It sounds as if someone just dropped a tricycle into a meat grinder. I’m sitting inside a narrow conference room at a research facility in Bristol, Connecticut, chatting with Joseph Longo, the founder and CEO of Startech Environmental Corporation. As we munch on takeout Subway sandwiches, a plate-glass window is the only thing separating us from the adjacent lab, which contains a glowing caldera of “plasma†three times as hot as the surface of the sun. Every few minutes there’s a horrific clanking noise—grinding followed by a thunderous voomp, like the sound a gas barbecue makes when it first ignites.
“Is it supposed to do that?†I ask Longo nervously. “Yup,†he says. “That’s normal.â€
Despite his 74 years, Longo bears an unnerving resemblance to the longtime cover boy of Mad magazine, Alfred E. Neuman, who shrugs off nuclear Armageddon with the glib catchphrase “What, me worry?†Both share red hair, a smattering of freckles and a toothy grin. When such a man tells me I’m perfectly safe from a 30,000˚F arc of man-made lightning heating a vat of plasma that his employees are “controlling†in the next room—well, I’m not completely reassured.
To put me at ease, Longo calls in David Lynch, who manages the demonstration facility. “There’s no flame or fire inside. It’s just electricity,†Lynch assures me of the multimillion-dollar system that took Longo almost two decades to design and build. Then the two usher me into the lab, where the gleaming 15-foot-tall machine they’ve named the Plasma Converter stands in the center of the room. The entire thing takes up about as much space as a two-car garage, surprisingly compact for a machine that can consume nearly any type of waste—from dirty diapers to chemical weapons—by annihilating toxic materials in a process as old as the universe itself. Called plasma gasification, it works a little like the big bang, only backward (you get nothing from something). Inside a sealed vessel made of stainless steel and filled with a stable gas—either pure nitrogen or, as in this case, ordinary air—a 650-volt current passing between two electrodes rips electrons from the air, converting the gas into plasma. Current flows continuously through this newly formed plasma, creating a field of extremely intense energy very much like lightning. The radiant energy of the plasma arc is so powerful, it disintegrates trash into its constituent elements by tearing apart molecular bonds. The system is capable of breaking down pretty much anything except nuclear waste, the isotopes of which are indestructible. The only by-products are an obsidian-like glass used as a raw material for numerous applications, including bathroom tiles and high-strength asphalt, and a synthesis gas, or “syngasâ€â€”a mixture of primarily hydrogen and carbon monoxide that can be converted into a variety of marketable fuels, including ethanol, natural gas and hydrogen.
Perhaps the most amazing part of the process is that it’s self-sustaining. Just like your toaster, Startech’s Plasma Converter draws its power from the electrical grid to get started. The initial voltage is about equal to the zap from a police stun gun. But once the cycle is under way, the 2,200˚F syngas is fed into a cooling system, generating steam that drives turbines to produce electricity. About two thirds of the power is siphoned off to run the converter; the rest can be used on-site for heating or electricity, or sold back to the utility grid. “Even a blackout would not stop the operation of the facility,†Longo says.
It all sounds far too good to be true. But the technology works. Over the past decade, half a dozen companies have been developing plasma technology to turn garbage into energy. “The best renewable energy is the one we complain about the most: municipal solid waste,†says Louis Circeo, the director of plasma research at the Georgia Institute of Technology. “It will prove cheaper to take garbage to a plasma plant than it is to dump it on a landfill.†A Startech machine that costs roughly $250 million could handle 2,000 tons of waste daily, approximately what a city of a million people amasses in that time span. Large municipalities typically haul their trash to landfills, where the operator charges a “tipping fee†to dump the waste. The national average is $35 a ton, although the cost can be more than twice that in the Northeast (where land is scarce, tipping fees are higher). And the tipping fee a city pays doesn’t include the price of trucking the garbage often hundreds of miles to a landfill or the cost of capturing leaky methane—a greenhouse gas—from the decomposing waste. In a city with an average tipping fee, a $250-million converter could pay for itself in about 10 years, and that’s without factoring in the money made from selling the excess electricity and syngas. After that break-even point, it’s pure profit.
Someday very soon, cities might actually make money from garbage.
popsci
