During the second presidential debate, Donald Trump made reference to something called clean coal, claiming that it could supply the country's energy needs for the next 1,000 years.
That would be nice, except that clean coal doesn't actually exist, as Jules Suzdaltsev explains in today's DNews report.
Clean coal is an oxymoron -- according to environmentalists, anyway. First of all, the term doesn't actually refer to a substance at all; it refers to a process. The phrase really means "clean coal technologies," which are designed to lessen the pollution that coal produces when burned. But it's still the same coal.
Coal is a relatively cheap, plentiful and efficient source of energy, but it has one giant drawback. It's so dirty that people regularly die from its pollutants. When burned, coal releases chemicals including sulfur dioxide, nitrogen oxides, carbon dioxide and even a bit of mercury. These substances, in turn, produce soot, smog, acid rain, global warming and toxic air conditions. In people, these trigger asthma, lung cancer, heart disease and other health problems. As lists go, these three are all remarkably grim.
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Clean coal technologies employ a variety of methods to lessen the health and environmental dangers of coal. Carbon capture and storage, for instance, snags carbon dioxide from power plant emissions and pipes it underground, so it can't get into the atmosphere. Check out our report on CO2 scrubbing here.
Then there's oxy-fuel combustion, in which power plant exhaust – or flue gas – is recycled back into the plant and mixed with pure oxygen to burn more coal. These techniques reduce nitrogen byproducts and can generate more efficient energy extraction. Some power plants can scrub sulfur out of coal before it's even burned.
The trouble with these methods is that they're incredibly expensive and energy-intensive themselves. That money and energy has to come from somewhere. What's more, clean coal technologies are simply not being used very much within the industry. Absent any regulations that mandate usage, companies don't really have an incentive to deploy the technology on a commercial scale.
The phrase "clean coal" is fundamentally misleading, but as a marketing term it's extremely useful to industry leaders and industry-friendly politicians.
-- Glenn McDonald
The Economist: The fuel of the future, unfortunately
BBC: Polluted air causes 5.5 million deaths a year new research says
Scientific American: China May Not Find Enough Coal to Burn