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[edit] Biofuels production
Main article: Biofuel from algae
Currently most research into efficient algal-oil production is being done in the private sector, but if predictions from small scale production experiments bear out then using algae to produce biodiesel, bioethanol and biobutanol may be the only viable method by which to produce enough automotive fuel to displace current world gasoline usage.[16]
Microalgae have much faster growth-rates than terrestrial crops. The oil yield per unit area of algae is estimated to be 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).[17]
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 (ie, type of photobioreactor) that is best suited to that strain.
Open-pond methods have largely been abandoned 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. Algae in an open-pond environment are subject to 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 open-pond method makes the entire effort dependent upon the hardiness of the strain chosen, requiring it to be unnecessarily resilient (compared to a closed system) in order to withstand the environmental conditions. For a given amount of photosynthetic energy, an algae strain producing relatively high levels of oil will produce relatively less protein and/or carbohydrate, 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.[18]
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.[19]
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. 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, an entity called "Green Star Products" announced that it has signed an agreement with "De Beers Fuel Limited" of South Africa 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. [20] 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.[21]
The corporations Chevron, Honeywell, and Boeing are starting algae businesses. According to Boeing's technology leader for energy and emissions, Dave Daggett, 'In the past two years, we have changed from algae skeptics to proponents'. [22] The development challenge is to reduce the cost of producing algae oil in commercial volumes, i.e. billions of gallons.
"'In Europe, refiners are producing 1.4 billion gallons a year from rapeseed, soy, and other plants. In all, the world consumed $1.7 billion worth of biodiesel last year. That should grow to $26 billion by 2020, says market researcher Global Insight.'" [22] These figures project an average growth of over 20% per year
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