Wood Utilization, Product Development, and their Environmental Impact
By Eva Haviarova
Wood is the most promising sustainable material for the future sustainable society. It is one of few renewable, recyclable, and biodegradable biomaterials. As a wood scientist with expertise in product development and strength design, I promote wood utilization through my research, teaching, and extension activities.
Figure 1: A comparison of LCA on different materials (wood- light green, plywood – dark green, PVC plastic - brown, primary aluminum - orange, and steel-red), developed by Haviarova at Purdue FNR.
Wood is described by many as a green material, which means that durable wood products can store (sequester) carbon for many years. Wood is economical material to use, and most people love to feel its presence (phenomena called biophilia). Wood is easy to work with, and it has technical possibilities unavailable to other materials. It is the world’s strongest material relative to mass. Wood is elastic – some wooden houses remain standing during calamities, such as earthquakes, that cause concrete houses to collapse. Wood is often cheaper to build with – wooden houses and bridges are often more economical when energy consumption and CO2 emissions are factored in. Under the right conditions, wood products could last generations, considering selecting the right type of wood species, correct design, and minimizing water exposure. However, wood is also a living biological material that could degrade by the sun, wind, and microorganisms and be dissolved back to nature.
Choice of the material is a crucial component of successful sustainable design and one of the most critical tasks for the designer or the product developer. Life Cycle Assessment (LCA) could help designers and producers quantify and evaluate a broad scope of environmental impacts of material and products made from them. This tool could help product developers to select their materials and benchmark the products they are proposing. Life Cycle Assessment is also one way for the wood industry to promote the environmentally-friendly properties of wood with scientific evidence 15. A classic LCA project comprises three stages: defined scopes and goals, a Life Cycle Inventory (LCI), and a Lifecycle Impact Analysis (LCIA). LCA analysis is complex and as good as the information and inventories inputted into the system. Obtaining all information throughout the product life cycle could be challenging, and very often, users rely on existing inventories and databases.
To demonstrate the environmental impact of materials and products made out of them, I selected a simple benchmarking example among basic building materials in Figure 1. Wood is marked in light green and is almost not visible because of its very low environmental impact compared to other materials. The environmental impact of plywood is shown as dark green. It is disproportionally lower than other non-renewable materials such as plastic, aluminum, and steel, all displayed in Figure 1. (PVC plastic - brown, primary aluminum - orange, and steel-red). Life Cycle Analysis outputs indicate the superiority of wood in all measured categories (ozone depletion, global warming, smog, acidification, eutrophication, carcinogenic, non-carcinogenic, respiratory effects, eco-toxicity, and fossil fuel depletion) when compared to other non-renewable materials.
To demonstrate the LCA on products, simplified benchmarking among three chairs made of different materials (wood, aluminum, and plastic) is shown in Figure 2. These LCA studies on chairs were also conducted at the Wood Research Lab, Purdue University. The lifespan of chairs and their strength were based on product performance testing. Chairs were subjected to cyclic loading until they failed, and their service life was estimated accordingly. Based on LCA, wooden chairs have the lowest environmental impact in each category. Based on these findings, it is possible to conclude that material selection significantly impacts product sustainability, and it should be taken into consideration by product designers and developers.
Figure 2: A comparison of LCA on three different chairs made of three different materials, based on TRAIC 2.1. , developed by Haviarova at Purdue FNR.
Eva Haviarova is a Professor of Wood Products Engineering and Furniture Strength Design in Department of Forestry and Natural Resources at Purdue University. Dr. Haviarova also serves as director of the Wood Research Laboratory (https://www.purdue.edu/woodresearch/).