RE: Your Cement NOx ACT Update

Linero, Alvaro 

to:

Bill Neuffer, Keith Barnett

08/31/2007 01:47 PM

Show Details

Bill:

You suggested based on the Texas report that low emissions at TXI are due 

to raw materials.

You may or may not have noticed that TXI Midlothian Kiln 5 and Holcim 

Midlothian Kiln 2 (contemporaneous PH/C projects in the same town) have 

widely different NOx emission characteristics and both employ staged 

combustion in the calciner (SCC).

I got some input from TXI and, together with my assessment and 

reconciliation with other reports and experts, here is the story:

The design of the calciner is critical and is the key element. (TXI has 

basically the same design as described for Cemex Sta. Cruz below. Holcim 

has the higher emitting early version of KHD Pyroclon). Both received 

permits in late 1990's or about 10 years ago.

Raw materials can have an effect on total NOx emissions, but are not a 

significant part of the overall equation.

In Midlothian, all three plants (TXI, Holcim, Ash Grove) mine limestone, 

the primary raw material, from the same formation. (Means if raw 

materials were the key, you would see emissions at Holcim Midlothian Kiln 

2 much closer to TXI Kiln 5).
Based on the calciner design TXI can do about 2 lb/ton. But they do even 

better - why?

They use some steel slag (CemStar) that reduces their overall energy 

need, 

reduces amount of limestone they must calcine, and allows kiln to operate 

at lower temperature. Hence less NOx than 2 lb/ton and much less than 

Holcim Midlothian Kiln 2.

That is why TXI does 1.7 lb NOx/ton or better and according to the Texas 

report is assumed to perform at 1.5 lb/ton prior to consideration of 

further NOx reduction strategies.

With this information and what I sent you regarding Titan Miami and Cemex 

Sta. Cruz as well as the daily details from Florida Rock (SCC using 

tires), I am confident in stating that a modern SCC system can do 2 

lb/ton 

on long term rolling average.

Additional control equipment might allow such facilities to back off on 

the aggressiveness of their SCC equipment and e.g. run it at 3 lb/ton 

while relying on SNCR at 33 to 67% reduction to achieve 2 or 1 lb/ton of 

clinker depending on permit conditions. But if their limit is 2 lb/ton 

on 

a 30-day average, they can tune their SCC system (as Cemex, Titan, TXI) 

to 

2 lb/ton and even 1.5 lb/ton with Cemstar.

TXI commented the following which they think is the best reason why their 

numbers are low: 

"One thing, which we feel is equally critical, is the desire and 

determination of our operations team to maximize the output and 

efficiency 

of the system. Without the people working toward the reduction of NOx, 

the design is just steel, motors, and fans."

I think it is accurate about the way they (TXI) run their plant. I think 

there are some throughout the country who do not run their plants in this 

manner and often rely on after-the-fact efforts and agency interactions 

to 

raise their NOx numbers when they don't meet them. 

I wouldn't create a new category (CemStar or well-run plants). I think 

it 

is enough to note the use of a successful SCC design at TXI, Cemex Sta. 

Cruz, Titan) and not accept failed designs or unoptimized installations 

in 

your baseline of what can be done prior to further control.

Al Linero.

From: Linero, Alvaro 

Sent: Monday, August 20, 2007 5:04 PM
To: Neuffer.Bill@epamail.epa.gov

Subject: NOx emissions from Cemex Sta Cruz.

Bill:

I talked with Monterey Bay District and Cemex rep. on conference call.

I'm convinced about the Cemex Sta. Cruz value of 2 lb/ton clinker.

You can follow up on this yourself if you want, but I would just quote 

the 

attached article and me as the source of the 2 lb/ton.

When I get some CEMS data I will let you have it.

I know your are busy with OMB and other things.

That's part of the reason I work hard at this.

Just call after you digest.

Thanks.

Al.

-----Original Message-----

From: Linero, Alvaro 

Sent: Mon 8/20/2007 4:57 PM 

To: msewell@mbuapcd.org; duane.cannon@cemex.com 

Cc: 

Subject: RE: NOx emissions from Cemex Sta Cruz.

Thanks Mike and Duane.

I had inferred from the Title V limit of 250 lb NOx/hr on a 24-hr basis 

that the long-term emissions might be around 220 lb/hr and the long term 

production around 110 tons per hour yielding 2 lb/ton clinker. I had 

heard a few years back that on a good day they could crank out 120 tons 

of 

clinker per day.

Sounds like we agree.

Here is the paper that F.L. Smidth wrote about their developmental work 

at 

the plant.

They concluded that the design ought to be able to achieve about 400 

mg/m3 

at 10% O2. That equates to a little less than 2 lb/ton.

Mike, please send a few months worth of publicly available lb/hr data and 

maybe the RATA tests.
Thanks again.

Al Linero