Permit approved for Warden plant
The Michigan Department of Environmental Quality (MDEQ) has approved the permit for the L’Anse Warden Electric Company, owned by Convergen Energy, to burn engineered fuel pellets.
The pellets are made of pre-consumer packaging waste that comes direct from manufacturers and consists of 60-85% paper and cardboard and 15-40% plastics — mostly polyethylene, polypropylene, polyester and nylon, according to MDEQ documents.
The plant conducted a long-term test burn that started in 2017 under a temporary permit. An extended public comment period ended in February, and a public hearing was held in January. The permit was issued at the end of March with three additional stipulations in response to the public comments.
The first two changes to the permit restrict the use of tire-derived fuel (TDF). The plant will not be allowed to burn TDF and fuel pellets at the same time.
“That’s exactly how we operated the plant during the test burn,” said Convergen Energy CEO Ted Hansen. “The pellets displace the tires when we’re burning pellets.”
The total amount of TDF that they can burn each day has also been reduced, from 96 tons to 70 tons.
The third change is additional testing of some of the hazardous air particles (HAPs) emitted by the plant. However, the additional testing is only required if emissions of “volatile organic compounds” surpasses the 9 tons per year allowed by the permit.
“In other words, a violation of VOC emissions has to occur before additional testing of other HAPs is required,” said Catherine Andrews.
Andrews is a board member with Friends of the Land of Keweenaw, a nonprofit that works to “preserve the ecological integrity of the Lake Superior Watershed” according to its website. The group has been actively pushing for greater environmental controls on LWEC ever since it was converted to biomass generation from natural gas.
“The announcement of ‘additional emissions testing’ is misleading,” Andrews said. “There are no protections to the public regarding the cumulative effects of exposure to the 89 toxic air contaminants that are legally emitted from this facility every day.”
Omitted from the additional testing, and not counted toward the 9-ton per year limit is hydrogen chloride, the most-emitted HAP at the facility. Hydrogen chloride can cause respiratory irritation, coughing or choking and dermatitis and reacts with atmospheric moisture to create hydrochloric acid, according to the Centers for Disease Control.
In June of 2017, test results showed hydrogen chloride emissions of 1.55 to 1.94 pound per hour. The legal limit is 2.17 pounds per hour. In August of 2018, during testing of the fuel pellets under the temporary permit, results were down to 1 to 1.45 pound per hour. That calculates to 5.65 tons per year on average. Hansen explains the decrease as a result of using the Dry-Sorbent Injection system installed to control emissions from burning the fuel pellets.
“People don’t realize what a benefit this DSI system is,” he said. “This plant will have the cleanest emissions it’s ever had.”