WILL ALGAE REPLACE PETROLEUM?
With record oil price increases accelerating, competing demands among foods and fuel sources and the looming world food crisis, there is rapidly-growing interest in algaculture (farming of algae) for making vegetable oil, biodiesel, bioethanol, biogasoline, biomethanol, biobutanol and other biofuels. Successful results from small-scale production experiments show promise that using algae to produce fuels may be the best future method by which to produce enough automotive fuel to displace current world gasoline usage. Algae may eventually be the ultimate in renewable energy. Algae are among the fastest growing plants in nature, and about 50 percent of their weight is oil. All over the world, both governments and private companies are exploring the use of algae to produce energy.
Algae as a possible alternative fuel is not a new idea. The US Department of Energy studied it for about 18 years, from 1978 to 1996. But at the end of that period, it decided that algae oil could never compete economically with fossil fuels, when the price of a barrel of oil was about 20 US dollars.
Now, with oil pushing above 130 US dollars, the U.S. government is back into algae. The 2007 Energy Security and Independence Act includes promoting the use of algae for biofuels. The US Department of Energy now estimates that if algae fuel replaced all the petroleum fuel in the United States, it would require 15,000 square miles (38,849 square kilometers), which is a few thousand square miles larger than Maryland or a third larger than Belgium. This is less than 1/7th the area of corn harvested in the United States in 2000.
Some recent estimates claim that all U.S. oil imports could be replaced by biocrude grown on 20 to 40 million acres of marginal lands that exist across the country. Only 0.3 percent of the land area of the U.S. could be needed to produce enough biodiesel to replace all transportation fuel the country currently uses.
Producing biodiesel from algae has been described as possibly the most efficient way to make biodiesel fuel. The advantage being that the land requirement for growing is very small. Independent studies show that algae is capable of producing 30 times more oil per acre than other traditional crops currently utilized for the production of biofuels. Some species of algae are well-suited to biodiesel production due to their high oil content, in excess of 50%, and extremely rapid growth rates. For example, it is estimated that 2.25 acres of soybean can create 2 drums (55 gallons) of biodiesel, while 2.25 acres of micro-algae can produce a jumbo railcar (23,000 gallons) of biodiesel.
Algae biofuel contains no sulfur, is non-toxic and highly biodegradable. Algae provides environmental benefits in terms of greenhouse gases and as a more efficient fuelstock than biodiesel from crops like soybeans. The amount of greenhouse gasses generated are small, since most of the carbon dioxide emitted during the burning process is simply recycling what was absorbed during plant growth. Algal oil is similar to soybean oil which now is used to produce biodiesel, but can be grown on marginal lands unsuitable for food crops and even in brackish water. Also, barren desert lands which receive high solar radiation could effectively grow the algae in great quantities. Furthermore, the algae could use farm wastes and excess carbon dioxide from factories and other sources to help the growth of the algae.
Algae oils have a variety of commercial and industrial uses, and are extracted through a wide variety of methods. Algae fuel, also called algal fuel or oilgae, is a biofuel from algae. Compared traditional-crop biofuels, algae are much higher-yield, up to 30 times more energy per acre. With an oil-per-acre production rate 250 times the amount of soybeans, algae offers the highest yield feedstock for biodiesel. Estimates of the cost to extract oil from microalgae vary, but now are around $1.80/kg (compared to $0.50/kg for palm oil). 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, which is 7 to 30 times greater than the next best crop, Chinese tallow (about 700 gallons per acre per year).
The latest research into algae for the mass-production of algae oil is mainly focused on microalgae, defined as organisms capable of photosynthesis less than 2 mm in diameter, including diatoms and cyanobacteria; as opposed to macroalgae, such as seaweed. This emphasis on microalgae is due largely to its less-complex structure, fast growth rate, and high oil content for certain species. Commercial interest in large-scale algae-cultivation is pointed toward systems that link into 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 renewable resources.
It is small wonder, that many people look to biofuels from micro-algae as a realistic future solution to the near-total replacement of petroleum fuels.
WILL ALGAE REPLACE PETROLEUM?