Warehouse F

Plastic Magic

The Unseen Enemy
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Technology To Suck Carbon Dioxide From The Air

By James Donahue

As world leaders have been struggling with proposals to peruade world industries and car-makers to stop burning carbon fuels and reduce the volume of carbon dioxide blamed on global warming, a few scientists have been discovering exciting alternative approaches to this issue.

For example, Toshiyasu Sakakura, of the National Institute of Advanced Industrial Science and Technology, recently told members of the American Chemical Society he and his colleagues have discovered a new way to manufacture of plastics that uses CO2 in place of the poisonous gas phosgene. Sakakura said they have developed a new catalyst the converts CO2 and methanol into a plastic precursor whose synthesis, under current methods, requires phosgene. Phosgene is a petroleum derivative. Sakakura is thus saying that he has found a way to manufacture plastic from carbon dioxide, instead of  total dependence on petroleum. What is exciting about the new process is that the only waste from this process is water.

Sakakura and his team say they have found that long chains of carbon CO2 also can react with a class of chemicals called epoxides to make that strong clear plastic used in compact disks, eyeglass lenses, and bulletproof windows.

To get completely away from using petroleum, Sakakura said it was found that an epoxide derived from the oil in orange peels can be used to make plastic with CO2.

But even if plastic makers turned to these new methods, experts say that making all of the world’s plastics from CO2 generated in power plants and other industries would not be enough to fix the climate change problem.

So there is more good news. Benny Freeman, a member of a research team at the University of Texas in Austin, says a new plastic filter “tweaked” to mimic cellular membranes, has been found effective in separating carbon dioxide from natural gas and can help reduce greenhouse gas emissions.

This technology, reported in the October issue of the journal Science, might be modified to isolate natural gas from decomposing garbage or filter impurities from water. They say this new plastic works like a selective sponge, capturing methane, the primary molecule in natural gas. It is four times more effective and 100 times faster at filtering carbon dioxide than conventional membranes used in “scrubbers.”

Research also is under way at Pacific Northwest National Laboratory to find ways to imitate the photosynthesis process in plants to turn the carbon in CO2 into more useful molecules. It can be done by using electrochemical cells, but this requires electricity which generates more carbon. Scientists are working on ways to accomplish this the way plants do, by using the energy from natural sunlight.

At Columbia University, physicist Klaus Lackner is leading a group of scientists who believe they have discovered a way to build a device that will “suck” carbon dioxide from the air. They hope to build and demonstrate a prototype within two years that will capture a ton of CO2 a day from the air yet will be small enough to fit inside a shipping container.

Lackner has not revealed just how his team hopes to accomplish this, but the UK Guardian says it obtained a copy of a US patent application that shows the technology is based on changes in humidity.

The devide would trap the CO2 from air on absorbent plastic sheets called ion exchange membranes, generally used to purify water. The researchers have discovered that humid air can make the membranes “exhale” trapped CO2.

Lackner’s team says their invention will not be a “magic bullet” to solve climate change because it would take millions of them to soak up the world’s carbon emissions. And the trapped CO2 would still need to be disposed of.

But who knows . . . with all of these new inventions popping up out of just the plastics industry, we might just be thinking optimistically that science might save us from ourselves afterall.