photo by Ian Thorpe
Although often portrayed as the savior which will allow us to continue exploiting our relatively abundant coal reserves without increasing global warming until something comes along to win the day, a new study to be published in the International Journal of Greenhouse Gas Control gives us another reason to believe that carbon sequestration isn't quite yet ready for prime time. Science News fills us in:
Capturing Carbon Does Reduce Greenhouse Gas Emissions
Though a coal power plant equipped to sequester carbon requires about 30% more coal to provide the power to compress the captured CO2 and pump it underground, the overall carbon emissions still are reduced by 71-78% compared with an average coal plant for every usable unit of electricity produced. That's the good news.
But Increases Ones Which Cause Acid Rain
The bad news is that if you take the entire lifecycle of a CO2-burying plant—the "cradle to grave" pollution which takes into account the extra energy required mine additional coal and bring it to the power plant—emissions of nitrogen oxide and sulfur oxides were 40% greater than a modern coal plant not set up to capture carbon. In addition to causing acid rain, these chemicals are linked with increased water pollution and destruction of the ozone layer.
The report notes that if the mining, transportation and support services around carbon capture were made greener the "pollution penalty" for sequestration could be reduced.
Greener mining? It may be a necessary evil to some degree, but I'm pretty sure green mining is an oxymoron. Solve one problem, increase another.
via :: Science News and :: Yale Environment 360
Carbon Capture and Sequestration (CCS)
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