From: O’Hare, Andrew <AOhare@cement.org> 

 

 To: Sharon Nizich/RTP/USEPA/US@EPA 

 

 Date: 11/30/2011 03:26 PM 

 

 Subject: FW: Thursday Conf Call with EPA 

 

Sharon,

Curtis Lesslie with Ash Grove has provided a response to your query from his 

perspective which we may discuss on the call tomorrow.

Regards,

Andy

From: Curtis Lesslie [mailto:curtis.lesslie@ashgrove.com]

Sent: Wednesday, November 30, 2011 2:43 PM

To: O’Hare, Andrew

Cc: Satish Sheth; Michael.Pelan@lafarge-na.com; Nugent, Daniel; 

Hector.Ybanez@holcim.com; Jason.Morin@holcim.com; tmatz@htcnam.com

Subject: Re: Thursday Conf Call with EPA

Andy:

Not sure if anyone else has attempted to provide a response to EPA's questions, 

but I put together the following, for what it's worth, if you want to consider 

providing something to them prior to our call.

1. How variable is the exhaust flow and Hg content of the kiln exhaust ducted 

from the kiln to the coal mill?

In-line coal mills that rely solely on kiln gas for heat can only operate with

the kiln is up, but do not operate at all time when the kiln is up (there is a 

ground coal storage bin for periods when the coal mill is down). When the coal 

mill is operating, the flow typically is about 7% to 10% of the kiln gas flow. 

Ash Grove's in-line coal mills run in the range of 15,000 to 20,000 cfm and flow 

should be stable when operating normally.

The gas supplied to the coal mill comes off the preheater tower. I am not aware 

of there being much mercury emissions data available from coal mill stacks. Data 

from our Durkee plant indicates that emissions of mercury from the coal mill are 

in the range of 3 lb/MM ton clinker (vs.

2670 lb/MM ton clinker at the kiln stack (if uncontrolled)). Mercury is a 

strange beast, but if the Durkee data is applied across the industry, we would 

expect very, very low mercury emissions from in-line coal mill stacks.
2. Is the kiln exhaust ducted to the coal mill before or after the kiln APC?

As noted above, kiln gas is routed to the coal mill from the preheater tower, so 

it is prior to the kiln APCD. We need gas temperatures in the 500 F range. Most 

kiln APCD inlets now run at maximum temperatures less than 400 F for compliance 

with D/F standards, so this gas would be too cool for use in an in-line coal 

mill.

3. Is it possible to reroute the coal mill exhaust back to the kiln APC? If 

there are facilities that already do this, what is the benefit - cost or 

otherwise?

This will vary by plant, depending on the location of the coal mill in relation 

to the kiln APCD. Of course, one cannot just add 15,000 to 20,000 cfm to any 

existing baghouse without considering the existing flow of the baghouse and 

potential impacts on production by adding this flow. As with any change in the 

method of operation or physical change, changes in the kiln stack flow and 

concentrations also could translate to permitting and/or modeling issues. If the 

stacks are currently permitted separately, it would require some work to get them 

combined.

I am not aware of any coal mill baghouse that subsequently vents to a kiln main 

baghouse, though many do vent to common stack shared with the kiln baghouse. 

Since indirect fired, in-line coal mill baghouses operate more like separators 

(ground coal from drying air), the coal mill baghouse operates independently and 

the kiln baghouse is unnecessary, furthermore, if you have a failure of the coal 

mill baghouse, you don't want to send dried & ground coal into the main baghouse 

when the temperature exceeds 200 F (they typical maximum safe coal mill baghouse 

inlet temperature).

Curtis Lesslie, PE

Vice President Environmental Affairs

Ash Grove Cement Company

11011 Cody St., Overland Park, KS 66210

P: (913) 319-6065

M: (785) 550-6330

www.ASHGROVE.com

On Tue, Nov 29, 2011 at 12:04 PM, O’Hare, Andrew <AOhare@cement.org>

wrote:

>

> Folks,

>

>

>

> A friendly reminder regarding the conference call with EPA on
Thursday, December 1 at 11:30 a.m. EST (details below). Also, I received a few 

questions from Sharon last week (pasted in below), which I explained we could 

discuss on the call. Lastly, I have forwarded to her attention the summary 

status of the various reconsideration issues from our perspective (attached).

>

>

>

> Regards,

>

> Andy

>

>

>

> Sharon’s questions:

>

>

>

> For our discussions next Thursday, I wanted to give you a list of

technical items we are trying to resolve relative to the coal mill that receives 

kiln exhaust. If these are cut and dry, perhaps you can just send me a response 

via email. Otherwise we can discuss Dec 1.

>

>

>

> 1. How variable is the exhaust flow and Hg content of the kiln

exhaust ducted from the kiln to the coal mill?

>

>

>

> 2. Is the kiln exhaust ducted to the coal mill before or after the

kiln APC?

>

>

>

>

>

> 3. Is it possible to reroute the coal mill exhaust back to the kiln

APC? If there are facilities that already do this, what is the benefit - cost or 

otherwise?

>

>

>

>

>

>

>

> From: O’Hare, Andrew

> Sent: Thursday, November 17, 2011 3:05 PM

> To: O’Hare, Andrew; 'Satish Sheth'; 'Curtis Lesslie'; '

Michael.Pelan@lafarge-na.com'; 'Nugent, Daniel'; '

Hector.Ybanez@holcim.com'; 'Jason.Morin@holcim.com'; 'tmatz@htcnam.com'

> Subject: RE: EPA Conference Call
>

>

>

> Folks,

>

>

>

> Just heard back from EPA. Call is scheduled for Thursday, December 1

at 11:30 a.m. EST. Dial in number: (919) 541-4332. Additional details on 

discussion topics to follow. Attached is a thumbnail of the status of the 

reconsideration issues to date.

>

>

>

> Regards,

>

> Andy

>

>

>

> From: O’Hare, Andrew

> Sent: Thursday, November 17, 2011 2:42 PM

> To: 'Satish Sheth'; 'Curtis Lesslie'; 'Michael.Pelan@lafarge-na.com';

'Nugent, Daniel'; 'Hector.Ybanez@holcim.com'; 'Jason.Morin@holcim.com'; 

tmatz@htcnam.com

> Subject: EPA Conference Call

>

>

>

> Folks,

>

>

>

> Sharon Nizich would like to have a conference to review some of the

NESHAP reconsideration issues on Thursday, December 1 at either 11:00 a.m. or 

3:30 p.m. EST. Please pencil in these times and I will be back in touch to 

confirm with additional details.

>

>

>

> Regards,

>

> Andy

>

>

>

> Andrew T. O'Hare

>

> Vice President, Regulatory Affairs

>

> Portland Cement Association

>
> 500 New Jersey Avenue, 7th Floor

>

> Washington, DC 20001

>

> Office: (202) 408-9494

>

> Fax: (202) 408-0877

>

> Cell: (202) 270-0094

>

> e-mail: aohare@cement.org