Super cooling coal smoke can slash noxious emissions

Washington, Aug 28 (IANS) Super cooling coal smoke would slash emission of carbon dioxide (CO2) and dangerous chemicals by more than 90 percent, according to a simple math-driven formula designed by a team of physicists.

Scientists from University of Oregon argue that using this method as an "energy penalty," would raise power costs by about a quarter, but provide huge benefits through subsequent reductions of healthcare and climate change costs.

An energy penalty is the reduction of power available for sale if plants used the same amounts of coal to maintain electrical output while using a cryogenic clean-up, the journal Physical Review E reports.

"The cryogenic treatment of flue gasses from pulverized coal plant is possible, and I think affordable, especially with respect to the total societal costs of burning coal," said Oregon physicist Russell J. Donnelly, who led the research, according to an Oregon statement.

"In the US, we have about 1,400 electric-generating units powered by coal. The estimated health costs of coal burning in the US are in the range of $150 billion to $380 billion, including 18,000-46,000 premature deaths, 540,000 asthma attacks, 13,000 emergency room visits and two million missed work or school days each year," Donnelly said.

In their separate economic analysis, Donnelly and Oregon research assistant Robert E. Hershberger, also study co-author, estimated that implementing large-scale cryogenic systems into coal-fired plants would reduce overall costs to society by 38 percent through the sharp reduction of associated health-care and climate-change costs.

The cryogenic concept is not new. Donnelly experimented briefly in the 1960s with a paper mill in Springfield, Oregon, to successfully remove odour-causing gasses filling the area around the plant, using cryogenics.

While the required cooling machinery would be large - potentially the size of a football stadium - the cost for construction or retrofitting likely would not be dramatically larger than present systems that include scrubbers, which would no longer be necessary, Donnelly said.

According to the study, CO2 would be captured in its solid phase, then warmed and compressed into a gas that could be moved by pipeline at near ambient temperatures to dedicated storage facilities that could be hundreds of miles away.