0
Home
News
Directory
E-newsletter
Magazine
Events
Data
AgReport
Subscribe
Sandia National Laboratories developed a new method to recycle nutrient from Algae cheaply
Aug. 21, 2015
Nitrogen and phosphate nutrients are among the biggest costs in cultivating algae for biofuels. But Sandia National Laboratories of US recently announced that they have developed a method to recycle critical and costly algae cultivation nutrients phosphate and nitrogen.
Sandia molecular biologists Todd Lane and Ryan Davis have shown they can recycle about two-thirds of those critical nutrients, and aim to raise the recycling rate to close to 100 percent.
Osmotic shock key to releasing phosphates
Lane and Davis found their nutrient recycling method works on many different algae feedstocks, even mixed feedstocks. Because algae have more genetic diversity than any other organism, many methods developed in the past haven't worked universally.
The researchers use a fairly simple process, osmotic shock, to liberate phosphate from the cultivated algae. The next step is fermentation to convert the nitrogen, which is mostly in the form of amino acids, into ammonia. The phosphates and ammonia are then recombined—with help from magnesium, present in great quantities in the algal biomass—to form struvite, a solid salt.
Lipid extraction enables nutrient recycling
The algae nutrient recycling research is part of a larger project funded by the Department of Energy's BioEnergy Technologies Office, part of the Energy Efficiency and Renewable Energy program. The Sandia team's partners include Texas A&M AgriLife Research, which grows marine strains of algae, and Texas-based OpenAlgae, which patented methods to lyse algal cells and recover algal lipids without using solvent. Recovered algal oils could be turned into fuel.
OpenAlgae's method subjects algae cells to high energy electromagnetic pulses that rupture the cell walls and cause the cells to burst, releasing the lipids. In this disrupted state, the algae cells are much more susceptible to osmotic shock.
The nutrient recycling process also releases more compounds that can be turned into fuels. "There is a lot of protein in biomass and that soaks up the nitrogen. As we're liberating the ammonia, we're also capturing that carbon so it can be turned into fuel," said Davis.
Better and easier nutrient recycling
Lane and Davis are working to further refine their method to recycle more of the nutrients, including a collaboration with James Liao of the University of California, Los Angeles, to genetically refine their fermentation strain to increase yield and extract different fuel products. Liao runs the Metabolic Engineering and Synthetic Biology Laboratory and is chairman of the department of chemical and biomolecular engineering and the department of bioengineering.
Another facet of the project is the development of a reactor system to capture the ammonia as the biomass is fermented to release phosphates. Currently, these steps are performed separately.
Pond-side processing is another goal. A single module combining lipid extraction and nutrient recycling could separate biomass into nutrients and fuel at a cultivation facility.
Panning for phosphate gold
Lane and Davis think their method could help the environmental if applied to agricultural runoff.
Nutrient recycling is like panning for gold—or in this case, phosphates—anywhere that fertilizer-laden agricultural runoff enters bodies of water. The key, said Lane, is getting the concentrated runoff before it enters the body of water and dilutes.
Source: Sandia National Laboratories
More from AgroNews
Change
Hot TopicSubscribe
| Subscribe Email: | * | |
| Name: | ||
| Mobile Number: | ||
Comment
0/1200
NEWSLETTER