Carbon capture and storage is the process of capturing carbon dioxide from the industrial flue gas stream and storing it underground in geological formations. In this process, the cost of capturing CO2 alone accounts for 75% of the total costs involved in sequestering the carbon dioxide. The adoption of CCS is getting delayed due to the high costs of CCS and additional energy requirements. In order to reduce the costs involved in capturing carbon dioxide, researchers and organizations around the world are working on developing new technologies that essentially consumes less energy for capturing CO2 and thus reducing the costs of CCS.
A research team from the Georgia Institute of Technology in Atlanta has developed a new technology using an amines based absorbent called hyperbranched aminosilica (HAS) to allow carbon dioxide capture at much lower energy consumption. Some of the advantages of this technology compared to its peers are as follows:
- HAS can be reused many times without losing its absorption capacity
- Low energy requirement compared to liquid amines
- The solid amines have to be heated to just 110 degrees to release the captured CO2, which translates into 75% lower energy consumption than liquid amines.
The institute is also working on a pilot carbon capture plant in California that aims to capture 2 tons of CO2 per day.
Similarly, a South Korean state laboratory has developed a commercially viable carbon capture system using industrial waste heat that can help power plants cut back on greenhouse gas emissions. The scientists at the laboratory said that the oxyfuel combustion system can effectively capture carbon dioxide gases with minimum drop in efficiency. A normal gas turbine power plant has an energy efficiency of around 57% of input but incorporating a carbon capture system; this number falls to 43-45%. That initial tests using the new systems have shown that efficiency rising to over 50% which experts say is the minimum needed for the carbon capture system to become commercially viable. In certain ideal cases, efficiency reached as high as 70% by making maximum use of waste heat and stream that is currently discarded.