Garbage in, clean energy out

Canada's Plasco Energy Group has been giving tours of its first full-scale waste to energy plant in Ottawa this week to officials from around the province and around the world.

It sits about 20 miles outside of downtown, right across the road from its competition, the Trail Road Landfill.

The plant, which is expected to take in 85 tonnes of waste per day when it starts operations by the end of September, uses a unique plasma torch process that applies intense heat to waste materials in a completely closed, controlled, and oxygen-starved environment.

With an output of mostly synthetic gas, used to generate electricity with an internal combustion engine, aggregate, which can be sold and used in asphalt, and potable water, this is definitely not your mother's incinerator.

Rod Bryden, president and CEO of Plasco, told the Cleantech Group that air is added in incineration. "That allows the waste to burn."

There's no oxygen in Plasco's process and no hazardous emissions are released into the atmosphere.

The garbage eating power plant >>

With incineration, Bryden said "the share of the waste that can be converted to power is not more than 18 to 22 percent."

"In ours we get about 44 percent to about 50 percent," he said. "A little more than twice as much power."

Bryden said gasification, which also uses oxygen, is about as inefficient as incineration.

Visitors to the plant this week are in town for the Association of Municipalities of Ontario Conference. Bryden said about 1,400 of the attendees are taking tours of the plant.

Mexico's secretary of the environment, in town for the Security and Prosperity Partnership meeting, also got a tour of the plant.

Mexico joins Spain, the United States, the United Kingdom and others who are looking at Plasco's technology.

The company, which finished construction on the commercial-scale plant at the end of June, has operated plasma-based research and development and test facilities in Ottawa and Spain for more than a decade.

Plasco and Spanish waste management company Hera have plans for a commercial-scale plant to be up and running in Barcelona by the fall of 2008.

In North America, Edmonton, Alberta, plans to open a facility in 2010, and Plasco has put in a bid for a plant in Los Angeles.

For the past three weeks, Plasco has been testing the Ottawa plant for one day a week, pouring about 4 tonnes an hour through the plant, or about 100 tonnes per day.

Starting next week, they'll up the ante, raising the number of days of testing through to the end of September.

"The system is designed to achieve close to optimal efficiency at about 200 tonnes a day," said Bryden. "That's about 20 garbage trucks a day" he said.

The company's permit with the Ontario Ministry of the Environment is only for 85 tonnes of municipal solid waste per day, which would generate a total of 5 megawatts of power.

With 1 MW required to power the facility, 4 MW will be left over, enough to power 3,600 homes in Ottawa.

Plasco plans to charge the municipality a tipping fee for disposing of waste and will sell its surplus electricity.

And Plasco plans to be as efficient in its energy delivery as it is in its waste-to-energy ratio. The plant is connected to the distribution system in Ottawa, not directly to the grid, which Bryden said decongests the grid.

"It's like having your job in the local community where you live, you are not one of those that clogs the highway at 5-o'clock," he said.

Keeping things local also avoids line loss during transmission, which Bryden said is typically 5 to 7 percent.

But even with Plasco's highly efficient system, there is still a very small amount left over in the waste processing that can't be used.

"There is 1.3 kilograms per tonne of waste that requires disposal," said Bryden. That includes the activated carbon filter and the heavy metals that are captured in that filter, typically mercury, cadmium and lead.

"So out of a tonne of waste that comes in, there is one tenth of one percent that requires still to be disposed of," he said.

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