August 27, 2010 ISSUE #225
Algae is a plant which enjoys continuing interest because it grows easily and plentifully, utilizing low value real estate. In the ocean, a wide variety of algae grow on their own accord, while specific species can be grown economically in shallow ponds in desert areas.
Currently Vincent Corporation is participating in several algae projects. Most of these, like one being conducted by General Atomics of San Diego, California, are focused on recovering oil from algae. (Some algae contain up to 70% oil by weight.) Other projects are aimed at the edible protein and food dye potentials of algae.
From Vincent's standpoint, the most difficult algae are the micro or uni-cellular variety. These are round cells that are only 1 or 2 microns in diameter. They are popular because they are the fastest growing, generally in circulating water about 6" deep (sunlight does not reach much deeper). These algae neither agglomerate readily nor want to give up their moisture content. This makes them difficult to pre-thicken ahead of a screw press. And, even after pre-thickening, they are unlikely to give up much moisture in the press. Still, significant technical progress is being made.
Another kind of algae is filamentous, long and stringy. Spirulina is a filamentous algae that is grown commercially for the production of nutraceuticals. An algae sample we received from the College of William and Mary was definitely in this category. It was relatively easy to prethicken and press.
Carbon Capture Corporation in Calipatria, California has an algae growing site. This started as a large scale 1980's project. Today the facility is leased for research and development programs.
Currently work is underway at Fundacion Chile, using a Vincent Fiber Filter. To date the results look promising for capturing uni-cellular algae using sleeves rated at 15 microns.
In another test, alcohol was added to uni-cellular algae. The result was that the material could be dewatered much more successfully in a screw press.
In still another test, steam was injected into a screw press while pressing algae. Again, a significant reduction in moisture content was achieved.
We expect this technology to develop rapidly because of the attention it is currently receiving.