Clearing the Air

A group of innovative 
scientists and engineers at the Northern Alberta Institute of Technology (NAIT) want to clear the air of that rotten-egg-smelling gas from industrial sites across the province.

Paolo Mussone, a chemical engineer and the Applied Bio/Nanotechnology Industrial Research chair at NAIT, and his team at the Edmonton-based post-secondary institution might just have cracked the code as to how to remove the gas safely, while also making use of one of Alberta’s pulp mill by-products.

About 60,000 tonnes of fly ash produced as a by-product of pulp mills ends up in Alberta landfills annually and Mussone’s research team has found a way to turn this material into a potentially low-cost, environmentally safe solution for removing noxious hydrogen sulphide – a common by-product at natural gas wellheads, water treatment plants and pulp mills themselves – from the air.

“The mills are very good about disposing of it properly and finding ways to safely redistribute it to the land. But there’s a limit to how much you can apply back to the forest because it does change the pH of the soil,” Mussone says. “Landfill use is running out … so (the mills) need to look at what to do with this stuff, and that’s where we come in.”

NAIT prides itself as a hands-on, technology-based education and applied research institution that supports the productivity and prosperity of Alberta. Mussone’s research project has resulted in a technology that’s designed to transform fly ash into tiny pellets that can absorb and filter stinky hydrogen sulphide from the atmosphere. The fly ash pellets that are being developed at NAIT are 10 times more effective at absorbing hydrogen sulphide than the activated carbon filters currently used by industrial operations.

“Ash is relatively non-toxic and non-invasive environmentally,” says Gordon Giles, business development manager at Alberta Pacific Forest Industries (ALPAC). “But anytime you don’t have to contribute waste, that’s a good thing.”

fly ash samples
Fly ash samples. Photo courtesy of Northern Alberta Institute of Technology.

ALPAC is based in Boyle – a town of approximately 845 people that sits a little more than 160 kilometres north of Edmonton – and operates Canada’s newest, and North America’s largest, single-line bleached kraft pulp mill. The company produces nearly 650,000 air dried metric tonnes of elemental-chlorine free pulp annually and is seeking new ways to use by-products of the pulping process to develop new products.

“In our case, we do have our own landfill on site. We are not shipping the ash great distances, but it’s still filling up our landfills. And in the greater scheme of things, it’s unlikely that the province will approve many more landfills,” says Giles, adding that using the ash to supply this service is another opportunity for the Alberta pulp industry to diversify off of pulp production in general.

ALPAC is just one of the forestry sector companies that has stepped in to help fund the research project led by Mussone. Mercer International in Peace River and International Paper in Grande Prairie are also co-funding the project, while natural gas producer Encana and Alberta Innovates round out the financial support.

Giles says the benefit to industry across the province comes from both cost savings and environmental impact, and notes that the work being done at NAIT is ground-breaking.

“I haven’t seen anything like it before. It’s a cool project that’s unique to Alberta,” he says. “The research and development show a lot of potentials, and we’re happy to be part of helping it to come to fruition.”