Electrochemical system proposed by the MIT researchers uses special chemicals and electricity to clear CO2 from coal-fired power plants’ emissions.
The novel solution, described in the journal Energy and Environmental Science, improves the existing technology and makes it more ‘user-friendly’.
In the process, a solution containing chemical compounds called amines is injected into the upper part of the absorption column. The amines bind with CO2 in the emission stream which then turns into liquid.
CO2 can later be removed in controlled conditions, using electrodes, regenerating the amines for another cleaning round while the greenhouse gas can be stored in underground reservoirs.
Similar technology has already been proposed but required the power plant to be retrofitted with complex plumbing system that diverts the steam. The biggest advantage of the MIT’s approach is that it doesn’t require any extensive investment.
“Our system is something you just plug in, so you can quickly turn it down when you have a high cost or high need for electricity,” said Michael Stern, one of the authors of the paper.
The innovative solution was praised by other researchers, not working on this particular project. “The electrochemical approach to CO2 capture has been previously proposed by other groups, but with varying degrees of success. What separates his team from the field is that they have demonstrated the first comprehensive study of the thermodynamic and engineering principles that are needed to project the performance of electrochemical systems,” said one of the reviewers.
The amine technology is capable of removing up to 90 per cent of CO2 from the plant’s emissions. While the conventional approach consumes about 40 per cent of a plant’s power output, the new solution would require only about 25 per cent.
So far, the research team, has modelled the process mathematically and performed a small-scale laboratory test. Next, they hope to move on to larger-scale tests to prove the system’s performance. They say it could take five to 10 years for the system to be developed to the point of widespread commercialization.
The authors believe the system might provide a convenient solution for CO2 removal in other settings – for example in submarines and spacecraft where high levels of the gas could harm health of the crew.