Exploring more cost-effective methods for CO2 Capture
My name is Bob Perry and I’m a chemist in the Chemical Technologies and Materials Characterization (CTMC) Laboratory at GE Global Research. My team has been working on a Department Of Energy sponsored program on capturing CO2 from coal-fired power plants for a little over a year. We are presenting our work today at the American Chemical Society (ACS) National Meeting. In fact, we’re also participating in a press conference on the project with ACS. It’s all very exciting.
As you may know, there are hundreds of power plants throughout the U.S. and the world that rely on coal as their energy source. These plants not only generate hundreds of gigawatts of electricity but billions of tons of CO2 every year. Currently, there are no CO2 -capture technologies in full-scale operation at coal-fired power plants, although there are several technologies that are being tested in pilot and slip stream scale. However, these routes have been calculated to significantly increase the cost of electricity (COE) if incorporated in a traditional coal plant. Our objective was to find a solvent-based process that would be efficient in capturing CO2 but still have a minimal effect on COE.
The approach we’ve taken is to design and synthesize a solvent that has a combination of chemical and physical CO2 absorbing properties that allow a high CO2 loading. In addition, the solvent is also designed to be more thermally stable than existing materials, possess a lower vapor pressure (so that it doesn’t evaporate as readily and need to be replaced as often) and has a more favorable CO2 absorption and desorption profile so that more CO2 can be carried and released by the solvent during use.
This seems like a tall order, but our team of chemists, chemical engineers and molecular and process modelers from GE Global Research, GE Energy and University of Pittsburgh have found that certain amino silicones meet these requirements. Interestingly, amino silicones are one of the active ingredients in hair conditioners. Preliminary experiments have indicated that a couple of materials in this class, when combined with a glycol co-solvent, have up to a 50% improvement in CO2 capture capacity, boil substantially higher than benchmark organic amines, and do not require an aqueous medium in which to perform. All these attributes combine to provide a CO2 capture solvent with lower calculated COE.
A continuous absorption/desorption unit is currently under construction, which will validate these early observations. Stay tuned as this unit comes on line.