Pacific Northwest National Laboratory
A dozen glass cylinders containing a potential payload of bright
green algae are exposed to hundreds of multi-colored lights, which provide all
of sunlight's natural hues.
The tiny LEDs brighten and dim to mimic the outdoors' constantly
changing conditions. To further simulate a virtual cloud passing overhead,
chillers kick in and nudge the algae a little cooler.
A new, approximately $6-million collaborative project is using
this unique climate-simulating laboratory system as part of a new streamlined
process to quickly pare down heaps of algae species into just a few that hold
the most promise for renewable fuels.
Discovering which algae species is best suited to make biofuel
is no small task. Researchers have tried to evaluate algae in test tubes, but
often find lab results don't always mirror what happens when green goo is grown
in outdoor ponds.
The Algae DISCOVR Project -- short for Development of Integrated Screening, Cultivar Optimization and Validation Research -- is trying out a new approach that could reduce the cost and the time needed to move promising algal strains from the laboratory and into production.
At the end of the three-year pilot project, scientists hope to
identify four promising strains from at least 30 initial candidates.
"Algae biofuel is a promising clean energy technology, but
the current production methods are costly and limit its use," said the
project's lead researcher, Michael Huesemann of the Department of Energy's
Pacific Northwest National Laboratory. "The price of biofuel is largely
tied to growth rates. Our method could help developers find the most productive
algae strains more quickly and efficiently."
The project started this fall and is led by PNNL, out of its
Marine Sciences Laboratory in Sequim, Washington. The project team includes
three other DOE labs -- Los Alamos National Laboratory, National Renewable
Energy Laboratory and Sandia National Laboratories -- as well as Arizona State
University's Arizona Center for Algae Technology and Innovation.
Step by step
The project's early work relies on PNNL's Laboratory
Environmental Algae Pond Simulator mini-photobioreactors, also known as LEAPS.
The system mimics the frequently shifting water temperatures and
lighting conditions that occur in outdoor ponds at any given place on earth.
The system consists of glass column photobioreactors that act
like small ponds and are placed in rows to allow scientists to simultaneously
grow multiple different types of algae strains.
Each row of LEAPS mini-photobioreactors is exposed to unique
temperature and lighting regimens thanks to heaters, chillers and heat
exchangers, as well as colored lights simulating the sunlight spectrum -- all
of which can be changed every second.
The first phase of the team's multi-step screening process uses
PNNL's photobioreactors to cultivate all 30 strains under consideration and
evaluate their growth rates.
Algae strains with suitable growth will be studied further to
measure their oil, protein and carbohydrate content, all of which could be used
to make biofuels.
The algae will also be tested for valuable co-products such as
the food dye phycocyanin, which could make algae biofuel production more
cost-effective.
The first phase will also involve evaluating how resistant
strains are to harmful bacteria and predators that can kill algae.
Next, the team will look for strains that produce 20 percent
more biomass, or organic matter used to make biofuel, than two well-studied
algae strains.
The top-performing strains will then be sorted to find individual
cells best suited for biofuel production, such as those that contain more oil.
Those strains will also be exposed to various stresses to
encourage rapid evolution so they can, for example, survive in the higher
temperatures outdoor ponds experience in the summer.
Outside the box
After passing those tests, the remaining strains will be grown
in large outdoor ponds in Arizona. Researchers will examine how algae growth in
the outdoor ponds compares with the algal biomass output predicted in earlier
steps. Biomass will also be harvested from outdoor-grown algae for future
studies.
Finally, the team will further study the final algae strains
that fare best outdoors to understand how fast they grow in different lighting
and temperature conditions. That data will then be entered into PNNL's Biomass
Assessment Tool, which uses detailed data from weather stations and other
sources to identify the best possible locations to grow algae.
The tool will crunch numbers to help the team generate maps that
illustrate the expected biomass productivity of each algae species grown in
outdoor ponds at any location in the U.S.
Data and strains will be made public in the hopes that algae
companies and other researchers will consider growing the most productive
strains identified by the project.
This project is supported by DOE's Office of Energy Efficiency
and Renewable Energy. EDITOR’s
NOTE: When Donald Trump’s pick as new Energy Secretary Rick Perry takes over,
expect this program to be among the first to be killed outright. Not only does
it run contrary to Trump’s preference for coal and oil, the program uses lots
of words that neither Perry nor Trump can understand or spell. – W. Collette
Potential future work not included in the current project could
include converting harvested algae into biofuels, examining operational changes
such as crop rotation to further increase biomass growth, and assessing the
technical feasibility and economic costs of making biofuel from algae selected
through this process.