Update: The MIT Technology
Review daily newsletter recently featured this
story, and NBC Channel 4 covered it on February 6.
If you missed the broadcast, you can now watch
Dr. Fan's story on NBC4i's website.
On February 20, FoxNews.com featured
this story on
the front page of its website.
Washington, D.C., U.S. Department of Energy — Researchers at The
Ohio State University (OSU) have successfully completed more than
200 hours of continuous operation of their patented Coal-Direct
Chemical Looping (CDCL) technology - a one-step process to
produce both electric power and high-purity carbon dioxide (CO2).
The test, led by OSU Professor Liang-Shih Fan, represents the
longest integrated operation of chemical looping technology
anywhere in the world to date.
The test was conducted at OSU’s 25 kilowatt thermal (kWt) CDCL
combustion sub-pilot unit under the auspices of DOE’s Carbon
Capture Program, which is developing innovative environmental
control technologies to foster the use of the nation’s vast coal
reserves. Managed by the Office of Fossil Energy’s National
Energy Technology Laboratory, the program’s specific goal is to
develop CO2 capture and compression technologies that can reduce
the capital cost and energy penalty of CO2 capture by more than
half—equivalent to CO2 capture at less than $40 per metric
ton—when integrated into a new or existing coal fired power
plant. The successful test moves chemical-looping a step closer
to full scale.
Chemical looping is an advanced technology that offers several
advantages over traditional combustion. In a chemical-looping
system, a metal oxide, such as an iron oxide, provides the oxygen
for combustion. The metal oxide releases its oxygen in a fuel
reactor with a reducing atmosphere, and the oxygen reacts with
the fuel. The reduced metal cycles back to an oxidation chamber
where the metal oxide is regenerated by contact with air. The
metal oxide is then reintroduced into the fuel reactor, thus
completing the loop. Since CO2 separation occurs simultaneously
with coal conversion, chemical looping offers a low-cost scheme
for carbon capture. The process can produce power, synthesis gas,
or hydrogen in addition to high-purity CO2.
OSU reports that the CDCL plant’s 200+ hours of operation, using
metallurgical coke and subbituminous and lignite coals, shows the
robustness of its novel moving-bed design and non-mechanical
valve operation. The combination resulted in nearly 100 percent
solid fuel conversion and a CO2 stream more than 99 percent pure,
making it applicable to CO2 enhanced oil recovery operations.
The OSU project is expected to benefit the DOE Carbon Capture
Program by identifying oxygen carriers and a chemical looping
process having the potential to control multiple pollutants,
including sulfur dioxide (SO2) and nitrogen oxides (NOx), along
with CO2. OSU research aims to identify potential barriers and
optimize the CDCL technology and provide realistic data for
future technological and economic analysis.
In addition to DOE, OSU is partnering on the project with the
Ohio Department of Development, Babcock & Wilcox Power
Generation Group, Inc., CONSOL Energy Inc., and Clear Skies
In a related project, DOE’s National Carbon Capture Center in
Wilsonville, Ala., will serve as the host site for the
construction and operation of a fully integrated 250 kWt
pressurized syngas chemical looping pilot unit starting this
year. The facility will be used to further prove the operability
and economic feasibility of OSU’s advanced chemical looping
Pictured top right: L.S. Fan (right) explains the chemical
looping process to U.S. Department of Energy's Assistant
Secretary of Fossil Energy Charles McConnell<br>