Meet the Scientists
structure or it’s too expensive to build the infrastructure to get this fuel to market. So
what we thought was rather than bring the fuel to market, why don’t we bring the market to the fuel? And in some ways, instead of a pipeline network like the trans-Canadian
or the Alberta … the Alaskan pipeline, you have this modular or movable plant that
can go up to the fuel, make liquid carbon … like make liquid fuels, which then you can
transport back away from it. The process is based on combining this stranded gas with
carbon dioxide. So, there you can see how it’s a bridge fuel because we’re taking a waste
product and turning it back into a fuel.”
Saudi Arabia of Coal
With crude oil prices at record levels, coal is getting more and more attention as a more economical alternative with abundant domestic supplies. The United States is the Saudi Arabia
of coal. U.S. coal reserves total almost 270 billion tons — 27 percent of the world total. Saudi
Arabia has about 20 percent of the world’s oil reserves.
Coal-fired electric power plants long have produced almost 50 percent of the electricity
consumed in the United States. Coal, however, is the single largest source of carbon dioxide
released into the atmosphere.
Dianne Wiley, Ph. D.
Switching to Switchgrass
Is there any way to increase use of coal, while minimizing releases of that greenhouse gas?
The answer takes us back to those pioneers and seas of switchgrass that launched this episode of Global Challenges. Energy and Environmental Economics, Inc.’s Dr. William Morrow believes there’s a way to reduce CO emissions while still using coal to fire our power
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plants. In April 2008, Morrow reported in the ACS journal Environmental Science & Technology that mixing switchgrass with coal can help reduce carbon dioxide emissions.
“Let’s say that you’re putting a ton of switchgrass into an existing coal-fired power plant,
you will displace roughly a half a ton of coal when you do so. And a ton of coal will produce a certain amount of CO , depending on the carbon content of the coal. So, displac-
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ing a half a ton of that coal will displace half of the CO that would have been emitted
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from that ton of coal.”
Frank S. Zeman, Eng. Sc.D.
Morrow tackled the research to check on the impact — the CO reduction — of using
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switchgrass in the generation of electricity rather than in producing ethanol for cars. He
found that roughly 2–3 times the amount of CO could be displaced if switchgrass is used to
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displace coal, rather than using it for ethanol production.
“Our estimate is roughly between 200 to 350, 325 million English short tons per year …
that’s about … 10 to 16 percent of the CO that is emitted in the electricity sector within
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the United States.
If all of the switchgrass that is forecasted to be capable of being grown were to go into
the electricity sector, this quantity of switchgrass has the capability, depending on what
future technologies are going to be, of producing maybe about 26 to 40 billion gallons of
ethanol per year, whereas we’re currently consuming 140, 150 billion gallons of gasoline
per year. So, it depends on the values that the United States as a public wants to go for in
the future. Do we want to have alternative transportation fuels or do we want to mitigate CO You mitigate more CO by using this switchgrass in the electricity sector than
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you would if you used it in the transportation sector.”
Switchgrass is just one of the many so-called biofuels — corn and other organic matter
that comes from renewable plants, trees, crops, and waste materials. Future episodes of Global Challenges will focus on biofuels, and differing views on their potential.
For the average person though, controlling climate change by using switchgrass or capturing
and storing carbon dioxide are things that only scientists and engineers really understand and
can accomplish. Some people might very well ask, so what can I do about climate change?
