Saving carbon in buildings can help against the greenhouse effect

Jan. 13 () –

Combined with measures to decarbonize the economy, storing CO2 in buildings could help the world achieve the objectives of reducing greenhouse gas emissions.

Civil engineers and earth systems scientists at the University of California at Davis and Stanford University have found in a new study published in the journal Science how building materials like concrete and plastic have the potential to trap billions of tons of carbon dioxide.

“The potential is quite big,” he said. in a statement Elisabeth Van Roijen, who led the study as a graduate student at UC Davis.

The goal of carbon sequestration is to take carbon dioxide, either from where it is produced or from the atmosphere, convert it into a stable form and store it away from the atmosphere where it cannot contribute to climate change. Proposed schemes have involved, for example, injecting carbon underground or storing it in the deep ocean. These approaches pose practical challenges and environmental risks.

“What if, instead, we could harness the materials we already produce in large quantities to store carbon?” Van Roijen said.

Collaborating with Sabbie Miller, an associate professor of civil and environmental engineering at the University of California, Davis, and Steve Davis at Stanford University, Van Roijen calculated the carbon storage potential in a wide range of common building materials, such as concrete (cement and aggregates), asphalt, plastics, wood and brick.

More than 30 billion tons of conventional versions of these materials are produced worldwide each year.

CONCRETE POTENTIAL

The carbon storage methods studied included the addition of biocarbon (obtained by heating waste biomass) to concrete; the use of artificial rocks that can be loaded with carbon as aggregate for concrete and asphalt pavement; plastics and asphalt binders based on biomass instead of fossil petroleum sources; and the inclusion of biomass fiber in bricks. These technologies are in different stages of preparation, some are still being investigated at laboratory or pilot scale and others are already available for adoption.

The researchers found that while bio-based plastics could absorb the most carbon by weight, by far the greatest potential for carbon storage is in the use of carbonated aggregates to make concrete. This is because Concrete is by far the most popular construction material in the world: More than 20,000 million tons are produced every year.

“If possible, a little storage in the concrete could go a long way,” Miller said. The team calculated that if 10% of global concrete aggregate production were carbonatable, could absorb a gigaton of CO2.

The raw materials for these new building materials manufacturing processes are mostly low-value waste materials, such as biomass, Van Roijen said. The implementation of these new processes would increase their value, creating economic development and promoting a circular economy, he said.

Some technological development is needed, particularly in cases where the material performance and net storage potential of individual manufacturing methods must be validated. However, many of these technologies are waiting to be adopted.Miller said.