Chemical Looping May Make Cleaner Coal-Fired Power Plants Possible
With coal the most abundant of fossil fuels on our planet the search for clean coal power continues. A new 25-Kilowatt facility at Ohio State University reported the results of a week-long test process that if scaled could dramatically reduce pollutants such as nitrogen oxides and CO2 from coal-fired power plants. The next step involves ramping up to a 1 Megawatt facility.
Today's power plants using coal as the primary fuel combine air and a coal powder to create the energy to drive steam turbines. The process pollutes. Scrubbers capture the particulate matter in the outflow gases but do not reduce the CO2 and nitrogen oxide enough to impact greenhouse gas emissions. The pilot plant developed by Ohio State, however, uses a process called chemical looping which doesn't expose the coal to air. Instead coal interacts with iron oxide producing CO2, iron and ferrous oxide in an artificial form called wustite (seen in an image below).
The burning of iron in air produces the energy that then gets converted into electricity. The process produces no nitrogen oxide, so no smog. And the chief byproduct of the process is pure CO2 which can be captured and sequestered.
Ohio State is also experimenting with a variation on this chemical looping process. This one involves gasifying the coal to create syngas, a combination of carbon monoxide (CO) and hydrogen. Iron oxide (rust) is introduced and reacts with the syngas to release oxygen and wustite. The oxygen combines with the CO to form CO2, and the hydrogen to form steam. The CO2 is streamed, captured and sequestered. The wustite then gets exposed to air and forms iron oxide (rust) and heat which then can be used to drive steam turbines. If the iron is exposed to steam it can separate out the hydrogen in the vapour and capture it as a fuel for fuel cells.
In another chemical looping test, calcium oxide from limestone is used to extract oxygen for use in burning coal. The process allows for the capture of pure CO2 while generating the energy needed to power steam turbines.
Although I have consistently ascribed oxymoron to the words "clean coal" it is encouraging to see that we may have answers that legitimately can allow us to continue to rely on coal as a primary energy source. Of course, that means retrofitting old coal powered plants or building new ones that used chemical looping technology. And it still doesn't resolve the issue that we will have to sequester the CO2 byproduct produced by these power plants. That means finding a way to permanently trap the CO2 either deep in the Earth's crust or in the deep ocean where it cannot emerge and further exacerbate the greenhouse effect.
Essays and comments posted in World Future Society and THE FUTURIST magazine blog portion of this site are the intellectual property of the authors, who retain full responsibility for and rights to their content. For permission to publish, distribute copies, use excerpts, etc., please contact the author. The opinions expressed are those of the author. The World Future Society takes no stand on what the future will or should be like.
Free Email Newsletter
To sign up for Futurist Update, our free monthly email newsletter, enter your email in the box below and click Save.
October 24, 2014 - The Nokia Sensing XChallenge has a goal to transform personal health through sensing technology. A $2.25 million purse is on the line for those organizations whether private or institutional that develop smarter digital health solutions incorporating bio-sensor technology. Sensing can be used for detection, assessment, management and treatment of disease.
What if we made the window into a digital device called a Teleportal? What if that were a two-way network that turns the Earth into a digital room with everyone in it? What if that digital world were you-centered and you gained immense abilities? Could your life’s dreams be as close as your screens? Could we build that fully digital world now, decades before it’s expected?
October 23, 2014 - Back in the 17th century our Sun went through a period in which there was an absence of sunspot activity. Known as the Maunder Minimum it lasted for 70 years.
October 21, 2014 - Don't know the answer. Well it's the people who occupy the biggest building in the world, the Pentagon in Washington, D.C.
Testing Forecast Repeatability: Before and After Data on the Move from TechCast.org to TechCastGlobal.com
October 20, 2014 - A recent edition of the journal Nature Communications, includes an article entitled,
October 18, 2014 - Think about it. Why would a small island nation that gets 300+ sunny days a year and fairly constant ocean winds import coal, oil, diesel or liquid natural gas to provide power to its citizens? Why would island nations of volcanic origin with active and passive geothermal capacity not be harvesting these resources rather than burning fossil fuels?