Modified wood with stronger mechanical properties can retain carbon dioxide

Modified wood with stronger mechanical properties can retain carbon dioxide

Scientists at Rice University in Houston have discovered a way to engineerwood so that it is able to trap carbon dioxide within it. This is through an innovative, scalable, energy-efficient process that makes the wood significantly stronger, which may allow it to be used more widely in applications such as construction.

Construction materials - such as iron, steel, or cement - require a large economic cost in order to produce them, and the building materials industries are energy-intensive industries. Consequently, it produces huge amounts of Greenhouse Gases (GHGs), especially carbon dioxide. Figures indicate that the construction and use of buildings is responsible for about 40% of emissions. Therefore, developing sustainable alternatives to materials used in construction operations will help mitigate climate change and reduce carbon dioxide emissions.

Using wood to trap carbon dioxide

Working to address this important issue, Muhammad Rahman, an assistant professor of materials science and nanoengineering at the George Brown School of Engineering at Rice University, and his collaborators have found a way to incorporate molecules of a crystalline porous material that can trap carbon dioxide in wood; This is according to a study published in the scientific journal “Cell Reports Physical Sciences”.

Rahman said: “Wood is a sustainable and renewable structural material that we already use on a large scale, but we wanted to develop this in a way that helps in other sustainable applications. So the new, innovative, engineered wood has greater strength, compared to regular, untreated wood. To achieve this feat, the network of cellulose fibers that gives wood its strength is first removed through a process known as lignin removal.”

Rahman added: “Wood consists of three basic components: cellulose, hemicellulose, and lignin. The latter is the material responsible for the distinctive color of wood. It is also the material responsible for giving wood its hardness and mechanical properties. Therefore, when the lignin is removed, the wood becomes colorless. Removing lignin is a fairly simple process, and it involves a two-step chemical treatment using environmentally friendly materials. After removing the lignin, the wood goes through a bleaching process, using hydrogen peroxide (H2O2). To remove hemicellulose.”

Then, the wood is soaked in a solution containing tiny particles of a type of metal-organic framework (MOFs), known as 20-CALF. MOFs are highly porous, large-surface-area adsorbents used for their ability to adsorb molecules of certain substances, and have recently emerged strongly as a promising option for capturing and sequestering carbon dioxide.

Modified wood represents an innovative solution for carbon capture and storage

In this context, Soumyabrata Roy, a researcher in materials science and nanoengineering at the university, and one of the lead authors of the study, said: “20-CALF particles fit easily into cellulose channels in wood, as they bind to them through surface interactions.”

MOFs are one of the emerging technologies for carbon capture, a technology developed to help solve human-caused climate change. “Currently there is no biodegradable and sustainable platform to house CO2 absorbers,” Rahman said. The improved wood we have developed with MOFs could provide a suitable adaptable platform; To house sorbents in many different applications, in order to capture and store carbon dioxide.”

It is worth noting that many of the current MOFs are not very stable when exposed to varying environmental conditions. Some of them, for example, are very sensitive to moisture, which would be completely undesirable when using a structural material such as wood, but the “20-CALF” material developed by University of Calgary professor George Shimizu and his team stands out from Where the level of performance and ability to withstand a variety of environmental conditions.

Rahman said: “Manufacturing construction materials - such as metals or cement - represents a major source of industrial carbon emissions. So we wanted to look for a more environmentally friendly material that could be somehow integrated into construction processes. We were able to achieve a simple treatment process on wood that significantly improves its mechanical properties, in addition to its absorption of carbon dioxide.”

The next step for the researchers and those working on this study will be to determine the appropriate processes to isolate carbon dioxide using this treated wood, in addition to a detailed economic analysis, to understand the extent of scalability and commercial feasibility of this material.