Pioneering a path to cleaner fuels and fewer emissions

Unconventional greenhouse gas reduction research brings biology and chemistry together in engineering

Matthew Menzies - 9 October 2019

(Edmonton) Released from oil and gas processing, animal agriculture and other human activities, methane gas emissions are one of the leading causes of pollution and climate change. It traps more heat than CO2 and makes up about 25 per cent of Canada's greenhouse gas emissions.

UAlberta engineering PhD candidate Fatemeh Bakhtiari Ziabari is investigating ways to eliminate atmospheric methane on an industrial scale while producing sustainable biofuels and biopolymers.

To do so, she's using microscopic bacteria that eat methane and convert it into valuable ingredients in biofuels.

"These bacteria produce biopolymers under certain conditions, and they use the biopolymers as energy source back-up," she said. "It's kind of like when we store fat in our bodies and when we need energy, our body uses that. Same thing with these bacteria," she said.

"That's how we solve this problem-using bacteria. Using the force of nature itself."

The challenge is growing the bacteria in a bioreactor, creating perfect conditions for them to thrive and devour methane on an industrial scale.

"Bacteria are like human beings," she said. "We get sick sometimes and can't perform as well as we did before. When it gets cold, we feel chilly and we just don't want to go out and work. The bacteria are the same way. They can be pretty temperamental, so sometimes they just don't grow because of a reason that can't be pinpointed."

Ultimately, the idea is to install bioreactors at industrial sites that produce methane. The gas can be piped into the bioreactor. Under ideal conditions, the bacteria will eat and process the methane-and multiply-at steady state. While byproducts are pumped out, more methane can be added to the vessel. This process is called self-cycling fermentation

"I'd have bacteria produced and harvested from the reactor the whole time," she said. "It's like having a very large reactor while I really don't. I have a limited volume in the reactor, but my productivity is actually continuous."

Bakhtiari Ziabari is targeting big industry with this technology. By piping into a methane-producing system, the bioreactors containing the methane-devouring bacteria will be able to eliminate as much methane as the tiny lifeforms can consume-which is a lot.

And she's optimistic for the future.

"There are a lot of people that might say climate change is not real. But I see a lot of people, including scientists, who are trying to think about what we are doing to the world and who are trying to come up with ways to minimize our impact on the world."