
Perfecting the Most Sustainable Building Material
Wood is one of the most sustainable building materials and it has gradually regained its popularity in the architectural world. Here, we´ll update you on what´s happening in the world of wood innovation.
It´s well known to our readers that timber used in construction has the ability to continue absorbing CO2 from the environment for years, as part of a building. Additionally, because it is a light, firm and resistant material, its ease of use means that any construction project can be disassembled or adapted to new ideas. But what if you were told that it could be strengthened over time? Would you believe that’s possible?
This very question was asked by scientists at Rice University in Texas, U.S.A., as they seek to make wood an even more sustainable building material in order to counteract the CO2 emissions of the construction industry, one of the most polluting industries on the planet.
Wood and Science
Specifically, the scientists aim to create a construction material with lower emissions and lower construction costs. Consequently, they have devised a type of engineered wood that is capable of capturing carbon dioxide (CO2) while it is strengthened in the process.
While still in the testing phase, this is called “engineered wood” because it is a product that has undergone chemical or thermal treatment, to specialize this material for construction, in this case.
The essential components of the wood (cellulose, hemicellulose and lignin) are treated. First, it is subjected to a delignification process by chemical treatment with environmentally friendly substances, resulting in a colorless wood, followed by a procedure based on bleach or hydrogen peroxide that removes the hemicellulose, which acts as a bridge between cellulose and lignin.
Once this process is complete, the wood is immersed in a solution containing Calgary Framework 20 (CALF-20) organometallic framework (MOF) microparticles, developed for large-scale CO2 absorption and noted for its performance and versatility. The MOF types are crystalline porous materials that bind easily to cellulose and have high absorption capacity, so a resistant solution that would not be affected by moisture was carefully selected, leading to the development of CALF-20. This way, the combination between the microparticles of this MOF and wood cellulose maximizes the capture of CO2 molecules.
As described by Soumyabrata Roy, co-author of the study, “the MOF particles easily fit into the cellulose channels and get attached to them through favorable surface interactions”.
Moreover, CALF-20 MOF microparticles are also being tested in different capacities; as a CO2 scavenger in other areas of construction, as well as specialized machinery for the decontamination of this greenhouse gas, capable of absorbing up to 1 ton of CO2 per day in cement plants.
Sustainable Construction
Although more tests are needed before launching this engineered wood in the market, the premise of the researchers is promising – even more so in a market that has gradually opted for wood as a preferred building material, thanks to options such as Mass Timber or CLT. Between 2020 and 2021, the number of Mass Timber buildings in the U.S. increased by 50%, reaching more than 1,300, according to The Wall Street Journal. As we have seen in previous articles, examples include skyscrapers from all around the world as well as the popularization and advantages of CLT modular buildings.
According to Muhammad Rahman, scientist and researcher on the team, this is explained by the fact that “the manufacturing of structural materials such as metals or cement represents a significant source of industrial carbon emissions. Our process is simpler and ‘greener’ in terms of both substances used and processing byproducts,” he said, as reported by the site Xataka.
You can find the full research paper on this engineered wood in the scientific journal Cell Reports Physical Science.
Timber has been at the forefront of sustainable construction in recent years, with more and more and better wood innovations to implement in pursuit of a more sustainable and greener world for all.