Managing carbon responsibly
Reducing energy consumption and greenhouse gas emissions
Our aim is to minimize fossil fuel consumption and maximize the use of green energy in our manufacturing facilities. Through conversion to renewable, green, energy sources and equipment upgrades, we’ve achieved significant reductions in fossil fuel consumption and greenhouse gas emissions over the last few years, while also reducing operating costs. Two notable examples came on-line in 2012:
- At our Béarn, Québec sawmill, a new biomass boiler burns bark to provide the energy to operate two wood kilns and heat buildings at the site. It replaces two oil-fired boilers, reducing the use of fossil fuels and lowering the sawmill’s greenhouse gas emissions by 88%.
- At our Tartas, France, specialty cellulose facility a new turbine, driven by a biomass boiler, generates green electricity and steam for use in manufacturing. The new equipment has also reduced carbon dioxide emissions.
Anaerobic wastewater treatment
Finding innovative ways to use waste is at the top of our agenda. Tembec operates anaerobic wastewater treatment plants at manufacturing sites in Temiscaming and Matane, Québec; and Tartas, France.
Basically, anaerobic wastewater treatment is an innovation in the biological treatment of wastewater. The treatment enables us to remove organic pollutants, which are then converted by anaerobic microorganisms to biogas.
Here’s what we can achieve:
1. Reduced energy consumption:
The anaerobic process uses significantly less energy compared to conventional aerobic systems because the microbial breakdown of the dissolved organic material in the wastewater does not require aeration (oxygen).
2. Production of biogas:
Conventional aerobic treatment generates carbon dioxide (CO2). Anaerobic microorganisms convert the dissolved organic material into methane biogas (CH4). The methane in turn is used as a fuel in part of the pulping process, and therefore replaces natural gas, a fossil fuel.
3. Reduced production of biological sludge:
Conventional aerobic treatment generates significant quantities of biological sludge; much of the dissolved organic material is converted into microorganisms, which eventually die (sludge). In contrast, only a small amount of biological sludge is produced in the anaerobic process.
Cogeneration is a highly efficient means of generating thermal and electric energy simultaneously from the same energy source. At Tembec, cogeneration plants produce heat by burning biomass (pulping liquor, bark, shavings, sawdust, and sludge). The heat is used to produce steam for the pulping and papermaking processes. The steam also produces electricity by operating a turbine. This green electricity is either used internally or sold to utilities.
In the end, the biomass replaces fossil fuels to produce green steam and green electricity.
We have four cogeneration plants in place at Tembec: Kapuskasing, Chapleau, Temiscaming, and Tartas.
Carbon storage and sequestration are important parts of the natural carbon cycle. Carbon is sequestered when atmospheric carbon dioxide (CO2) is absorbed into living trees and other plants, and is then stored in forest soils, mosses, trees and plants until affected by a natural event such as a forest fire, insect infestation, disease, old age, or windthrow. Timber harvested from managed forests can end up in solid wood products (lumber, panelling, furniture, etc.), where the stored carbon in sustainably harvested trees remains until the wood is burned or biodegrades.
Young and healthy trees sequester carbon at a faster rate than older trees, while older, larger trees store more carbon than younger trees. Maintaining a diversity of forest types (various age classes and tree species mixtures) and management regimes from intensive to natural regeneration to protected areas helps to maintain the forest carbon balance over the long term. Forests are complex ecosystems and much research remains to fully understand their role in the mitigation of climate change.