From pond scum to plastics:

Even as the general appreciation for all things natural reaches stratospheric heights, most of us probably remain noncommittal about algae. On the one hand it’s great in sushi, but on the other hand it chokes the boat propeller in shallow water. El Segundo, Calif.-based bioplastics maker Cereplast Inc., however, hopes to turn these simple sea-borne organisms into a game-changer for plastics manufacturers looking to go green.

The company is planning to commercialize its first grade of algae-based resins by the end of the year, intended to complement its existing Compostables and Hybrid resins product lines.

With starches from corn, tapioca, wheat, and potatoes already used in the manufacture of the Compostables and Hybrid materials, why bother adding another biomass to the mix? Because algae is cheap, plentiful, doesn’t take away from the human food chain, and represents the near-perfect closing of the renewable products loop, said Cereplast researcher William Kelly. “The use of algae as a feedstock for plastics allows us to go full circle,” he explained. “The very substance that can absorb and minimize CO2 and polluting gases from the industrial process can now also be turned into sustainable, renewable plastic products and biofuels while reducing our use of fossil fuels.”

HEAT TOLERANCE? YES. FISHY SMELL? NO.

How does it work? Algae from a photo-bioreactor is harvested daily and can be treated as a biomass, Kelly explained. Cereplast dries the material at its new plant in Seymour, Ind. until the biomass becomes a powder. To date, Cereplast has made a hybrid prototype, with organic ingredients and polypropylene or other traditional resins mixed with between 35 and 50 per cent algae powder using a proprietary process. The company has also injection molded a test part made from the algae powder and polypropylene.

The algae-based biomass behaves like traditional starch-based resins, Kelly continued, and also has a high heat tolerance. And while the algae plastic had a strong fishy smell in the project’s early days, the company has mercifully found a way to get rid of that.

Cereplast is currently in contact with several companies that plan to use algae to minimize carbon dioxide and nitrous gases, and also with potential chemical conversion companies that could convert the algae biomass into viable monomers for further conversion into potential biopolymers.

Cereplast isn’t the only company wading into the algae-based plastics pool. In fact, it’s getting crowded. In August 2009,

London-based BP Amoco Plc contributed US$10 million to a project with Martek Biosciences Corp. of Columbia, Md., designed to bring large-scale algae biofuels to commercialization. Irving, Tex.-based oil conglomerate Exxon Mobil Corp. has also jumped in recently with a whopping US$600 million investment in algae-based biofuels; the company is joining biotech specialist Synthetic Genomics Inc., of La Jolla, Calif., to research and develop next-generation biofuels produced from sunlight, water and waste carbon dioxide by photosynthetic pond scum.

In short, the word seems to be getting out that feedstock like algae– that’s unrelated to fossil fuels and to the food chain–might be the next frontier for renewable plastics. “Commercial algae resins represent a significant breakthrough in the greening of the plastics industry,” Kelly said.