Aug. 28, 2004. 01:00 AM

Methane research offers promise

 


In Canada, in the struggle against global warming, we've been successful in cutting methane emissions from landfills. Methane, an extremely powerful greenhouse gas, is 21 times more potent than carbon dioxide.

 

However, despite the success, we're still falling behind, emitting more methane than ever from landfills. All we've done is simply slow the rate of increase for emissions.

 

So, is the glass half-empty, or half-full? Have we been a failure, or are we set to turn the tide? I see the glass as half-full, because out of past experience a new level of expertise is developing that offers great promise.

 

Here's the size of the problem: Landfills account for 26 per cent of methane released in Canada. (The other two big producers of methane emissions are the oil and gas industry, at 39 per cent, and farmers with livestock and manure, at 30 per cent.) The amount that still escapes from landfills each year is the equivalent of putting 4.2 million cars on the road.

 

That's a lot, and it obscures the fact that we're already capturing 23.6 per cent of the methane released, all of it from larger landfills. This is more than the 18.8 per cent that we captured 10 years ago. However, we're sending more garbage to landfills now than we did then, so even as we capture more methane, we keep falling behind.

 

The amount we've fallen behind is equivalent to having 500,000 more cars on the road than was the case 10 years ago.

 

This is about to change, I hope, thanks both to research financed by Environment Canada at Canmet, the federal government's research laboratory, and to the proposed emissions trading system. Together, they'll offer landfill operators the incentive of making money by eliminating methane emissions.

 

Rob Brandon, project manager for Canmet's distributed generation group, has been looking for ways to reduce the cost of collecting methane from smaller landfills. The problem he's faced is that a "blower" is needed to suck methane from collector pipes in landfills, and it draws 50 to 60 kilowatts of electricity. It also needs to operate 24 hours a day. For municipalities, especially for small ones, 50 kilowatts translates into a prohibitive cost of at least $35,000 a year for electricity.

 

To eliminate the cost, Brandon has been working with equipment manufacturers to develop microturbines that can operate on methane, and produce enough electricity to run a blower and related equipment. Current tests are looking good.

 

Now for the crowning touch. Environment Canada is developing proposals for an emission trading system, and expects to release a design for it in about six months. It would allow landfill operators to sell "credits" for capturing methane to companies that haven't reduced their greenhouse gas emissions to a required level. Present thinking is that credits would sell at about $10 a tonne (measured as carbon dioxide equivalent) for the methane eliminated.

 

At that price, a landfill operator would get about $56,000 a year for the methane used to operate a 50-kilowatt blower. The payback time for installing the equipment would be about 4.5 years, and money would keep rolling in until the methane was exhausted up to 45 years later.

 

This would make it possible to capture methane profitably from a full range of landfills, right down small ones perhaps holding no more than 200,000 tonnes of waste.

 

Faced with the prospect of these kinds of tools, can anyone be blamed for optimism?

 


Cameron Smith is a writer and environmentalist who lives near Gananoque, Ont.

 

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