Reversible Ionic Liquids as Double-Action Solvents
for Efficient CO2 Capture

U.S. Department of Energy Contract #DE-NT0005287

Project Description

The objective of this project is to develop reversible ionic liquids as solvents for post-combustion recovery of CO2 from fossil fuel-fired power plants. These are novel solvents which have been developed by the project team, and are quickly finding many applications. The project team will: (1) create, test, and apply optimum reversible ionic liquids for CO2 capture; (2) do the process design and cost analysis for their implementation; and (3) develop a process for commodity-scale production of these solvents. These novel solvents offer distinct advantages over current methods.


Before carbon dioxide (CO2) gas can be sequestered from power plants and other point sources, it must be captured as a relatively pure gas. On a mass basis, CO2 is the 19th largest commodity chemical in the United States, and CO2 is routinely separated and captured as a by-product from industrial processes such as synthetic ammonia production, H2 production, and limestone calcination. Existing capture technologies, however, are not cost-effective when considered in the context of sequestering CO2 from power plants.


We propose to develop a novel class of solvents for post-combustion recovery of CO2 from fossil fuel-fired power plants which will achieve multiplication of capacity with a concomitant plummet in cost. We propose to use a class of reversible ionic liquids capable of molecular tailoring through structure-property relationships to optimize both physical properties and thermodynamic properties.

Research summary and updates

We shall discuss the strengths and weaknesses of ionic liquids, and show how our development of reversible ionic liquids overcomes the latter. We shall show novel liquids which we have developed for CO2 capture, and show how they can be further improved to perform even better – they have the capability of absorbing from one-third to one-half pound of CO2/pound liquid!


The Eckert/Liotta group occupies the entire northwest wing of the second floor of the new Environmental Science and Technology Building, with about 4000 ft2 of laboratory space, plus separate office space for all researchers. This new space has copious hoods and services, and was designed specifically for the needs of the Liotta/Eckert combined groups.

For the determination of equilibrium constants, we will be using attenuated total reflectance (ATR) fourier-transform infrared (FT-IR) spectroscopy.  The ATR FT-IR optics bench used for data collection will be the Heated Golden Gate ATR accessory.