FUEL FROM ALGAE: The National Academy of Sciences's review of the sustainability of biofuels produced from algae raises concerns about where the water for the process might come from—or go.
Image: Flickr/PNNL - Pacific Northwest National Laboratory
The National Academy of Sciences' report on the sustainability of algae biofuels highlights concerns that have already been resolved, industry heads said yesterday.
NAS released a comprehensive report yesterday, identifying potential issues of sustainability in the burgeoning algal biofuels industry. In its report, NAS measured the resources needed to produced 39 billion liters -- or 5 percent of American transportation fuel -- highlighting the low energy output.
Companies are already recycling potentially polluting nutrients and using water that is too salty or too dirty for other uses. Sustainability is a priority, but so are economics, said John Williams, a spokesman for the Algae Biomass Organization.
"Sustainability metrics are inextricably linked with cost-efficient ones," said Williams. "No major algae producer is currently using fresh water."
Water is a major concern, as is the use of nitrogen fertilizers to stimulate growth of cyanobacteria and microalgae -- two microorganisms typically lumped together as algae biofuels. To produce 1 liter of algae biofuel, manufacturers must use 3.15 to 3,650 liters of water -- or up to 123 billion liters for 39 billion liters of algal fuel.
NAS found algae biofuels would need up to 15 million metric tons of nitrogen and up to 2 million metric tons of phosphorus, unless the elements are recycled or included in byproducts. Nitrogen and phosphorus, used in fertilizers, can in excess pollute natural waterways.
Energy output in relation to inputs, or "energy return on investment," remains an issue for algae, says the report. Overall, algae biofuel yields a low energy output for all of the energy needed to produce it. Fossil fuels can produce up to six times more energy than even the most efficient algae fuels, as a ratio of output to the input energy.
The greenhouse gas reduction benefits, which would help contribute to a slowdown of climate change, vary wildly according to study, NAS found, a finding that is related to the poor energy return on investment. As a designated advanced biofuel under the federal renewable fuel standard, it must achieve at least 50 percent reduction compared with fossil fuels.
Using salty and leftover water
While the report does highlight concerns, Williams sees the guidance and framework included in the paper as a "green light" for algae fuels. It encourages companies to keep developing to commercial scale and continue investment in research to improve algae strain selections, mechanisms to grow the algae, and the refining and processing of the algae oil.
"We can run some scenarios today that identify risk factors; none of them are insurmountable through technology," he said.
The issue of water is a "non-starter," said Tim Zenk, vice president of corporate affairs for Sapphire Energy, because no one in the industry uses freshwater resources.
"They rightly point out the issues around freshwater use, but I know of no company using fresh water," he said. Sapphire recycles all its nitrogen and phosphorus leftovers so nothing is released as runoff into the environment.
Sapphire opened in August the first commercial-scale algae facility in Columbus, N.M., a Southwestern desert town that sits atop vast saltwater aquifers. At full capacity, the facility will produce 100 barrels a day of algae crude, culling from 300 acres of ponds.
This weak ratio and other concerns, like the leakage of waste material, remain, said Zenk. The ultimate goal at Sapphire is to create a closed-loop system in which virtually no waste is released. The company isn't there yet, said Zenk. In the meantime, the basic materials for making algae will remain abundant.
The search for a 'drop-in' fuel
"At least for the next several decades, we are not going to be encumbered by the lack of resources: minerals, CO2 and salt water," he said.
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11 Comments
Add CommentWhile they may only be pumping in water that is too salty for other uses, at least the open tanks in the enclosed photo seems to indicate that they do use any rainfall that enters the system. While the "ultimate goal at Sapphire is to create a closed-loop system in which virtually no waste is released," what happens to the released waste water in the meantime? I didn't find that crucial question mentioned in the article...
Reply | Report Abuse | Link to thisNo matter the method of capture, bio fuel relies on solar energy & organic capture of that energy. It all boils down to energy density firstly. It simply is not there. This coupled with organic capture efficiency & parasitic energy losses & refining should tell any honest engineer that it can never be viable.
Reply | Report Abuse | Link to thisSewer water from cities and factory farms has all the needed nutrients in excess. Both phosphorous and nitrogen. Plus, the needed water.
Reply | Report Abuse | Link to thisHow much would it cost to pump that water to a flat desert area out of any flood threat not subject to national park zones & where the land & labour are cheap with ready access to supporting infrastructure?
Reply | Report Abuse | Link to thisIt's cleaning dirty water, that's not useable.
Reply | Report Abuse | Link to thisSapphire recycles all its nitrogen and phosphorus leftovers so nothing is released as runoff into the environment, they provide cleaner water and some energy.
Some people just don't get the fact that we will not be able to live a good life, if everything is polluted with toxins.
They have some sort of mental issues, if the only benefit they see is $$$.
You're right, the article does state:
Reply | Report Abuse | Link to this"Sapphire recycles all its nitrogen and phosphorus leftovers so nothing is released as runoff into the environment."
However, two paragraphs later is states:
"... other concerns, like the leakage of waste material, remain, said Zenk. The ultimate goal at Sapphire is to create a closed-loop system in which virtually no waste is released. The company isn't there yet"
It also states:
"Sapphire opened in August the first commercial-scale algae facility in Columbus, N.M., a Southwestern desert town that sits atop vast saltwater aquifers."
Presuming that Sapphire is pumping saltwater from the aquifers for use in algae production, I'd guess that saltwater that otherwise would have remained in storage may be released into the environment.
From this it's difficult to understand exactly what is being done at Sapphire...
And that is worrying.
Reply | Report Abuse | Link to thisThose saltwater aquifers, are plants that are pumping saltwater from the ocean to desalinize the water in order to make water and salt. The pipes are already running from the ocean to the desert, so cost for the pipping has already been done.
Reply | Report Abuse | Link to thisAs far as waste or anything that is escaping into the environment, could be coming from leaks, or ponds overflowing, or a number of other things, and not necessarily the company deliberately putting waste back into the environment. If a company is trying to become a closed loop system and is developing what is hopefully a cleaner fuel, then I doubt they would be careless with the environment.
I trust Sapphire more than I trust BP or Exxon.
The pipes you mention are fictitious - a complete fabrication!
Reply | Report Abuse | Link to thisAccording to
http://www.biofuelsdigest.com/bdigest/2012/10/02/change-the-world-sapphire-energys-green-crude-farm-illustrated/
the groundwater at the site is saline as a result of irresponsible irrigation of chili pepper and cotton fields in the 1970s. Sapphire Energy is pumping up the brackish underground water for use in its algae production facility. My best guess is that they're returning the waste back into the already ruined groundwater, but I don't find any discussion of that part of the process. At least they don't seem to be contaminating any more land...
The preceding comment was intended to be a reply to 'Levide'...
Reply | Report Abuse | Link to thisI've got only casual interest in this topic and have not studied the details, but my initial observation that works against fuels made from algae is that we are looking for drop-in technologies for existing engines, which means lots of energy, structures, and labor are needed to turn algae oils into suitable fuels to drive our current transportation fleet, when simple, washed and dried oils from any seed plant can be used in diesel engines, but there are problems with the designs of newer diesel engines with respect to the modern fuel delivery systems that have been designed specifically for petro-based diesel fuel. If for instance, we had lower pressure injection systems, they would be flexible enough to accept unrefined oils as long as tanks and lines were heated to avoid gelling in the winter, but then the problem becomes, if one puts in regular diesel, it will pollute like an old freight train.
Reply | Report Abuse | Link to thisI'm also perplexed at the comment regarding poor energy densities of algal fuel. Last I checked, biodiesel has about the same density as gasoline. Is this agal fuel something different? Gasoline is pretty energy dense. That's one reason it's so popular as a fuel.