Concrete: In the Bad-Air Mix
Here's something else to add to the list of Things That Are Slowly Killing Us and The Earth and Stuff: cement kilns. Never gave it much thought till, oh, 18 minutes ago, when--like you, no doubt--I cracked the latest issue of the subscription-only Clean Air Report to find a story headlined, "EPA study to help states set new ozone controls for cement kilns." You see that, how can you not stop dead in your tracks and find out more? (In the same issue is another riveting story on Mayor Laura Miller's concern over those proposed coal-fire plants and the memo she sent to other Texas mayors in which she proposed "that local governments intervene in the permitting process for the new plants with the Texas Commission on Environmental Quality.") Anyway, it says here, a cement kiln "is the world's largest moving manufacturing machine...a huge cylindrical furnace 12 to 25 feet in diameter and 450 to 1,000 feet in length set on a slight incline [that] can process up to 200 tons of raw material such as limestone, clay, and sand each hour [with] internal temperatures [that] exceed 3,000�F, nearly one-third the temperature of the sun's surface." That much heat and waste and energy consumption sounds like it's gonna be an issue. Sun-hot can't be good for much, unless you're Superman and you need to recharge your powers that come from the yellow sun. Did I say that out loud?
Anyway. So, yeah, kilns discharge a lot of waste, much like my father-in-law. To cut down on some of those noxious discharges, the Texas Commission on Environment Quality's been monitoring the situation and trying to figure out some way to get emissions under control. All of this stems from a 2005 settlement in a lawsuit brought by clean-air activists Blue Sky Alliance against TCEQ over this subject, which most people know nothing about because it's as exciting as watching cement dry. Nonetheless, it's an enormous deal, and if you wanna read more go here for a library of docs related to the Dallas-Fort Cement Kiln Study. But the long and short of it's this, says the Clean Air Report after the jump: --Robert Wilonsky
"A new report commissioned by Texas environmental officials suggests that cement plants could begin using the stringent emission control known as selective catalytic reduction (SCR), which is widely used on power plants but not in the U.S. cement industry...State and local officials in Texas are evaluating the issue as they develop strategies for bringing the Dallas-Fort Worth area into attainment with EPA's ozone standards. The Texas Commission on Environmental Quality (TCEQ) has issued a new report that was required under a settlement with environmentalists last year to evaluate the potential for cement plant control technologies, as it develops a state implementation plan (SIP) to bring the region into attainment.
The July 14 report found SCR could achieve 85 percent emissions reductions at many local cement plants, compared to 35 to 50 percent for SNCR, while at the same time it found SCR was not nearly as cost-effective...But several industry groups submitted comments on a December 2005 draft version of the report disputing its conclusions. In Jan. 24 comments, the Portland Cement Association argued the state should not consider SCR a viable technology for cement kilns, since at the time it was only used at a single facility in Germany...
The North Central Texas Council of Governments clean air steering committee...has set up a cement kiln study committee to look at options for controlling the industry. A local government source says the committee is asking air pollution control vendors to consider a pilot project on the use of SCR, and has asked for a response by Aug. 11."
Sounds good to me--and Al Gore too, most likely. Kilns. Really, who knew? Well, except the EPA, TCEQ, the group that brought the lawsuit and pretty much anyone who works in the cement-making business.