Algae fuels, the Earth Room Problem, and Osmotic Shock Around the Clock

August 26, 2015 |
The Washington Generals, RIP. You know, they even kinds of look like algae in those green uniforms.

After losing 16,000 times to the Harlem Globetrotters, the Washington Generals even sort of look like algae in those uniforms.

What is the Earth Room Problem and how is osmotic shock helping us to solve it?

You may have wondered to yourself — at some point between 2009’s Summer of Algae and now, in 2015’s Summer of Where Are the Gallons?  — “Gee, I wonder what happened to all those algae technologies that were going to fuel the world, are they still around?”

The quick answer is that many of them are; most of them switched to nutraceuticals, and thereby we’ll be in better physical shape when climate change kills us all.

Of course, the evolution from “saving the world via advanced fuels” to “astaxanthin at everyday low prices” left some observers with the same feeling many experienced when Michael Jordan left the NBA to take up minor league baseball.

A handful of intrepid algae technologies remain on the “fuels, baby” or “fuels for volume, co-products for profit” pathway, including Algenol and Cellana. But what happened to the rest of companies of the Algae Generation?

In most cases, they couldn’t get the costs down, which can be best described as the Earth Room Problem.

More coverage on algae

Algae and Energy: The Digest’s 8-Slide Guide to the DOE’s Algae Program
Where are are we with algae biofuels? Part I
Where are we with algae biofuels? Part II

The Earth Room

If you happen to be in Manhattan sometime, and find yourself in the SoHo area and looking for something artistically adventurous, you can stop by The Earth Room at 141 Wooster Street, and as you gaze at Walter De Maria’s 1977 minimalist installation, you might consider the problem of algae fuels.

demaria_earthroom

It’s a room, of course, and it’s filled with earth. Inert, dark chocolate earth and nothing else, 22 inches thick, 140 tons of earth spread out over the entire floor of the SoHo building. You experience it from a small, glass-protected viewing area.  It’s one of De Maria’s greatest installations, and there you have it, just earth.

(Also, there you have it, interesting things to do with the Schlumberger oil fortune, as you ponder that oil giant’s $14.8 billion bid this week for Cameron International. Yes indeedy, Schlumberger granddaughter Philippa de Menil funded The Earth Room.)

That in a nutshell is why algae technologies cost too much to make fuels cost-competitively right now. You have to spend a whole bunch of money building the land-based farm where algae were never supposed to be, just like the Earth Room which sits, gazing at you like the abyss, in a place where soil was never designed to be.

The little algae critters were engineered by Nature to bloom quickly yet unpredictably in our oceans and lakes, and get devoured by grazers, hunted by predators, outgunned by competitors. Algae were designed, like the Washington Generals who lost 16,000 times to the Harlem Globetrotters before being disbanded earlier this month, to lose, lose, lose.

As a farmer, you have to build algae a shelter, fatten them up like prize porkers against the odds, and then find a way to keep them alive. The Shackleton Expedition had a less daunting task.

Sometimes, the thing that really races in a raceway is the cost

To overcome the Earth Room problem, researchers for nigh on 40 years have been trying to get algae to grow faster, grow more lipids, or grow more days of the year — these have been identified as the three most important costs levers, in awesome works of techno-economic analysis performed primarily at NREL, Sandia and Argonne. The most comprehensive of which came out in 2012 and you can read here.

Basically, algae R&D is attempting to invert the goals of infomercials that sell you wonder weight-loss cures. Over in the Algae Cinematic Universe, just about everyone is supersizing their algae, and the fatter the better, and the faster they grow fat, the better.

The most valuable algae grow like little roly-poly Gerber babies, chock-full of blubber and appetite — ready to eat and grow almost any hour or day of the year. Algenol being the exception to the rule: in their case, they overfeed their microorganisms until they defecate whiskey. It’s a weird world, algae.

In all our focus on “fatten, fatten, fatten ‘em up”, one major cost factor that’s been holding back algae fuels is the cost of the fertilizer. Yes, you have to fertilize algae like the crops we want them to be, with nitrogen and phosphorus primarily. To get them to grow as a commercially-viable pace, you have to shovel in the Ns and Ps so fast it feels like alphabet soup there in the raceway pond.

It’s the fourth biggest cost lever in algae growth — nutrient inputs, that is— after the growth rate, lipid content and “days open for business”.

Screen Shot 2015-08-26 at 4.39.08 PM

The Ammonia and Phosphorus Problem

And, you might have wondered from time to time where all the ammonia and diammonium phosphate was going to come from anyway. To make 9 billion gallons of algal fuels — and in a world of something like a 600 billion gallons of global fuel consumption  that’s around a 1.5% market share — you need 4.8 million tons of DAP and 5.1 million tons of ammonia, so our friends at NREL tell us.

Consider that global ammonia production is around 180 million tons today, and global phosphate production is around 60 million tons — and you see the Earth Room problem all over again. It’s expensive, strange and logistically challenging to re-create the world that Mother Nature handed to us for free. Even something as simple as fertilizer.

And, we’re running out of mined phosphorus. See our report on Peak Phosphorus for that, but make sure you are within 50 feet of a bathroom facility before reading, it’s disturbing. For all these reasons, nitrogen and phosphorus re-cycling is a priority, just on sustainability grounds.

“We have a finite amount of phosphate in the world, but it’s in high demand as a fertilizer. Half of the phosphates that go into our crops in the form of fertilizer end up in the Gulf of Mexico, contributing to hypoxic zones,” said Sandia’s Todd Lane.

From the Department of Government Math

And, if you’ve been reading your algae economics reports carefully, you might have seen the target cost of algae feedstock at $430 per ton in 2022, in order to produce a $3.50 algae drop-in (diesel) fuel — and if you’ve also spotted a cost variance of up to $1.25 per gallon based on whether you can recover and re-use that nitrogen and phosphorus, you weren’t in an algae literature-induced psychosis. It’s right here.

Now you might subtract $1.25 from $3.50, get $2.25, and shout Eureka! Affordable algae fuels at scale! The math works, but we’re never exactly sure ourselves in those $3.50 scenarios if someone in the Government Math  office at the Department of Energy hasn’t already taken all those costs savings even before there is a technology invented to achieve them.

You have to forgive our friends in government, sometimes, and their floating decimal points. They’re the ones handed the task of selling the TARP bank bailout, the Savings and Loan bailout — well, just about any Wall Street bailout of any sort — while still being able to pronounce laissez-faire without laughing.

Good news on algae nutrient recovery

But there is good news on the nutrient recovery technology front. A team led by Sandia’s Todd Lane and Ryan Davis came up with the single simplest technology we’ve ever run into, to produce a 70% nutrient recovery.

If your calculator is whirring and you’ve dialed up something on the order of $0.85 cents savings per gallon on algae costs — we won’t dispute the math of 0.7 times $1.25, but we re-issue the warning on counting on savings because someone might have already counted it before the technology was invented. Why count your chickens before they hatch when you can count them before they are even in egg form?

Osmotic Shock Around the Clock

To use the grand phrase, the team employed “osmotic shock,” which we profiled recently here in The Digest. Simplest way to describe it is to mention that you can’t drink salt water when you’re thirsty, because it further dehydrates you. That’s because cells trained to be doused with fresh water respond in a funny way to a change in salinity levels. The cells walls get disrupted, and stuff starts to pour out that should have stayed on the inside. Fraternity keg chug parties are known to have the same effect, although the science is different.

It works the other way around, too. Shocking cells, used to salt water, with rapid immersion in fresh water. Turns out, it causes nitrogen and phosphorus to fall out, in a recoverable format. Up to 70%.

That’s it, simply put. Take salt water algae. Dewater it down to a paste. Add fresh water, quickly. Remove liquid. Recover all those Ns and Ps.

“We shock the algae with fresh water while controlling certain conditions like pH and temperature. This disrupts the internal structure of the cell and releases naturally occurring enzymes,” explained Lane. “These enzymes chew up the cell and rapidly release the phosphates.”

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.

In 2014, a Sandia team proved the method with 20 weeks of continuous recycling and reuse of phosphates and nutrients. They were able to carry over 60 to 80 percent of the nutrients from batch to batch.

“Every two weeks, we recycled the nutrients and fed them back into the next batch of algae,” said Davis. “The process worked better than we expected, as we saw enhanced growth with the recycled nutrients. We aren’t quite sure why this happened. It could be from trace metals carried over in the phosphate.

Next steps

Osmotic shock is at lab scale right now. In the next 6 months the research team will scale it to 1000L algae cultures, then take it to a pilot raceway scale; there are engineering parameters to tune.  “The goal is a one-pot system,” said Davis. “That will be the tipping point for scaling up our method. We grew 2 liters of algae in our 20-week test. The next step is to grow 3,000 liters in our raceways.”

Later this year, Sandia will open three 1,000-liter raceway testbeds, shallow artificial ponds for algae cultivation. 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.

Plus, 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. Sandia’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.

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.

“We were very interested in OpenAlgae’s lipid extraction because it doesn’t use solvents, so the biomass is left in a native conformation that works very well with our process,” said Lane.

The Bottom Line

To grow algae on land when it was designed by Nature to grow in water — well, you get control but you have the Earth Room problem of re-creating Nature, without being able to charge tickets at your aquarium. It is possible to take advantage of algae’s astonishing growth rates to overcome the cost problem, but then we ran into the nutrient problem. Here, we may have a way around that cost and sustainability challenge.

And for that, you might whisper a quiet hallelujah, if you happen to be in SoHo sometime, on Wooster Street, looking at the Earth Room and marveling at Nature’s sustainable, affordable, reliable, available growth medium: a Christmas gift from the cosmos to you, soil.

Print Friendly, PDF & Email

Tags: ,

Category: Top Stories

Thank you for visting the Digest.