follow-up

Hector.Ybanez 

to:

Keith Barnett

09/17/2010 02:31 PM

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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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