Researchers at the Pacific Northwest National Laboratory (PNNL) have announced the imminent availability of a cost-effective decking material with the potential to sequester more carbon dioxide than it emits during production.
This picture, taken on March 16, 2021, shows planks of wood stacked in a yard of Sokol Timber Company near Vologda, 500 kilometers northeast of the Russian capital Moscow. - Already a leader in a number of sectors such as paper packaging and various types of wood for construction, Segezha Group has launched the first factory in Russia to manufacture CLT panels, or laminated wood, one of the essential elements to build High wooden buildings from wood. (Photo: DIMITAR DILKOFF/AFP via Getty Images)
Addressing Environmental Challenges in Construction
Expected to hit the market by next summer, this innovation addresses the environmental challenges the construction industry poses, which historically contributes significantly to carbon emissions.
As reported by EurekAlert, the construction sector accounts for 11% of global carbon emissions. With increasing pressure to achieve net-zero emissions, there's a growing demand for sustainable building materials.
While alternatives often incorporate recycled or plant-derived components, they tend to be more expensive and lack the strength and durability of traditional materials. Consequently, researchers strive to develop viable replacements that offer comparable performance while reducing environmental impact.
Exploring Innovative Composite Materials
Utilizing a blend of wood and plastic composite, decking boards have emerged as a resilient alternative to traditional lumber. Their robustness and resistance to ultraviolet radiation have positioned them as a preferred choice for outdoor installations.
In a bid to enhance sustainability, researchers at PNNL have explored innovative methods to augment composite materials. Keerti Kappagantula, among these researchers, has investigated the integration of pulverized brown coal or lignin, a byproduct from wood processing, as fillers.
Kappagantula has employed esters, organic compounds commonly used in flavorings, and industrial solvents to strengthen the cohesion of these materials with plastics.
A Promising Solution
Upon sharing her findings with colleague David Heldebrant, an intriguing idea emerged: could the process be adapted to incorporate carbon dioxide into the particles? This proposed modification aimed to render the material more eco-friendly while enhancing its mechanical properties.
To evaluate the viability of this approach, the researchers embarked on a series of experiments. Employing a traditional chemical reaction involving CO2 and phenol, an organic compound prevalent in coal and lignin, they observed the incorporation of 2-5 percent carbon by weight.
The researchers combined these particles with HDPE to create innovative composites. They found that a formulation with 80 percent filler achieved optimal CO2 levels while meeting international building standards for strength and durability.
Using PNNL's shear-assisted processing and extrusion (ShAPETM) machine, the team produced 10-foot-long decking boards similar to those currently used in the industry. Remarkably, this approach also reduced manufacturing costs by 18 percent compared to traditional boards.
Moreover, these boards can sequester more CO2 than is emitted during their production. If all US decking boards were replaced with this alternative, approximately 250,000 tonnes of CO2 could be sequestered annually, equivalent to the emissions of 54,000 cars.
Moving forward, the researchers aim to explore new composite formulations while working to bring their carbon-negative boards to market. They plan to make these environmentally friendly products available to building supply retailers by early next summer.
