Ammonium Nitrate Chemistry

Another Dirty Side to Coal

Coal is dirty and it can't be cleaned.

We just saw another facet of this problem when particulate matter reached hazardous levels across much of the Hunter Valley on Monday.  Specifically, PM10 levels (the concentration in air of particles 10 micrometers and smaller) were reported to have exceeded national air quality standards at all nine monitoring stations in the coal mining hub of the Upper Hunter.  The cause, not surprisingly, looks to be coal mining.

Although carbon dioxide is the pollutant of most concern from coal, there are a range of air quality issues that arise from the mining, transport, and burning of this fossil fuel.  Even if we do manage to remove CO2 from the emissions of coal fired power stations we can't guarantee that other pollution sources will be eliminated, and this is why "clean coal" is a fallacy.  The mining and transportation of coal, as we saw on Monday, releases dangerous particles into the air.  These particles have both acute and chronic impacts on our respiratory and circulatory systems; they have been linked to health problems as diverse as asthma and heart disease.  Coal mine fires are also a real risk in Australia, such as the 45 day fire that released a deadly plume of smoke across Victoria's Latrobe Valley.

Even if you could avoid all of this while digging up the coal and then conveying, trucking, or shipping it to a coal fired power station, you then have combustion byproducts such as carbon dioxide, nitrogen and sulfur oxides, and even mercury to deal with.  Ironically, attempts to capture CO2 emissions for possible storage using amines (the leading proposed technology) lead to new air pollution issues - nitrosaminesisocyanates, and other nasty compounds - a problem that my colleagues and I are currently working on.

Ultimately, I think this serves as a reminder that Australia does have real air quality issues, and that our reliance on coal is a big part of the problem.  I often hear that air pollution isn't an issue in Australia, and it's true that we do have it better than many of our neighbours in Southeast Asia.  But this latest event in the Hunter underlines the need to maintain a broad and comprehensive network of monitoring stations, and to continue agitating for change that will reduce the frequency and severity of these incidents in the future.