p. 1 of 5 

From: Coomes, Jamie [mailto:JCoomes@centuryky.com] 

Sent: Thursday, August 21, 2014 9:05 AM 

To: Putney, David; French, Chuck; David Green; Marksberry, James; Paulin, Nick 

Subject: RE: Discuss Cent Al of KY bake furnaces 

• David, just 2 comments or clarifications ; 

• The addition rate of unreacted alumina to the dry alumina scrubber/baghouse system associated with the

bake furnaces at this facility is similar to the addition rates utilized in dry alumina scrubber/baghouse systems 

associated with bake furnaces at other primary aluminum facilities;- The rate at which the alumina is fed to 

our scrubber is adequate for scrubbing our POM and TF emissions. We are not aware of what other facilities 

alumina feed rates are with their bake scrubbers. 

The firing operations (e.g., natural gas fuel usage, pitch burn rate and temperature) of the bake furnaces at the 

Century Aluminum of KY facility are manual (as opposed to automatic). As far as Century Aluminum of KY

facility personnel are aware, their facility is the only primary aluminum production facility whose bake furnaces 

utilize manual firing operations; and- We operate our furnaces manually. We stated that our facility in Sebree 

has an automated firing system. We do not know if we are the only facility that operates its firing system 

manually. 

Thanks 

Jamie 

From: Putney, David [mailto:putney.david@epa.gov] 

Sent: Wednesday, August 20, 2014 8:22 PM 

To: French, Chuck; Coomes, Jamie; David Green; Marksberry, James; Paulin, Nick 

Subject: RE: Discuss Cent Al of KY bake furnaces 

Hello all,

Just a quick note to summarize our discussion of the bake furnaces at the Century Aluminum of KY earlier 

today. If you notice any errors or omissions, please let me know by close of business this Friday (08/22/14).

Summary of facts:

• Century Aluminum of KY operates 3 anode bake furnaces whose emissions are comingled and then 

routed through a dry alumina scrubber/baghouse system; 

• PM emissions from the bake furnaces are tested annually by the same contractor. These PM emission 

rates have varied over the years by a factor of about 7 and between the runs of a given 3 run test they have 

varied by as much as an order of magnitude; 

• The dry alumina scrubber/baghouse system associated with the bake furnaces at this facility is equipped 

with a bag leak detection system which has not indicated bag leaks during the test runs associated with the 

higher PM emissions rates; 
p. 2 of 5 

• Visible emissions observations made during the PM tests run on dry alumina scrubber/baghouse system 

associated with the bake furnaces at this facility have not indicated elevated visible emissions during the test 

runs associated with the higher PM emissions rates;

• Century Aluminum of KY personnel are not aware of any operating conditions or throughput variations 

which occurred during the PM tests runs associated with the higher PM emissions rates that would explain 

those higher PM emissions rates; 

• The addition rate of unreacted alumina to the dry alumina scrubber/baghouse system associated with 

the bake furnaces at this facility is similar to the addition rates utilized in dry alumina scrubber/baghouse 

systems associated with bake furnaces at other primary aluminum facilities; 

• The dry alumina scrubber/baghouse system associated with the bake furnaces at this facility is essentially 

the same control system utilized to control emissions from bake furnaces at other primary aluminum facilities; 

• Century Aluminum of KY facility personnel conduct a bake furnace exhaust manifold check every 4 hours 

to ensure the proper work practices are being implemented and that excessive pre-control system emissions 

are not being generated; 

• The firing operations (e.g., natural gas fuel usage, pitch burn rate and temperature) of the bake furnaces 

at the Century Aluminum of KY facility are manual (as opposed to automatic). As far as Century Aluminum of 

KY facility personnel are aware, their facility is the only primary aluminum production facility whose bake 

furnaces utilize manual firing operations; and 

• Century Aluminum of KY facility personnel estimate that the capital costs associated with installing the 

automatic bake furnace firing operations would be around $8 million to $10 million. 

Follow up items:

• Century Aluminum of KY facility personnel will provide EPA with electronic copies of the test reports 

associated with the bake furnace PM testing during 2012, 2013 and 2014; 

• Century Aluminum of KY facility personnel will provide EPA with information on the air to cloth ratio of 

the dry alumina scrubber/baghouse system associated with the bake furnaces at that facility; 

• Century Aluminum of KY facility personnel will discuss the higher grain loading associated with the test 

runs conducted on 06/20/12, 06/10/14, and 06/11/14 with BWF (the supplier of filter bags utilized in the dry 

scrubber/baghouse system associated with the bake furnaces at their facility) and provide EPA with a summary 

of those discussions; 
p. 3 of 5 

• Century Aluminum of KY facility personnel will provide EPA with a summary of the exhaust manifold 

check that they perform every 4 hours (i.e., a list of the associated work practices, etc.); 

• EPA personnel will review the test reports associated with the bake furnace PM testing during 2012, 2013 

and 2014 in search of any explanation of the higher test runs; and 

• EPA personnel will contact The Aluminum Association for information on whether or not any member 

companies utilize manual bake furanace firing operations at any of their primary aluminum production plants. 

Thanks.

David Putney, Environmental Engineer

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Sector Policies and Programs Division

109 T.W. Alexander Drive, RTP, NC 27711

Mail Drop D243-02

Ph: (919) 541-2016 Fax: (919) 541-3207

Email: putney.david@epa.gov

-----Original Appointment----- 

From: Putney, David 

Sent: Friday, August 08, 2014 3:07 PM 

To: French, Chuck; Coomes, Jamie 

Subject: Discuss Cent Al of KY bake furnaces 

When: Wednesday, August 20, 2014 10:00 AM-11:00 AM (UTC-05:00) Eastern Time (US & Canada). 

Where: RTP-Line-541-1591/Phone-Line/RTP-Conf-Bridge 

 

 

Hello all, 

 

Let’s have a telephone conference to discuss the bake furnaces at the Century Aluminum of KY facility (see 

associated email string below). I have scheduled the discussion for 10:00 AM eastern time (9:00 AM central 

time) on call in line (919) 541-1591. 

 

Please let me know if this date or time does not work for you. 

 

Thanks, 

 

David Putney, Environmental Engineer 

U.S. Environmental Protection Agency 
p. 4 of 5 

Office of Air Quality Planning and Standards 

Sector Policies and Programs Division 

109 T.W. Alexander Drive, RTP, NC 27711 

Mail Drop D243-02 

Ph: (919) 541-2016 Fax: (919) 541-3207 

Email: putney.david@epa.gov

 

 

 

From: Coomes, Jamie [mailto:JCoomes@centuryky.com] 

Sent: Friday, August 08, 2014 10:51 AM 

To: Putney, David 

Subject: RE: PM from bake furnace at Century Aluminum of KY facility 

 

Yes I believe it would be good for us to talk through what the proposed PM limit may be and what if any 

progress has been made on changing the way we calculate our emissions based on three furnaces (one new

and two existing) ducted to a common control device . I know Sean Lane had sent you some information on 

this point.

IM available Tuesday or Wednesday of that week at 9:00 AM CST. 

I will have a representative from the bake furnace operations, scrubber operations and stack testing company 

on the call.

Thanks

Jamie

From: Putney, David [mailto:putney.david@epa.gov] 

Sent: Friday, August 08, 2014 9:36 AM 

To: Coomes, Jamie 

Cc: French, Chuck 

Subject: FW: PM from bake furnace at Century Aluminum of KY facility

 

Jamie,

With regards to the new (June 2014) PM emissions test data for your bake furnaces - I assumed bake furnace 

operation for 720 hours during June (24 hours per day for 30 days) and 13,896 tons of green anode (this is the 

average of the historical values provided in your email dated 05/28/14) and came up with an emissions value 

of 0.178 lb PM per ton of green anode for the testing done in June 2014. This is probably off a bit since I used 

an average green anode value as opposed to the actual value for June 2014 – but close. So, over the last 14 1⁄2 

years the PM emissions from this source have ranged from about 0.025 lb PM per ton of green anode (May of 

2009) to about 0.178 lb PM per ton of green anode (June of 2014). That is, the highest value is about 7 times 

the lowest value. This is quite a bit of variability, especially for a source controlled via dry alumina scrubbers 

(as my records indicate).

I think we need to set up a conference call with some personnel from your facility to discuss the bake furnaces 

at the Century Aluminum of KY facility. Specifically, I would like to discuss:
p. 5 of 5 

• Whether, perhaps, some aspect of the associated operations would suggest that the bake furnaces at 

your facility should be in a separate subcategory than those at other primary aluminum facilities;

• The representativeness (or lack thereof) of the tests associated with higher PM emissions from the bake 

furnaces (i.e., April of 2001, April of 2007, May of 2010, June of 2012, and June of 2014); and

• Any information Century Aluminum of KY personnel may have which could help explain the high 

variability in the PM emissions from the bake furnaces at this facility (e.g., bag failures during testing, new 

personnel operating the associated controls, etc.).

As I mentioned in my email dated 05/23/14, based on the data I currently have available, it would appear that 

the bake furnaces at the Century Aluminum of KY facility would have trouble consistently meeting the 

associated MACT floor (based on testing conducted on bake furnaces at 7 primary aluminum facilities in 2013). 

It is imperative that we determine whether or not this is indeed the case before the upcoming residual risk and 

technology review (RTR) amendments to the primary aluminum reduction facility NESHAP are finalized.

Would Century Aluminum of KY personnel be available for such a telephone conference some time on Tuesday 

(08/19/14) through Friday (08/22/14)? If so, please send me a list of preferred dates/times for such a

conference call. If not, then please send me a list of alternative preferred dates/times for such a conference 

call.

Thanks so much.

David Putney, Environmental Engineer

U.S. Environmental Protection Agency

Office of Air Quality Planning and Standards

Sector Policies and Programs Division

109 T.W. Alexander Drive, RTP, NC 27711

Mail Drop D243-02

Ph: (919) 541-2016 Fax: (919) 541-3207

Email: putney.david@epa.gov