Cleaner, More Efficient Method for Capturing CO2
By Grace V. Jean and Sandra I. Erwin
Researchers at Lawrence Livermore National Laboratory have developed a screening method that would use ionic liquids — a special type of molten salt that becomes liquid under the boiling point of water (100 degrees Celsius) — to separate carbon dioxide from its source.
This is a cleaner, more viable and stable method than what is currently available, said a Livermore news release.
Before CO2 emissions from burning fossil fuels can be sequestered, they must first be separated from the source, a step known as “capture.”
Currently, a handful of coal plants with commercial CO2 capture capability use processes based on chemical absorption with monoethanolamine, a general-purpose solvent developed by chemists some 75 years ago. According to Livermore researchers, this method is corrosive, requires the use of large equipment, and effective only under low to moderate partial pressures of CO2.
Chemists recently became interested in ionic liquids because they are solvents with almost no vapor pressure, and do not evaporate, even under high temperature conditions.
A Livermore scientist devised a computational strategy that can reliably screen any solvent, including an ionic liquid, for high CO2 capture efficiency. The expectation is that the accuracy of the computational method will allow scientists to see useful trends, which could potentially lead to the discovery of practical solvents with significantly higher CO2 capture efficiency.