Monday, April 04, 2011

Algae Biodiesel



algae, biofuel, biocrude, LiveFuels, algae-based fuel, bio-based fuel, biodiesel, Solix, Greenfuels, NREL, US DOE, Department of Energy
While several companies like Algae BioFuels and Greenfuels and Solix Biofuels are working on algae cultivation research for biofuel, the LiveFuels Alliance differs in that it is a national initiative. Lead by Sandia National Laboratories, a U.S. Department of Energy National Laboratory, the collaborative will sponsor dozens of labs and hundreds of scientists within the next three years making it the largest endeavor focused on commercial biocrude from algae.
The current research builds off of a U.S. Department of Energy funded study that ran from 1978-1996. Through the National Renewable Energy Laboratory (NREL), the 18-year-long ‘Aquatic Species Program’ focused on high-oil algae cultivation for biodiesel. At the time the program was canceled, algae was competing against low oil prices. However, surging oil prices and advances in biotech over the past decade have refueled the algae biocrude race. LiveFuels aims to infuse U.S.-based research and refine the processes to increase algae oil production at competitive prices.
The scientists involved in the LiveFuels project are focusing on specialized aspects of the algae-to-biocrude process. Some are breeding algae to find the best high-fat strains, others are refining the fat and oil extraction process and others still are developing cost-effective harvesting techniques. The biggest challenge is to make algae biocrude within a fraction of the time that nature’s biomass decomposition occurs and to do it economically, for less than $60 a barrel.
The process of extracting oil from algae is basically the same as other biofuel technology. However, algae doesn’t require prime agricultural land and has a potential yield that far exceeds other renewable sources. For instance, algae yields 10-200% more oil per acre than soy which produces about 117 gallons of oil per acre. Another perk is that under the right conditions algae grows rapidly. It’s also non-toxic, biodegradable and can be grown in fresh, brackish or wastewater.
Theoretically, algae can yield between 1,000 to 20,000 gallons of oil per acre, depending on the specific strain. The potential yield from 20 – 40 million acres of marginal land in the U.S. could produce enough algae to replace imported oil and leave 450 millions acres of current farmland for use as food crops. Turning that potential into a domestically-grown reality is the goal of the LiveFuels Alliance.

So, we've talked about the chemical process that takes algae and turns it into biodiesel fuel. The real question, and one which many companies all over the globe are trying to answer, is how can we produce enough to meet the demand for biodiesel?
The most natural method of growing algae for biodiesel production is through open-pond growing. Using open ponds, we can grow algae in hot, sunny areas of the world to get maximum production. While this is the least invasive of all the growing techniques, it has some drawbacks. Bad weather can stunt algae growth, as can contamination from strains of bacteria or other outside organisms. The water in which the algae grow also has to be kept at a certain temperature, which can be difficult to maintain.
illustration of algae bioreactor

Vertical growth/closed loop production has been developed by biofuel companies to produce algae faster and more efficiently than open pond growth. With vertical growing, algae are placed in clear plastic bags, so they can be exposed to sunlight on two sides. The bags are stacked high and protected from the rain by a cover. The extra sun exposure increases the productivity rate of the algae, which in turn increases oil production. The algae are also protected from contamination.
illustration of algae bioreactor process

Other companies working to produce algae for biodiesel are constructing closed-tank bioreactor plants to help increase oil rates even further. Instead of growing algae outside, indoor plants are built with large, round drums that grow algae under ideal conditions. The algae are manipulated into growing at maximum levels and can be harvested every day. This yields a very high output of algae, which in turn yields large amounts of oil for biodiesel. Closed bioreactor plants can also be strategically placed near energy plants to capture excess carbon dioxide that would otherwise pollute the air.
Researchers are testing another variation of the closed-container or closed-pond process -- fermentation. Algae are cultivated in closed containers and fed sugar to promote growth. This method eliminates all margin of error since it allows growers to control all environmental factors. The benefit of this process is that it allows the algae biodiesel to be produced anywhere in the world. But, researchers are trying to figure out where to get enough sugar without creating problems.
Let's learn more about the pros and cons of algae biodiesel.

No comments: