At the Port of Monroe, waste is opportunity. Through a robust beneficial reuse supply chain, the Port is transforming byproducts of energy production into valuable materials that power regional construction and agriculture industries. This is more than sustainability—it’s a circular economy in motion.
The DTE Monroe Power Plant, on the shores of Lake Erie, is considered to be a modern “cargo machine.” Every week, thousand-foot vessels deliver coal to the power plant that provides electricity to households, businesses, and industries around southeast Michigan.
In 2009, a scrubbing system was installed at the DTE Monroe Power Plant to reduce the number of harmful pollutants released into the atmosphere. A scrubber works by spraying a wet slurry of limestone into a large chamber, where the calcium in the limestone reacts with the SO2 in the flue gas. Outside of the emission reductions, which are critical to human health and wellbeing, the scrubbing process also creates several byproducts, which are now staple cargoes at the Port of Monroe.
The Port’s facilities were largely dormant in 2012 when the Monroe Port Commission hired Paul C. LaMarre III from the Toledo-Lucas County Port Authority to reestablish maritime operations in Monroe. To do this, the Port had to focus on developing cargo opportunities, and that focus began at the DTE Monroe Power Plant.
A study was commissioned with the University of Michigan to analyze beneficial reuse markets for the byproducts produced at the power plant, and this led to a partnership between the Port and DTE. This was the start of the Port of Monroe’s rebirth and the beginning of the port’s beneficial reuse journey. Today, the Port exports synthetic gypsum and bottom ash to beneficial reuse markets in the United States and Canada.
Synthetic gypsum, a byproduct of the flue gas scrubbing process, has the same chemical structure as natural gypsum. After processing, it is used in agriculture and construction, replacing more costly virgin materials. Bottom ash is coarse, granular residual ash that collects at the bottom of a coal boiler.
Both materials are “supplementary cementitious materials” meaning they have practical applications for replacing cement mixtures instead of virgin materials, which are more expensive to mine. A majority of the beneficial reuse materials are shipped to the LaFargeHolcim Cement plant in Alpena, Michigan.
The handling of these beneficial reuse materials at the Port is just one part of a Pure Michigan beneficial reuse supply chain:
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Stoneport, MI to Monroe, MI: The journey begins at a quarry in the northern lower peninsula where a self-unloading lake freighter loads limestone.
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Monroe, MI to Alpena, MI: This limestone is delivered to the DTE Monroe Power Plant where it is crushed and blended with coal to “scrub” the emissions out of the plant. The byproducts are brought from the power plant to the port and staged for shipment. When enough product is accumulated, the port’s terminal operator, DRM Terminal Management, loads the materials onto vessels.
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Alpena, MI to various destinations: At Alpena, the materials are used to make cement mixtures at the plant. The result is powdered cement, which is distributed throughout the Great Lakes region by specialized cement carriers.
The Port of Monroe is a critical connector in developing circular supply chains across the Great Lakes, transforming industrial byproducts into valuable resources through efficient, sustainable logistics. Maritime shipping remains the smartest and most scalable way to link these regional markets—and Monroe is leading the way.
The tug/barge Undaunted/Pere Marquette 41 depart the Port of Monroe with a load of synthetic gypsum, while the thousand-footer Paul R. Tregurtha unloads coal at the DTE Monroe Power Plant.
