Why Bother Thinking About Coal?
No one finds the truth more inconvenient that true believers. In Bali, Al Gore's Peace Prize only drove him to greater rhetorical violence in denouncing America's dependence on its largest energy resource.
Al may go on bellowing about the world's immanent crucifixion on a cross of coal, even as Deep Greens dream of its becoming a road kill on the information superhighway. Yet despite decades of alternative energy evangelism, the wretched low tech fuel remains the mainstay of America's power supply, lighting half the nation's lamps and laptops from reserves reckoned in centuries.
That's what the National Academy of Science told Congress to expect at the height of the "Energy Crisis" a generation ago. But while coal lingers in parental memory, the post-modern power industry has hunkered down so far that few children would recognize a lump of the black stuff if it fell out of a Christmas stocking. Nor is solid fuel on Europe's domestic mind--most homes there are heated by Russian natural gas. Yet from Berlin to Bilbao, coal figures in executive nightmares. Carbon taxes mean Euros going up in smoke.
When natural gas burns, the exhaust gas is two thirds water vapor. But what you see coming out of a coal-fired power station plume may be less than half CO2, because the hydrogen that makes natural gas "Green" is present in coal as well. The burning question is how much ?
The answer is surprising. Enough to matter --a lot.
Coal composition ought to concern to environmental realists because China, and India are set to build nearly 850 new plants to burn the stuff. These threaten to bury Kyoto by creating up to five times as much carbon dioxide as the Protocol seeks to reduce--2.7 billion tons of carbon dioxide by 2012. Another 58 nations have 340 new coal-fired plants under development. Even Green Germany plans to build 26, while Russian coal demand is expected to triple by 2020 as thermal plants double their share of the electricity market.
The world can no longer afford to ignore what coal is made of, for its low free market cost--just 12% that of natural gas, assures its growing use even in Green Europe, where a permit to
burn a truckload can rival the cost of an ounce of gold.
While commonsense dictates a rebate for any CO2 saving strategy, Green polemics
have driven regulation in the opposite direction by equating coal and carbon. To do so is to ignore material reality--
coal is never pure carbon, it contains from roughly 50 to 90% on a dry weight basis. This variability has real implications for managing coal's impact on climate. Though high carbon 'hard coal' called anthracite exists--
anthrax is Greek for coal, it is as rare as high-hydrogen bituminous
coal
is common. Within this broad spectrum of fuels, the content of hydrogen rich volatiles varies by a factor of nine.
Among American coals that produce virtually the same
amount of thermal energy per ton, some yield 40% less CO2
than others. An 8% improvement in what power plants burn would cut CO2 emissions as much as replacing half the nation's cars with the Prius !
America
has high-volatile coal in abundance, and the hydrogen it contains already generates a considerable fraction of the nation's electrical power. How much more is possible? Right now, the inconvenient truth is that nobody knows.
Half the available data are antique, lumping together hydrogen in hydrocarbons with the H in H2O. So to avoid the risk of crucifixion for sharp analytical practice, I've had to lower my policy sights, from a geochemically possible 40%,to a very conservative 8% goal. Whatever the true numbers turn out to be, coal quality scarcely figures in the global warming debate, for though coal may be superabundant, chemical literacy is an all too rare political commodity.
Few Greens understand the geochemical paradox of rocks containing volatile hydrogen, and fewer journalists grasp the elementary fact that, carbon atoms being twelve times heavier than those of hydrogen,
coals containing nearly 90% carbon by weight can still be nearly half hydrogen.At its best , the atomic ratio of hydrogen to carbon in this solid fuel can approach that of liquid benzene
or acetylene welding gas.
Atoms matter because they burn one at a time. CO2 emissions can't
be reckoned by fuel weight alone because of the twelve-fold difference
between the number of atoms in a ton of hydrogen and one of carbon . This means switching from low to high hydrogen coal can redouble the
CO2 saved by conserving electricity. Growing America's economy will require far more electricity than screw-in fluorescents can save. One way to accommodate growth while containing greenhouse gas inflation is to reduce the CO2 emissions of existing power plants by switching their fuel source to better coal fields.
Business as usual dictates that coal companies balk at this idea, but Big Coal lobbyists have not been alone in keeping this issue off the policy table. Natural gas
spokesmen and Green activists share the responsibility. Solid fuel is easier to demonize than explain, and neither group stands to benefit from a shift to higher hydrogen coal. This has created a research vacuum. Billions are being spent to advertise the possibilities of alternative energy,but even hydrogen enthusiasts remain clueless as to how much of their favorite element the nation's hundreds of coal deposits each contains.
Only a few per cent of America's are being mined , and elementary geochemistry suggests the idle ones contain an opportunity for CO2 reductions rivaling one of the giant "wedges" made famous by An Inconvenient Truth. Yet when it comes to the potential environmental merits of
'black hydrogen.' ardent Greens seem avatars of denial ,finding It simply too far off message for ideological comfort.
In Uncommon Carriers, New Yorker writer John
McPhee shrewdly pointed out that transport cost has always dictated which coal gets dug first. What we burn now is a matter not of policy, but past economic contingency ,leaving geological room for improvement even in Dick Cheney's back yard--some of the highest hydrogen seams in Wyoming's producing coal fields remain untouched. High infrastructure costs make Big Coal's reluctance to move mining operations understandable, but the silence of
the Greens is perplexing. With good coal so abundant, the specter of carbon taxes may help drive the bad out of
circulation in the developed world, even as hydrogen rebates for burning better coal help stem the flux of CO2 from nations that, in the economic here and now, cannot afford the luxury of the fuels of the future.
The author has written on science technology and energy policy in
Nature, Physics Today and Forbes. Copyright 2007 Russell Seitz