[Terrapreta] Agrichar in NYT today

[KELPIE WILSON]

http://www.nytimes.com/2008/03/26/business/businessspecial2/26negative.html?_r=1&pagewanted=1&ei=5088&en=24707e2a7e4e5dd5&ex=1364270400&partner=rssnyt&emc=rss&adxnnlx=1206533164-coAz21AtDrwJHH7jfV2X0A&oref=slogin

For Carbon Emissions, a Goal of Less Than Zero

By MATTHEW L. WALD
Published: March 26, 2008

IF the world is going to sharply reduce the amount of carbon dioxide
pumped into the atmosphere by midcentury, then many businesses will
have to go carbon neutral, bringing their net emissions of the
greenhouse gas to zero.
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Jose A. Martinez/Solena Group

GREEN GIANTS Algae, which have a high energy value per pound and
consume carbon dioxide, are being cultivated at a biofuel
demonstration facility run by the Solena Group in Alicante, Spain.

But some could go even further by removing more CO2 than they produce.
Instead of carbon neutral, how about carbon negative?

In academic and industrial labs worldwide, researchers are working on
technologies to reach that goal. Success could create the ultimate
green business — for example, one that produces fuel whose emissions
are more than offset by carbon dioxide stored during production. The
businesses would be successful if, as anticipated, Congress puts a tax
on emissions or starts a trading plan that makes carbon credits
valuable.

For some experts, it's not a question of whether businesses will go
carbon negative but when.

Carbon-negative technologies of some sort will be essential, said
Daniel M. Kammen, director of the Renewable and Appropriate Energy
Laboratory at the University of California, Berkeley. The world is
facing the certainty of massive emissions for decades to come from
plants already running, he said, adding that atmospheric
concentrations must be stabilized. "We've got such a carbon overshoot
looming in the future that this is going to have to happen," he said.

The United Nations Intergovernmental Panel on Climate Change said that
an 80 percent cut in carbon dioxide emissions was necessary to avoid
the worst consequences of climate change. But capturing the gas from
coal plant smokestacks or switching to fuels that produce less of it
when burned goes only so far.

"The great problem is actually removing carbon dioxide from the
atmosphere," said Geir Vollsaeter, an environment expert and former
general manager of carbon dioxide at Shell International, a subsidiary
of the oil giant.

While much engineering work would have to be done to make a business
carbon negative, the outlines are clear.

Take the concept of building a coal plant that captures and stores
carbon dioxide. Such a plant could have zero emissions, because the
coal would be turned into gas and processed to produce hydrogen and
carbon dioxide. The hydrogen, a pollution-free fuel, would be burned,
and the CO2 pumped underground for permanent storage.

But Robert Williams, a research scientist at Princeton University,
said that not only coal could be gasified; you could also make the
same fuel by starting with plant matter or other biomass.

And then, he said, "if you put any CO2 underground that is derived
from biomass, that's negative CO2 emissions." That is because plants
or trees — the raw material for the fuel —pull carbon dioxide from the
atmosphere as they grow, and the gasification and storage takes that
carbon out of circulation.

Mr. Williams said the more likely route would be to gasify a mixture
of coal and biomass to keep the process carbon neutral. But the
balance depends on the cost of separation and storage versus what kind
of tax or other fee Congress might put on emissions.

More audacious is a plan by two professors at Columbia University to
suck carbon dioxide out of the air, using waste heat from a solar
plant, which has no smokestack.

Peter M. Eisenberger, a professor of earth and environmental sciences
whose résumé includes positions at Exxon and other major companies,
and Graciela Chichilnisky, an economist and mathematician, have
proposed a "global thermostat strategy," which would adapt a chemical
process for capturing carbon dioxide from smokestacks.

Ordinarily, the process requires a large amount of energy. But the
professors noted that McMahan L. Gray, a scientist at an Energy
Department laboratory, has modified the process so that the relatively
small amount of waste heat from a solar-generating plant could do the
job. They estimate that they could remove about five pounds of carbon
dioxide per kilowatt-hour of electricity produced. (A coal plant emits
about two pounds when it makes that much electricity.)

"If you want to solve the global warming problem, you can't do that by
staying even," Dr. Eisenberger said.

It will probably take a bounty on a ton of carbon, though, before
anyone will do tests to see how well the chemistry will work on a
practical scale.

A carbon-based process that may be a step closer to commercialization
was created by George A. Olah, a Nobel laureate in chemistry, and G.
K. Surya Prakash, a fellow faculty member at the University of
Southern California. To recycle carbon dioxide, they developed a kind
of reverse fuel cell, which makes methanol by mixing the gas with
water and applying a jolt of electricity.

If the source of the electricity is carbon-neutral — from a windmill
or a nuclear reactor, for example — the process would be carbon
negative. (Although if the methanol is used as vehicle fuel, the
carbon would be released back into the environment, making the process
carbon neutral.)

UOP, a subsidiary of Honeywell, announced in December that it had
acquired rights to the technology, a sign somebody thinks it could be
profitable.

The Department of Agriculture is considering carbon storage as a new
crop, so to speak. "It's one of the many, many ways the agriculture
community is going to be a viable player in the renewable-energy field
as we go forward," said Edward T. Schafer, the secretary of
agriculture, at a renewable-energy conference this month.

The method is called agrichar, in which some biological material —
grass or trees grown specifically for the purpose; or a cornstalk or
other agricultural waste — is cooked at a very high temperature in the
absence of oxygen. That produces an oil that, with a little chemical
work, can be used as a vehicle fuel.

But in a world focused on carbon, the important part may be the
leftovers, a charcoal-like material that retains most of the carbon.
It also has useful minerals, like potassium and phosphorus. Plowed
back into a field, it helps the soil retain water and nutrients, which
also enhances plant growth, said Robert C. Brown, director of the
Bioeconomy Institute at Iowa State University.

Senator Ken Salazar, Democrat of Colorado, has introduced legislation
that would pay for more research. If it works, he said, farmers would
have a new crop. "You'd be growing allowances," he said.

If being carbon negative becomes important, then some existing
industries may try to describe themselves that way. In some cases, it
may even be true.

For example, Covanta Energy of Fairfield, N.J., operates plants that
make electricity by burning municipal solid waste, which is about 80
percent paper and other organic materials. But Anthony J. Orlando,
Covanta's president and chief executive, says he is hoping to collect
carbon credits, because each ton burned, he said, would have otherwise
been buried in a landfill where bacteria digest garbage to make
methane, a potent greenhouse gas. The company is building plants in
China that will qualify for credits, issued by the European Union,
which companies in Europe can buy to offset their own carbon output,
Mr. Orlando said. As for the United States, he said, "it depends on
the legislation."

A Washington company, the Solena Group, also has a carbon-negative
plan, which emerged from the decision by regulators in Kansas last
year to turn down a permit for two new coal-burning power plants
because of the millions of tons of carbon dioxide they would produce.
The regulators insisted that the builder of the plants, an electric
co-op called Sunflower, had to permanently remove the carbon from
circulation. Gov. Kathleen Sebelius and the Kansas State Legislature
are still arguing over whether the plants should be built.

Solena says it can use the carbon. The company employs a
high-temperature process to break up anything organic into a flammable
gas. The organic material could be algae, which have an extremely high
energy value per pound. And algae eat carbon dioxide.

Solena is in discussion with Sunflower to build a 40-megawatt power
plant that would run on gasified algae; the algae would be grown in
thousands of clear plastic cylinders, 3 feet wide by 10 feet tall,
sitting in the Kansas sun and fertilized with sodium bicarbonate, made
with carbon captured from Sunflower's coal plant. For each 1.8 tons of
carbon dioxide, the columns would yield a ton of algae.

A Solena subsidiary has been growing algae at a facility in Alicante, Spain.

If built, the system would make double use of the carbon from the coal
and avoid digging more coal for more power. Alternatively, the gas
could be turned into diesel fuel or other vehicle fuel, if prices
favored that.

For the truly adventurous, there is the plankton ocean digester, the
brainchild of Mark E. Capron, an American civil engineer. His idea is
to take a natural process, the bacterial breakdown of algae in the
ocean, and carry it out in an underwater tank without air. The process
would produce methane, which could be piped to shore for use as fuel,
and carbon dioxide, which could be pumped to the ocean depths, where
it would stay.

Since the system would replace the need for oil or natural gas, it
would reduce carbon loading in the atmosphere. And it would run on
plants or anything else that came into the digester. "Fish, octopuses,
we're not picky," Mr. Capron said.
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-- 
Kelpie Wilson
www.kelpiewilson.com