Cavendish Farms completes potato waste-to-biogas plant

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North American potato product producer Cavendish Farms has completed construction of an anaerobic digestion facility to generate biogas from potato waste, a project the company believes is a first for the potato industry.

Feedstock materials include potato plant residues, starch, spent frying oil and aerobic sludge from the existing wastewater treatment plant. The facility will handle production rates of 120,000 tons per year of feedstock, or an estimated average blended input of 360 tons per day.

Cavendish Farms began developing the facility in 2006, after two years of project evaluation. The wastewater treatment plant has been operating for more than 10 years, and has used the anaerobic sludge resulting from the treatment process as a soil conditioner.

Now, the company will use the generated biogas from the anaerobic digestion facility to power boilers in its two co-located processing plants. The leftover digestate material will serve as a fertilizer to be spread over fields in place of potato waste/sludge, reducing odors.

Cavendish expects the new plant, in New Annan, Prince Edward Island, will provide numerous benefits and savings to the company, and will potentially reduce its carbon footprint by 30 percent to 35 percent. The company also estimated it will reduce current fossil fuel requirements by 10 million liters (2.6 million gallons) per year, significantly reduce the amount of fueling trucks required, and eliminate trucks required to remove potato waste from the plant-a decrease of 1,450 kilometers (900 miles) or 10 to 14 truckloads per day.