Big Biomass 101
The Alberta Pacific Forest Industries (ALPAC) pulp mill near Boyle in northern Alberta is North America’s largest single-line Kraft pulp mill. FSC certified for progressive forest management, ALPAC has what may be the biggest wood yard in the world. Each year it takes in 3.38 million cubic metres of aspen, balsam poplar, birch spruce and pine.
But the mill’s raison d’etre is to harvest aspen. In Alberta, one out of every two trees is aspen and while the wood does not make good lumber it can be turned into pulp and made into any number of paper products.
In 2009, ALPAC installed a condensing steam turbine to make electricity from its waste wood. Most of the 2.56 million cubic metres of aspen ALPAC harvests each year is chipped and tossed into a chemical cocktail called “white liquor” that breaks the chips down. The leftover chemicals are known as “black liquor,” and burned to power ALPAC’s operations. Aside from using its waste to serve its own power needs, ALPAC has a 32-megawatt power plant that contributes power to Alberta’s grid.
“We process logs and from those logs and what we get from that is bark and residual waste from that process. That goes into what we call a biomass pile. We fire that into a power boiler. And we burn that to make steam and power,” says Daryl Nichol, the vice-president of pulp at ALPAC. About 450,000 tons of this waste fires the power boiler a year.
Turning these former economic hubs into green power nodes, burning biomass for power, might be a way forward for these communities.
“On the other side, when we feed our chips into our digesting process, we recover all of the spent cooking chemicals and we use that as a fuel source in our recovery boiler.”
Inside the recovery boiler nozzles spray this black liquor into an inferno; an 11-storey tall boiler that together with the power boiler drives two giant high-pressure turbines.
ALPAC received $63 million in federal subsidies to build the power plants and to upgrade their transmission lines and build a substation.
On an annual basis ALPAC brings in $14 to $18 million from selling power to the grid, about $2 million in carbon credits and $7 million from the Alberta Bio-Producer credit program.
But the forestry industry in Canada isn’t doing too well overall. It has shed 118,000 jobs in the past 10 years as operations shut down. Turning these former economic hubs into green power nodes, burning biomass for power, might be a way forward for these communities.
And perhaps there is a lesson for these communities to learn from Finland. Their pulp and paper mills actually turned into utilities. Finns get almost one third of their electricity after industrial consumers have used it. In a low carbon economy it makes sense to recycle your power like this.
Alberta has over 350 megawatts of installed biomass capacity. That’s the equivalent of a large, centralized fossil fuel power plant, but instead of burning coal it’s burning something that grows.