Deem said the new study is the first to compare the "parasitic energy" costs for a whole class of carbon-capture materials. The study found dozens of zeolites that could remove CO2 from flue gas for a lower energy cost than amines could.
Zeolites are common minerals made mostly of silicon and oxygen. About 40 exist in nature, and there are about 160 man-made types. All zeolites are highly porous -- like microscopic Swiss cheese -- and the pore sizes and shapes vary depending upon how the silicon and oxygen atoms are arranged. The pores act like tiny reaction vessels that capture, sort and spur chemical reactions of various kinds, depending upon the size and shape of the pores. The chemical industry uses zeolites to refine gasoline and to make laundry detergent and many other products.
In 2007, Deem and colleagues used computers to calculate millions of atomic formulations for zeolites, and they have continued to add information to the resulting catalog, which contains about 4 million zeolite structures.
In the new study, the zeolite database was examined with a new computer model designed to identify candidates for CO2 capture. The new model was created by a team led by co-author Berend Smit, UC Berkeley's Chancellor's Professor in the departments of chemical and biomolecular engineering and of chemistry and a faculty senior scientist at LBNL. Smit and his UC Berkeley group worked with study co-author Abhoyjit Bhown, a technical executive at EPRI, to establish the best criteria for a good carbon capture material. Focusing on the energy costs of capture, release and compression, they created a formula to calculate the energy consumption for any materials in the zeolite database.
Running the painstaking calculations to compare the CO2-capture abilities of each zeolite would have taken approximately five years with s
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