	
	follow-up
	Hector.Ybanez 
	to:
	Keith Barnett
	09/17/2010 02:31 PM
	Show Details



History:	This message has been forwarded.







Keith

      During our August 31, 2010 meeting we discussed numerous issues and
as part of that discussion we identified some follow-up items.  Follow-up
items included (i) article regarding the design of wet scrubbers to control
HCl and SO2; (ii) Clinker production; (iii) Calculation of 30-day rolling
average expressed in lb per ton of clinker; and (iv) the alternative PM
limit for combined sources.

        HCl and SO2 have different optimum pHs where maximum adsorption
occurs.  For example; the optimum pH for HCL is between 2 and 3 and the
optimum for SO2 is about 7.  Therefore, it is possible that EPA's
assumption; that any SO2 scrubber will additionally control HCl emissions
to the degree necessary to meet the final standard.  The second item deals
with measuring clinker production.  This is an important issue to the
cement industry.  For instance, each plant is equipped with specific
measuring devices (i.e. weight feeders) to determine the daily production.
In accordance with CORPORATE guidelines, if the difference between the
measured value and the value calculated based on the Monthly Inventory
Verification Process is 5% or greater the plant must calibrate the
measuring device.  This is how many (if not all cement manufacturing
facilities) complete their month end closures.  My concern is that the
final promulgated rule is written with no realization of the operational
realities.  To that end, EPA should clean-up this matter as part of its
efforts to improve the Final Rule.  However, in the meantime, I think that
this can be accomplished using an alternative monitoring request.  Would
you agree with that approach?

      On the third item you asked for our opinion of how to best calculate
a 30-day rolling average.  We would agree that each 30-day average is best
calculated by dividing the total mass of pollutant emitted in 30-days by
the total mass of clinker produced in 30-days.

The fourth major item deals with the alternative particular matter (APM)
limit.  The final rule describes the situation when there is an alkali
bypass associated with a kiln, the combined PM emissions from the kiln or
in-line kiln/raw mill and the alkali bypass stack are subject to the PM
emissions limit of 0.04.  Existing kilns that combine the clinker cooler
exhaust with the kiln exhaust for energy efficiency purposes and send the
combined exhaust to the PM control device as a single stream may meet an
alternative PM emissions limit.  This limit is calculated using the
following equation:

         PM alt  =  0.004 x 1.65 x (Qk + Qc)/7000

However, the industry contains numerous other plant configurations not
addressed by the final rule.  For instance, several plant configurations
include the following:

   a.   In-line kiln/raw mill, alkali bypass, and in-line coal mill
   b.   In-line kiln/raw mill and in-line coal mill
   c.   In-line kiln/raw mill, alkali bypass, in-line coal mill, and cooler

Holcim believes that the above configurations should be allowed to use the
above equation to establish an alternative PM limit. Item "c" above fits
the definition in the final rule with the exception of the in-line coal
mill.  The in-line coal mill can use hot gases from the kiln or the cooler
and Holcim recommends that depending on the configuration Qk or Qc should
include airflow volumes associated with the in-line coal mill.  Items "a"
and "b" above are configurations where the clinker cooler vents to the
atmosphere however because of the in-line coal mill we believe that the
appropriate alt PM limit equation is:

                  PM alt  =  0.004 x 1.65 x (Qk + 0)/7000

      Where Qk would include those sources listed in items "a" or "b"
associated with the kiln and in that case Qc would equal zero.  Qc would
equal zero because the cooler in such configurations is vented to
atmosphere. I think that this can be accomplished using an alternative
monitoring request.  Would you agree with that approach?


Let's discuss these issues once more if you need any additional
clarifications.

Thanks


(See attached file: HCL and SO2 Scrubbers.pdf)



_____________________

Hector Ybanez
Corporate Manager, Environmental
122 West Carpenter Freeway
Suite 485
Irving, Texas 75039
Phone (214) 524 - 2814
Cell (972) 268-1139
Hector.Ybanez@holcim.com
hybanez@gmail.com
www.holcim.com/us
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