Environment

Cryogenic treatment could cut coal-fired power plant emissions by 90%

Cryogenic treatment could cut ...
Cooling the emissions from coal-fired power plants would significantly reduce the levels of dangerous chemicals entering the atmosphere (Photo: Shutterstock)
Cooling the emissions from coal-fired power plants would significantly reduce the levels of dangerous chemicals entering the atmosphere (Photo: Shutterstock)
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Cooling the emissions from coal-fired power plants would significantly reduce the levels of dangerous chemicals entering the atmosphere (Photo: Shutterstock)
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Cooling the emissions from coal-fired power plants would significantly reduce the levels of dangerous chemicals entering the atmosphere (Photo: Shutterstock)
UO physicist Russell J. Donnelly
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UO physicist Russell J. Donnelly

A team of physicists from the University of Oregon (UO) has calculated that cooling the emissions from coal-fired power plants would result in a reduction of the levels of dangerous chemicals entering the atmosphere, including CO2, by 90 percent. While cryogenic treatment would also see a 25 percent drop in efficiency, and therefore result in electricity costs increasing around a quarter, the researchers believe these would be offset by benefits to society, such as reductions in health-care and climate-change costs.

Previous studies, including one conducted in the 1970s by the Bechtel Corp. of San Francisco, have shown that cryogenic treatment of flue gases from coal-fired power plants can work. While the Bechtel study was looking at its effectiveness in capturing sulfur dioxide emissions, it also noted that large quantities of CO2 would also be condensed – something that didn’t warrant much attention back in the 70s but is of tremendous interest now.

Building on previous research he carried out in the 1960s into using cryogenic treatment technology as a way to remove odor-causing gases being emitted from a paper mill in Springfield, Oregon, UO physicist Russell J. Donnelly and his team have now composed a math-driven formula on an electronic spreadsheet that could be used by industry to weigh up the potential benefits of the technology.

UO physicist Russell J. Donnelly
UO physicist Russell J. Donnelly

The team’s paper says that CO2 condensed and captured as a solid would then be warmed and compressed into a gas that could be delivered via pipeline at near ambient temperatures to dedicated storage facilities that could be located hundreds of miles away. Additionally, other chemicals including sulfur dioxide, some nitrogen oxides and mercury would also be condensed so they could be safely removed from the gases emitted by the power plants.

The team’s calculations show that a cryogenic system would capture at least 90 percent on CO2, 98 percent of sulfur dioxide, and virtually 100 percent of mercury emissions. This is more than the capturing of 41 percent of sulfur dioxide and 90 percent of mercury emissions called for by the new mercury and air toxic standards (MATS) issued by the EPA in December 2011.

The team’s formula doesn’t take into account the cost of construction or retrofitting of the cooling machinery to existing power plants, which would be much larger than existing systems that use scrubbers – potentially as large as a football stadium. Nor does it take into account the cost of disposing of the captured pollutants. However, Donnelly thinks such systems are affordable, “especially with respect to the total societal costs of burning coal.”

“In the U.S., we have about 1,400 electric-generating unit(s) powered by coal, operated at about 600 power plants," Donnelly said. “That energy, he added, is sold at about 5.6 cents per kilowatt-hour, according to a 2006 Congressional Budget Office estimate. "The estimated health costs of burning coal in the U.S. 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."

A separate, unpublished and preliminary economic analysis carried out by the team estimates that implementing large-scale cryogenic systems into coal-fired plants would see an overall reduction in costs to society of 38 percent through a sharp cut in associated health-care and climate-change costs.

The team’s paper appears in the journal Physical Review E.

Source: University of Oregon

25 comments
Steven Senatori
So it will be "delivered via pipeline at near ambient temperatures to dedicated storage facilities that could be located hundreds of miles away". Okay, then what? Storing CO2 is like hiding the problem under the carpet...
MasterG
DO IT. I hereby reduce the military budget and allocate the funds to this project to save the health and lives of the very people that my military are supposed to be defending.
GiolliJoker
So... you have to burn 25% more coal to achieve the same output... that including the costs of commissioning and storage of the condensed gases would easily raise the cost of power for the end user up to 100%... And ok, sulphur dioxide and mercury are surely dangerous and it's worth trying to control them, but CO2, that is now "the enemy", is a natural byproduct even of our breathing http://en.wikipedia.org/wiki/Breathing and it's not really proven that it can affect our climate. Are we really willing to pay the price of such a system? More than a scientific study I see someone that smelt a business in re-proposing old theories in a period when media attention for the mighty CO2 is high.
mrhuckfin
It's like trying to look for a solution that doesn't have a problem? CO² is not now or has ever been a pollutant! We don't have to much of it and what ever amount we generate is a tiny fraction of what occurs naturally, the earth has seen MUCH higher CO² levels in it's history and those time have been beneficial over all to the progress of man. Cut pollutants I agree with but this hiding and prevention of CO² is a colossal wast of money and will be our down fall.
Clay Jones
No deal. CO2 isn't poisonous any more than oxygen is. Just ask a tree. Keeping smoke out of the air is great, but I'm not willing to pay 25% more for my electricity. Smoke washes out eventually.
jerryd
Except they already by making O2 and using that to gasify coal, the byproducts are H2, CO and CO2, no N2 so by compressing to liquidfy the CO2, allowing it to be shipped to here needed for oil well recovery, etc or just stored underground is more eff than this proposal. Look up TECO Electric for details among many others now. TECO's been running 15-20 yrs now.
The the H2/CO also called syn gas, is easily cleaned of sulfur, radioactive metals, mercury, etc that make coal kill so many, 30k/yr and hospitalize 200k/yr in the US.
Far less expensive, polluting to the consumers is make their own power. PV is now at $1/wt, $1k/kw retail and wind at $2k/kw. An eff home needs just 2-3kw plus 1kw for each extra person above 1. Sadly few wind generators are available at such prices except Axial Flux wind generators.
Well shopped renewable energy for many pays off in 2-4 yrs and then almost free for 20-50 yrs afterward. Most RE is less complicated than a moped and really little reason to cost too much.
Bruce H. Anderson
A football-stadium-sized cryogenic tunnel? Running liquid nitrogen maybe? I sure would like to see some end-to-end numbers here on the total cost.
Jerry Peavy
Yes, anything to keep using coal! Heaven forbid they we should move away from coal, oil and natural gas to clean, abundant, renewable wind water and sunlight. Was this idea backed by the coal industry?
DrPepper59
Did you know that most large greenhouses use CO2 generators? If there is too much CO2 already, why are they making more of their own? Because it helps the plants to grow better.
Edward Kerr
It amazes me that anyone even considers such gyrations when if we would simply ramp up the existing alternatives to burning coal (you all know what they are) we could have inexpensive electricity, avoid the exigent "societal costs" and save the coal for better uses.
But wait, that might make sense.....