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Algae fuel

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Algae growing on smokestack pollution and sunlight, producing oil

Algae fuel, or algal fuel, [1] is a second-generation biofuel made from algae. Compared with other second generation biofuels, algae are relatively 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][5]According to René Wijffels the current systems do not yet allow algae fuel to be produced competitively. However using new (closed) systems, and by scaling up the production it would be possible to reduce costs by 10X, upto a price of 0,4 € per kg of algae. [6]

Algae can potentially thrive on exhaust gases from power plants which run on fossil fuel (or any fuel that is burnt to product carbon dioxide. The algae grows faster thanks to the high concentration of carbon dioxide, which would otherwise be emitted as a greenhouse gas in the atmosphere, increasing climate change.

However, it does appear to have greater environmental impact than other forms of biofuel.[7]

Other advantages[edit]

Algae can de-nutrify water, hereby acting as a secondairy wastewater treament.

Heineken's Zoeterwoude brewery already de-nutrifying its used water using algae; it's appearantly 97% efficient.

It can possibly also be used as a secondairy wastewater treatment in sewage systems. This would then be similar to the method described by Bas Ibelings (of NIOO-KNAW) for its Algae toilet.[8]

Companies[edit]

Companies working on producing biofuel include:

  • Proviron : this company has been working on a new type of reactor (using flat plates) which reduces the cost of algae cultivation.
  • Enhanced Biofuels & Technologies[1] - The process combines a bioreactor with an open pond, using waste CO2 from coal-fired power plant flue gases.
  • GreenFuel Technologies[2] - "Emissions-to-Biofuels™" process to capture CO2 and produce high-energy biomass. This company appears to have collapsed.[9]
  • GreenShift[3] - with an agreement with Ohio University for its bioreactor process based on a iron-loving cyanobacterium (blue-green algae).
  • Solazyme[4] - uses genetic engineering to optimize commercially relevant biochemical pathways, to produce energy and specialty chemicals.
  • LiveFuels - Working on breeding strains of algae.
  • Valcent Products[5] - has designed a high density vertical bio-reactor for the oil bearing algae, for removing large quantities of CO2 from the atmosphere.
  • Aquaflow Bionomics Corporation[6] -, New Zealand-based, focused on wild algae harvested from open-air environments.
  • Infinifuel Biodiesel[7] - in Nevada, a geothermal-powered and heated biodiesel plant.
  • Solix Biofuels[http://www.solixbiofuels.com) - developing massively scalable photo-bioreactors for producing biodiesel and other commodities from algae oil. The closed photo-bioreactors allow exhaust from fossil-fuel power plants to be captured by the system.

Algal jet fuel[edit]

A number of universities and businesses are working on algal fuel for aviation - algae jet fuel. These include: the companies Solazyme, Honeywell UOP, Solena, Sapphire Energy, Imperium Renewables, and Aquaflow Bionomic, along withArizona State University and Cranfield University.

Inputs[edit]

  • Carbon dioxide, from burnt fuel or the atmosphere,
  • Nutrients - sewage is one possible source.
  • Light for photosynthesis. Sunlight is the obvious choice - electric lighting is not feasible as it will make the energy cycle much more difficult - the algae would need to be getting significant extra energy from somewhere other than the light.

Obstacles[edit]

The key difficulties in the production of oil from algae are:

  • Algae require CO2 as well as nitrogen and potassium. The latter 2 can generally not be administered using ie green manure. Regular manure (ie fish droppings, ...) can be used though but in many cases artificial fertiliser probably needs to be used. A lot of systems also require a lot of electricity as the water needs to be circulated (the level of oxygen in the water needs to be kept low, hence the requirement of circulation). These requirements put a strain on the ecology.
  • Unlike seaweed algae species generally require sweetwater, which may not always be available in the vicinity or needs to be acquired from the potable water distribution network, hence competing with the water availability for humans
  • Oil-rich algae must be protected from consumption or displacement by other organisms. If they are grown in open ponds, this is a major challenge. Open ponds can be used however for growing certain algae species such as Spirulina platensis and Chlorella pyrenoidosa; however for the purpose of making fuels, these species are not very suitable
  • The algae are most productive within a narrow temperature band.
  • The expense of the containment used to protect from invading organisms and maintain a suitable temperature.
  • Controlling the growth. If the algae grows faster than it can be harvested, it can die off and decompose - this was reported as a factor in the failure of GreenFuel.[10]
  • Better understanding of growth rates under various conditions is needed, as well as better harvesting equipment

See also[edit]

References[edit]

The discussion on the cited Oil Drum article refers to problems in the thermodynamics, i.e. in the basic energy equations, suggesting that algae fuel may never be affordable. Calculations by Odum are among the references for this argument.[verification needed]

External links[edit]