Carbon Capture and Storage Will Increase Pollution

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Study finds that burying carbon dioxide from coal-fired plants will increase acid rain

By Patrick Barry

From Science News, August 13th, 2008

As pollution bad guys go, carbon dioxide may be the media darling, but trying to capture it and lock it away could allow other repeat offenders to go free.

Power plant emissions that cause acid rain, water pollution and destruction of the ozone layer may actually be made worse by capturing the CO2 and pumping it deep underground, a new study reported online and in an upcoming International Journal of Greenhouse Gas Control suggests.

This increase of other emissions is largely because collecting and burying CO2 — a process called carbon sequestration — requires additional energy, new equipment and new chemical reactions at the plants. And using current technology, meeting all of these requirements releases extra pollutants.

“Other studies mostly just look at one aspect, the carbon capture,” says study coauthor Joris Koornneef, an environmental scientist at Utrecht University in the Netherlands. “This is a first step in trying to quantify the [environmental] trade-offs.”

Captured CO2 must be compressed to about 100 times atmospheric pressure (which takes energy), transported to a suitable underground reservoir (which takes energy) and pumped into the ground (which takes energy). A coal-fired power plant that sequesters its CO2 must burn about 30 percent more coal than conventional plants to cover these energy needs. And that extra coal must first be mined (which has environmental effects) and transported to the plant (which takes fuel) — the list goes on and on.

Even with this extra burden, a CO2-burying plant emits between 71 and 78 percent less CO2 than a normal coal-fired plant for each unit of usable electricity produced, Koornneef and his colleagues report. But when the researchers factored in all the “cradle to grave” pollution of a CO2-burying plant, emissions of acid rain-causing gases like nitrogen oxides and sulfur oxides were up to 40 percent greater than the total cradle-to-grave emissions of a modern plant that doesn’t capture its CO2.

If the mining, transportation and other supporting technologies become greener in the future, the pollution penalty for carbon sequestration would be reduced, the researchers note.

“The decision to substantially reduce greenhouse gas emissions is going to be intertwined with decisions about how to deal with these other emissions,” comments Jim Dooley, an expert in carbon sequestration at the Joint Global Change Research Institute in College Park, Md., and one of the lead authors for a major 2005 report on carbon sequestration by the Intergovernmental Panel on Climate Change. That IPCC study concluded that nearly all properly buried CO2 would probably remain underground for centuries.

“People are turning their attention to this, which is great,” Dooley adds, referring to the environmental costs of sequestration.

At the time that IPCC scientists were writing the 2005 report, “everyone was thinking what are the environmental benefits of [carbon capture], not so much the environmental costs,” comments Ken Caldeira, an ecologist at the Carnegie Institution for Science in Stanford, Calif., and another lead author of the IPCC report. “The costs people talked about were mostly economic costs.”


  • Last week, the University of Calgary demonstrated a carbon extration device that removes carbon from the atmosphere, saying that they expect that they could set up next to a coal fired plant and remove TEN times the amount of carbon that the plant could emit. I wonder if we could actually get back to addressing pollution then? Pollutants are particulate matter and noxious oxides. No one seems to onsider their real and harmful effects these days. Carbon dioxide is NOT a pollutant. Why the confusion?

  • Rising atmospheric CO2 concentration is scientific fact. What is debatable are the consequences of it.
    Operating on the well-known Precautionary Principle, I assume that CO2: (1) is heading us in the wrong direction climatically and (2) is threatening to destabilise the oceans ecologically. Both have dire potential implications for humanity.
    CCS (carbon capture and storage), if managed properly, appears to be the best hope of buying the time necessary for putting things back into reasonable order in the atmosphere. This arguably will happen anyway about 200 years hence when the coal finally runs out. The problem is getting to that point.
    As I see it, the carbon sequestration envisaged by some as ‘locking CO2 away forever’ could be just as foolhardy as doing nothing at all about CO2 emissions. The reason: humanity in future will need the carbon; London to a brick.

    For details go to

  • LESS consumption, LESS production, FEWER people.
    I guess there is no government in the world but Bhutan will make such policy.
    I do not oppose such ideal. I even used to think about how to introduce Buddhism into economics, or it’s really very hard to ask people to consume less.
    Besides, such extreme suggestions only frighten people and stop them to listen/read any word you give.