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Wood composite panels (WCP) are well known for their environmentally friendly attributes of being sustainable, renewable, biodegradable, and predominantly made from wood residues generated during lumber and plywood production. This paper focuses on the ability of WCPs to store carbon for long periods of time in nonstructural applications such as cabinets, furniture, and flooring. WCPs, include particleboard, medium density fiberboard (MDF), and hardboard--engineered wood siding and trim (EWST). These panels are anticipated to have an average service life of 25--30 years. In 2019, there was an estimated 291 million cubic meters ([m.sup.3]) of WCPs in use in North America that corresponds to a carbon pool of 354 million metric tons of carbon dioxide equivalents. This WCP carbon pool is enough to offset 24 years of cradle-to-gate cumulative carbon emissions (fossil and biogenic sources) emitted during production of these panels. In other words, producing and using WCPs stores carbon for long periods because the amount of carbon emitted during the production of the panels is far less than what the panels themselves are capable of storing over their lifetime of product use., Demand for sustainable 'green' products, desired for their favorable environmental performance, is increasing in the marketplace. Recent life cycle assessment (LCA) studies document the environmental performance of composite panels (Puettmann [...]

Life-cycle inventory (LCI) and life-cycle assessment (LCA) were used to provide quantitative assessments of the environmental impacts of forest management activities that are required to produce feedstock for wood products such as lumber, engineered panels, and pulp. Primary and secondary data were gathered for the Pacific Northwest Douglas-fir region of the United States to produce an attributional LCA that includes planting, growing, and harvesting trees that are destined for use in wood manufacturing. Using the Tool for the Reduction and Assessment of Chemical and other environmental Impacts (TRACI) method, under average management conditions, forest operations can expect to generate from 10 to 18 kg C[O.sub.2] equivalent (C[O.sub.2] eq) per cubic meter ([m.sup.3]) of logs ready to leave the landing for the manufacturing facility, depending on the amount of forest residues that are piled and burned. This same cubic meter of log plus bark will have sequestered 960 kg C[O.sub.2] eq during its growth cycle, for a net greenhouse gas sink of 942 to 950 kg C[O.sub.2] eq per [m.sup.3]. Forest management impacts are from 1 to 13 percent of the total impacts from the cradle to gate for global warming potential and the potential to increase smog, eutrophication, and acidification. Upstream impacts associated with the production of herbicides are reflected in the ozone potential impact category. These LCA results can be used as upstream processes for wood manufacturers interested in developing Environmental Product Declarations for products that use these resources as inputs., The Consortium for Research on Renewable Industrial Material (CORRIM) has developed research protocols (CORRIM 1998) and methodologies that have been used to conduct a wide range of attributional life-cycle inventory [...]

This study was an update on the 2000 life-cycle inventory data on material and energy inputs associated with the production of 1 [m.sup.3] of glued-laminated (glulam) timbers produced in the Pacific Northwest (PNW) and the Southeast (SE) regions of the United States. This article looks at the cradle to gate for the entire glulam production processes, which include forest harvest, lamstock production, and glulam beam production. Data collected from glulam beam manufacturers in 2013 allowed for the development of a life-cycle assessment utilizing the product category rules for North American Structural and Architectural Wood Products so that the results from these analyses can be used for the development of environmental product declarations of glulam beams produced in the United States. Comparing the results of this study with the life-cycle assessment based on the 2000 survey data shows 30 percent reductions in global warming potential of glulam beams produced in both the PNW and the SE and reductions in the use of energy derived from fossil fuels by 40 percent in the PNW and SE. The overall net carbon sequestered in 1 [m.sup.3] of PNW glulam is equivalent to 938 kg of C[O.sub.2] and 1,038 kg of C[O.sub.2] in the SE. Utilizing techniques that reduced the use of electricity and minimizing the transportation distances of the raw materials and resins to the mill could help to further reduce the carbon footprint of the glulam beam manufacturing process., The environmental impacts of wood products manufactured in the United States is directly related to the specific product under consideration, the exact process and raw materials utilized to manufacture the [...]

Since its inception in 1996, the nonprofit Consortium for Research on Renewable Industrial Materials (CORRIM; www.corrim.org) has developed comprehensive environmental performance information on wood building materials consistent with International Organization [...]

Many wood production facilities use wood-based fuels for steam generation for drying wood or pressing boards or panels. This process contributes to the life-cycle impacts of the products produced downstream. Past life-cycle assessment studies of wood products have relied on wood boiler data sets that represent both the paper and the wood products industries as well as on secondary data from the US Environmental Protection Agency primarily based on the potential to emit or collect from an uncontrolled source. Primary data were collected by survey for the material and energy inputs and outputs of wood-fired boilers at lumber and plywood wood production facilities in the Pacific Northwest and Southeast regions of the United States. The results were averaged to create a life-cycle inventory model to represent wood-fired boilers at wood production facilities. Results indicated that regional differences, as well as type of wood waste burned, did not warrant separate boiler data sets for each industry and region. The model is useful for including the effects of steam production in the life-cycle assessment of wood products. The primary data used in the model should better represent wood-fired boilers used in US wood production facilities than existing data sets do., Most wood products production facilities generate residues, such as bark, chips, sawdust, hog fuel, trimmings, shavings, mill rejects, and sander dust. These can be green (typically around 50% moisture content [...]

Wood processing often involves an array of products and coproducts and a cascade of primary and secondary uses. Prior life-cycle assessment (LCA) reporting allocated environmental burdens to products and coproducts based on mass for multiproduct systems to develop environmental product declarations, which are developed from LCAs following the procedures detailed in product category rules (PCRs). A recent PCR for North American structural and architectural wood products requires allocation by economic value when the main products exceed the value of coproducts by greater than 10 percent. Using recent LCAs of wood-based panels, this article describes the differences in LCA results when using mass and economic allocation methods. For wood panel products that do not use wood residues from primary wood manufacturers (e.g., plywood), an increase in environmental impacts results from an economic allocation approach. For wood panel products made from wood residues (e.g., cellulosic fiberboard), there is a slight decrease in most environmental impact metrics with economic allocation. Sensitivity and variability in LCA results are discussed for the mass and economic allocation approaches., Wood processing often involves an array of products and coproducts. Life-cycle assessment (LCA) of wood products therefore must divide--or allocate--the environmental impacts of the whole process to these various products [...]

A cradle-to-gate life-cycle inventory was done for 2 by 4 to 2 by 12 dimension lumber produced from logs in the Pacific Northwest (PNW) and Southeast (SE) regions of the United States. Seven mills in the PNW and 11 mills in the SE provided data for 2012 lumber and coproduct production, raw material and fuel use, electricity consumption, and on-site emissions. The mills represented 17 and 11 percent of the production volumes in the regions, respectively. Five processes existed within the mill, log yard, sawing, drying, planing, and energy generation. Data for the first four processes came exclusively from the survey. The functional unit was 1 [m.sup.3] of planed dry wood. Data for energy generation were based on a nationwide wood boiler survey that included PNW lumber mills. The cradle-to-gate processing energy in the PNW region was 3,434 MJ/[m.sup.3] of planed, dry lumber, 96 percent of which is owing to log transport and wood processing. The value was higher, 5,151 MJ/[m.sup.3], for the SE region in part owing to a higher initial wood moisture content. In each region, more than 70 percent of the energy is from bio-based residuals with less than 30 percent from fossil sources. The global warming impact indicator is 58.7 kg C[O.sub.2] eq per [m.sup.3] in the PNW and 81.4 kg CC_ eq per [m.sup.3] in the SE, of which 85 percent is a result of log transport and processing. Planed, dry lumber from the PNW region stores 856 kg C[O.sub.2] eq per [m.sup.3] compared with 935 kg C[O.sub.2] eq per [m.sup.3] for lumber from the SE region. The coproducts, emissions, and material and energy inputs are further discussed in this article., The environmental consequences of extracting raw materials and producing a product, such as lumber, are carried forward into the life cycle of products, such as wooden structures. These consequences arise [...]

Abstract Wood products have many environmental advantages over nonwood alternatives. Documenting and publicizing these merits helps the future competitiveness of wood when climate change impacts are being considered. The manufacture [...]

Abstract Using wood wastes provides an opportunity to avoid fossil carbon emissions from the combustion of natural gas or other fossil fuels. Using a life-cycle assessment, a new biomass boiler [...]

Abstract The use of wood waste for heating in urban settings provides an opportunity for communities to reduce annual fossil emissions by directly reducing the amount of fossil fuel used. [...]

We conducted a life-cycle assessment (LCA) of ethanol production via bioconversion of willow biomass crop feedstock. Willow crop data were used to assess feedstock production impacts. The bioconversion process was modeled with an Aspen simulation that predicts an overall conversion yield of 310 liters of ethanol per tonne of feedstock (74 gal per US short ton). Vehicle combustion impacts were assessed using Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) models. We compared the impacts of bioconversion-produced ethanol with those of gasoline on an equivalent energy basis. We found that the life-cycle global warming potential of ethanol was slightly negative. Carbon emissions from ethanol production and use were balanced by carbon absorption in the growing willow feedstock and the displacement of fossil fuel-produced electricity with renewable electricity produced in the bioconversion process. The fossil fuel input required for producing 1 MJ of energy from ethanol was 141 percent less than that from gasoline. More water was needed to produce 1 MJ of ethanol fuel than 1 MJ of gasoline. The life-cycle water use for ethanol was 169 percent greater than for gasoline. The largest contributors to water use were the conversion process itself and the production of chemicals and materials used in the process, such as enzymes and sulfuric acid., ********** The Energy Independence and Security Act (EISA) mandates that at least 16 billion gallons (61 billion liters) per y of cellulosic fuel be in production by the year 2022 [...]

The goal of this study was to estimate the greenhouse gas (GHG) emissions and fossil energy requirements from the production and use (cradle-to-grave) of bioethanol produced from the indirect gasification thermochemical conversion of loblolly pine (Pinus taeda) residues. Additional impact categories (acidification and eutrophication) were also analyzed. Of the life-cycle stages, the thermochemical fuel production and biomass growth stages resulted in the greatest environmental impact for the bioethanol product life cycle. The GHG emissions from fuel transportation and process chemicals used in the thermochemical conversion process were minor (less than 1 percent of conversion emissions). The net GHG emissions over the bioethanol life cycle, cradle-to-grave, was 74 percent less than gasoline of an equal energy content, meeting the 60 percent minimum reduction requirement of the Renewable Fuels Standard to qualify as an advanced (second generation) biofuel. Also, bioethanol had a 72 percent lower acidification impact and a 59 percent lower eutrophication impact relative to gasoline. The fossil fuel usage for bioethanol was 96 percent less than gasoline, mainly because crude oil is used as the primary feedstock for gasoline production. The total GHG emissions for the bioethanol life cycle analyzed in this study were determined to be similar to the comparable scenario from the Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation model. A sensitivity analysis determined that mass allocation of forest establishment burdens to the residues was not significant for GHG emissions but had significant effects on the acidification and eutrophication impact categories., ********** The United States is the largest bioethanol producing country, with 49.2 billion liters as of 2010 (Renewable Fuels Association [RFA] 2010). Controversy around conventional biofuels, which are usually produced [...]

The heightened interest in biofuels addresses the national objectives of reducing carbon emissions as well as reducing dependence on foreign fossil fuels. Using life-cycle analysis to evaluate alternative uses of wood including both products and fuels reveals a hierarchy of carbon and energy impacts characterized by their efficiency in reducing carbon emissions and/or in displacing fossil energy imports. Life-cycle comparisons are developed for biofuel feedstocks (mill and forest residuals, thinnings, and short rotation woody crops) with bioprocessing (pyrolysis, gasification, and fermentation) to produce liquid fuels and for using the feedstock for pellets and heat for drying solid wood products, all of which displace fossil fuels and fossil fuel-intensive products. Fossil carbon emissions from lignocellulosic biofuels are substantially lower than emissions from conventional gasoline. While using wood to displace fossil fuel-intensive materials (such as for steel floor joists) is much more effective in reducing carbon emissions than using biofuels to directly displace fossil fuels, displacing transportation fuels with ethanol provides the opportunity to also reduce dependence on imported energy. The complex nature of wood uses and how wood fuels and products interact in their environments, as well as the methods needed to understand these impacts and summarize the relative benefits of different alternatives, are discussed herein. Policies designed to increase biofuel use by subsidies or mandates may increase prices enough to divert biomass feedstock away from producing products, such as for composite panels, resulting in increased emissions from fossil fuel-intensive substitutes. Policies that fail to consider life-cycle implications are discussed, identifying their unintended consequences., The life-cycle inventory (LCI) data for the many different uses of wood reveal a hierarchy of different opportunities to reduce carbon emissions or increase energy independence, both being current national [...]

As part of the Consortium for Research on Renewable Industrial Materials' Phase I life-cycle assessments of biofuels, lifecycle inventory burdens from the production of bio-oil were developed and compared with measures for residual fuel oil. Bio-oil feedstock was produced using whole southern pine (Pinus taeda) trees, chipped, and converted into bio-oil by fast pyrolysis. Input parameters and mass and energy balances were derived with Aspen. Mass and energy balances were input to SimaPro to determine the environmental performance of bio-oil compared with residual fuel oil as a heating fuel. Equivalent functional units of 1 MJ were used for demonstrating environmental preference in impact categories, such as fossil fuel use and global warming potential. Results showed near carbon neutrality of the bio-oil. Substituting bio-oil for residual fuel oil, based on the relative carbon emissions of the two fuels, estimated a reduction in [CO.sub.2] emissions by 0.075 kg [CO.sub.2] per MJ of fuel combustion or a 70 percent reduction in emission over residual fuel oil. The bio-oil production life-cycle stage consumed 92 percent of the total cradle-to-grave energy requirements, while feedstock collection, preparation, and transportation consumed 4 percent each. This model provides a framework to better understand the major factors affecting greenhouse gas emissions related to bio-oil production and conversion to boiler fuel during fast pyrolysis., ********** This report has been produced as part of the Consortium for Research on Renewable Industrial Materials (CORRIM) Phase I reports on the life-cycle inventory (LCI) and life-cycle impact assessment [...]

In this article, we present cradle-to-gate life-cycle inventory (LCI) data for wood fuel pellets manufactured in the Southeast United States. We surveyed commercial pellet manufacturers in 2010, collecting annual production data for 2009. Weighted-average inputs to, and emissions from, the pelletization process were determined. The pellet making unit process was combined with existing LCI data from hardwood flooring residues production, and a life-cycle impact assessment was conducted using the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) model. The potential bioenergy and embodied nonrenewable energy in 907 kg (1 ton, the functional unit of this study) of wood fuel pellets was also calculated. The pelletization of wood requires significant amounts of electrical energy (145 kWh/Mg), but the net bioenergy balance is positive. Wood pellets require 5.8 GJ of fossil energy to produce 17.3 GJ of bioenergy (a net balance of 10.4 GJ/Mg). However, if environmental burdens are allocated to the pellet raw material (flooring residues) by value, then the embodied fossil energy is reduced to 2.3 GJ. The pelletization unit process data collected here could be used in an assessment of the environmental impacts of pellet fuel, or when pellets are a pretreatment step in wood-based biorefinery processes., ********** The wood manufacturing industry in the United States obtains more than 50 percent of their heat energy requirements by burning wood residues produced during production (Puettmann and Wilson 2005, [...]

Using life-cycle inventory production data, the net global warming potential (GWP) of a typical inland Northwest softwood lumber mill was evaluated for a variety of fuel types used as boiler inputs and for electricity generation. Results focused on reductions in carbon emissions in terms of GWP relative to natural gas as the fossil alternative. Woody feedstocks included mill residues, forest residuals, and wood pellets. In all fuel-substitution scenarios, increasing the use of biomass for heat generation decreased GWP. Using woody biofuels for electricity production is somewhat less effective in lowering carbon emissions than when used for heat energy. Heat generation at the mill under the current practice of using about half self-generated mill residues and half natural gas resulted in a 35 percent reduction in GWP over 100 percent natural gas. The greatest reduction in GWP (66%) was from increased use of forest residuals for heat energy, eliminating the use of fossil fuels as a direct heating fuel at the mill. We summarize the results by documenting that greater use of woody biomass for heat energy will reduce carbon emissions over fossil-based fuels., ********** Recent technological advances have provided numerous options for the conversion of biomass to energy. These technologies include electricity production, pellet production for residential and industrial heating, woody and agricultural [...]

This study summarizes environmental impacts of 'premium' wood pellet manufacturing and use through a cradle-to-grave life-cycle inventory. The system boundary began with growing and harvesting timber and ended with use of wood pellet fuel. Data were collected from Wisconsin wood pellet mills, which produce wood pellets from a variety of feedstocks. Three groups of manufacturers were identified, those who use wet coproduct, dry coproduct, and harvested timber. Pellet mill data were weight averaged on a per unit basis of 1.0 short ton of 'premium' wood pellets, and burdens for all substances and energy consumed were allocated among the products on a 0 percent moisture basis. Wood pellets produced from dry coproduct required 60 percent less energy at the pellet mill. However, when considering all cradle-to-gate energy inputs, producing wood pellets from whole logs used the least energy. Pellets from wet coproduct and dry coproduct used 9 and 56 percent more energy across the life cycle, respectively. This study also compared environmental impacts of residential heating fuels with wood pellet fuel. Environmental impacts were measured on net atmospheric carbon emissions, nonrenewable energy use, and global warming potential (GWP). Assuming 'better than break-even' forest carbon management, cordwood and wood pellet fuels emitted 67.3 and 26.6 percent less atmospheric carbon emissions per megajoule of residential heat across the life cycle than natural gas, the best fossil fuel alternative. Cordwood and wood pellets consumed fewer nonrenewable resources than natural gas, which consumed fewer resources than petroleum-based residual fuel oil. However, wood pellet fuels had a smaller GWP and effect on respiratory health because they have more efficient combustion., ********** The increasing economic and environmental cost of acquiring energy from fossil fuels has led the United States to explore the development of a variety of renewable and domestic energy [...]

The different uses of wood result in a hierarchy of carbon and energy impacts that can be characterized by their efficiency in displacing carbon emissions and/or in displacing fossil energy imports, both being current national objectives. When waste wood is used for biofuels (forest or mill residuals and thinnings) fossil fuels and their emissions are reduced without significant land use changes. Short rotation woody crops can increase yields and management efficiencies by using currently underused land. Wood products and biofuels are coproducts of sustainable forest management, along with the other values forests provide, such as clean air, water, and habitat. Producing multiple coproducts with different uses that result in different values complicates carbon mitigation accounting. It is important to understand how the life-cycle implications of managing our forests and using the wood coming from our forests impacts national energy and carbon emission objectives and other forest values. A series of articles published in this issue of the Forest Products Journal reports on the life-cycle implications of producing ethanol by gasification or fermentation and producing bio-oil by pyrolysis and feedstock collection from forest residuals, thinnings, and short rotation woody crops. These are evaluated and compared with other forest product uses. Background information is provided on existing life-cycle data and methods to evaluate prospective new processes and wood uses. Alternative management, processing, and collection methods are evaluated for their different efficiencies in contributing to national objectives., ********** Sustainably managed forests remove carbon from the atmosphere during their growth cycle, transferring that carbon by harvesting and processing to product carbon stores or fuels that displace fossil fuel-intensive [...]

The nonprofit Consortium for Research on Renewable Industrial Materials (CORRIM) has been developing comprehensive environmental performance information on wood building materials consistent with life-cycle standards (http://www.corrim.org/). The articles published in [...]