by Tamara Scully
The next big thing in alternative energy may be pretty small. Algae, which are aquatic, single-celled organisms, produce oxygen while consuming carbon dioxide. Nitrogen, phosphorous and other nutrients which can degrade our waterways, plus sunlight and carbon dioxide, provide algae with a steady diet. From that diet, they rapidly produce biomass in the form of proteins, carbohydrates and lipids.
It’s the lipids that are of special interest to biodiesel production. Some algae produce more lipids than others. But while lipid production is needed for biofuel, there are other components produced by the algae which can be readily utilized for animal feeds, nutraceutical purposes and more.
In a video produced by the Vermont BioEnergy Initiative – Vermont Sustainable Jobs Fund, and funded by Senator Patrick Leahy and a grant from the United States Department of Energy, Bioenergy Program Director Netaka White, along with several Vermont researchers, discuss the potential for microalgae biomass potential. http://vermontbioenergy.com/algae/
“Microalgae biomass has a lot of potential for different feedstocks for energy, for our use,” researcher Sam Couture said. “One of the ones that many people are focusing on currently is liquid biofuel from algae, such as biodiesel. Our overall yields (in New England) could never compete with a very sunny place. But if we’re looking at co-products and oil per footprint per year, there’s a real potential in the Northeast.”
At General Systems Research LLC, algae strains with potential for production for biofuels are being studied. These high-lipid strains of locally-available algae can be scaled up for biofuel production, as well as used in waste-water treatment. Using algae to treat wastewater not only removes damaging nutrients from waterways, but also can help to make algae biomass production cost-effective.
While algae with high lipid production are needed, it’s also important for the algae to grow rapidly. Other ongoing studies are using flow dynamics to optimize algae cell reproduction. Oscillation maximizes the growth rate of algae. The turbulence provides algae with a variety of light exposure, which is beneficial to their growth. Rapid growth, combined with high lipid production, is one key to the economic feasibility of utilizing algae for biofuel production on a commercial scale.
Energy from algae
To extract lipids oils from the algae cells, water is separated from the cells, a process which requires a large energy footprint. At Green Mountain Spark, they are working to eliminate that step, and to extract the oils without the need to remove the water.
The innovative process uses an ultraviolet lamp, shaped in a helix, to break the algae’s cells. Oils are released from the cells, and are treated by reagents to create a biofuel. The process takes the lipid feedstock and converts it to green biofuel in one step, reducing costs. The technology can also be applied in other applications, such as treating grease at wastewater treatment facilities.
The biofuel produced by the algae in the photo-reaction system can operate in cold weather. This gives it an advantage over biodiesel from other renewable oil sources, such as canola or sunflower, which becomes too viscous at cold temperatures. The photo-reaction process is scalable, and can apply to any other vegetable oil feedstock, according to the researchers.
At Carbon Harvest Energy, methane from landfills is being captured, and used to generate power for the grid. During this process, energy captured here is also used for aquaculture production. The resulting fish waste provides a nutrient source, and is used to feed plants in an aquaponic system. Algae, too, play a role here, cleaning the water in the aquaponics system, so it can be returned to the fish tanks. The algae also utilize carbon dioxide, captured from generator exhaust gas, as a feed source.
“Algae stands out for its ability to produce an abundant amounts of oil in a short period of time,” White said. “By locating algae production where waste nutrients and CO2 are readily available, and by concentrating on algae co-products as well as biofuel …even small scale facilities producing algae in the Northeast can make a viable contribution to the region’s clean energy portfolio.”
In 2015, Marine Algae Industrialization Consortium (MAGIC), based at Duke University, received a grant from the U.S. Department of Energy to produce protein-based human and poultry nutritional products, and to develop methods for the large-scale production of fuels. Cornell University is a member of MAGIC.
Algae-based pet, fish and livestock feeds can be co-products of algae biofuel harvesting. And, in November 2017, an algae-based nutrition bar, Nonbar, was released by a Los Angeles company, Nonfood.
Algae can also be utilized in plastic production. Whether algae by-products from lipid extraction are used, or algae is simply used as a feedstock, plastic polymers can be made from the carbohydrates and hydrocarbons produced by the algae. There are numerous applications being tested, with the goal of creating consumer goods from algae-derived bioplastic.
According the United States Department of Energy, the natural oils from algae can potentially produce 60 percent more oil per acre than those acquired from land-based plants. With hundreds of thousands of algae strains, both fresh water and salt water species, the algae supply is varied and readily available. Particular algae strains grow better under various conditions, and can be locally adapted to a variety of environments.
Producing biofuel from algae can help to reduce reliance on fossil fuels, and can help to clean up the environment, capturing carbon dioxide, as well as excess nutrients in water, thus reducing environmental pollutants in air and water. While there is much more work to be completed, microalgae could offer big gains in biofuel and bioproduct production.