Case Study #1: Glass Furnace Exhaust for Container
and Flat Glass Manufacturing
Case Study #2: Glass Fiber Manufacturing Case Study #3: Fiber Optics Manufacturing
Case Study #4: Abrasives, Ceramics and Other
Non-Soluble PM2.5 and Submicron Particulate
Case Study #5: Coal and Solid Fuels Combustion
Case Study #6: Diesel Exhaust Emissions /
Locomotive Diesel Pollution
Case Study #5:
Coal Fired Boilers and Solid Fuels Combustion
Coal-fired Boilers. Applications where several pieces of conventional equipment
are required to meet regulations provide an opportunity for the Cloud Chamber Scrubber (CCS)
to showcase its unique capabilities as a multi-pollutant device. There are many instances where
coal fired boilers require removal of particulate, chlorine in the form of HCl, and mercury in its
various forms to achieve industrial boiler MACT compliance. In addition, regulations for new
sources and/or additional regulations that apply in certain locations have strict limitations on
SO2 for flue gas.
Tri-Mer Corporation, in cooperation with a major mid-western university, has completed pilot testing
on coal combustion, testing the flue gas from a 1950s vintage coal-fired boiler at the physical plant
that produces steam for the campus. An isokinetic slipstream was taken to the CCS pilot unit from a
point in the exhaust flow following the multiclone and prior to the stack. The tests were conducted over several weeks in November of 2005. A third-party testing company was engaged. Results from the
CCS were excellent and surpassed expectations of the operator of the coal fired boilers.
Test results were presented at the CIBO (Council of Industrial Boiler Owners) Emissions Control
conference in 2006. Flue gas from coal combustion contains a high percentage of submicron
particulate. As such, older technologies such as dry ESP are ineffective in this range and often
unable to meet the regulations. In the case of the CCS, particulate was reduced to one-ninth
of the PM limit for existing coal fired boilers. See Graph 1.
Particulate Removal
Graph 1. Particulate removal. The first two bars indicate the outlet concentrations of the
non-condensable particulate from the boiler and multiclone, prior to treatment by the CCS.
The Boiler MACT for existing units is 0.07 lbs/MMBtu and 0.03 for new units. The final bar
shows the concentration at the CCS stack for a total system removal including the multiclone
of 99%. These results are from a third-party testing firm using approved EPA methods.
Mercury was reduced by 89% to less than one-tenth of the limit for existing boilers. This is less
than one-tenth of the regulation limit. This type of coal has wide variability in mercury (as reported
by other users in the state) and there was concern that some loads could exceed the regulations,
so the reported levels were considered “borderline” and the ability of the CCS to capture
mercury deemed important.
The success on mercury is due to the fact that a fraction of the mercury exists as a condensable
(posing special problems for ESP and baghouses), and that other forms of mercury are generally
associated with the submicron and ultrafine (below 0.1 micron) fraction of the particle distribution.
The pre-conditioning chamber of the CCS cools the flue gas to saturation, causing condensables
to form. The charged droplets are then able to collect a high percentage of these condensables
in addition to the other submicron and even ultrafine particles. See Graph 2.
Mercury Removal
Graph 2. Mercury removal, all forms. The Boiler MACT for existing units is 9.0 lbs/TTBtu and for
new units 3.0 lbs/TTBtu. The final bar shows the mercury concentration at the CCS stack for a
total system removal including the multiclone of 89%. These results are from a third-party testing
firm using approved EPA methods.
The CCS simultaneously removes both the particulate and the gases. While hydrochloric acid gas
was not out of compliance for this type of coal, the testing was structured in a general way to reflect
industrial boiler MACT compliance. There are families of coal that have a high chlorine content.
The CCS removed over 99% of the HCl gas. See Graph 3.
HCl Removal
Graph 3. HCl removal. The third bar shows the Boiler MACT limit of 0.09 lbs/MMBtu for existing
units and the fourth bar the limit of 0.02 lbs/MMBtu for new units. The final bar indicates the
concentration at the stack of the CCS for a removal of over 99%. These results are from a
third-party testing firm using approved EPA methods.
While there is not an SO2 requirement for industrial boiler MACT compliance, other federal
regulations require limitations of 0.2 lb/MMBtu or over 90% reduction on new units. There are
also overarching federal regulations for non-compliance areas that require SO2 abatement,
and/or local and state regulations that control acid rain gases. Sulfur content in coal varies
widely between types of coal. The CCS is able to remove over 99% of SO2, as indicated in
the summary below which shows CCS performance compared to industrial boiler MACT
compliance requirements for existing boilers. See Graph 4.
Graph 4. CCS performance test results for PM, Hg, HCl on a typical coal-burning industrial boiler
substantially out of MACT compliance. The boiler was an older model using only multi-clone bulk
removal of coarse particles. SO2 removal was also important for this project.
Have a potential application? Tell Us About It . . .
We Can Help You with Some Guidelines.
For more information contact:
Kevin Moss (801) 294-5422
kevin.moss@tri-mer.com
(NOTE: For larger particulate, see Whirl /Wet® page.)
See our CCS Scrubber Q&A Page for more information.
CCS HOME / CCS NEWS / CLOUD CHAMBER SCRUBBER BULLETIN /
CCS or Fabric Filters / Baghouses? Considerations and Comparisons /
HISTORY / PILOT TESTING / CCS Q&A / CONTACT US / TRI-MER HOME
Tri-Mer Corporation
1400 Monroe Street
P.O. Box 730
Owosso, MI 48867; USA
Phone: (989) 723-7838
Fax: (989) 723-7844
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