From: "Cerri, Gus" <gus.cerri@honeywell.com> 

To: Deborah Ottinger/DC/USEPA/US@EPA 

Date: 11/13/2009 12:52 PM 

Subject: RE: Proposed Rule and Recap of Questions 

Debbie: 

I read the proposed rules, if I understand them correctly, a fluorocarbon plants would only have 

to track HFC emissions. HCFC's and CFC's would not be tracked. In my opinion the method 

that is proposed could work well for the main HFC product over a reasonably long time period, 

but would be difficult to implement accurately for the byproducts. If I understand correctly that 

only HFC byproducts are covered, then it certainly makes it less complicated, but not problemfree. 

As I mentioned before, daily tracking of the main HFC product from each plant would be difficult 

because it requires information that is often not available on a real time basis (truck and railcar 

weights) and changes in tank levels (which are not particularly accurate values). A longer 

tracking period (about one month or quarterly) would be more meaningful, since we could wait 

until all the truck and railcar weights are in and changes in tank levels become a smaller 

percentage of the total value the longer the time period that is used. Daily tracking of small 

byproducts is just about impossible because these are usually very small numbers so small 

changes in inventory in process equipment, which are impossible to measure, can significantly 

affect the calculated number. Also, recycles in the process make if difficult to determine exactly 

how much of a particular component is made in the reactor. Generally, we can get reasonably 

good estimations of most of the main byproducts, but assumptions have to be made about 

recycles and fugitive losses. In general to operate the unit we can look at ratio of components 

rather than absolute rates to determine if a particular byproduct is within normal range, high, or 

low at any particular time. But normally a single analysis is not necessarily indicative of a trend 

so we will use several analyses over several days before trying to make adjustments if 

necessary. 

In my opinion, tracking the main HFC product by material balance over a reasonable time period 

is feasible. Our overall yield is relatively easy to track because it is a simple issue of material 

balance: how much HFC leaves the plant vs. how much raw material came into the plant. 

However, separating that yield loss into the various ways of losing product is a lot more 

complicated because it involves a lot of small numbers. Yield losses consist of: byproducts of 

reaction that are either destroyed or vented (through permitted vents); product that is not 

separated from these byproducts, and therefore is also lost when the byproduct is destroyed or 

vented; fugitive losses, which consist of product and byproducts, depending where the fugitive 

loss occurs; losses from clearing equipment for maintenance or emergencies (e.g.: pressure 

relief). 

The flow of streams sent to destruction or permitted vents can be measured and analyzed. But 

there are so many components in these streams that it is often difficult to obtain a good analysis 

of the composition on a routine basis. The analysis is simpler if we only have to track the 

HFC's, but again, where there are many components the analysis would still only be an 

estimation (there are often interference between components, unknowns for which response 
factors cannot be determined, etc.). However, it is nearly impossible to accurately determine 

the fugitive and losses for maintenance and emergencies. The amount of these might be 

estimated by material balance (feed in minus product out minus measured losses) over a 

reasonably long period (monthly or quarterly). But it is impossible to accurately determine how 

much of these losses are HFC's or other byproducts of the reaction (HCFC's and CFC's). Even 

the subtraction of raw material in minus product and measured streams to destruction or vents 

to determine the fugitive loss rate can only be an estimation since it requires knowing the 

composition of the known vents and as I mentioned above, that composition will include an 

error. 

Essentially, the issue is that we are trying to measure small differences in large numbers. The 

smaller the difference the more it approaches the error band of the large number. For example, 

if we can measure the raw material and product material balance at +/- 1% accuracy (for 

example only) and approximately 5% of the raw material is known to go to byproducts, then the 

error in flow measurements can be as much as 20% of the byproducts. If we then add errors in 

analytical measurements and the fact that what we want to know is the portion of the HFC's that 

went to atmosphere (potentially an even smaller number), then the error in the original flow 

measurement can be an even greater % of the number we need to report (emissions to 

atmosphere). In addition, the 0.2% accuracy for the flow measurements may be very difficult to 

implement. The mass flow meters advertise this accuracy, but I believe that it applies to liquid 

measurement within the normal range. I think it may be lower for gases (all our vents to 

destruction are gases) and for both liquids and gases the accuracy reduces significantly if the 

flow is in the low range of the meter. These vent flows can vary significantly because they are 

very small flows out of a large plant, so an oversized flow meter may have to be used to prevent 

from going out of range when the flow is high. 

Regarding whether Honeywell would be interested in the material balance approach, I cannot 

speak for the many operating plants but in my opinion a combination of material balance to 

determine the amount of total emissions (tons per month, quarter, or other period) combined 

with standard factors (based on historical measurements and engineering judgment) to account 

for composition and other difficult to measure variations may be workable. I hope this 

information is helpful. 

I am trying to identify a contact for the SF6 plant and will let you know when I can. 

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

From: Ottinger.Deborah@epamail.epa.gov 

Sent: Tuesday, November 10, 2009 5:11 PM 

To: Cerri, Gus 

Subject: Proposed Rule and Recap of Questions 

Gus, 

Thanks once again for answering my questions. FYI, here is a link to 

the overall website for the proposed mandatory reporting rule: 

http://www.epa.gov/climatechange/emissions/archived/ghgrulemaking.html

You can find the preamble here: 

http://www.epa.gov/climatechange/emissions/archived/downloads/Preamble_E9-5711.pdf 

The proposed regulatory text is here: 

http://www.epa.gov/climatechange/emissions/archived/downloads/RULE_E9-5711.pdf 

The text relevant to emissions from fluorinated gas production (Subpart L) begins on page 

16503 of the preamble and on page 16655 of the regulatory text. 

As I mentioned during our phone call, we received quite a few comments objecting to 

performing the mass-balance calculation daily. Some commenters also objected to the 

proposed accuracy and precision requirements. We are taking this comments into 

consideration as we move forward. 

To recap my questions: we were wondering whether (1) Honeywell might be interested in using 

the mass-balance approach (which will be revised taking into account the comments we have 

received) and whether (2) Honeywell's process for producing SF6 posed any special emission 

estimation issues (i.e., issues different from those raised for processes making HFCs). My 

understanding from our conversation was that you thought Honeywell would probably be 

interested in using the mass-balance approach for at least some of its processes, and that you 

would send me contact information for one of your colleagues who is familiar with Honeywell's 

processes for making SF6. 

Thanks again for your help! 

Best Regards, 

Debbie 

Deborah Ottinger Schaefer 

Inventory Analyst for High-GWP Emissions 

Climate Change Division 

U.S. Environmental Protection Agency 

e-mail: ottinger.deborah@epa.gov

phone: 202-343-9149