A vacuum that sucks carbon dioxide (CO2) out of the atmosphere might sound far-fetched, but the device already exists, and you may see one in your neighborhood within in the next five years.

Scientists at Global Research Technologies (GRT), an R and D company in Tucson, Arizona, have joined forces with Columbia University researchers to create a giant CO2 vacuum that removes the greenhouse gas from the atmosphere.

"About 30 percent of the CO2 that’s up there is from the transportation industry—cars, ships, airplanes, trains,” says George Grimm, research director at GRT. The electric power industry, meanwhile, is responsible for about another 40 percent of CO2 emissions.

Capturing the gas directly from tailpipes isn’t yet possible, and retrofitting power plants to trap gases will take time and money. And, as researchers reported in the journal Science in March, even reducing emissions might not be enough to stop global warming. Making a real dent in the problem will require pulling CO2 out of the air, says Klaus Lackner, a geophysicist at Columbia who is involved with the vacuum project and has been toying with the idea for years. The machine uses an acid-based chemistry that attracts CO2, dissolves it into a water-based solution, and then separates it into gas.

In a test run last spring, the collector was more efficient than researchers anticipated. “Everything went right in the sense of each of the individual unit’s function, which is why we’re calling this a successful prototype demonstration,” says Grimm. Researchers found that they had to stop collecting and send the material to the separator themselves.

They’re now working to create a stand-alone CO2 device that captures one ton per day. Grimm estimates it will take two years to get a system that doesn’t require human assistance into the field.

Researchers already have a few suggestions for what to do with the end product, CO2 gas. It could be sold to oil companies, which use the gas to extract additional oil from depleted wells, or used for food shipping and dry ice production. Or it could be injected deep into the ground, where it would naturally convert into a harmless solid over time. The vacuum, about the size of a 40-foot shipping container, could even be located at these geological storage areas.

Grimm estimates that within five years, about 100 vacuums will be parked around the country, each sucking up a ton of CO2 per day at a cost of $30 to $100. Worldwide, he says, it would take 250,000 to neutralize the CO2 currently being emitted.

Story by Jennifer Nelson. This article originally appeared in Plenty in December 2007.

Copyright Environ Press 2007