Algas que crecen en la contaminación de las chimeneas y la luz solar, produciendo petróleo.

El combustible de algas , o combustible de algas , [1] es un biocombustible de segunda generación elaborado a partir de algas . En comparación con otros biocombustibles de segunda generación, las algas son materias primas de alto rendimiento y alto costo (30 veces más energía por acre que los cultivos terrestres) para producir biocombustibles. Dado que todo el organismo convierte la luz solar en aceite, las algas pueden producir más aceite en un área del tamaño de un garaje para dos autos que en un campo de fútbol lleno de soya . [2]

Hoy en día cuestan $ 5-10 / kg y existe una investigación activa para reducir los costos operativos y de capital de producción para que sea comercialmente viable. [3] [4] [5] Según René Wijffels, los sistemas actuales aún no permiten producir combustible de algas de manera competitiva. Sin embargo, utilizando nuevos sistemas (cerrados) y aumentando la producción, sería posible reducir los costes en 10X, hasta un precio de 0,4 € por kg de algas. [6]

Las algas pueden prosperar potencialmente con los gases de escape de las centrales eléctricas que funcionan con combustibles fósiles (o cualquier combustible que se queme para producir dióxido de carbono . Las algas crecen más rápido gracias a la alta concentración de dióxido de carbono, que de otro modo se emitiría como gas de efecto invernadero en la atmósfera, aumentando el cambio climático .

Sin embargo, parece tener un mayor impacto ambiental que otras formas de biocombustibles. [7]

Otras ventajas

Las algas pueden desnutrir el agua, actuando como un tratamiento secundario de aguas residuales .

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 secondary 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]

Compañías

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 - The process combines a bioreactor with an open pond, using waste CO2 from coal-fired power plant flue gases.
  • GreenFuel Technologies - "Emissions-to-Biofuels™" process to capture CO2 and produce high-energy biomass. This company appears to have collapsed.[9]
  • GreenShift - with an agreement with Ohio University for its bioreactor process based on a iron-loving cyanobacterium (blue-green algae).
  • Solazyme - uses genetic engineering to optimize commercially relevant biochemical pathways, to produce energy and specialty chemicals.
  • LiveFuels - Working on breeding strains of algae.
  • Valcent Products - 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 -, New Zealand-based, focused on wild algae harvested from open-air environments.
  • Infinifuel Biodiesel - in Nevada, a geothermal-powered and heated biodiesel plant.
  • Solix Biofuels - 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.

Combustible de algas para aviones

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.

Entradas

  • 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.

Obstáculos

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

Ver también

enlaces externos

Referencias

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]

  1. "Oilgae.com – Oil from Algae!". Retrieved 2008-06-10.
  2. "Why Algae?". Solix Biofuels. Retrieved 2008-06-11.
  3. Hartman, Eviana (2008-01-06). ""A Promising Oil Alternative: Algae Energy"". The Washington Post. Retrieved 2008-06-10.
  4. "{PhD thesis on algae production for bioenergy}" (PDF). Murdoch University, Western Australia. Retrieved 2008-06-10.
  5. ""Algal Oil Diesel, LLP"".
  6. EOS magazine, 6, 2012
  7. Engineers Find Significant Environmental Impacts with Algae-Based Biofuel
  8. NWT magazine, february 2012
  9. Cost Viability and Algae, The Oil Drum, May 29, 2009.
  10. Oil Drum
Datos de la página
Palabras clavealgae, biofuel, sustainable transport gallery fuels
AutoresChris Watkins
Publicado2008
LicenciaCC-BY-SA-4.0
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