I must look like a drunk Darth Vader, fumbling to get my bearings through the thick, dull green lens of a black welder’s helmet. I’m standing next to an outdoor furnace that sounds like it has an idling TIE Fighter inside. My guide motions me through a wavy blast of warm exhaust and points toward a round opening in the oven. I hunch over and peer inside at a torch tip that’s glowing as hot and bright as the surface of the sun.
This is the only way to get a glimpse of this super-heating technology, called a plasma arc or plasma torch. The steel industry has used the torches for decades to keep molten metals up to temperature. Now, some think the heaters might have a new future making our garbage disappear into thin air, literally, and generating a relatively clean energy source at the same time.
Or, they might just vaporize a chunk of the state budget.
It sounds too good to be true — and skeptics insist it is — but a Minnesota manufacturer is asking the state for $2.5 million to test how well the torches transform waste into energy. Phoenix Solutions Company, headquartered in Crystal, Minn., is the world’s largest maker of plasma torch equipment. I visited its test site in Hutchinson last week after owner Leonard Frame spoke to a House energy committee about the project.
Rep. Paul Thissen, DFL-Minneapolis, has introduced a bill to offer state bonding funds for the trial, which would be matched by $500,000 from the company and $1 million from Hutchinson Utilities, a partner on the project. The goal is to see how effective the torches are at generating energy using various materials, ranging from corn stalks and wood chips to old tires and televisions sets.
The devices haven’t caught on in the United States in part because we’ve always had plenty of space to pile our garbage. But plasma arc technology is getting more attention lately as our landfills crest and the need for new energy sources becomes more acute. The first large-scale U.S. project is being built in Florida. St. Lucie County plans to vaporize all its garbage through a $425 million arc that’s expected to be up and running in 2009. It also plans to process 4.3 million tons of trash collected since 1978 and empty its landfill within two decades.
Many of Phoenix Solutions’ current customers are in Japan, where landfill space is at more of a premium. Instead of directly landfilling garbage, trash there is incinerated and the ash is captured and processed with one of Phoenix Solutions’ plasma torches. The byproducts are a burnable fuel similar to natural gas and a super-compacted, glass-like silicate that can be recycled in asphalt and road projects.
Last week, employees at the Hutchinson site were testing a new plasma torch for a Japanese company that plans to use it to destroy PCB pollution. The work order requires Phoenix Solutions to test the device, disassemble it, reassemble it, and test it again before disassembling and shipping it out for installation in Japan.
“Should we stuff this turkey?” quips technician Mark Pedersen as he and supervisor Jim Pease wander toward a long, missile-shaped stainless steel cylinder. It might look like a weapon, but Its insides are more like a super-sized welder’s torch.
Here’s how it works:
A slug of wires hooks up to the rear of the torch, enough to drain a small power plant. Once the power is switched on, that electricity is carried through a copper tube to the edge of a bullet-shaped chamber that’s filled with gas, usually argon, nitrogen or compressed air. A spark causes the electricity to jump into the chamber, electrocuting the gas with something like a mini lighting bolt inside the torch.
This super heats the gas, which technically becomes a plasma. (Plasma is a gas that conducts electricity. It’s the stuff static-electricity sparks are made of.) The electricity strikes another copper piece on the other end of the chamber, but the gas is belched out the front end of the torch at temperatures hotter than the surface of the sun, higher than 10,000 degrees Fahrenheit. The inch-thick copper that holds it all in will wear out and need replacing within a few hundred hours of use.
“There’s really nothing else that can achieve these temperatures,” said Rodney Reeve, a product development engineer for Phoenix Solutions.
Materials placed in the torch’s path don’t burn. They melt, and then mostly vaporize. The intense heat causes things to come apart at their molecular seams. About all that’s left is a hydrogen-rich synthetic gas that can be collected and used as fuel for electricity generation, and a glass-like residue or “slag” containing all of the metals and other materials that couldn’t be vaporized.
It’s not a new technology. What is new is rising prices and uncertainty about natural gas, said the company’s founder and chairman, Leonard Frame.
“The appeal is that we can generate, today, energy that is a whole lot cleaner than coal, that discharges less carbon dioxide than fossil fuels, and that is less expensive than today’s price of natural gas,” he said.
Just how much cleaner and efficient plasma torch technology is compared to other alternatives is a subject of debate. Rep. Jean Wagenius, DFL-Minneapolis, raised questions during a House energy committee meeting last week about the possible air quality impact. Part of the bonding proposal would collect data on the environmental impact.
In a closed system where the gases are being collected for energy use, plasma systems have virtually no emissions, according to Frame and others. The Florida project, for example, will collect every last byproduct generated by the melting and vaporizing process, from synthetic gas to make electricity to slag sold for use in road and construction projects.
Rep. Paul Thissen”The key point here is that this is not actually burning,” Thissen said. “It’s actually a different type of process.”
It’s also an expensive and energy-intensive process, though. The city of Honolulu, which like Japan has its own garbage storage problems, looked into building a plasma arc in 2004 but decided against it in part because it would have significantly increased the cost of waste disposal and not provide any environmental advantages to justify the cost.
“It’s ungodly expensive, and there’s questions about the environmental impact,” said Susan Hubbard, chief executive officer of Eureka Recycling in St. Paul.
Plasma torch technology, by a long shot, is nowhere near the most efficient way to reduce waste or generate energy, Hubbard said. She doesn’t actively oppose plasma torch projects, but she thinks it’s unwise to invest taxpayer dollars in them because the state could get a far better return — in waste reduction, in job creation, in emission cuts — by funding recycling and composting programs. Minnesota has enormous public subsidies for garbage incineration, for example, but nothing for curbside organic collection.
The economic value of recyclables that are annually thrown into the waste stream in Minnesota exceeds $200 million, Hubbard said.
“And we want to use public funds for a facility that will torch it?,” she said. “It doesn’t pass the laugh test.”
The House Energy Finance and Policy committee has not yet voted on the bill, which has a companion bill in the Senate Business, Energy and Jobs committee supported by Sen. Dan Larson, DFL-Bloomington.