Cedar waste, also called hog, is a headache for B.C. sawmills
Growing heaps of cedar bark have long left B.C. lumber producers stumped, but innovators are looking for ways to cash in on a troublesome byproduct
Revelstoke has beautiful mountains—except for maybe one.
“This is Mount Hog,” says Downie Timber Ltd. sawmill co-manager Angus Woodman, a guy with an appropriate last name. We scale a bulldozed path to the summit of the mill’s ever-growing pile of bark, or hog—cedar, mostly—in the middle of the log yard. Day and night, the mill keeps spitting it out into a 50,000-tonne heap. Standing on top, you get a 360-degree view of the mill, the yard and the partly denuded patchwork of mountainsides up and down the Columbia Valley.
“You ever come up here to think?” I ask.
“Yup,” says Woodman with a chuckle. “Just to get away from it all.”
What Woodman would really like to get away from is this gunky, steaming pile of rotting bark. Like many managers of mid-size sawmills in B.C., he has no use for it. “Anything you try to do with it is fraught with problems,” Woodman says.
Same thing down the road at Stella-Jones Inc., which shaves and sizes cedar utility poles. People stop by to take samples of cedar bark in their own entrepreneurial efforts to figure out what to do with it. “Then we never hear from them again,” says yard supervisor Pat McMechan, who just mailed four full Ziploc bags to somebody in Texas.
Mills sell other wood waste: chips, sawdust and shavings. Those that process wood other than cedar can usually turn their hog into pellets or burn it for steam-powered electricity and/or heat. But as cedar bark grows, it picks up dirt and silica. In a boiler, it turns into chunky, caked-on lava. And because cedar bark is stringy, it doesn’t feed easily into an auger. As for transforming it into pellet form, cedar is like a sponge that doesn’t compress, Woodman says.
So Mount Hog sits—an eyesore that serves no purpose, has no value and takes up prime real estate. “It’s also a major fire hazard next to our mill,” Woodman laments.
Wood residuals manager Doug (Dirty) Hill’s job is to ensure that the hog doesn’t catch fire. Hill has moved the problem by trucking much of it about 30 kilometres west to a yard beside the Trans-Canada Highway, where the hope is that it will make its way to a cogeneration plant in Castlegar, Cranbrook or Armstrong.
Hog isn’t a headache for everyone. Turning wood waste into biofuel, biocoal and biogas is a global industry that is growing ever more advanced and efficient. Some of the best work is in Germany, Holland and Sweden, where energy costs are high, so mills look to capitalize on wood waste as fuel alternatives.
In Canada, the biggest players in lumber, such as Canfor Corp., Tolko Industries Ltd. and West Fraser Timber Co. Ltd., are looking to get more value out of residuals. Vancouver-based Canfor is in the early stages of developing a technology that will turn wood waste from its pulp mills into mass quantities of renewable crude oil.
“We will take biomass up to very high pressures and temperatures and take oxygen off the carbon and hydrogen compounds found in wood,” says Martin Pudlas, Prince George-based VP of pulp and paper operations, nutshelling the company’s catalytic hydrothermal reactor process. The aim is to create renewable biocrude for the petrochemical industry that feeds into existing refining infrastructure, or fuels for marine and rail use.
For those who can’t do anything with hog here, why not just send it somewhere that someone can? “One of the largest factors with biomass is the cost of transportation,” Pudlas says. “In many cases, the cost of transport to a facility that can efficiently extract the heat value from it becomes prohibitive.”
Another wrinkle: the province’s pulp mills are major electricity producers, and several are at the end of 10-year power purchase agreements with the BC Hydro and Power Authority, notes Cornelius Suchy, a Revelstoke-based consultant with Canadian Biomass Energy Research. As those run out, with the U.S. market relying on cheaper fracked natural gas—not to mention the Site C dam coming online—BC Hydro will likely drop any high-cost electricity providers. For their part, pulp mills will produce only as much power as they need, Suchy reckons. Soon no one will pay for hog or even pick it up for free at mills such as Downie Timber, he says.
The only hope is green-energy tax initiatives and regulatory changes. “The writing is on the wall,” Suchy says, citing the provincial government’s strong preference for renewable natural gas. “The bio-gas market in B.C. is expected to grow rapidly over the next few years, creating exciting opportunities to turn manure, food waste, yard waste and bio-solids into renewable energy.”
Downie’s Woodman remains hopeful. “At some point, government is going to have to show some leadership or give us some ideas where to go. It’s a real challenge,” he says of hog. “It does have a use. It’s just figuring out what it is.”
Good Wood: Cedar hog wasn’t a problem for B.C.’s First Nations
As the first to harvest cedar, Indigenous people used every part of the tree. They made canoes and homes from the straight, rot-resistant wood, and hats, clothing and diaper liners with long strips of soft bark.
Today the same bark can be used to make wood-wool cement board, a spaghetti-like inlay in cement siding that’s good for reinforcement and sound absorption.
Another option: fluff hog and use it as insulation. But existing mill debarkers mangle the trunk, so the machinery needs refining to remove the bark in a cleaner way.
Sources: Tracey Herbert, CEO, First Peoples’ Cultural Council; Cornelius Suchy, principal, Canadian Biomass Energy Research