Using an approach that sounds a little like "Flash Gordon meets Waste Management", a company in Georgia is using "high heat" (10,000°F.) to vaporize municipal solid waste (MSW). Sounds great as far as it goes but I have four technical questions:1. How much energy does it use?
2. What will be the source of the plasma arc energy?
3. What does the energy source emit?
4. Is the high heat of the plasma-arc being captured and utilized?
5. How are they going to combust the syngas to keep the emissions low?
If you visit the Geoplasma website, you can hear the company principals explain the application of a D.O.D.-financed technology being applied to solve a societal need - the reduction of landfill waste.
Expect to be challenged
In the article below, it sounds like the combustion of syngas is not a closed loop system. While the emissions may indeed be "cleaner than burning coal or natural gas" that is not very reassuring. Emissions tests of other pilot plant processes for harnessing syngas (see Results of Independent Study of Emissions) prove that they emit small fractions of the allowable emissions of dioxins, nitrous oxides, and particulate matter permissable for modern generating facilities. That is the new standard and, by comparison, the Geoplasma plan is brute techology in need of refinement.
I also question the assertion by Hilburn Hillestad, president of Geoplasma that "This is sustainability in its truest and finest form." As the full system is described, the company would face considerable outrage and resistance by environmentalists over the misuse of the term "sustainability." First, they will complain that material natural resources will be pulverized out of their original state and we will lose their material reusability.
Secondly, there is nothing inherently natural or close-looped about a system that atomizes trash and combusts the syngas. Something productive has to come from the carbon and even then, it needs to be "sunk" - otherwise the greenhouse gases produced by the process will contribute to global warming.
Don't get me wrong - this system and many others should be deployed in commercial-scale so that institutions like Georgia Tech can improve system deficiencies. But the second problem they will have to solve from a marketing standpoint is reducing combustion emissions. The first one is their simplistic use of hyperbole.
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County to Vaporize Trash - Poof!
Wired News
FORT PIERCE, Florida -- A Florida county has grand plans to ditch its dump, generate electricity and help build roads -- all by vaporizing garbage at temperatures hotter than parts of the sun.
The $425 million facility expected to be built in St. Lucie County will use lightning-like plasma arcs to turn trash into gas and rock-like material. It will be the first such plant in the nation operating on such a massive scale and the largest in the world.
Supporters say the process is cleaner than traditional trash incineration, though skeptics question whether the technology can meet the lofty expectations.
The 100,000-square-foot plant, slated to be operational in two years, is expected to vaporize 3,000 tons of garbage a day. County officials estimate their entire landfill -- 4.3 million tons of trash collected since 1978 -- will be gone in 18 years.
No byproduct will go unused, according to Geoplasma, the Atlanta-based company building and paying for the plant.
"This is sustainability in its truest and finest form," said Hilburn Hillestad, president of Geoplasma, a subsidiary of Jacoby Development.
For years, some waste-management facilities have been converting methane -- created by rotting trash in landfills -- to power. Others also burn trash to produce electricity.
But experts say population growth will limit space available for future landfills.
"We've only got the size of the planet," said Richard Tedder, program administrator for the Florida Department of Environmental Protection's solid waste division. "Because of all of the pressures of development, people don't want landfills. It's going to be harder and harder to site new landfills, and it's going to be harder for existing landfills to continue to expand."
The plasma-arc gasification facility in St. Lucie County, on central Florida's Atlantic Coast, aims to solve that problem by eliminating the need for a landfill. Only two similar facilities are operating in the world -- both in Japan -- but are gasifying garbage on a much smaller scale.
Up to eight plasma arc-equipped cupolas will vaporize trash year-round, nonstop. Garbage will be brought in on conveyor belts and dumped into the cylindrical cupolas where it falls into a zone of heat more than 10,000 degrees Fahrenheit.
"We didn't want to do it like everybody else," said Leo Cordeiro, the county's solid waste director. "We knew there were better ways."
No emissions are released during the closed-loop gasification, Geoplasma says. The only emissions will come from the synthetic gas-powered turbines that create electricity. Even that will be cleaner than burning coal or natural gas, experts say.
Few other toxins will be generated, if any at all, Geoplasma says.
Louis Circeo, director of Georgia Tech's plasma research division, said that as energy prices soar and landfill fees increase, plasma-arc technology will become more affordable.
"Municipal solid waste is perhaps the largest renewable energy resource that is available to us," Circeo said, adding that the process "could not only solve the garbage and landfill problems in the United States and elsewhere, but it could significantly alleviate the current energy crisis."
He said that if large plasma facilities were put to use nationwide to vaporize trash, they could theoretically generate electricity equivalent to about 25 nuclear power plants.
Americans generated 236 million tons of garbage in 2003, about 4.5 pounds per person, per day, according to the latest figures from the Environmental Protection Agency. Roughly 130 million tons went to landfills -- enough to cover a football field 703 miles high with garbage.
"It addresses two of the world's largest problems -- how to deal with solid waste and the energy needs of our communities," Craft said. "This is the end of the rainbow. It will change the world."
technorati bioenergy, gasification, conversion, biofuels, cellulosic, plasma-arc, sustainability
1 comment:
No argument that there well be emissions, however it is a huge step in the right direction, and compared to simply burying the garbage or dumping it in the ocean as they do now, converting it to electricity and materials to build roads- despite the emission of some unknown amount of greenhouse gasses is a good thing.
It does produce usable materials - the article spells out the 'slag' used for road contruction. Although I agree, it not as useful or diverse as what went into the process.
As far as defining sustainability, it meets the critera, assuming people continue to produce garbage. And it is the best option we have right now for garbage. Also, define "inherently natural".
I like this because it works now and can probably be improved in the future, and we need to do something now.
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