''Carbon capture and sequestration'' is an emerging critics say unproven technology that takes carbon dioxide or CO2 that normally would spew from industrial smokestacks and pumps it deep into the earth. Once there, it is, ostensibly, trapped forever unless something goes wrong.
The dialogue over the carbon sequestration worst-case scenario has come out of the laboratory and into New Jersey's backyard with a plan to link the technology for the first time to a large, commercial electric plant proposed in Linden.
Last month, Linden planners received designs for a $5 billion project called ''PurGen.'' It is a 500 megawatt, coal-fueled facility using a 100-mile, underground pipeline to push as much as 10 million tons of CO2 annually emissions from the new plant and eventually neighboring industrial operations to a point 70 miles off the coast and about 2,200 yards beneath the Atlantic Ocean.
The proposal took on greater significance last week, when the Environmental Protection Agency declared CO2 and other greenhouse gases a public health danger triggering a regulatory process that may drastically restrict emissions from existing and new power and industrial plants.
Critics question the viability of piping CO2 under the ocean floor in a heavily traveled area and say the state should instead pursue windmill and solar technology. Proponents argue the plant will provide a reliable source of energy without spewing pollutants into the air.
''With New Jersey importing about a third of its electrical energy, the 500 megawatts coming from this plant will reduce the state's reliance on power that comes predominantly from uncontrolled dirty coal plants out of state... while also addressing New Jersey's environmental challenges,'' said Bradley Campbell, the lawyer spearheading the project.
A former commissioner of the state Department of Environmental Protection now in private practice, Campbell was hired to steer SCS Engineers of Massachusetts through the maze of local, state and federal approvals needed for the project. The plant is slated for a former DuPont chemical site along the Arthur Kill, with the pipeline running under Raritan Bay to the ocean.
Frank Smith and Jim Croyle, two principals of SCS, said their commercial energy plant will be the ''first of its kind in the world'' to link carbon capture with another so-called ''clean energy'' process known as coal gasification or Integrated Gasification Combined Cycle technology.
''But if you look at each component to be included in the plant, they are each well-established, standard and tried technologies. Gasification has been around since the early 1930s, and sequestration since the 1970s,'' Smith said.
The five coal plants already generating electricity in New Jersey burn coal, creating a toxic by-product known as fly ash. PurGen's gasification process heats coal with pressured oxygen and steam. Gas is formed, and the process also allows PurGen to offset higher operating costs by selling ammonia, hydrogen and other by-products, Croyle said.
Oil companies already sequester CO2 deep underground at dozens of locations around the world, although not to control greenhouse emissions. They inject CO2 into oil reservoirs to force every last oil drop to the surface.
One of the first commercial operations to sequester CO2 was in Norway. Statoil of Norway, faced with a CO2 byproduct from its natural gas operation, has been piping nearly a million tons of carbon emissions annually into a sandstone aquifer about 1,100 yards beneath the North Sea.
But some activist groups insist carbon sequestration has yet to be used by a large coal-fueled energy plant, and the potential impacts of storing large amounts under an ocean bed are still unknown.
''The sequestration of carbon dioxide in the ocean and its possible impacts are not well understood, so this represents a large experiment with a part of the environment that is already in bad shape ecologically,'' said Tim Dillingham of the American Littoral Society, a national group of scientists, naturalists and environmentalists based in New Jersey.
''The ocean has quickly become the new dumping ground for energy for siting industrial facilities and now industrial waste,'' he added.
''Why do they think the carbon will be held there for centuries?'' asked Jeff Tittel of the New Jersey Sierra Club. ''No one knows. No one can say for sure. This is a gamble. We'd be better off investing in wind, solar and energy efficiency.''
Researchers at Princeton, Harvard and Stanford universities, however, advocate sequestration technology, with some testifying before public agencies. The Natural Resources Defense Council and Clean Air Task Force also is urging exploration of carbon capture.
The Union of Concerned Scientists, usually on the side of activists, is cautious in its assessment.
''We're agnostic on its long-term contribution as an energy source because we don't have any long-term demonstrations. We don't have many carbon sequestration operations linked to coal facilities, and we don't have anything on a large commercial scale,'' said Barbara Freese, co-author of the UCS's 2008 report, ''Coal Power in a Warming World.''
The North Sea operation, she noted, involves a million tons of CO2 annually. The average coal plant generates 4 million tons annually, and PurGen anticipates generating nearly 5 million tons a year from its plant.
The UCS also contends sequestration must overcome potential challenges of contaminating ground water, seismic events and leakage slow leaks that send CO2 back into the air and fast leaks that kill. Activists such as Greenpeace often cite a 1986 natural release of CO2 from Lake Nyos, a volcanic crater lake in Cameroon, that left about 1,700 people dead from asphyxiation.
The U.S. Department of Energy's National Energy Technology Laboratory concluded such catastrophic releases ''are virtually nonexistent for geologic sequestration,'' and geologists called it absurd to compare operations such as those planned by PurGen to the natural disaster at Lake Nyos.
''You have a mile of impermeable clay on top of the sandstone. The really big earthquake in Sumatra caused a rupture that was about 10 meters. We're talking about sequestering the CO2 under at least 2,000 meters of clay. It's not possible to have an earthquake to fracture that,'' said professor Daniel Schrag of the Harvard University Laboratory for Geo-chemical Oceanography, who has reviewed the project.
''I am as green as green gets. But I'm not like groups like Greenpeace, which is saying we can take care of all our energy demands with wind and solar,'' Schrag added.
Coal also remains the cheapest source of electrical energy in the nation. The Department of Energy estimates the United States has enough natural reserves to meet energy needs for another 250 years.
''Coal is like heroin cheap, plentiful and addictive, but very dangerous and to get it they take down mountains along with square-miles of trees, adding to the carbon output and environmental damage,'' said Tittel of the Sierra Club, arguing projects like PurGen continue the nation's reliance on fossil fuels.
The proposal is too new to gauge local resistance, but initial response appears to be concerns based on the mistaken notion that PurGen would be a traditional, smokestack-belching coal plant, said Linden Mayor Richard Gerbounka, adding, ''It is our job to educate local residents.''
Approvals on the project may take months, but Gerbounka said an information campaign starts tomorrow night with a meeting at Trembley Point, the residential neighborhood closest to the PurGen site.
Trembley Point is more than a mile from the PurGen site and separated by the New Jersey Turnpike, which bisects the city. The site itself is brownfields redevelopment and surrounded by other heavy industry or abandoned factories.
''I'm excited about the project. I think it will be beneficial to the city of Linden, the state of New Jersey and the nation,'' Gerbounka said. ''It helps wean us off Middle East oil, and hopefully the technology is there to do the project as they say it can be done.''