel has an energy density similar to 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 corosion resistance than that of ethanol or E85.
The green waste left over from the algae oil extraction can be used to produce butanol.
Biogasoline can be produced from algae.
Global air carriers Air New Zealand, Continental, Virgin Atlantic Airways, and biofuel technology developer UOP LLC, a Honeywell company, will be the first wave of aviation-related members, together with Boeing, to join Algal Biomass Organization.
Twenty-five airlines went bust or stopped operations in the first six months of 2008 and more could fold as fuel prices soar, aviation industry association IATA has warned. Algal jet fuel can be used as alternative: IATA recognizes that aircraft are long lived and will be using kerosene or kerosene-type fuels for many years. It supports research, development & deployment into alternative fuels that produce less GHG emissions over their life cycle and do not compete for land with fuel crops. IATA’s goal is for its members to be using 10% alternative fuels by 2017.
The hard part about algae production is growing the algae in a controlled way and harvesting it efficiently.
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 photobioreactors or PBR).
Running a PBR is more difficult than a open pond, and more costly.
There is an option currently being deployed at the Woods Hole Oceanographic Institution and the Harbor Branch Oceanographic Institution and s using wastewater for breeding algae. The wastewater from domestic and industrial sources contain rich organic compounds, which accelerate the growth of algae.
Algaewheel, based in Indianapolis, Indiana, presented a proposal to build a facility in Cedar Lake, Indiana that uses algae to treat municipal wastewater and uses the sludge byproduct to produce biofuel.
Nutrients like nitrogen (N), phosphorous (P), and potassium (K), are important for plant growth and are essential parts of fertilizer. Silica and iron may also be considered important marine nutrients as the lack of one can limit the growth of, or productivity in, an area.
Another 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 digester is liquid, and nearly suitable for algae growth, but it must first be cleaned and sterilized.
One company, Green Star Products, announced their development of a micronutrient formula to increase the growth rate of algae. According to the company, its formula can increase the daily growth rate by 34% and can double the amount of algae produced in one growth cycle.