Biofuel
Vegetable Oil Biodiesel Bioalcohols BioGas Syngas Methanol DMF Fischer-Tropsch Algae Fuel

Algae fuel, also called algal fuel, oilgae^[1] 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 converts sunlight into oil, algae can produce more oil in an area the size of a two-car garage than an entire football field of soybeans.^[2]

Nowadays they cost $5–10/kg and there is active research to reduce both capital and operating costs of production so that it is commercially viable.^[3][4]

Algal fuels do not impact fresh water resources ^[5] and can use ocean and wastewater.

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)^[6] 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.^[7][8][9]

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.^[3] This is less than 1/7th the area of corn harvested in the United States in 2000.^[10]

In the 2008 U.S. Department of Energy Biomass and Biofuels Update to Congress (by the Office of Biomass Program)^[11] appears the move to algae fuels.^[12]

Biofuel applications of botryococcene

The practice of farming cultivating is known as algaculture. Botryococcus braunii has great potential for algaculture because of the hydrocarbons it produces, which can be chemically converted into fuels. Up to 86% of the dry weight of Botryococcus braunii can be long chain hydrocarbons [3]. The vast majority of these hydrocarbons are oils called botryococcenes. Transesterification can NOT be used to make biodiesel from botryococcenes. This is because botryococcenes are not 'vegetable oils' in the common meaning, in which they are fatty acid triglycerides. While botryococcenes are oils of vegetable origin, they are inedible and chemically very different, being triterpenes, and lack the free oxygen atom needed for transesterification. Botryococcenes can be used as feedstock for hydrocracking in an oil refinery to produce octane (gasoline, a.k.a. petrol), kerosene, and diesel.

Botryococcenes are the major oil constituents of the green algae Botryococcus braunii. The hydrocarbons this species produces can be chemically converted into fuels. Transesterification can NOT be used to make biodiesel from botryococcenes, the major oil of Botryococcus braunii. This is because Botryococcene is not a 'vegetable oil' (which is a fatty acid triglyceride) but is instead a triterpene, and lacks the free oxygen for transesterification. It can be used as feedstock for hydrocracking in an oil refinery to produce octane (gasoline, a.k.a. petrol), kerosene, and diesel. Up to 86% of its dry weight can be long chain hydrocarbons.

There are several challenges which must be met in order to economically produce the desired alkanes such as gasoline. This will only be briefly covered in this article at this time, as it has only just begun.

First is that a suitable strain of Bb (Botryococcus braunii) must be found. Several strains are available from algae specimen banks, but there is no guarantee that these are high-producing strains. Some plant patent applications have been filed and patents granted, for high producing strains. It is within reason for even a small scale producer of boytrococcenes to breed successively higher producing strains of Bb, due to the reasonably fast generation rate. However, in selecting Bb strains for high Botryococcene production, it is likely that other beneficial attributes may be bred out. For instance, resistance to disease, competitive advantages against other organisms, and survivability in less than ideal climates. In this case, a photobioreactor may be needed.

The practice of farming algae is know as algaculture. However, there are properties of Botryococcus braunii which make its harvest a bit different than the harvest of other algae. Compared to other green algae species it has a relatively thick cell wall that is accumulated from previous cellular divisions; making extraction of cytoplasmic components rather difficult. Fortunately, much of the useful hydrocarbon oil is outside of the cell. This gives rise to the hope that the algae will not have to be killed in order to extract its useful oil. Indeed, this is the case. Several methods are available to extract the botryococcene. One that shows the most promise is the use of hexane as a solvent. If used at the proper molarity, it does not kill the majority of the Bb, while extracting the botryococcene. However, like all organisms Bb is less productive in old age. It is said the become 'senescent' and produce less boytococcene. It will eventually die of old age. However, some algae farmers may wish to weed out these non-producing algae and not return them to the photobioreactor.

Fuels

The vegoil algae produce can then be harvested and converted into biodiesel; the algae’s carbohydrate content can be fermented into bioethanol. ^[13]

Biodiesel production

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 produce biodiesel may be the only viable method by which to produce enough automotive fuel to replace current world diesel usage.^[14]

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).^[15]

Algae can also grow on marginal lands, such as in desert areas where the groundwater is saline.^[16]

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.^[17]

Open-pond systems for the most part have been given up for the cultivation of algae with high-oil content.^[18] 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.^[19]

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.^[20][21] 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.^[16]

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.^[22]

Research into algae for the mass-production of oil is mainly focused on microalgae; organisms capable of photosynthesis that are less than 2 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.^[23] 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.

In November 8, 2006, Green Star Products announced it had signed an agreement with De Beers Fuel Limited of South Africa (but no relation to the diamond cartel) to build 90 biodiesel reactors with algae as raw material. Each of the biodiesel reactors will be capable of producing 10 million gallons of biodiesel each year for a total production capacity of 900,000,000 gallons per year when operating at full capacity, which is 4 times greater than the entire U.S. output in 2006. Also, GreenFuel Technologies Corporation has delivered a bioreactor to De Beers Fuel. Doubts have been expressed about Green Star's expertise in biodiesel technology.^[24] Green Star's president did however answer questions in an online interview with WallSt.net where he claimed that the South African biodiesel production has exceeded the original expectations.^[25] People who paid De Beers Fuel for franchises have nothing to show for their investment.^[26] GreenFuel has terminated its licensing agreement with De Beers Fuel owing to “nonperformance” and requested that the company remove any reference to the agreement from its website.^[27]

Aquaflow Bionomic Corporation of New Zealand announced that it has produced its first sample of homegrown bio-diesel fuel with algae sourced from local sewerage ponds.

The Department of Environmental Science at Ateneo de Manila University in the Philippines, is working on producing biofuel from algae, using a local species of algae.^[28]

PetroSun has announced it has begun operation of its commercial algae-to-biofuels facility on April 1st, 2008. The facility, located in Rio Hondo, Texas, will produce an estimated 4.4 million US gallons (17 million l) of algal oil and 110 million pounds (50 million kg) of biomass per year off a series of saltwater ponds spanning 1,100 acres (4.5 km²). Twenty acres (8.1 ha) will be reserved for the experimental production of a renewable JP8 jet-fuel.^[5]

Biobutanol

No modifications are need to be made to use butanol in gasoline engines.

Butanol can be made from algae or diatoms using only a solar powered biorefinery. This fuel has an energy density similar to, but greater than that of gasoline (petroleum gasoline).

The green waste made from the algae oil extraction can be used to produce butanol.

Biogasoline

Biogasoline can be produced from algae.

Methane

Through the use of algaculture grown organisms and cultures, various polymeric materials can be broken down into methane.^[29]

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

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 gasoline and diesel.^[30]

Green Crude

Green crude refers to a green-colored crude which yields clean versions of gasoline and diesel from algae, sunlight, carbon dioxide and water. The result is chemically equivalent to the light, sweet crude oil traditionally used for distillation of carbon-based fuels.

DIY, small and open source technology production

People can grow their own fuel at home, on the roofs of their homes, using open source technologies. A 185 m² (2,000 square foot) home could produce 10 US gallons (38 l) of algal diesel a week. It could supply the needs of either a single truck or a family of efficient cars.

References

External links

• Biodiesel from Algae (NREL).
• Algal Biomass Organization
  • Algae Biomass Summit.
• Remarks to the Algae Biomass Summit (EERE).
• Better Than Corn? Algae Set to Beat Out Other Biofuel Feedstocks (Worldwatch Institute).
• Biofuelsdatabase.org
• Bio-Hydrocarbons from Algae -Impacts of temperature, light and salinity on algae growth (RIRDC).
• Algae system transforms greenhouse emissions into green fuel (MIT/MITEI).
• Oil_from_algae Yahoo Group
• Phyco, algal fuel wiki
• Soley Institute Biodiesel from algae
• UNH Biodiesel Group
• Solar Biofuel Consortium.
• http://www.scoop.co.nz/stories/SC0605/S00030.htm
• National Defense Center of Excellence for Research in Ocean Sciences
• Algal commercialization
• Algae as a Biodiesel Feedstock: A Feasibility Assessment
• Widescale Biodiesel Production from Algae (University of New Hampshire).
• Work on biofuels (Worldwatch).

News

• Department of Defense and NASA Look to Fuel Jets with Algal Fuels.
• New Algae Trade Group Forms - Algal Biomass Organization (Cleantech.com)
• Inagural Algae Biomass Summit a Success
• Department of Energy Remarks at Algae Biomass Summit
• First Algae Biodiesel Plant Goes Online: April 1, 2008.
• A Promising Oil Alternative: Algae Energy (The Washington Post)
• German scientists see use for algae in biofuels.
• Biodiesel production to begin soon.
• Pond-Powered Biofuels: Turning Algae into America's New Energy (Popular Mechanics).
• Solazyme hopes to begin mass-producing Soladiesel at a competitive price within three years.
• Algae: 'The ultimate in renewable energy' (CNN).
• Biofuels Media London Conference