New systems reduce emissions at Monroe Power Plant

The first of two flue-gas desulfurization systems — commonly known as scrubbers — recently was put into service. The second scrubber is scheduled to go into operation in October.

"The startup of the first scrubber is a significant achievement in an emissions control construction program that began 10 years ago and cost $1.7 billion," said Steve Kurmas, president, Detroit Edison. "This investment will make a significant improvement to air quality in the region, support the long-term operation of the Monroe Power Plant and benefit the community with 40 new, full-time jobs to operate and maintain the scrubbers."

In addition to construction of the two scrubbers, the plant's emissions control program also included construction of selective catalytic reduction (SCR) systems on three of the plant's four generating units. The scrubbers will reduce sulfur dioxide (SO2) emissions from each generating unit by about 97 percent. The SCRs provide 90 percent nitrogen oxide (NOx) reduction per unit.

On the two units where both SCRs and scrubbers will be operating, mercury emissions will be reduced by 80 to 90 percent due to the interaction of both systems. The Monroe Power Plant is the first in Michigan with both SCRs and scrubbers.

The systems will help the Monroe Power Plant meet current and expected reductions in federal and state emissions limits. "Even though we don't know exactly what emissions limits we will be required to meet, we felt it was in the best interest of our company, our customers and the environment to build these emissions control systems over the last 10 years so that they are in place and operational today," said Skiles Boyd, DTE Energy vice president, environmental management and resources. "And because we expect ever-stricter controls in the future, we are planning now how best to reduce emissions even further."

Kurmas said engineering work is under way for construction of the third and fourth scrubbers and the fourth SCR. Some site work for those systems is expected to begin next year.

Monroe Power Plant Director, Frank Wszelaki, noted that the construction of the scrubber has changed appearance of the landmark plant. To support scrubber operation, a new 580-foot tall chimney was constructed. "Not only does that add a third chimney to the plant's profile, the scrubber system also produces a constant white cloud of water vapor from that chimney," he said, adding that the original 800-foot chimneys were designed for a "dry" exhaust that was barely visible.

While there is no timetable established, both of the plant's original chimneys will be removed.