Indian scientists capture carbon with bacteria

A team of scientists from four universities in India say they have discovered a low-cost method of converting carbon dioxide emissions into a into useful building material.

The researchers developed a method to use enzymes to turn CO₂ into calcium carbonate, which can be used in cement or limestone aggregate for building roads. Calcium carbonate, or CaCO₃, is typically found in rocky materials such as limestone and chalk.

The scientists' Rs 98.6 lakh ($202,798) project uses seven bacteria enzymes to speed up chemical reactions and convert carbon dioxide to calcium carbonate.

The chemical reaction can be implemented in places such as inside a factory chimney, according to Sadhana Rayalu, the project coordinator from the National Environmental Engineering and Research Institute, Nagpur.

Halifax, Nova Scotia-based Carbon Sense Solutions and Los Gatos, Calif.-based Calera are also developing chemical processes to convert carbon dioxide into substances that can be used in concrete (see Capturing carbon with concrete). In January, Calera raised $10 million, bringing its funding to more than $17 million from investors such as Khosla Ventures (see Investors keep eyes on water filtration).

Researchers are exploring other methods for carbon sequestration. In February 2008, scientists at the University of California, Los Angeles, used crystal structures to capture carbon dioxide from power plants (see Carbon capture gets crystal powered).

And the Canadian government backed Houston-based Spectra Energy's research to capture carbon with deep underground saline reservoirs (see Spectra Energy looking at carbon capture in Canada).

Aluminum producer Alcoa mixes an aluminum-making byproduct with carbon dioxide to prevent its release into the atmosphere (see Alcoa develops carbon capture for aluminum plants).

The Indian team was comprised of Rayalu, Anjana Sharma of Rani Durgavati Vishwavidyalaya, K. Krishnamurty of the National Environmental Engineering and Research Institute, T. Satyanarayana of Delhi University and A. K. Tripathi of Banaras Hindu University.