A Cheap CO2 Trap

It’s possible today to chemi­cally capture carbon dioxide emitted by smokestacks. But the process is expensive and energy intensive, and it can inflate the cost of electricity produced from coal by 80 to 90 percent.

A new material could reduce that cost significantly. A group led by Omar Yaghi, a chemist at University of California, Los Angeles, combined organic molecules and metal atoms to form highly porous crystals whose structure resembles that of industrial materials called zeolites. A liter of the UCLA crystals stores up to 80 liters of carbon dioxide. Yaghi’s materials, which can be custom-made with different pore sizes and internal structures, have an electrostatic attraction to carbon dioxide, selectively trapping molecules of the gas inside their pores. The carbon dioxide can be released by a mere drop in pressure. Then it could be compressed and stored underground indefinitely, never entering the atmosphere.

Yaghi is continuing to develop versions of the material that could offer even better performance. The power industry will need to get involved to see what savings will result at real power plants, he says. But he adds that it should be possible within two to three years to test the materials under actual operating conditions.