Richard D. Bergman

The Carbon Impacts of Wood Products

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 of wood products requires less fossil fuel than nonwood alternative building materials such as concrete, metals, or plastics. By nature, wood is composed of carbon that is captured from the atmosphere during tree growth. These two effects—substitution and sequestration—are why the carbon impact of wood products is favorable. This article shows greenhouse gas emission savings for a range of wood products by comparing (1) net wood product carbon emissions from forest cradle–to–mill output gate minus carbon storage over product use life with (2) cradle-to-gate carbon emissions for substitute nonwood products. The study assumes sustainable forest management practices will be used for the duration of the time for the forest to regrow completely from when the wood was removed for pr...

Cradle-to-Gate Life-Cycle Inventory and Impact Assessment of Wood Fuel Pellet Manufacturing from Hardwood Flooring Residues in the Southeastern United States

Abstract 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 environme...

EPD--environmental product declarations for wood products : an application of life cycle information about forest products

Transparent and credible environmental labeling of products is vital for a sustainable future. Ecolabeling shows information on the environmental performance of products, processes, and services. T...

Evaluating physical property changes for small-diameter, plantation-grown southern pine after in situ polymerization of an acrylic monomer

Because of the large percentage of juvenile wood in small-diameter southern pine, this material has lower strength properties compared with the historic published values in the ASTM Standard D2555. Finding new, simple, and inexpensive ways of increasing these strength properties would increase the use of this material for residential construction. For this study, we chose in situ polymerization using the monomer 1,6-hexanediol dimethacrylate to enhance bending strength and stiffness. After determining the lower range of density, modulus of rupture (MOR), and modulus of elasticity (MOE) of juvenile wood from small southern pine logs, southern pine specimens were polymerized using both a vacuum-impregnation and a surfaceapplication approach. The results showed some significant physical property increases for the fully impregnated material that used a large amount of monomer. Although the surface-application approach used less monomer, the physical properties of the juvenile wood did not increase as expected. Only the 1-minute dip treatment showed a significant increase in both bending stiffness and strength, with a weight gain of 11.9 percent. For the surface-application approach, monomer moving to the wood surface during polymerization reduced their effectiveness in increasing MOR and MOE to the expected levels. Therefore, the challenge is finding a method that maintains polymer loading inside the wood structure during the curing process.

Carbon Mitigation Impacts of Increased Softwood Lumber and Structural Panel Use for Nonresidential Construction in the United States

Abstract More wood use in the United States to construct low-rise nonresidential (NR) buildings would increase consumption and production of softwood (SW) lumber, engineered wood products, and structural and nonstructural wood panels. Using a consequential life-cycle analysis, we estimated the change in net CO2 emissions that would be caused by increased use of SW lumber and structural panels in NR construction. Carbon (C) storage and emissions were projected over 50 years for baseline and increased wood use scenarios using the US Forest Products Module operating within the Global Forest Products Model (USFPM/GFPM) and the Southern region timber supply model (SRTS). Increased wood use in NR construction (C content of 428 million tons of carbon dioxide equivalent [tCO2e]) could provide an emissions reduction of 870 million tCO2e over 50 years or a net emissions reduction of 2.03 tCO2e/tCO2e of extra wood used in NR buildings over 50 years. The CO2 savings varied for products provided in the South, North, a...

Heat sterilization of ash (Fraxinus spp.) firewood: Heat-treating options, temperature monitoring and thermal verification

Abstract Because of the potential risk associated with moving emerald ash borer (EAB)-infested firewood, the interstate movement of all hardwood firewood in the USA is currently restricted under the Federal quarantine. Communities and firewood producers are now faced with decisions on how to treat their firewood for interstate commerce. The new US Federal regulations for heat sterilization of ash firewood require holding a core temperature of 71°C for 75 min, which is higher than current international standard for heat treating solid wood packaging materials (ISPM 15). A study funded by the US Forest Service Wood Education and Resource Center examined the efficacy of different heat-treatment schemes for meeting the new regulations and developed empirical models for estimating heating times under various heating conditions. This paper addresses some practical issues of the heat-treatment process in terms of meeting the current heating standard for EAB, monitoring temperature changes during heating process and providing thermal verification after the heat-treatment operations.

Evaluating warp of 2 by 4s sawn from panels produced through green gluing dimension lumber from small ponderosa pine logs.

Overstocked small-diameter softwood timber in western US forests has created a serious forest health and fire hazard, and the costs of removing this material are high. One way to lower costs is to ...

Exploring methods for prevention of oxidative stain in soft maple

Interior gray enzymatic oxidative stain for white woods such as maple has plagued the wood industry for many years because methods that have been found to reduce stain are hard to scale up to industrial levels. We examined possible alternative treatments to eliminate stain in soft maple (Acer rubrum L.), and found that exposure to sulfur dioxide gas eliminates interior gray stain and that staining might occur at different temperatures depending on the age of the logs. Comparing sawn and split boards showed that both eliminated surface stain, but sawing eliminated it to a greater depth. A mild kiln schedule also seems to reduce staining, and this solution may be easier and more economical to implement on an industrial scale, both domestically and internationally, because no other processing is required.

CORRIM: Forest Products Life-Cycle Analysis Update Overview

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 for Standardization (ISO) standards for life-cycle inventory (LCI) and lifecycle assessment (LCA) research. The majority of prior CORRIM work on structural wood products has been published in two special issues of Wood and Fiber Science (CORRIM 2005, CORRIM 2010) based on data collected and analyzed starting in 1999. Many changes that were likely to affect the life-cycle results have occurred since the mill survey data were collected and compiled for the reports published in 2005 and 2010. These include changes in environmental regulations, both at the manufacturing facilities and in the forests; changes in operational efficiency due to forest sector restructuring after the 2008 economic downturn; and improvements in data quality across the supply chain. Market demand for consistent, transparent information on the environmental footprint of products has expanded greatly over the past decade. In particular, the emergence of environmental product declarations (EPDs) for North American wood products, which are based on specific guidelines as included in product category rules (PCRs), meant that data had to be reported in specific formats to be usable outside the academic community. Taken together, these changes warranted this effort to revisit the 2005 and 2010 research, collect new primary mill survey data, update life-cycle inventory data to reflect current forest management and manufacturing operations, and revise life-cycle impact assessments (LCIA) for development of new EPDs. To that end, this special issue of the Forest Products Journal updates and expands on the prior CORRIM research of six structural wood products, with two regions analyzed for each product. In addition, we develop for the first time an LCA based on primary survey data on boilers used in forest product manufacturing facilities (Puettmann and Milota 2017). We also update regional forest resource life-cycle data for the Pacific Northwest (PNW) region and report on a strategy to develop longitudinal survey methodologies for continuous data collection.

Impacts of the Allocation Assumption in Life-Cycle Assessments of Wood-Based Panels*

Abstract 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 ...