Onsite Research
Trace Metal Capture Laboratories
|
|
|
CLICK ON GRAPHIC TO ENLARGE
|
|
|
|
|
NETL supports research on integrated, multi-task modeling and experimentation
that is helping to meet Administration goals for reducing mercury emissions
from power plants. The Laboratories' trace metal capture research directly
addresses initiatives of the 2005 Clean Air Mercury Rule and Energy Policy
Act, and 2002 Global Climate Change and Clear Skies Initiatives. By simulating
and studying coal-derived gases, researchers have been able to examine numerous
sorbents and their ability to capture mercury and arsenic. Onsite research
in the area of trace metal capture now is developing low-cost and effective
mercury removal techniques to meet national goals of capturing more than 90
percent of mercury emissions from U.S. coal-fired plants by 2010. This research
has led to several NETL patents for trace metal capture - conceived and studied
at in-house laboratories - that are now licensed and being demonstrated commercially.
|
|
|
CLICK ON GRAPHIC TO ENLARGE |
|
|
|
|
The Photochemical Oxidation (PCO™) Process is a promising
low-cost technology that uses ultraviolet light to capture, oxidize, and enhance
the removal of elemental mercury from the flue gas treatment systems of coal-fired
power plants. Preliminary bench and field tests have achieved a greater than
90 percent oxidation and capture rate in simulated flue gas streams containing
elemental mercury. NETL researchers received the 2005 Award for Excellence
in Technology Transfer from the Federal Laboratory Consortium for the PCO method,
which has been licensed to Powerspan Corp. for commercial application with
subbituminous and lignite fuels.
The Thief Process is a cost-effective alternative to the
use of activated carbon injection (ACI) for removing mercury from flue gas.
The Thief Process involves extracting partially combusted coal from the plant
furnace and re-injecting it as a sorbent. Activated carbons are expensive,
ranging from $500–3,000/ton compared to $90–200/ton for Thief carbon sorbents.
Laboratory-, bench-, and pilot-scale tests, as well as field tests demonstrate
that extracted carbon sorbents are comparable to activated carbons for mercury
capture efficiency. The Thief Process has been licensed to Mobotec USA.
PG Sorbents for Trace Metal Capture from Coal-Derived Gases represent
the most recent collaborative R&D effort in this area, resulting in a Cooperative
Research and Development Agreement (CRADA) between NETL and Johnson Matthey,
PLC. Power Generation (PG) sorbents are used to remove mercury, arsenic, and
selenium in coal-derived fuel gas streams from coal gasification at high temperatures.
NETL has set the foundation for the joint effort by performing initial testing
with various mercury-capturing sorbents.
Onsite facilities used to process and analyze sorbents and gases include laboratory-scale
and bench-scale packed-bed reactors, catalysts, and photochemical techniques.
These state-of-the-art facilities and techniques make it possible for advances
to be made in the trace metal treatment and control of coal-derived gas streams.
Packed-bed reactors:
- Lab-scale reactor – outer diameter ¼-inch-by-20-inch quartz tube with flow rates from 60–120 ml/min
- Bench-scale reactor – outer diameter 1-inch-by-20-inch quartz tube with flow rates from 2–10 l/min
- Gases containing mercury include simulated flue gases, simulated fuel gases, or slipstreams of flue gas from an onsite coal combustion facility
- Mercury continuous emissions monitors (CEMs) measure mercury in the gas phase
- Cold vapor atomic absorption spectrophotometer analyzes spent sorbent
- Operating temperature: ambient to 750°F
For more information, contact Evan Granite |
|
|