London company derives green energy and fertilizer from food waste

By Matt McIntosh    Source: AgInnovationOntario

London ON – Food waste is a big issue, but StormFisher Environmental, a London-area green energy company, is turning part of the problem into an environmental positive.

Using once-edible food from Ontario processors, grocery stores, and restaurants, the company produces organic-based fertilizer that can be used by landscapers to beautify lawns, and farmers to grow crops. Generating electricity from biogas – a key byproduct of producing the fertilizer – is also a key part of the business.

“Generating biogas and turning it into a renewable fuel is well-known technology, and there’s a real need here for the sustainable disposal of organic waste […] our design fits well” says Chris Guillon, vice-president of StormFisher Environmental.

Each year, the company converts about 80,000 tonnes of food waste into enough energy to power about 3,000 homes, and make 2,000 tonnes of organic-based fertilizer. Electricity is fed back into the provincial grid, while the fertilizer is all locally sold.

The whole process, says Guillon, starts with clients delivering food waste to an enclosed terminal at the facility. The waste is inspected for any non-organic or foreign material, then transferred to a large anaerobic – or oxygen free – tank called a biodigester.

Bacteria in the tank ferments the food waste into a nutrient-rich liquid, while the biogas generated from that same process is converted to electricity with a series of generators. In turn, the residual heat from the generators is used in a large dryer, which dehydrates the nutrient-rich liquid into a more workable fertilizer product.

“It’s a completely closed loop system. We even use the exhaust heat to keep our tanks at a uniform, working temperature,” says Guillon.

To help ensure high quality and public confidence in the fertilizer, Guillon and his colleagues made sure their product received – and continues to receive –  regular accreditation from the Canadian Food Inspection Agency.

The plant itself also operates on a completely closed circuit, meaning the entire process occurs inside – considering the potential smell of fermenting food waste, that’s important in maintaining good neighbour relations.