Swamp Stomp

Volume 14, Issue 37

For years Algae has been used as fertilizers, soil conditioners, and as a source of nutrition for animals. Derived from the first declension Latin word ‘alga’, algae literally means ‘seaweed’, and has generally not been used as much more than that. It captures runoff nutrients from soil deposits, and in turn becomes harvested as a fertilizer itself.

Algae also contains other useful molecules, such as lipids, and thereby has the potential to be used in order to make a number of profitable items, including high-energy fuel. However, the ability to extract these molecules is an arduous and expensive task, and, therefore, has yielded little reward. Until now, that is.

Algae Systems, a company based in Nevada, owns a pilot plant in Alabama that is used to generate behavioral information on algae. It is a smaller facility that is intended to identify a specific focus for algae study before larger plants are devoted to the cause. Subsequently, it claims to have found a way to produce diesel fuel from algae.

The process works by performing three separate tasks. First, municipal sewage, a treatment used to fertilize algae, must yield clean water. Second, a carbon-heavy residue must be used as fertilizer for the algae. Finally, valuable credits for advanced biofuels must be generated. If these tasks are completed in conjuncture with one another, then Algae Systems claims that a greater level of carbon will be extracted from the atmosphere then is added during the consumption of fuel.

The system works by heating the algae, along with the other solids found in the sewage, to temperatures in excess of 550 degrees Fahrenheit, at 3,000 pounds per square inch. This produces a liquid that appears similar to crude oil from a well. The chief executive of Algae Systems, Matt Atwood, refers to this as a “hydrothermal liquefaction” system.

Once produced, the liquid was studied by scientists at Auburn University, who, acting in line with the common procedure for oil refinement, added hydrogen to the liquid. This, subsequently, produced diesel fuel, which was later confirmed by Intertek, an independent laboratory, to meet all of the industries specifications.

The intriguing aspect of Algae Systems’ process is the means by which they separate the individual molecules from the algae. The high level thermal process they implement is a new system in algae treatment. It produces the potential to greatly reduce the amount of energy exerted on extracting molecules from algae.

Halil Berberoglu, an assistant professor of mechanical engineering at the University of Texas at Austin, is also researching this area of algae treatment—separate from Algae Systems—and is excited by the prospect of such a “hydrothermal liquefaction” system. He described the older system as being “very energy-intensive,” whereby one must “dewater the algae, poke holes in the cell walls, and do all kinds of separation technologies.”

The high thermal process would not only allow the separation of lipids from the algae, but also the separation of proteins and carbohydrates, which may lead to further uses of algae.

Many obstacles remain in the advancement of such a process, for example the possible incorporation of heavy metals, nitrogen, and sulfur in crude oil compounds. Nonetheless, Algae System’s new perspective on algae treatment is both promising and refreshing.