Using the Full Range of Aquatic Plants for Energy

PetroAlgae is now reporting that, in its 5000-hectare system, it can produce 9-10 metric tons of purified high-value proteins per acre per year, plus 4700-6000 gallons of biofuels (plus biochar) per acre per year. This pencils out to up to 125,000 tons of protein per year, plus 75 Mgy of renewable fuels, for the full system.

“The future is not years away but here today,” noted Executive VP Business development Harold Gubnitsky at the Florida Farm to Fuel Summit last week in Orlando. The PetroAlgae system costs, “several hundred million dollars,” according to the company, but has payback within three years, making the investment not for the faint of heart, but potentially lucrative. _BiofuelsDigest

We know about the promise of energy from algae and diatoms. But the full range of aquatic plants that could be used to produce abundant energy is far wider than most of us realise. Besides producing biofuels, aquatic systems can produce high value proteins and other nutrients and high value chemicals. The additional high value products provide for higher profits and more rapid payback of investment.

The first public hint that new breakthroughs were on the horizon arrived in early April, when a research team at North Carolina State University reported that it has realized up to six times the average corn starch yield by growing duckweed, a microscopic aquatic plant, using hog farm waste water. The researchers concluded that the process cleans up waste water and produces a high-yield biofuel, and the duckweed starch can be converted to ethanol at existing corn ethanol processors.

One of the advantages of the tiny aquatic plants is that so little of their biomass is needed to support their structure, since they float on water instead of standing freely in the air. As little as five percent of some species is fiber - with the rest an attractive mix of proteins, carbs and lipids.

The researchers said at the time that their process will work on any type of nutrient-rich wastewater, including municipal wastewater. However, the team was not far advanced in developing a large-scale system, indicating that they were in the process of establishing a pilot-scale demonstration of their system for growing, harvesting and drying duckweed.

Later in the spring, PetroAlgae was evolving its message to emphasize “microcrops” over “microalgae”, signaling that it was working on several different aquatic plant platforms.

Last week, Joule Biotechnologies made a cryptic announcement of a novel biofuel production system using a modified and otherwise mysterious aquatic, photosynthetic microorganism that, housed in a closed photobioreactor replete with brackish water, would use CO2 and sunlight as sources of reproductive energy. Lipids and fuels would be continuously harvested without destroying the micro-organisms. _BiofuelsDigest

These aquatic systems can be genetically tweaked and selected for optimal growth and targeted production, using high speed genetic screening and modification techniques as described by Brian Westenhaus.

The world of biological production of fuels, chemicals, and other high value products is just beginning. Stay tuned.