Featured Research

from universities, journals, and other organizations

Getting the carbon out of emissions

Date:
June 26, 2013
Source:
Massachusetts Institute of Technology
Summary:
Researchers propose a new method to remove carbon from emissions that could be more efficient than previous systems and easier to retrofit in existing power plants.

Graduate student Michael Stern and his co-workers built this laboratory-scale device to prove the principles behind the electrochemical carbon-capture system.
Credit: Photo courtesy of Michael Stern

Proposed method could be more efficient than previous systems and easier to retrofit in existing power plants.

Many researchers around the world are seeking ways to "scrub" carbon dioxide (CO2) from the emissions of fossil-fuel power plants as a way of curbing the gas that is considered most responsible for global climate change. But most such systems rely on complex plumbing to divert the steam used to drive the turbines that generate power in these plants, and such systems are not practical as retrofits to existing plants.

Now, researchers at MIT have come up with a scrubbing system that requires no steam connection, can operate at lower temperatures, and would essentially be a "plug-and-play" solution that could be added relatively easily to any existing power plant.

The new electrochemical system is described in a paper just published online in the journal Energy and Environmental Science, and written by doctoral student Michael Stern, chemical engineering professor T. Alan Hatton and two others.

The system is a variation on a well-studied technology that uses chemical compounds called amines, which bind with CO2 in the plant's emission stream and can then release the gas when heated in a separate chamber. But the conventional process requires that almost half of the power plant's low-pressure steam be diverted to provide the heat needed to force the amines to release the gas. That massive diversion would require such extensive changes to existing power plants that it is not considered economically feasible as a retrofit.

In the new system, an electrochemical process replaces the steam-based separation of amines and CO2. This system only requires electricity, so it can easily be added to an existing plant.

The system uses a solution of amines, injected at the top of an absorption column in which the effluent gases are rising from below. The amines bind with CO2 in the emissions stream and are collected in liquid form at the bottom of the column. Then, they are processed electrochemically, using a metal electrode to force the release of the CO2; the original amine molecules are then regenerated and reused.

As with the conventional thermal-amine scrubber systems, this technology should be capable of removing 90 percent of CO2 from a plant's emissions, the researchers say. But while the conventional CO2-capture process uses about 40 percent of a plant's power output, the new system would consume only about 25 percent of the power, making it more attractive.

In addition, while steam-based systems must operate continuously, the all-electric system can be dialed back during peak demand, providing greater operational flexibility, Stern says. "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," he says.

Another advantage is that this process produces CO2 under pressure, which is required to inject the gas into underground reservoirs for long-term disposal. Other systems require a separate compressor to pressurize the gas, creating further complexity and inefficiency.

The chemicals themselves -- mostly small polyamines -- are widely used and easily available industrial materials, says Hatton, the Ralph Landau Professor of Chemical Engineering Practice. Further research will examine which of several such compounds works best in the proposed system.

So far, the research team, which also includes former MIT research scientist Fritz Simeon and Howard Herzog, a senior research engineer at the MIT Energy Initiative, has done mathematical modeling and a small-scale laboratory test of the system. 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.

Because it does not rely on steam from a boiler, this system could also be used for other applications that do not involve steam -- such as cement factories, which are among the leading producers of CO2 emissions, Stern says. It could also be used to curb emissions from steel or aluminum plants.

It could also be useful in other CO2 removal, Hatton says, such as in submarines or spacecraft, where carbon dioxide can accumulate to levels that could endanger human health, and must be continually removed.

The work was supported by Siemens AG and by the U.S. Department of Energy through the Advanced Research Projects Agency for Energy.


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. The original article was written by David L. Chandler. Note: Materials may be edited for content and length.


Journal Reference:

  1. Michael C. Stern, Fritz Simeon, Howard Herzog, T. Alan Hatton. Post-combustion carbon dioxide capture using electrochemically mediated amine regeneration. Energy & Environmental Science, 2013; DOI: 10.1039/C3EE41165F

Cite This Page:

Massachusetts Institute of Technology. "Getting the carbon out of emissions." ScienceDaily. ScienceDaily, 26 June 2013. <www.sciencedaily.com/releases/2013/06/130626143110.htm>.
Massachusetts Institute of Technology. (2013, June 26). Getting the carbon out of emissions. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2013/06/130626143110.htm
Massachusetts Institute of Technology. "Getting the carbon out of emissions." ScienceDaily. www.sciencedaily.com/releases/2013/06/130626143110.htm (accessed July 31, 2014).

Share This




More Matter & Energy News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Britain Testing Driverless Cars on Roadways

Britain Testing Driverless Cars on Roadways

AP (July 30, 2014) British officials said on Wednesday that driverless cars will be tested on roads in as many as three cities in a trial program set to begin in January. Officials said the tests will last up to three years. (July 30) Video provided by AP
Powered by NewsLook.com
Amid Drought, UCLA Sees Only Water

Amid Drought, UCLA Sees Only Water

AP (July 30, 2014) A ruptured 93-year-old water main left the UCLA campus awash in 8 million gallons of water in the middle of California's worst drought in decades. (July 30) Video provided by AP
Powered by NewsLook.com
Smartphone Powered Paper Plane Debuts at Airshow

Smartphone Powered Paper Plane Debuts at Airshow

AP (July 30, 2014) Smartphone powered paper airplane that was popular on crowdfunding website KickStarter makes its debut at Wisconsin airshow (July 30) Video provided by AP
Powered by NewsLook.com
U.K. To Allow Driverless Cars On Public Roads

U.K. To Allow Driverless Cars On Public Roads

Newsy (July 30, 2014) Driverless cars could soon become a staple on U.K. city streets, as they're set to be introduced to a few cities in 2015. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins