New method may turn carbon dioxide into concrete

Scientists, including one of Indian-origin, have devised a unique method that may harness carbon dioxide (CO2) emissions from power plants to create a new, sustainable kind of concrete.

About 5 per cent of the planet's greenhouse gas emissions come from concrete, researchers said.

An even larger source of CO2 emissions is flue gas emitted from smokestacks at power plants around the world. Carbon emissions from those plants are the largest source of harmful global greenhouse gas in the world, they said.

A team of researchers at University of California, Los Angeles (UCLA) has been working on a unique solution that may help eliminate these sources of greenhouse gases.

Their plan is to create a closed-loop process: capturing carbon from power plant smokestacks and using it to create a new building material - CO2NCRETE - that would be fabricated using 3D printers.

"What this technology does is take something that we have viewed as a nuisance - carbon dioxide that is emitted from smokestacks - and turn it into something valuable," said J R DeShazo, professor of public policy at the UCLA Luskin School of Public Affairs.

"This technology tackles global climate change, which is one of the biggest challenges that society faces now and will face over the next century," said DeShazo.

"We hope to not only capture more gas, but we are going to take that gas and, instead of storing it, which is the current approach, we are going to try to use it to create a new kind of building material that will replace cement," said DeShazo.

"The approach we are trying to propose is you look at carbon dioxide as a resource - a resource you can reutilise," said Gaurav Sant, associate professor and Henry Samueli Fellow in Civil and Environmental Engineering at UCLA.

Till now, the new construction material has been produced only at a lab scale, using 3-D printers to shape it into tiny cones.

"We have proof of concept that we can do this," DeShazo said.

"But we need to begin the process of increasing the volume of material and then think about how to pilot it commercially. It is one thing to prove these technologies in the laboratory. It is another to take them out into the field and see how they work under real-world conditions," he said.

"We can demonstrate a process where we take lime and combine it with carbon dioxide to produce a cement-like material," Sant added.