DISCOVER Vol. 24 No. 5 (May 2003)
Table of Contents
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
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."...
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...
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...
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."
