"Serpentine naturally sequesters carbon dioxide over geologic time, but it is too slow to help us," says Dr. M. Mercedes Maroto-Valer, assistant professor of energy and geo-environmental engineering and program coordinator for sustainable energy, the Energy Institute.
The metamorphic mineral serpentine -- or magnesium silicate hydroxide -- is composed of magnesium, silicon and oxygen and is plentiful. He researchers used material from the Cedar Hills quarry on the Pennsylvania/ Maryland border for this study, but the mineral is available in large quantities in many places. The U.S. deposits of the minerals that can be used for this process serpentine and ovivine can sequester all the carbon dioxide emissions produced from fossil fuels.
"Previous researchers investigating serpentine for use in sequestering carbon dioxide have crushed serpentine very finely, to sizes smaller than beach sand, but, even at these small sizes, it takes high temperatures to speed up the reaction, "says Maroto-Valer. "With our method, we do not need to crush it that fine and we do not need high temperatures. In fact, the reaction gives off heat. Our method is much less energy expensive."
The researchers, who also include John M. Andresen, director of the Consortium for Premium Carbon Products from Coal (CPCPC), the Energy Institute; Yinzhi Zhang, post doctoral fellow, the Energy Institute; Matthew E. Kuchta, graduate student in geo-environmental engineering, all at Penn State; and Dan J. Fauth, U.S. Department of Energy's National Energy Laboratory in Pittsburgh, dissolved the crushed serpentine in sulfuric acid.