Algae's Impact on the Food-Versus-Fuel Debate
The growing use of algae biomass for nutraceutical purposes is expected to provide an attractive revenue stream for those using algae oil for biodiesel.
It's possible for certain types of algae, such as Nannochloropsis and Chlorella Vulgaris, to have a complete branch chain amino acid profile. These high-value products can be extracted from the algae and taken to market. Chlorella Vulgaris has been proven in clinical studies to reduce, and in some cases prevent, the side effects from chemotherapy treatments. It has also been proven to reduce the risk of getting cancer as it contains the highest known source of chlorophyll content.
Spirulina is another popular algae strain that is used as a protein supplement in diets of the health-conscious.
Now that many companies are trying to commercialize the production of algae lipid oil for biodiesel production there will likely be a large influx of algae biomass into a variety of market avenues. The current wholesale price for a metric ton of Nannochloropsis for an aquaculture facility is $18,000. Chlorella Vulgaris has a retail value of $36,000 per metric ton. These prices should drop once commercial-scale algae farms for lipid oil production facilities begin coming on line. Algae biomass can be dried and processed into a powder similar to whey or soy protein that can be used for protein supplements. It may also be added to different types of foods for protein content an vitamin enrichment.
Proteins, Vitamins and Minerals
The further development of a large-scale algae protein market will be the driving force to making algae oil a reality for biodiesel production. The path forward is awaiting, but more marketing and penetration into existing food sectors is needed. The sports nutrition market is worth more than $27 billion per year and has a great potential as an algae protein market.
Algae, of course, are a fish food, used for many common species including tilapia. The demand for more fish meal will increase as the demand for fish farms being utilized for human consumption grows due to the environmental effects over open ocean fishing. Algae are also used to feed the brine shrimp used to feed other species of farm-raised fish such as salmon. Regardless, algae are in high demand for fish food in the aquaculture market and provide a great revenue stream for the algae industry.
The vitamins and minerals within algae may be fractionated from the biomass. This application has been used for years for a wide array of products in cosmetics and pharmaceuticals. After the algal biomass is fractionated, the remaining cellulosic material and sugars make a great feedstock whole, or blended with other feedstocks, for the production of cellulosic ethanol.
As these potential new markets open, and due to the high value of biomass, algae lipid oil will become a reality as a feedstock for biodiesel production. These are some of the factors that need to be considered in order to make an algae farm for lipid oil profitable and provide an inexpensive high-grade feedstock for biodiesel production.
Production Optimization Ahead
Algae farm production optimization is a key factor to the profitability of the facility. Using raceway ponds is not economically feasible given the current state of technology for commercial production of algae. Raceway ponds are profitable in the nutrition market but not as lipid oil production for biodiesel. Producers can not make enough highly dense biomass with normal photosynthetic conditions.
Photobioreactors are the answer to breaking through the theoretical limits of normal solar photosynthesis for algae biomass production. Studies have shown the ability to raise algae culture densities to 24 grams per liter on a dry weight basis. The production rate in photobioreactors has achieved high production rates up to 242 percent of the total capacity of the photobioreactor in a 24-hour period using artificial light that was of a specific light spectrum enabling the optimization of the cell reproduction process. Reaching these figures on a commercial-scale has yet to be proven, but so was the turbine engine before it was made on a mass scale.
A wide array of algae production systems are being marketed. The BioFence photobioreactor is an efficient and reliable method for producing high density monocultures of marine and freshwater algae. The BioFence has been in production for these markets for the past five years, where it has yielded up to 140 grams per day in a 200-liter system. This output is much higher than a raceway pond or bag-type reactor. All parameters of the photosynthetic process-temperature, light, nutrients and carbon dioxide-are controlled in order to increase production rates. These figures would make the algae farm profitable and give it the ability to provide enough extra revenue to cover the expenses of an indoor environmentally controlled facility.
A hybrid system is another option for the mass production of algal biomass. This system would employ both a raceway pond and photobioreactors. The photobioreactor would provide a continuous supply of high-density monoculture algae for further propagation and lipid oil production. The major advantage to a hybrid system is that it reduces a large amount of the capital expense for installation.
Culturing Solutions has developed a low kilowatt consumption process to extract algae from the oil. It utilizes the remaining water in the algae slurry as a solvent along with a reactor to rupture the cell walls releasing the lipids. The downstream process further separates the remaining biomass, algae oil and water. From that point the oil may be dehydrated for transesterification.
Whatever the specific technology, algal oil production is certain to increase in the next few years. Nutraceutical markets demand it, and soon so will the biodiesel industry. The primary question remaining is how soon commercial-scale production will become profitable.
Dean Tsoupeis is chief executive officer for Culturing Solutions Inc. Reach him at firstname.lastname@example.org or (727) 686-5291.