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One important characteristic of forest products is that several co-products (products that are produced as the result of the same shared process) can be manufactured in the same value chain. Very often, the objective of a life cycle assessment (LCA) or carbon footprint study is to describe the environmental attributes of only one of these co-products. (Note: While LCA studies generally cover several different potential impact indicators, carbon footprint studies focus only on the global warming indicator.) In that situation, it is necessary to decide how to partition, or to allocate, the environmental loads in the value chain between the different co-products. This report describes, discusses, and illustrates, with forest product examples, the most common approaches for co-product allocation and proposes a step-by-step approach to address complex allocation situations at pulp and paper mills (i.e., how to allocate pulp and paper mill environmental loads between the different paper grades, chemicals and energy produced). It is shown that, in some cases, the choice of allocation method can have significant implications for the results.

In this document, the allocation methods for open-loop recycling most frequently used in pulp and paper case studies or presented as options in the ISO standards on life cycle assessment (LCA) are presented, illustrated, discussed and compared. It is shown that the choice of one allocation procedure over another can have a significant effect on the results of an LCA. In particular, the ISO standards on LCA require that sensitivity analyses be performed when several methods seem applicable. In part because of this, LCA may not be useful for obtaining unambiguous conclusions if the objective of the LCA is to compare virgin and recycled paper. When selecting an allocation method for recycling, the following should be kept in mind: the method should be consistent with the objective of the study; the set of values inherent to the selection of the method should be transparent; the selected method should preserve mass and energy balances (with the exception of the closed-loop procedure); and a similar allocation method should be applied to both the inflows and outflows of recovered material in the system boundary.

In aquatic systems, total ammonia concentration is comprised of ionized (NH4 +) and un-ionized (NH3) forms, with NH 3 being more toxic to fish than NH4 +. The relative concentration of these two forms depends on water temperature and pH, with the relative concentration of NH3 increasing as temperature and pH increase. This has implications for regulatory compliance because pH shifts during bioassay testing may indicate effluent toxicity when, in fact, a pH-associated increase in the fraction of un-ionized ammonia, and not the presence of some other toxic compound(s), was responsible for the bioassay response. Environment Canada does not currently allow the use of pH stabilization techniques during the acute lethality testing of pulp and paper mill effluents. This restriction is based on EC's concern that the use of such techniques could mask the toxicity of certain constituents of these effluents. The available literature, however, suggests that pH stabilization is necessary (a) to avoid inadvertent toxicity resulting from the formation of artefact un-ionized ammonia, and (b) to reduce the risk of masking the toxicity of compounds whose acute effects in fish decrease as a result of a pH change. This report summarizes published research addressing the relationship between pH and the acute lethality of substances typically found in pulp and paper mill effluents. Results from this review suggest that the acute toxicity of substances like resin acids, hydrogen sulphide, polychlorinated phenolics, and certain metals (e.g., chromium, lead, mercury, copper, and zinc) may be masked if pH is not stabilized during acute bioassay tests of pulp and paper mill effluents.

van Deusen P.C.,NCASI
Canadian Journal of Forest Research | Year: 2010

Managing the forest to store carbon is a relatively new concept. Various regional greenhouse gas initiatives and new Federal legislation are providing financial incentives for forest owners to manage for carbon in addition to other forest products. These incentives are intended for landowners who engage in activities that go beyond business as usual practices. Managing for carbon will likely involve foregoing other investment alternatives and increasing rotation lengths. The analysis approach demonstrated here provides a relatively simple method for an owner to compare traditional forest management and regular harvests with letting the trees grow to accumulate more carbon in the forest. Several financial decision statistics are considered and demonstrated with examples. A derivative of land expectation value, called rotation equivalent value, is shown to be a useful decision tool for comparing carbon storage with other management options having different rotation lengths.

Amor M.B.,Ecole Polytechnique de Montreal | Pineau P.-O.,HEC Montreal | Gaudreault C.,NCASI | Samson R.,Ecole Polytechnique de Montreal
Energy Policy | Year: 2011

Worldwide electricity sector reforms open up electricity markets and increase trades. This has environmental consequences as exports and imports either increase or decrease local production and consequently greenhouse gas (GHG) emissions. This paper's objective is to illustrate the importance of electricity trade's impact on GHG emissions by providing an estimate of the net GHG emissions resulting from these trades. To achieve this objective, Quebec hourly electricity exchanges with adjacent jurisdictions were examined over the 2006-2008 period. In order to associate a specific GHG emission quantity to electricity trades, hourly marginal electricity production technologies were identified and validated using the Ontario hourly output per power plant and information released in the Quebec adjacent system operator reports. It is estimated that over three years, imports into Quebec were responsible for 7.7. Mt of GHG, while Quebec hydropower exports avoided 28.3. Mt of GHG emissions. Hence, the net result is 20.6. Mt of avoided emissions over 2006-2008, or about 7. Mt per year, which corresponds to more than 8% of the Quebec yearly GHG emissions. When GHG emissions from all life cycle stages (resource extraction to end-of-life) are accounted for, the net avoided GHG emissions increase by 35%, to 27.9. Mt. © 2011 Elsevier Ltd.

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