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Renewable Separations Drive Renewable Oil Economies
8:08 AM MDT | October 10, 2011 | By PETER B. KIPP
By Peter B. Kipp v.p./OpenAlgae (Austin, TX), an algae process technology firm
OpenAlgae recently published a column that addressed the challenge algae companies have recovering algae oil cost-effectively and environmentally consciously. We called it “separation anxiety,” because we know it’s a persistent challenge, and like a dark family secret, it’s seldom discussed by emerging renewable oil companies.
The more we listen to algae growers and processors, the more we hear their concern about the lack of simple, affordable and scalable separation solutions. Algae oil is a complex mixture of insoluble “oils” including a variety of hydrocarbons, anti-oxidants, pigments and acylglycerols. Efficiently and cost-effectively recovering the oil from the water and away from the cells was a new problem that didn’t have an immediate solution, so we developed one. And we think overcoming the industry’s separation challenge may be a tipping point for algae and other renewable oil platforms to become more cost-competitive in commodity markets.
The old saying “oil and water don’t mix” has run afoul of biotechnology. Microscopic droplets of the various oils made by algae, for example, not only do mix with water, they don’t “unmix” easily. Solvents break emulsions, and soy- and palm-oil production and existing nutraceutical algae oil platforms rely on hexane for oil extraction. Renewable oil production should incorporate green chemistry practices, not solvent.
Several of the leading biocatalyst platforms are also green chemistry leaders. In addition to engineering microbes to perform specific synthetic reactions, they’ve designed their bio-catalysts to secrete oil products. Oil secretion offers enormous process benefits by enabling continuous production without having to recover or sacrifice the microbe. But how do you continuously recover the oil without harming the “golden goose” organism? Centrifugation is expensive and has well-known technical limits with emulsions.
When green chemistry biological platforms have a better way to separate oil from cells, they will achieve higher margins and discover new opportunities to make use of the cells.
Certainly, separation is a clear and present challenge for the algae industry. But it isn’t unique to algae companies. The sooner an oil recovery solution is in place for microbe-produced oils, the sooner the broader green chemicals market will benefit.