by Alyssa A. Lappen
Forbes | Jul. 29, 1985
Vol. 136, No. 14, pp. 78-79
Stand at Edison’s Bruce Mansfield power station on the Ohio River in southwestern Pennsylvania and you get a pretty good idea why the U.S. Coal card has been so hard to play.
Amid a deafening din, dirty smoke and gases from the 15,000 tons of coal the plant burns in its boilers daily are piped into 16 seven-story scrubbing towers spread over 250 acres in Shippingport, Pa. Water and quicklime roar in at the bottom. Nearly invisible hot air issues from the top, scrubbed clean of sulfur, soot and ash. Steel pipes lined with rubber take away 9 million gallons of sludge every day to a 1,300-acre man-made disposal lake 7 miles away.
When the first unit began operating in 1976, Mansfield represented the state of the art in coal scrubbing. It’s a showcase that attracts visitors from all over the world. The process takes 99% of the particulates out of coal smoke and 92% of the sulfur dioxide. But it is enormously costly and cumbersome. The scrubbers accounted for a third of he plant’s $1.4 billion construction cost. They consume half its $80 million annual operating budget (not including $250 million in coal costs) and 2.5% to 5% of its 2,360-megawatt power output. Each of the scrubbers has to be shut down every six weeks so workers can climb inside and remove clcium sulfate caked inside with high-pressure water jets. “Right now scrubbers are the only answer,” says Robert McWhorter, an Ohio Edison senior vice president. “But I hope we don’t have to do this again. It’s not a good technology.”
Coal-fired plants now account for 43% of installed capacity and generate 55.5% of the nation’s electricity. With the nuclear option all but dead (FORBES, Feb. 11), by the end of the century there could be a lot more of them. There are 86 coal units planned or being built, compared with just 38 nuclear units. Most of the new coal units–and all those using high-sulfur coal–will need scrubbers at least as effective as Mansfield’s. Under the Clean Air Act, coal-fired plants ordered after 1971 can emit no more than 1.2 pounds of sulfur dioxide for every million Btu of coal burned. Plants ordered after 1978 must remove 90% of the sulfur dioxide.
About 120 generating units are currently equipped with advanced scrubbers. Another 100 are planned or under construction. Over the next ten years or so, the utility industry will spend $95 billion on air pollution control, most of it for scrubbers. With scrubbers accounting for up to 40% of the construction cost of a new generating plant, new coal-fired units run about $1,000 to $1,200 per kilowatt to build, compared with $2,000 to $2,500 for nuclear plants.
Any alternatives in sight? Coal companies like Peabody Coal, Westmoreland Resources and Consolidation Coal are all funding research. The Electric Power Research Institute, a utility-funded outfit headquartered in Palo Alto, Calif., will spend $1.2 billion over the next five years working on cheaper and more effective ways of cleaning coal. Among them:
* Fluidized bed combustion, in which small chunks of coal are mixed with limestone and burned above a cushion of air at temperatures a half to a third lower than in conventional boilers. FBC techniques both cut emissions more effectively than conventional scrubbers and allow for modular construction, a significant advantage to an industry plagued by uncertain demand predictions and lead times of up to 12 years. All existing fluidized bed combustion plants are under 25 megawatts, or industrial scale, but three big utility-scale demonstration projects are on the boards (FORBES, July 15).
* Coal washing–cleaning the fuel before it burns rather than scrubbing the smoke and gases afterward. Roughly 500 coal-washing facilities of varying degrees of size and sophistication are now in place in the U.S. But only a small percentage of these are effective enough to meet the post-1978 requirements.
One of the best is in Homer City, Pa., where 16,000 tons of coal per day run through the Rochester & Pittsburgh Coal co.’s Iselin plant. First the raw coal is mixed with a slurry of magnetite and water and is pumped into cylindrical vessels called cyclones, where centrifugal force separates out the sulfur. After that the coal runs over concentrating tables, which further separate heavy particles from lighter coal.
Washing is far cheaper than scrubbing but not yet as effective–it cuts the sulfur content only by up to 70%. Still, it has many advantages, claims Clyde Sypult, Iselin’s plant manager. “Cutting coal’s abrasive content extends the life of the boilers,” says Sypult in a soft Appalachian drawl. “Washing also improves Btu content, increasing electric output, probably by 10%.”
* In coal gasification, one of the most promising technologies, a mixture of oxygen and coal slurry is heated to form gas, which is then cleaned and burned. Southern California Edison has already bought 375 million kilowatt-hours of power from Cool Water, a $269 million, 100-megawatt demonstration coal gasifier built in a California desert by an industry consortium. “Gasification has all the benefits of fluidized bed combustion and then some,” Dwain Spencer, an EPRI vice president, says enthusiastically. “Cool Water is the cleanest coal-fired plant operating today.”
Also expensive. After all, 100 megawatts at $269 million works out to a construction cost of $2,690 a kilowatt. And the price Southern California Edison pays for that electricity is made possible only by $120 million in price subsidies. But Cool Water, after all, is a demonstration plant. Spencer claims commercial plants can soon be built for $1,500 per kilowatt, cheap compared with the $5,192 spent at Long Island Lighting’s troubled Shoreham nuclear facility.
All these technologies have been around in primitive form for decades. Why were utilities not running flat out to bring them to the commercial stage long ago? Because clean coal technology became cost effective only in the 1970s, when oil prices shot up.
The coal industry claims it needs big money from the federal government–Uncle Sam has already spent nearly $2 billion on coal-related projects since 1981–and the long-term commitment big money would imply. Congress has authorized another $750 million. The industry wants that appropriated promptly. “The scope and urgency of this effort exceeds the capability of the private sector alone and will require an accelerated national effort,” R.E. Balzhiser, EPRI senior vice president, told a Senate subcommittee at hearings in May.
The U.S. needs 100,000 to 200,000 megawatts of new capacity, Balzhiser says, to meet expected demand growth of 2.2% to 2.7% annually over the next 15 years. New plant orders will be made in the next five years. And without federal funds, he argues, those promising technologies may not be fully developed in time.
Perhaps. But this is an industry notorious for overestimating demand–a major reason for its troubles in nuclear–and President Reagan and Energy Secretary John S. Herrington don’t agree that the government should pay the tab. The industry can and should finance clean-coal technologies itself, says Herrington. In fact, he $750 million in authorized but unappropriated funds does more harm than good, he says, by encouraging the industry to hold out for federal money rather than pushing ahead on its own. Will coal finally clean up its act?
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