Coal gasification: “clean coal” or subsidy-hungry boondoggle?
Governing magazine has an excellent, compact overview of current developments in coal. If you’re hazy on gasification this, coal-to-liquid that, and Fischer-Tropsch the other, I recommend it.
With oil and natural-gas prices rising and coal in plentiful supply, it’s more or less inevitable that coal’s going to get used, so it makes sense that (some) enviro organizations are biting the bullet and joining the push for the cleanest possible applications.
There is reason for cautious optimism. Coal mining is destructive as hell, but in places like northeastern Pennsylvania — where the article focuses, and where the first U.S. coal-to-liquid plant will be built starting this Spring — there’s waste coal laying all over the place, leaching acid into groundwater (the legacy of pre-regulatory coal mining). The plant will gather that coal as feedstock and replace it with solid waste covered in soil, thereby creating farmland or forest.
Converting coal to a synthetic gas — "gasification," which involves heating it alongside oxygen to 2,000 F — has its advantages. Most importantly, once coal’s converted to a gas, it’s fairly straightforward to remove pollutants. Mercury, sulfur, and particulates can be stripped out and sold commercially.
Via the Fischer-Tropsch process, the gas can be reconstituted into a variety of liquid fuels, which can sub for oil in heating homes or fueling vehicles. (The Penn. plant will produce low-sulfur diesel, which Gov. Ed Rendell has pledged to buy for the state’s vehicles.) This is why gasification boosters, including Rendell and Montana Gov. Brian Schweitzer, play the energy-independence card.
The gas can also sub for natural gas, fueling "integrated gasification combined-cycle" (IGCC) power plants to create electricity. Pennsylvania hopes to replace many of its filthy coal-fired power plants with IGCC plants.
"You could put a million scrubbers on an old coal-fired power plant and never even approach the environmental performance of a coal gasification plant," says Kathleen McGinty, secretary of Pennsylvania’s Department of Environmental Protection.
So those are the bennies: Pennsylvania reduces air pollutants, solves its waste-coal problem, boosts its economy, and gets a reputation as a clean-power, energy-independence leader. Not bad.
There are three drawbacks, and they are substantial:
- If gasification takes off, there isn’t enough waste coal in the country to feed the beast. Thus, you’re back to coal mining, which is a nightmare.
- Gasification is largely untested and unproven, at least in the U.S. And IGCC plants are more expensive than old-fashioned dirty coal-fired plants. Thus, gasification relies heavily on subsidies. State and U.S. Dept. of Energy tax incentives for the Penn. plant, for instance, add up to over $140 million. More big industries getting chummy with gov’t; more semi-permanent corporate welfare recipients.
- Carbon dioxide. Global warming. That whole thing. IGCC plants are certainly an improvement over dirty coal-fired plants — they use less coal to create more energy — but they still produce plenty of CO2. They do make the CO2 fairly easy to capture, which is nice, but the question is what to do with it once it’s captured. The big idea is to sequester it: pump it underground or into plant tissues and soil. However:
“The effectiveness of CO2 storage in those systems is completely unknown,” says Anne Hedges, program director for the Montana Environmental Information Center. “It’s a nice theory, and I sure hope it works. But there’s absolutely no evidence it does on a long-term basis.”
So that’s a problem.
In short, if you view coal gasification from the perspective of today’s energy situation, it’s an improvement. If you view it from the perspective of the optimal renewable-energy future, it’s a big scam. Whether you take the former, pragmatic view or that latter, idealistic view will depend on your temperament. Me, I choose to vacillate wildly between them from day to day. Iyam what Iyam!
Anyway, I’m sure there are summaries of coal-gasification more comprehensive and educated than this one (here, for instance). I’ve written this up as much for my benefit as anybody else’s, just to get clear on the lay of the land. Hopefully it’s of use to some of y’all as well.