Jul 14, 2011Ontario anaerobic digester closes energy loop
For a pair of Canadian entrepreneurs in Leamington, Canada, renewable energy is living up to the hype.
Dennis Dick and Roger Tiessen launched Seacliff Energy in January. Central to their 1.6-megawatt plant is the anaerobic digestion of processing vegetable wastes.
“This is something that satisfies my conservation gene,” Dick said.
“We’re not the only green energy technology around, but we figure we’re the best. We’re better than carbon neutral; we’re a carbon sink.”
Organic materials are trucked in from the nearby Bonduelle Canada plant in Windsor. They’re used as the feedstock for methane production.
The methane powers an enormous Toromont Cat engine to produce enough electricity for 1,600 homes. Heat captured from the engine comes close to meeting the requirements of a greenhouse Dick leases to an organic tomato grower.
“For every kilowatt of electricity produced here, almost an equal amount of thermal power is produced,” he said.
The digestate can be land-applied as a valuable source of agricultural nutrients, including nitrogen. Dick and Tiessen are developing fertilizer markets, and Dick said there may be further value-added opportunities.
According to the Renewable Energy Association in the United Kingdom, the liquid portion of digestate may have hydroponic applications due to its ammonium content. The fiber content of digestate may also have potential.
The process utilizes a small amount of cattle manure – needed for its micronutrient content – sweet corn waste and other vegetables. The methane is cleaned up with a two-stage process to remove most of the hydrogen sulfide. The remaining biogas has a content of about 60 percent methane. The electricity is sold to the grid for 12 cents per kilowatt-hour through a contract with the Ontario Power Authority, according to Dick and Tiessen.
The owners are using know-how from an Austrian company, Agrinz Technologies. It’s a two-state process.
The thermophilic stage involves a higher temperature that kills pathogens. After 48 hours, the material is moved to the mesophilic digester, where a lower temperature is maintained for another 20 to 25 days. The gas is collected under flexible membranes over the digesters.
The green energy journey for Dick and Tiessen began about five years ago.
“Roger and I are first cousins. One night after dinner, and enjoying some wine, we were discussing our businesses. Roger had a tire business and I had a greenhouse.”
Their initial idea was to burn tires – in a low-emission way – as a means to provide heat for the greenhouse, but that concept was eventually set aside.
Taking advantage of a small provincial grant, they looked at other combustion technologies. After hiring a consultant, they launched an investigation into anaerobic digestion that included a tour of facilities in Europe.
“Five minutes into our first visit of a digestion plant, we were sold,” Dick said. “The thing we really like about the digestion is that there are so many upsides to it – so many things that can be developed.”
Seacliff Energy employs Dick and Tiessen, along with three employees.
Additional economic activity will be generated when the cousins, together with their financing partners – Gemini Power Corp. and Alpenglow Energy – build phase two to double the electricity generation capacity to 3.2 megawatts. Final approval through the Ontario Power Authority is needed.
To learn more about Seacliff Energy, visit their website.
By Jeffery Carter, Ontario correspondent