Most of the energy used to make Canadian paper products is renewable
Waste-based biomass now provides almost 70% of the Canadian pulp and paper industry’s overall energy requirements1. For the mills that produce virgin bag material, the carbon-neutral biomass or “renewables” percentage (wood chips and sawmill residue) is even higher, 85%.
The aim of a modern kraft mill, and Canadian mills are inching ever closer to achieving it, is to be energy-neutral or better, net energy positive. In other words, the mill generates sufficient energy and power from burning residual materials such as black liquor to meet all its own energy requirements (although it may still occasionally draw electricity from the local power grid, or natural gas, for a boiler start-up). But it can also export surplus power to the local grid at peak times. Over a year, the net balance could be zero or even positive, providing the mill with some extra income. Very few other industries are anywhere near being able to close the energy loop in this way.
Nothing is wasted
Nothing is wasted in a modern kraft pulp mill. Branches and needles (the most valuable parts of the tree for their nutrient value) are returned to the forest soil. Bark and other wood residuals are efficiently combusted to make electricity and steam. Logs are sawn into high-value lumber. Wood chips and other residual materials (from sawmilling) are used to produce not only pulp and paper but also the energy that drives the kraft process.
A modern kraft mill separates wood fibres from one another, using the dissolved components such as lignin and hemicelluloses as fuel, minimising both waste and ecological impact. The by-products of one part of the process become the fuel for another, not unlike the efficient closed loop system of nature. Virtually 100% of any tree harvested for kraft paper production in Canada is used and/or re-used.
1 Between 2007 and 2009, members of the Forest Products Association of Canada increased their use of waste-based biomass from 58% to 68 per cent http://www.fpac.ca. (January, 2012). FPAC and co-signatory World Wildlife Fund have committed to achieving carbon neutrality through the use of biomass. The Intergovernmental Panel on Climate Change (IPCC) currently considers biomass emissions to be carbon-neutral, that such emissions do not add to atmospheric concentrations of carbon dioxide.