Following the United States on the Thermal Depolymerization Plant. Asbena is currently researching it to.
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.
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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.
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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
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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.
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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.
Research - 2 years. $20 million.
Construction - 4 years. $50 million.