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ccording to the U.S.
Environmental Protection
Agency, the United States produced 254 million
tons of municipal solid waste in 2013. And
though 87 million tons of that material from
landfills was diverted through recycling and composting,
what if the nation could do better? What if landfills could
become local sources of clean energy production? Better
yet, what if all waste streams, like those from agricultural,
livestock, and food production, could essentially become
fuel refineries at a local level?
It’s a question being asked by a collaboration of national
laboratory researchers who want to create energy conversion
technologies designed to mine the carbon out of waste
processes that traditionally have been an environmental
burden to the planet and a disposal headache for humans.
“The idea of using waste as energy source really isn’t new,”
said Cynthia Jenks, assistant director of Scientific Planning
and division director for Chemical and Biological Sciences
for Ames Laboratory. “For example, some municipal and
regional utilities already burn landfill waste as a source
for electrical power. But we think there are better, cleaner
and more efficient ways to get at that carbon and use the
potential energy from it.”
A new concept was born of the Big Ideas Summit, held
by the Department of Energy and its national laboratories
in 2015. The effort, being co-led by Ames Laboratory and
Pacific Northwest National Laboratory, is a collaboration of
12 national laboratories to find new catalytic technologies
that can efficiently produce biofuel from waste streams.
The goals are specific. Make the technology as simple
as possible, yet adaptable to diverse waste streams. Locate
it right at the waste stream source, whether it’s a landfill,
livestock farm or commercial facility. Make it easy and
economical to produce and deliver through the use of
modular manufacturing.
“The idea brings together a lot of overlapping interests:
chemical research, applied engineering, modular
manufacturing, waste management, agriculture, industry,
A
What if America’s next big fuel source is its trash?
B Y L A U R A M I L L S A P S
Waste Stream to
Energy Source:
“That’s really the‘big idea,’”said Jenks.
“Where there is waste, there is energy.”
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and energy-sector investors. It’s a complex idea with a lot of
moving parts, but one that we think will get us a lot closer to
accessing the potential energy in these underused resources,
and a lot closer to the nation’s sustainable energy production
goals,” said Jenks.
To meet the goal, the participating national laboratories
will pool their skills in materials and chemical sciences,
high-performance computing, engineering, and applied
technology. Ames Laboratory will lend its expertise in
catalysis to the project through its Chemical and Biological
Sciences Division. Scientists Igor Slowing and Aaron Sadow
have already done extensive work in creating catalysts that
are able to convert carbons, by placing catalytic agents on
high-surface-area nanomaterials. They want to develop
processes that make possible the controlled decomposition
of waste polymers into useful hydrocarbons.
“A large amount of the waste that goes into landfills
is polymers…plastics. These are very carbon rich, very
processed materials, and if we were to be able to convert
that waste into new, useful compounds or energy, that
would make much better use of them,” said Sadow. “Right
now, we’re wasting all that carbon. It’s just sitting there in
the trash.”
Sadow and Slowing will also be applying similar techniques
to the conversion of wet sludge and agricultural wastes.
Sadow said the scientific challenges are complex, with
a need for chemical reactions that can be highly efficient,
operating at low temperature and low pressure. They will
also need to be capable of adapting to changes in the raw
material feeding them.
“Any waste stream is verymixed, and its composition varies
over time,” said Sadow. “We can physically sort and then
convert, but then there’s that separation step. We don’t really
know how to chemically convert mixtures in general. That is
a really big, interesting, fundamental challenge that research
hasn’t yet tackled, and that’s exciting to contemplate.”
While the group estimates that these localized biofuel
refineries would produce small quantities of biofuel—an
average of the equivalent of 125 barrels of oil per day—the
collective impact could be staggering. Transforming the
available national waste streams into fuels and other useful
chemical products could translate to the equivalent of 2.7
billion barrels of oil per year, or 40 percent of the nation’s
annual crude oil use.
“That’s really the ‘big idea,’ ” said Jenks. “Where there
is waste, there is energy. We believe that the collective
expertise of the national labs, including the chemical
research strengths of Ames Laboratory, puts that big idea
within reach.”
“A large amount of the waste that goes
into landfills is polymers…plastics.
These are very carbon rich, very
processed materials, and if we were to
be able to convert that waste into new,
useful compounds or energy, that would
make much better use of them. Right
now,we’re wasting all that carbon. It’s
just sitting there in the trash.”
Aaron Sadow