28. 06. 2024


From the conference of the IRG on Wood Protection: focus on circular economy

The International Research Group on Wood Protection aims to disseminate knowledge on the multidisciplinary topic of wood protection science. In today's scenario, where the circular economy rewards materials that lend themselves to recycling and reuse with the goal of minimizing waste generation, promoting the use of wood over traditionally competing materials also means enhancing the potential of wood products as durable, recyclable, reusable and environmentally friendly. (read more....)

The mission of the International Research Group on Wood Protection (IRG-WP) is to promote the use of wood by fostering, through its annual conference and other means of communication, the exchange of information and updates among practitioners on current research and technological innovations in wood protection science. With the prospect of a looming climate crisis, the wood industry faces a new challenge in which carbon footprint can be a strong competitive force. In this context, the circular economy plays a key role in promoting the use of sustainable practices that address the need to reduce natural resource consumption and greenhouse gases emissions.

A special session of the IRGWP annual conference, held in Knoxville, Tennessee, May 19-24, focused on circular economy issues for wood protection. Speakers from Australia, Europe, the United States, and Canada presented their research and studies aimed at identifying alternative pathways for end-of-life treated wood, as well as analyzing residual chemicals as a key determinant of potential reuse or repurposing.

The production of materials that traditionally compete with wood in construction, such as steel and concrete, is already shifting toward the use of low-carbon, fossil-fuel-free renewables; this, in addition to the fact that such materials can be easily recycled, leads to the general perception that they are inherently "greener." For wood to compete with these materials, end-of-life planningfor wood products that has a favorable impact on life cycle assessment (LCA) and carbon footprint is essential.

We all know that trees offer many benefits, such as atmospheric carbon sequestration, improved air and water quality, erosion control, biodiversity, as well as being a renewable source of fuel and timber. However, the end-of-life scenario plays a key role in determining the extent to which wood products can be classified as low-carbon footprint products. Careful end-of-life planning for wood products, so that the carbon dioxide captured during tree growth is stored permanently, or as long as possible in the wood at the end of its life cycle, is critical to the circular economy strategy. In the case of wood treated with preservatives, processes aimed at recovering and recycling chemicals are also a key objective.

While the production of biochar by burning plant biomass in a controlled system allows most of the CO2 stored in the wood to remain trapped in the charcoal, which can later be used as a soil conditioner, insulation material, and feedstock additive, another way to prolong the CO2 sink function of wood is to extend the useful life of wood products, and reuse them.

Studies presented at IRG-WP show that it is possible to recover significant volumes of wood from structures that are demolished or renovated, and that wood reuse can have a positive impact by reducing demand for forest resources and carbon emissions associated with felling, sawing, and long-distance transport.

Examples of potentially reusable wood commodities are CCA-treated wineyard poles, which at the end of their useful life still retain a level of chemicals within specified limits for use in ground contact in countries where such chemicals are allowed for nonresidential use (e.g., railroad sleepers, fences, landscape structures).

Another case study concerning breakwater structures demonstrated that careful deconstruction of expired groyns allows parts of the removed structures to be reused on replacement groyns, while timber that cannot be reused has potential for repurposing.

A cornerstone concept of the circular economy, initially developed by the wood sector, is that of cascading use. The principle is to use raw materials and products made with them in sequential stages, for as long and as efficiently as possible, and to recover energy from them only at the end of the product life cycle. An example of how to apply this principle is the production of composite biomaterials using post-production sawdust and fungal mycelium as a binder. The resulting composite has potential as an alternative to heat-insulating materials currently available on the market.

In countries where wood is widely used as a structural material in construction, a considerable amount of solid waste generated from building renovations and demolitions is wood. In Canada, this amount has been reported as 40 percent of the total waste composition, which includes "clean" wood, painted wood, composite wood, and pressure-treated wood. Decreasing the volume of wood waste sent to landfill and incineration requires a regulated approach, including analysis of the composition of wood waste and, where necessary, decontamination processes to ensure safe recycling and valorization of wood waste.

In essence, the concept of the hierarchy in waste management, according to which the first objective is to prevent waste generation and the last, in that order, responsible disposal, requires careful planning, investment in infrastructure, collaboration among stakeholders, and the implementation of effective waste management policies and regulations.

In conclusion, reducing the consumption of nonrenewable resources and extending the life cycle of materials are key to the modern circular economy strategy. With this in mind, the various forest management schemes and due diligence regulations aim to ensure that the wood used for human uses comes from renewable and legal sources; recycling wood-based materials also promotes carbon storage, thus helping to mitigate the effects of climate change. While research demonstrates the potential of wood reuse and repurposing, there is a need for government authorities to implement these approaches in collaboration with industry and R&D institutions to find and create viable pathways for the use of wood waste.

To learn more about IRG-WP click here          

For info:
Elena Conti
+39 0432 747219