Keith Barnett/RTP/USEPA/US 
05/23/2008 12:42 PM	To
Cortney_Higgins@omb.eop.gov
cc
"Michael Laney" <mnl@rti.org>, Charlotte Bertrand/DC/USEPA/US, Steve 
Fruh/RTP/USEPA/US@EPA, Steven Silverman/DC/USEPA/US@EPA
bcc

Subject
Conversion of cement kiln input to output
	
		
		Dear Courtney:
		
		Here is information the original source of the 1.65 factor of feed to 
clinker:
		
		Docket item II-B-37, A-92-53 (this is the docket for the 1999 Portland 
Cement NESHAP final rule), has a reference for the 1.65 lb feed/ton 
clinker. It was RN Shreve, in Chemical Industries Processes (something  
like that), 1967, p. 171. Apparently the original reference (Chemical 
Industries Processes) is not in the docket.  In docket item II-A-1 or 2, 
there was an EPA document on methods for measuring process feed rate. In 
the appendix, a  
footnote says a typical conversion is 1.6 tons feed per ton of clinker.
		
		I also talked to Hector Ybanez of Holcim (the author of the email I 
sent).  Hector said the theoretical conversion is 1.58 lb feed yields 1.0 
lb clinker.  In reality (due to dust losses) the factor is typically 1.59 
to 1.6.  He described 1.65 as a "good safe number".  
		
		hector said there may be some long dry of wet kilns that are around 1.7 
due to dust removal that is done for product quality reasons, but there 
will be no new long dry or wet kilns built, so these types of kilns are 
not affected by this rulemaking.
		
		Using the "safe" number of 1.65 actually results in a higher standard when 
converting from an input based standard to an output based standard.  
		
		For example, Assume you currently have an input based standard of 0.3 
lb/ton feed.
		
		A conversion factor of 1.65 results in an output based standard of 0.495
		
		A conversion factor of 1.6 results in an output based standard of 0.48.  
Therefore, using the 1.65 factor results in a higher standard and give the 
benefit of doubt to the source.  
		
		I am also forwarding an email form Mike Laney on the Florida data.  I 
assume the conversions in these data were based on site specific 
information supplied to Florida by the plants.  The values are a little 
higher than I would expect based on what Hector told me - ranging from 
1.62 to 1.75 with and average of 1.69.  Maybe Florida raw materials have 
more carbonate than is typical.  However, even the range of the Florida 
data is only an 8 percent difference.  Given that these is already 
considerable variability allowance already built into the proposed rules, 
I would say this variation in input to output ration is not significant.
		
		Keith W. Barnett
USEPA/OAQPS/SPPD/MMG
Mail Code D243-02
Research Triangle Park, NC  27711
919-541-5605
barnett.keith@epa.gov
		----- Forwarded by Keith Barnett/RTP/USEPA/US on 05/23/2008 12:10 PM -----
		"Laney, Michael N." <mnl@rti.org> 
05/22/2008 07:13 PM	
To
Keith Barnett/RTP/USEPA/US@EPA
cc

Subject
FL conversion factors
	

	


The conversion factor used for each kiln is shown on far right of 
spreadsheet. You can also see that FL set some limits in both units of 
lb/ton feed and  lb/ton clinker (limits in blue shaded cells were 
calculated).
 
Michael Laney
Environmental Engineering
Environmental Health & Safety Division
RTI International
TEL:  919-316-3413
FAX:  919-316-3420
EMAIL:  mnl@rti.org
 