HIGH-TECH BOILER YIELDS TO LOW SULFUR

Southeast Missouri State University went high-tech four years ago with installation of a $4.7 million boiler designed to burn high-sulfur coal.

But plagued by repeated operational problems, it has been used only sparingly since then. Now, however, the boiler is back in operation but burning low-sulfur coal.

It was designed to use limestone in the burning of high sulfur coal to reduce sulfur dioxide emissions.

But since it first went on line in February 1989, it had been used only haltingly because of a continuing array of operational problems.

In August the university brought in the boiler's designer to fine tune the computerized equipment in the power plant. That effort was successful, but Southeast was still faced with a problem finding a new supply of the right type of limestone.

Bill Moon, university physical plant director, said Tuesday that with the problem of obtaining the limestone it just makes sense right now to use low-sulfur coal. But at the same time, Moon is looking at getting a new supply of limestone.

"This boiler will run on low-sulfur coal without limestone. It's just that low-sulfur coal has always been expensive in this area," he said.

But Moon said the university has been able to secure a supply of low-sulfur coal from Peabody Coal Co.

"We went to our supplier, which is Peabody Coal, and they were supplying low-sulfur coal, and we bought some of their stockpile," said Moon.

About two weeks ago the university fired up the boiler and burned about 100 tons of the coal over a four- or five-day period. "It ran well," he said.

The boiler, designed to produce about 50,000 pounds of steam an hour, supplied all of the campus' heating needs during the test period.

The boiler was then shut down for some adjustments and minor repairs. "We changed some parts and put in some different types of motors to help the No. 1 (boiler) be a little more efficient," said Moon.

Recently, the United Mine Workers strike has affected coal supplies.

"The supplies are being diminished because the strike is affecting the minehead, the production of coal," he said. But he explained there are stockpiles of coal available.

"When we saw that this strike was imminent, I brought in and stockpiled 500 tons of coal," said Moon, adding that the university plans to continue to truck in coal as it becomes available.

Moon said the boiler was put back into operation a week ago. The university has a sufficient supply to last 20 to 25 days, he estimated.

He said he hopes to have a sufficient supply of coal to operate the boiler through at least mid-March.

In the meantime, the university plans to make needed repairs to its other major but conventional boiler.

Despite the strike, Moon said he expects to build on the university's supply of coal, which is currently coming from stockpiles in West Virginia.

"The way I understand it, the unions have agreed to allow coal to be supplied from the stockpile to hospitals and schools," explained Moon.

The coal is shipped to St. Louis and then delivered by truck to Southeast.

When high-sulfur coal is burned at the power plant, there's a cost to the university for coal, limestone and the removal of the ashes, which have to be buried in a hazardous-waste landfill. With low-sulfur coal, there's no limestone needed and the ashes from the burning of the coal can be buried in a regular landfill, Moon said.

Even so, low-sulfur coal still costs about $1.50 more a ton than the high-sulfur variety, he said.

But, at some point, the university may get back into the burning of high-sulfur coal.

Said Moon: "We are at a stage now where I have a source of limestone. I am still negotiating with that company on the crushing and sizing of it."

The university is considering purchasing limestone from the Tower Rock Stone Co. quarry at Ste. Genevieve or from the old West Lake Quarry at Scott City, which the company has purchased.

Moon said the company wants the university to pay for the equipment needed to provide the fine-grade, white limestone needed for the boiler.

"We could probably put that part of the plant in operation for less than $50,000," he said.

"They (company officials) don't want to make that capital investment because we are the only ones that use it right now," he said. "Most of the other limestone burned in boilers is of a much larger size and grade," explained Moon.

The company has indicated it might mine the white limestone at its Scott City quarry, Moon said.

That would cut down on hauling costs, a benefit to Southeast, he said. But at this point, the whole issue remains unsettled.

"If we can continue using low-sulfur coal, then there is no point in using the limestone at this stage," he said, "and I would hate to purchase that part of the plant and have it sit there idle."

Moon said, however, that if the university is to rely on low-sulfur coal, it needs a long-term contract.

He said he hopes the university can reach some decision on the whole issue within the next month or two. But for now, the boiler continues to run without the aid of limestone, fueled by a supply of low-sulfur coal.