- Number 335 |
- April 18, 2011
Lee Elliott – Algae hunter
Call Lee Elliott a slime
Elliott is a 21st century prospector. His Eldorado isn't gold, but that elusive briny pond or brackish puddle that houses an algal species that both is rife with oil and multiplies quickly.
Elliott is a biomass researcher at DOE’s National Renewable Energy Laboratory.
He logged 3,500 miles last year driving his car across the West in search of promising algae, the kind with the potential to grow like weeds and fuel the airplanes and automobiles of tomorrow.
He dips his beakers into ponds, ditches, even puddles, captures the slimy water, filters it and analyzes it.
Eight times, his tires went flat in the deserts of the Southwest while searching for saline lakes. But it wasn't until this year, as he was looking for a few last samples close by NREL's Golden, Colo., campus, that he had an encounter with a prairie rattlesnake — a four-foot diamondback.
"The rattlesnake was a surprise," Elliott said. "It just happened to be sitting right where I wanted to be."
With nonchalance, he grabbed a six-foot tree limb, picked up the rattler, and deposited the snake out of harm's way.
When he's not transplanting rattlers, Elliott searches for algae everywhere: in rivers, ponds, lakes and puddles, in red, green, purple, brown or orange muck. Along with road maps, he carries a portable lab, a large Tupperware box with a water quality meter, several filters, and other sampling equipment.
He dips his sampler into dirty water, measures its salinity and pH, and filters it to remove debris and organisms that might graze on the algae. He pinpoints the location via geo-positioning satellite.
Microalgae can grow in brackish, saline, or brine water that can't be used by humans, farms, ranches or nurseries. So, microalgae have a clear advantage over other biofuel crops in that they can use this marginal water source – including all the water in the oceans.
Not only do algae grow in unlikely settings, but their ability to convert the light they receive into biomass has the potential to outperform that of land plants. Elliott found algae growing in evaporation basins in Nevada where the salinity was so high it was on the verge of precipitation.
"I got a very good idea of how much salt there is in the southwest," Elliott, a doctoral candidate at the Colorado School of Mines, said. "There is a lot of barren wasteland out there where you can dig a basin, fill it with salty water from a brackish, saline, or brine aquifer, put some algae in and they can grow just fine."
Microalgae produce chemicals that can be converted readily to fungible fuels that seamlessly integrate into today's fuel-making process. The algae use photosynthesis to turn carbon dioxide into organic matter, establishing a carbon-neutral fuel source.
Microalgae can be used as biological solar cells to capture the energy in sunlight and fix inorganic carbon into renewable, energy-rich lipids that can be converted readily to biodiesel. That's why the major oil companies are pumping money into projects like Elliott's. They understand the potential for microalgae to make a serious dent in the current demand for liquid transportation fuels, which is at 130 billion gallons a year in the United States alone.
Once back in the lab, Elliott began isolating and screening the algae. Initially, he adds chemically diverse growth media as a tool for selection of robust and diverse strains that can later be isolated. He and his fellow researchers stain the algae samples with a dye which, when a blue light is shined on them, turns the lipids a fluorescent green while chlorophyll naturally appears as a fluorescent red.
"They light up like Christmas trees," Elliott said. The blue light is generated by lasers in a specialized microscope and in a Fluorescent-Activated Cell Sorter, or FACS. The goal is to screen the collection, now numbering 360 isolates, and determine the five best performers. The strains best at combining fast growth and enhanced lipid production will likely be developed further as promising biofuel feedstock.
Eventually, the most promising algae may grow in big algae farms in the arid southwest, in ponds a foot or two deep, propelled by paddle wheels. The tiny energy producers will churn, harvesting the light-energy of the sun, proliferating and making oils and other valuable co-products right there under the desert sun.
Learn more about microalgal biofuels projects and NREL's bioenergy research. — Bill Scanlon
Submitted by DOE's National Renewable Energy Laboratory