The leftover oils from the common source of omega-3 supplements, Nannochloropsis salina, make up more than 70 percent of the algae plant and are usually either thrown away or burned, but researchers at the University of California have found a way to cleanse and transform them It in azelaic acid – a building block for flexible polyurethanes.
The study, published in Green Chemistry, even found a way to convert the by-product heptanoic acid into food flavor and smell.
According to the scientists, their process can be carried out on oils from multiple algal species to create valuable molecules that participate in a chain reaction to form polymers for a highly sustainable source of bio-based plastics. However, they chose the N. salina because of its established high production of eicosapentaenoic acid (EPA), a valuable omega-3 oil.
Co-author Michael Burkart said, “We have shown that we can convert waste products from algae-based omega-3 oil production into valuable and renewable polyurethane foams. These have all kinds of commercial uses, from flip-flops to running shoe soles, Mattresses and yoga mats. In addition, we made a flavor molecule from the remaining by-product that is worth over $ 500 per kilogram.
“Coproduction of Flexible Polyurethanes and Renewable Solvents from a Microalgae Oil Waste Stream.”
When the work began, the research team, which included scientists from the Department of Physical Sciences, the Department of Life Sciences, and the California Center for Algal Biotechnology at UC San Diego, first came up with a scalable and inexpensive way to improve the purity of algal oil using simple physical methods with saponification. This is a process in which oils react with sodium or potassium hydroxide to create glycerin and a fatty acid salt or soap.
In addition to the fatty acids, the team identified several contaminants in the used oil. #
Co-author Stephen Mayfield stated, “Unlike plants, which primarily store triacyglycerides or vegetable oil in their seeds, microalgae contain a variety of metabolic components that are insoluble in water but freely soluble in algal oil when extracted. Presence these pigments inhibit the efficiency of the downstream reaction, so removing them is a key process in making renewable chemicals from algae oil. “
Burkart added, “We are already working with big footwear companies to turn them into commercial products that people want to buy. We find that consumers are concerned about all of the petroleum-based plastic waste we generate as a society, and about.” Our team quickly develops solutions for future products. Stay tuned! “
Source: Green Chemistry
“Coproduction of Flexible Polyurethanes and Renewable Solvents from a Microalgae Oil Waste Stream”