How much, if any, wood should be added to the trash burned for electricity in Penacook?

  • Crane operator Dan Parkinson maneuvers a grapple to move trash to the feed chute, which leads to the boiler, at the Wheelabrator facility in Penacook last week. Parkinson has been with the company for almost 27 years. ELIZABETH FRANTZ / Monitor staff

  • A grapple crane is used to move trash at the Wheelabrator facility in Penacook last Wednesday. ELIZABETH FRANTZ / Monitor staff

  • John Nasan, a plant operator, in the control room of the Wheelabrator Concord plant, where the speed and amount of trash fed to the two boilers can be controlled. Closed-circuit TVs examining parts of the plant are on the far wall. April 19, 2016. DAVID BROOKSMonitor staff

  • Members of the House of Representatives Science, Technology and Energy Committee look at the 2,500-degree fire that burns trash in the Wheelabrator Concord plant during a tour on April 19, 2016.  DAVID BROOKSMonitor staff

Monitor staff
Published: 4/26/2016 12:45:38 AM

When you see a mechanical claw the size of an SUV swoop down and grab 3,000 pounds of trash, raise it 40 feet into the air and then drop the load with a thunderous whoosh, you can be sure there’s a specialized term for what you’re watching.

“We call that fluffing the trash,” said John LaRiviere, general manager of the state’s only trash-to-energy plant, in Penacook.

Fluffing? Not very industrial-sounding.

But accurate, LaRiviere said during a recent tour of the Wheelabrator Technologies plant on Whitney Road, just off Exit 17 of Interstate 93.

“You know how when newspaper is wadded up, it’s harder to light in the fireplace? It’s the same here,” he said, gesturing down at 2,200 tons of municipal garbage sent by 20 New Hampshire communities, as crane operator Dan Lacasse tweaked a pair of joysticks that maneuvered the 5-ton claw. Raising and dropping the trash loosens it and makes it more likely to burn easily when dropped into one of the two massive boilers, where fires can reach 2,500 degrees.

If Wheelabrator has its way, processed wood from construction debris will be added to the mix in the wintertime, when the company says the amount of trash declines and tends to be wet from snow and thus hard to burn. The company says such wood, which has higher energy content than trash, can replace propane that is sometimes used to keep the incinerator going.

A proposed state law would allow up to 10,000 tons of “wood residue” to be burned at “any municipal waste combustor,” which indirectly refers to the Penacook site, because Wheelabrator closed the only other trash-to-energy plant in the state, located in Claremont. The bill, SB 381, has passed the Senate and is being considered by the House Science, Technology and Energy Committee.

The proposal has drawn opposition from those who fear it is a way for C&D, the shorthand term for debris created by construction and demolition projects, to sneak back into the incineration mix, either for trash-to-energy or biomass power plants.

Toxins associated with C&D, particularly lead in old paint and arsenic in certain wood preservatives, can be emitted in chimney vapor or leftover ash, due to incineration. New Hampshire banned C&D incineration in 2007, as have many other states, which is why a new law would be required.

The debate over the bill touches on the bigger issue of the value of burning trash to make electricity. Waste-to-energy plants are much more common in Europe than the U.S., where they suffer from a legacy of pollution and poor oversight.

Proponents argue that trash-to-energy does good in two ways: by removing material from landfills and generating power that doesn’t have to be produced by fossil fuels.

Opponents, however, argue that by putting a dollar value on trash and turning it into a valuable commodity, trash-to-energy plants make it harder to reduce the amount of waste we make.

“At the very base of this issue is that we do not consider trash a renewable resource,” said Catherine Corkery, chapter director for the New Hampshire Sierra Club, which opposes the bill. “We don’t want to be creating a market for trash.”

“It has had a bad reputation, you’re correct,” said Rich Geisser, division manager for recycling for ReEnergy, which owns Environmental Resource Return Corp. recycling facilities in Epping and Salem. ERRCO hopes to sell wood residue to Wheelabrator if the bill passes and the companies can reach an agreement.

In a tour given last Tuesday to members of the House energy committee, Geisser talked about how the company separates out painted and treated wood before grinding the rest of the wood into a product that would be burned in the plant.

Critics say the bill provides no funding or structure to make sure that the wood is properly sorted before being burned.

Wheelabrator argues that emissions controls on its smokestack and regular testing of the ash it produces, under license from the New Hampshire Department of Environmental Services, is the way to ensure that adding the wood product won’t produce too much pollution.

Geisser said the product is currently taken to pulp mills where it is burned to generate heat and steam, although that business has declined as New England’s paper industry has shrunk. It is also sent to Canada, where it is used either by pulp mills or to make chipboard, an inexpensive version of particle board. Selling some to Wheelabrator would expand the market.

Although 10,000 tons is a lot of ground-up wood, Geisser said the company’s two New Hampshire facilities make about 75,000 tons of it a year. Overall, he said, the plants take in a total of about 300,000 tons of debris annually, including wallboard and other building materials, that is processed in various ways.

Municipal trash has been burned in the Penacook plant since 1989. The plant was owned by Waste Management before it sold off its Hampton-based Wheelabrator division to investors in 2014. The seven-story-tall plant burns up to 575 tons of trash a day – 191,000 tons last year – and produces up to 14 megawatts of electricity, enough for about 14,000 homes, although it uses about 1.5 megawatts to operate the plant.

The ash left over after burning, about 52,000 tons of it last year, is sent to a Wheelabrator landfill in Shrewbury, Mass.

Tractor-trailers bring trash into the loading bay throughout the year, although the facility can store enough garbage in its enormous pit to keep going for three days without a refill over a holiday weekend, LaRiviere said. Workers can turn haulers away if they try to bring in demolition debris or a full load of tires (a few tires or pieces of drywall or wood mixed in with trash is okay), but there’s no sorting – that should be done at the transfer stations where trash is collected.

“Haulers know they don’t want to be told, ‘Take the trash away,’ so they’re careful,” LaRiviere said.

A mild winter like the one we just had is good for the plant, because trash isn’t as wet from snow, and deliveries of trash weren’t disrupted by weather. The late snow of the previous winter, however, left the plant virtually out of its usual fuel at times, forcing the use of much more propane and prodding a move to burn some wood debris.

Less wood is needed by volume than trash, because a pound of the wood contains about 6,500 British Thermal Units of energy, compared with between 4,800 and 5,200 BTU for a pound of trash, depending on its condition.

That variation reflects another fact about trash as fuel: it’s much more complicated to deal with than the ground-up wood, not to mention wood chips or coal and oil. Varying size, heat content and material in garbage mean that operators need to be much more diligent when running the plant than if they were burning other fuels, LaRiviere said.

Even so, the plant can be run by as few as five people.

(David Brooks can be reached at 369-3313, dbrooks@cmonitor.com or on Twitter @GraniteGeek)


David Brooks bio photo

David Brooks is a reporter and the writer of the sci/tech column Granite Geek and blog granitegeek.org, as well as moderator of Science Cafe Concord events. After obtaining a bachelor’s degree in mathematics he became a newspaperman, working in Virginia and Tennessee before spending 28 years at the Nashua Telegraph . He joined the Monitor in 2015.



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