Sunday, October 17, 2021

From trash to gas: Green things happening at landfill

  • January 6 2021
  • By Lois Ann Dort, Local Journalism Initiative reporter    

The saying goes that one person’s trash is another person’s treasure. In this case, trash is gas and that, in turn, is power – of the electric kind.

The Guysborough Waste Management Facility has embarked on a new green project: the mining of closed landfill cells for gas.

Landfills naturally produce gases through the process of decomposition; chief among them methane. The smell often associated with landfill sites is the release of methane gas into the air. At the Guysborough site, this gas is now being collected through wells installed in capped landfill cells and channeled into a continuously burning flare. This helps eliminate odors caused by the gas created during decomposition, but it’s also an opportunity to use the waste by-product to create energy.

Last year, the facility installed 14 gas monitoring wells on two capped landfill cells. These have been collating data on the gas collected from the site and been burning off the gas through a flare since November of 2019.

Waste management facility manager Bruce Avery told The Journal, during a tour of the facility Dec. 30, that they are collaborating with Highland Energy – a company that has successfully extracted methane gas from the former Upper Sackville landfill site and converted it into electricity – in the hopes of creating a similar operation at the Guysborough site.

Avery said the company feels confident they can “get a meg (megawatt) of power from the landfill gas we are producing right now.”

That’s just the first possible benefit. There could be others.

“One thing that costs us the most is to get rid of our leachate,” said Avery. “We have to truck it down to Port Hawkesbury and pay so much per gallon to have it treated. There’s technology out there that will allow us to use the heat from the generator (of the gas-powered turbine) to evaporate the leachate … So we could benefit two ways.”

Highland Energy would sell the power generated to Nova Scotia Power, with which they have a purchase power agreement, said Avery.

As of yet no agreements have been signed; the project will be put out to tender when the research on gas production is completed.

“This is just an example of what we could do,” said Avery.

According to the data to date, the gas produced by the landfill is 50 per cent methane; which is good, according to Avery.

“If everything works out, we could benefit a lot,” he said.