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Energy Policy Forum > 2003
Articles
Anything into Oil
Technological savvy could turn 600 million tons of turkey
guts and other waste into 4 billion barrels of light Texas
crude each year
By Brad Lemley
Photography by Tony Law
DISCOVER Vol. 24 No. 5 (May 2003)
Gory refuse, from a Butterball Turkey plant in Carthage,
Missouri, will no longer go to waste. Each day 200 tons of
turkey offal will be carted to the first industrial-scale
thermal depolymerization plant, recently completed in an
adjacent lot, and be transformed into various useful products,
including 600 barrels of light oil.
In an industrial park in Philadelphia sits a new machine
that can change almost anything into oil. Really.
"This is a solution to three of the biggest problems
facing mankind," says Brian Appel, chairman and CEO
of Changing World Technologies, the company that built this
pilot plant and has just completed its first industrial-size
installation in Missouri. "This process can deal with
the world's waste. It can supplement our dwindling supplies
of oil. And it can slow down global warming."
Pardon me, says a reporter, shivering in the frigid dawn,
but that sounds too good to be true.
"Everybody says that," says Appel. He is a tall,
affable entrepreneur who has assembled a team of scientists,
former government leaders, and deep-pocketed investors to
develop and sell what he calls the thermal depolymerization
process, or TDP. The process is designed to handle almost
any waste product imaginable, including turkey offal, tires,
plastic bottles, harbor-dredged muck, old computers, municipal
garbage, cornstalks, paper-pulp effluent, infectious medical
waste, oil-refinery residues, even biological weapons such
as anthrax spores. According to Appel, waste goes in one
end and comes out the other as three products, all valuable
and environmentally benign: high-quality oil, clean-burning
gas, and purified minerals that can be used as fuels, fertilizers,
or specialty chemicals for manufacturing.
Unlike other solid-to-liquid-fuel processes such as cornstarch
into ethanol, this one will accept almost any carbon-based
feedstock. If a 175-pound man fell into one end, he would
come out the other end as 38 pounds of oil, 7 pounds of gas,
and 7 pounds of minerals, as well as 123 pounds of sterilized
water. While no one plans to put people into a thermal depolymerization
machine, an intimate human creation could become a prime
feedstock. "There is no reason why we can't turn sewage,
including human excrement, into a glorious oil," says
engineer Terry Adams, a project consultant. So the city of
Philadelphia is in discussion with Changing World Technologies
to begin doing exactly that.
"The potential is unbelievable," says Michael
Roberts, a senior chemical engineer for the Gas Technology
Institute, an energy research group. "You're not only
cleaning up waste; you're talking about distributed generation
of oil all over the world."
"This is not an incremental change. This is a big,
new step," agrees Alf Andreassen, a venture capitalist
with the Paladin Capital Group and a former Bell Laboratories
director.
The offal-derived oil, is chemically almost identical to
a number two fuel oil used to heat homes.
Andreassen and others anticipate that a large chunk of the
world's agricultural, industrial, and municipal waste may
someday go into thermal depolymerization machines scattered
all over the globe. If the process works as well as its creators
claim, not only would most toxic waste problems become history,
so would imported oil. Just converting all the U.S. agricultural
waste into oil and gas would yield the energy equivalent
of 4 billion barrels of oil annually. In 2001 the United
States imported 4.2 billion barrels of oil. Referring to
U.S. dependence on oil from the volatile Middle East, R.
James Woolsey, former CIA director and an adviser to Changing
World Technologies, says, "This technology offers a
beginning of a way away from this."
But first things first. Today, here at the plant at Philadelphia's
Naval Business Center, the experimental feedstock is turkey
processing-plant waste: feathers, bones, skin, blood, fat,
guts. A forklift dumps 1,400 pounds of the nasty stuff into
the machine's first stage, a 350-horsepower grinder that
masticates it into gray brown slurry. From there it flows
into a series of tanks and pipes, which hum and hiss as they
heat, digest, and break down the mixture. Two hours later,
a white-jacketed technician turns a spigot. Out pours a honey-colored
fluid, steaming a bit in the cold warehouse as it fills a
glass beaker.
It really is a lovely oil.
"The longest carbon chains are C-18 or so," says
Appel, admiring the liquid. "That's a very light oil.
It is essentially the same as a mix of half fuel oil, half
gasoline."
Private investors, who have chipped in $40 million to develop
the process, aren't the only ones who are impressed. The
federal government has granted more than $12 million to push
the work along. "We will be able to make oil for $8
to $12 a barrel," says Paul Baskis, the inventor of
the process. "We are going to be able to switch to a
carbohydrate economy."
Making oil and gas from hydrocarbon-based waste is a trick
that Earth mastered long ago. Most crude oil comes from one-celled
plants and animals that die, settle to ocean floors, decompose,
and are mashed by sliding tectonic plates, a process geologists
call subduction. Under pressure and heat, the dead creatures'
long chains of hydrogen, oxygen, and carbon-bearing molecules,
known as polymers, decompose into short-chain petroleum hydrocarbons.
However, Earth takes its own sweet time doing this—generally
thousands or millions of years—because subterranean
heat and pressure changes are chaotic. Thermal depolymerization
machines turbocharge the process by precisely raising heat
and pressure to levels that break the feedstock's long molecular
bonds.
Many scientists have tried to convert organic solids to
liquid fuel using waste products before, but their efforts
have been notoriously inefficient. "The problem with
most of these methods was that they tried to do the transformation
in one step—superheat the material to drive off the
water and simultaneously break down the molecules," says
Appel. That leads to profligate energy use and makes it possible
for hazardous substances to pollute the finished product.
Very wet waste—and much of the world's waste is wet—is
particularly difficult to process efficiently because driving
off the water requires so much energy. Usually, the Btu content
in the resulting oil or gas barely exceeds the amount needed
to make the stuff.
That's the challenge that Baskis, a microbiologist and inventor
who lives in Rantoul, Illinois, confronted in the late 1980s.
He says he "had a flash" of insight about how to
improve the basic ideas behind another inventor's waste-reforming
process. "The prototype I saw produced a heavy, burned
oil," recalls Baskis. "I drew up an improvement
and filed the first patents." He spent the early 1990s
wooing investors and, in 1996, met Appel, a former commodities
trader. "I saw what this could be and took over the
patents," says Appel, who formed a partnership with
the Gas Technology Institute and had a demonstration plant
up and running by 1999.
Thermal depolymerization, Appel says, has proved to be 85
percent energy efficient for complex feedstocks, such as
turkey offal: "That means for every 100 Btus in the
feedstock, we use only 15 Btus to run the process." He
contends the efficiency is even better for relatively dry
raw materials, such as plastics.
So how does it work? In the cold Philadelphia warehouse,
Appel waves a long arm at the apparatus, which looks surprisingly
low tech: a tangle of pressure vessels, pipes, valves, and
heat exchangers terminating in storage tanks. It resembles
the oil refineries that stretch to the horizon on either
side of the New Jersey Turnpike, and in part, that's exactly
what it is.
Appel strides to a silver gray pressure tank that is 20
feet long, three feet wide, heavily insulated, and wrapped
with electric heating coils. He raps on its side. "The
chief difference in our process is that we make water a friend
rather than an enemy," he says. "The other processes
all tried to drive out water. We drive it in, inside this
tank, with heat and pressure. We super-hydrate the material." Thus
temperatures and pressures need only be modest, because water
helps to convey heat into the feedstock. "We're talking
about temperatures of 500 degrees Fahrenheit and pressures
of about 600 pounds for most organic material—not at
all extreme or energy intensive. And the cooking times are
pretty short, usually about 15 minutes."
Once the organic soup is heated and partially depolymerized
in the reactor vessel, phase two begins. "We quickly
drop the slurry to a lower pressure," says Appel, pointing
at a branching series of pipes. The rapid depressurization
releases about 90 percent of the slurry's free water. Dehydration
via depressurization is far cheaper in terms of energy consumed
than is heating and boiling off the water, particularly because
no heat is wasted. "We send the flashed-off water back
up there," Appel says, pointing to a pipe that leads
to the beginning of the process, "to heat the incoming
stream."
At this stage, the minerals—in turkey waste, they
come mostly from bones—settle out and are shunted to
storage tanks. Rich in calcium and magnesium, the dried brown
powder "is a perfect balanced fertilizer," Appel
says.
The remaining concentrated organic soup gushes into a second-stage
reactor similar to the coke ovens used to refine oil into
gasoline. "This technology is as old as the hills," says
Appel, grinning broadly. The reactor heats the soup to about
900 degrees Fahrenheit to further break apart long molecular
chains. Next, in vertical distillation columns, hot vapor
flows up, condenses, and flows out from different levels:
gases from the top of the column, light oils from the upper
middle, heavier oils from the middle, water from the lower
middle, and powdered carbon—used to manufacture tires,
filters, and printer toners—from the bottom. "Gas
is expensive to transport, so we use it on-site in the plant
to heat the process," Appel says. The oil, minerals,
and carbon are sold to the highest bidders.
Depending on the feedstock and the cooking and coking times,
the process can be tweaked to make other specialty chemicals
that may be even more profitable than oil. Turkey offal,
for example, can be used to produce fatty acids for soap,
tires, paints, and lubricants. Polyvinyl chloride, or PVC—the
stuff of house siding, wallpapers, and plastic pipes—yields
hydrochloric acid, a relatively benign and industrially valuable
chemical used to make cleaners and solvents. "That's
what's so great about making water a friend," says Appel. "The
hydrogen in water combines with the chlorine in PVC to make
it safe. If you burn PVC [in a municipal-waste incinerator],
you get dioxin—very toxic."
Brian Appel, CEO of Changing World Technologies, strolls
through a thermal depolymerization plant in Philadelphia.
Experiments at the pilot facility revealed that the process
is scalable—plants can sprawl over acres and handle
4,000 tons of waste a day or be "small enough to go
on the back of a flatbed truck" and handle just one
ton daily, says Appel.
The technicians here have spent three years feeding different
kinds of waste into their machinery to formulate recipes.
In a little trailer next to the plant, Appel picks up a handful
of one-gallon plastic bags sent by a potential customer in
Japan. The first is full of ground-up appliances, each piece
no larger than a pea. "Put a computer and a refrigerator
into a grinder, and that's what you get," he says, shaking
the bag. "It's PVC, wood, fiberglass, metal, just a
mess of different things. This process handles mixed waste
beautifully." Next to the ground-up appliances is a
plastic bucket of municipal sewage. Appel pops the lid and
instantly regrets it. "Whew," he says. "That
is nasty."
Experimentation revealed that different waste streams require
different cooking and coking times and yield different finished
products. "It's a two-step process, and you do more
in step one or step two depending on what you are processing," Terry
Adams says. "With the turkey guts, you do the lion's
share in the first stage. With mixed plastics, most of the
breakdown happens in the second stage." The oil-to-mineral
ratios vary too. Plastic bottles, for example, yield copious
amounts of oil, while tires yield more minerals and other
solids. So far, says Adams, "nothing hazardous comes
out from any feedstock we try."
"The only thing this process can't handle is nuclear
waste," Appel says. "If it contains carbon, we
can do it." à
This Philadelphia pilot plant can handle only seven tons
of waste a day, but 1,054 miles to the west, in Carthage,
Missouri, about 100 yards from one of ConAgra Foods' massive
Butterball Turkey plants, sits the company's first commercial-scale
thermal depolymerization plant. The $20 million facility,
scheduled to go online any day, is expected to digest more
than 200 tons of turkey-processing waste every 24 hours.
The north side of Carthage smells like Thanksgiving all
the time. At the Butterball plant, workers slaughter, pluck,
parcook, and package 30,000 turkeys each workday, filling
the air with the distinctive tang of boiling bird. A factory
tour reveals the grisly realities of large-scale poultry
processing. Inside, an endless chain of hanging carcasses
clanks past knife-wielding laborers who slash away. Outside,
a tanker truck idles, full to the top with fresh turkey blood.
For many years, ConAgra Foods has trucked the plant's waste—feathers,
organs, and other nonusable parts—to a rendering facility
where it was ground and dried to make animal feed, fertilizer,
and other chemical products. But bovine spongiform encephalopathy,
also known as mad cow disease, can spread among cattle from
recycled feed, and although no similar disease has been found
in poultry, regulators are becoming skittish about feeding
animals to animals. In Europe the practice is illegal for
all livestock. Since 1997, the United States has prohibited
the feeding of most recycled animal waste to cattle. Ultimately,
the specter of European-style mad-cow regulations may kick-start
the acceptance of thermal depolymerization. "In Europe,
there are mountains of bones piling up," says Alf Andreassen. "When
recycling waste into feed stops in this country, it will
change everything."
Because depolymerization takes apart materials at the molecular
level, Appel says, it is "the perfect process for destroying
pathogens." On a wet afternoon in Carthage, he smiles
at the new plant—an artless assemblage of gray and
dun-colored buildings—as if it were his favorite child. "This
plant will make 10 tons of gas per day, which will go back
into the system to make heat to power the system," he
says. "It will make 21,000 gallons of water, which will
be clean enough to discharge into a municipal sewage system.
Pathological vectors will be completely gone. It will make
11 tons of minerals and 600 barrels of oil, high-quality
stuff, the same specs as a number two heating oil." He
shakes his head almost as if he can't believe it. "It's
amazing. The Environmental Protection Agency doesn't even
consider us waste handlers. We are actually manufacturers—that's
what our permit says. This process changes the whole industrial
equation. Waste goes from a cost to a profit."
He watches as burly men in coveralls weld and grind the
complex loops of piping. A group of 15 investors and corporate
advisers, including Howard Buffett, son of billionaire investor
Warren Buffett, stroll among the sparks and hissing torches,
listening to a tour led by plant manager Don Sanders. A veteran
of the refinery business, Sanders emphasizes that once the
pressurized water is flashed off, "the process is similar
to oil refining. The equipment, the procedures, the safety
factors, the maintenance—it's all proven technology."
And it will be profitable, promises Appel. "We've done
so much testing in Philadelphia, we already know the costs," he
says. "This is our first-out plant, and we estimate
we'll make oil at $15 a barrel. In three to five years, we'll
drop that to $10, the same as a medium-size oil exploration
and production company. And it will get cheaper from there."
"We've got a lot of confidence in this," Buffett
says. "I represent ConAgra's investment. We wouldn't
be doing this if we didn't anticipate success." Buffett
isn't alone. Appel has lined up federal grant money to help
build demonstration plants to process chicken offal and manure
in Alabama and crop residuals and grease in Nevada. Also
in the works are plants to process turkey waste and manure
in Colorado and pork and cheese waste in Italy. He says the
first generation of depolymerization centers will be up and
running in 2005. By then it should be clear whether the technology
is as miraculous as its backers claim.
EUREKA:
Chemistry, not alchemy, turns (A) turkey offal—guts,
skin, bones, fat, blood, and feathers—into a variety
of useful products. After the first-stage heat-and-pressure
reaction, fats, proteins, and carbohydrates break down into
(B) carboxylic oil, which is composed of fatty acids, carbohydrates,
and amino acids. The second-stage reaction strips off the
fatty acids' carboxyl group (a carbon atom, two oxygen atoms,
and a hydrogen atom) and breaks the remaining hydrocarbon
chains into smaller fragments, yielding (C) a light oil.
This oil can be used as is, or further distilled (using a
larger version of the bench-top distiller in the background)
into lighter fuels such as (D) naphtha, (E) gasoline, and
(F) kerosene. The process also yields (G) fertilizer-grade
minerals derived mostly from bones and (H) industrially useful
carbon black.
Garbage In, Oil Out
Feedstock is funneled into a grinder and mixed with water
to create a slurry that is pumped into the first-stage
reactor, where heat and pressure partially break apart
long molecular chains. The resulting organic soup flows
into a flash vessel where pressure drops dramatically,
liberating some of the water, which returns back upstream
to preheat the flow into the first-stage reactor. In the
second-stage reactor, the remaining organic material is
subjected to more intense heat, continuing the breakup
of molecular chains. The resulting hot vapor then goes
into vertical distillation tanks, which separate it into
gases, light oils, heavy oils, water, and solid carbon.
The gases are burned on-site to make heat to power the
process, and the water, which is pathogen free, goes to
a municipal waste plant. The oils and carbon are deposited
in storage tanks, ready for sale.
— Brad Lemley
A Boon to Oil and Coal Companies
One might expect fossil-fuel companies to fight thermal
depolymerization. If the process can make oil out of waste,
why would anyone bother to get it out of the ground? But
switching to an energy economy based entirely on reformed
waste will be a long process, requiring the construction
of thousands of thermal depolymerization plants. In the meantime,
thermal depolymerization can make the petroleum industry
itself cleaner and more profitable, says John Riordan, president
and CEO of the Gas Technology Institute, an industry research
organization. Experiments at the Philadelphia thermal depolymerization
plant have converted heavy crude oil, shale, and tar sands
into light oils, gases, and graphite-type carbon. "When
you refine petroleum, you end up with a heavy solid-waste
product that's a big problem," Riordan says. "This
technology will convert these waste materials into natural
gas, oil, and carbon. It will fit right into the existing
infrastructure."
Appel says a modified version of thermal depolymerization
could be used to inject steam into underground tar-sand deposits
and then refine them into light oils at the surface, making
this abundant, difficult-to-access resource far more available.
But the coal industry may become thermal depolymerization's
biggest fossil-fuel beneficiary. "We can clean up coal
dramatically," says Appel. So far, experiments show
the process can extract sulfur, mercury, naphtha, and olefins—all
salable commodities—from coal, making it burn hotter
and cleaner. Pretreating with thermal depolymerization also
makes coal more friable, so less energy is needed to crush
it before combustion in electricity-generating plants.
—
B.L.
Can Thermal Depolymerization Slow Global Warming?
If the
thermal depolymerization process WORKS AS Claimed, it will
clean up waste and generate new sources of energy.
But its backers contend it could also stem global warming,
which sounds iffy. After all, burning oil creates global
warming, doesn't it?
Carbon is the major chemical constituent of most organic
matter—plants take it in; animals eat plants, die,
and decompose; and plants take it back in, ad infinitum.
Since the industrial revolution, human beings burning fossil
fuels have boosted concentrations of atmospheric carbon more
than 30 percent, disrupting the ancient cycle. According
to global-warming theory, as carbon in the form of carbon
dioxide accumulates in the atmosphere, it traps solar radiation,
which warms the atmosphere—and, some say, disrupts
the planet's ecosystems.
But if there were a global shift to thermal depolymerization
technologies, belowground carbon would remain there. The
accoutrements of the civilized world—domestic animals
and plants, buildings, artificial objects of all kinds—would
then be regarded as temporary carbon sinks. At the end of
their useful lives, they would be converted in thermal depolymerization
machines into short-chain fuels, fertilizers, and industrial
raw materials, ready for plants or people to convert them
back into long chains again. So the only carbon used would
be that which already existed above the surface; it could
no longer dangerously accumulate in the atmosphere. "Suddenly,
the whole built world just becomes a temporary carbon sink," says
Paul Baskis, inventor of the thermal depolymerization process. "We
would be honoring the balance of nature."
—
B.L.
RELATED WEB SITES:
To learn more about the thermal depolymerization process,
visit Changing World Technologies' Web site: http://www.changingworldtech.com/.
A primer on the natural carbon cycle can be found at www.whrc.org/science/carbon/carbon.htm.
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