You may have noticed that this website devotes the majority of its focus on algae biofuels, however these fuels are fairly new. Therefore, this page will hopefully give you a little background on the topic.
Algae biofuels are derived from algae cells. There are many different ways in which these cells can produce fuel components. Because of the variability of algae and the composition of the cells, almost any kind of fuel can be created. For example, some species of algae can produce ethanol while others can produce a “green crude” that has the potential to be refined into anything from diesel to gasoline to jet fuel.
Description of Technologies
There are two main technologies utilized to grow algae. One way that seems to be the main focus of startup companies is growing one specific strain of algae in a bioreactor. One company using this method is OriginOil. For those not familiar with a bioreactor, an explanation of the technology can be found here.
Another way that algae can be grown is in an open pond. In comparison to the bioreactor method, algae farmers are hard pressed to keep “contaminate” strains of algae from growing in the ponds. Aquaflow Bionomic Corporation is one company using this method and has opted to use wild strains of algae to convert to biofuel instead of worrying about a specific strain of algae to harvest. In fact, Aquaflow has been quite successful with using wild algae and has even created key jet fuel components from it.
The last major method of algae growth currently being researched is the use of fermentation technologies. Essentially, algae is fed sugars in the dark and the algae produces oil. One company looking into this method is Solazyme.
Comparison with Other Biofuels
Algae also has the potential to produce literally thousands of gallons more of fuel annually than compared with the next best biofuel currently being researched. Most estimated have algae being able to produce between 1,000 to 4,000 gallons of oil/acre/year whereas soybeans can only produce 48 gallons of oil/acre/year and corn even less than that.
Here is a graph that illustrates some of the other comparisons between algae and other crops:
At this point, many people may be wondering about the increased water usage required by algae. Fortunately, algae cultivation does not have to affect the world’s freshwater supply. In fact, unlike other biofuels, algae can be grown in anything from wastewater to brackish water to saltwater.
By using these non-freshwater sources, algae puts itself in a league of its own. Most traditional biofuel crops like corn, soybeans, or jatropha, need freshwater for their growth. By utilizing wastewater, algae actually uses something that would essentially go to waste and helps to filter out the pollutants in the process. Therefore, there are two benefits to using algae: one, it helps to filter out pollutants before releasing the water into the environment and two, the algae can be harvested and used for biofuel production. This isn’t a revolutionary idea; some countries are already looking into algae wastewater treatment with the UK being one of the latest.
Also, with the saltwater and brackish water being other potential water sources for algae, one might not have to worry about algae’s growth affecting the local water supply.
Other Information Sources
The algae biofuel field is constantly advancing. To keep up with the latest in the field, consider subscribing to the free online magazine “Biofuels Digest” or frequently visit the websites of the companies listed above.
For more basic information on algae biofuels, check out this article I wrote at Celsias.com or take a look at the Department of Energy’s “National Algal Biofuel Technology Roadmap.”