New York, Sep 20: Researchers in the US have found a new way to cut down pollution caused by carbon dioxide emitted by power plants.
The chemical reactions that are used to carve out caves in limestone can also be useful to capture carbon dioxide emitted from a power plant, MIT Technology Review reported, citing researchers at Standford University and the University of California – Santa Cruz.
The new process using seawater and crushed limestone to capture carbon dioxide will be simpler than the conventional method of carbon capturing and storage (CCS) technologies, and cheaper and more practical.
The researchers at UC-Santa Cruz have demonstrated the idea in laboratory tests, but not yet at an actual power plant.
Conventional CCS is a complex process which first needs to isolate carbon dioxide from other exhaust gases, then compress it and ship it to an underground storage site.
As a result, these old technologies are expensive and haven’t been adopted widely by the emitters.
The new approach is simple and takes only one step to capture and store the carbon dioxide.
“The basic concept is extremely simple,” Ken Caldeira, a professor of Environmental Earth System Sciences at Stanford University, was quoted as saying.
He said the new method speeds up the entire process of capturing carbon dioxide.
When carbon dioxide in air mixes with water it becomes slightly more acidic and if this water comes in contact with limestone, the limestone reacts with carbon dioxide to form calcium bicarbonate – a common material that’s a constituent of hard water.
The new process makes it possible to capture and store 70 to 80 percent of the carbon dioxide emitted from a power plant, says Greg Rau, a senior researcher with the Institute of Marine Sciences at University of California.
The product of the reaction, seawater containing dissolved calcium bicarbonate, can be pumped into the ocean.
If all coastal power plants deployed the technology, they would only modestly increase the amount of calcium bicarbonate already in the ocean as a result of natural processes, he said.
However, the main problem with the new approach is that it will require large amounts of water and limestone.
Coastal power plants already pump large amounts of seawater for cooling, so they’d be the best candidates to use the approach.
Although researchers calculated that the new technique would be cheaper but the efficacy of the new carbon capturing process can only be confirmed after it is tested at a power plant.
Experts say it would help to keep environment clean in areas close to power plants.