1 

### Icenhour, Melissa K.

From: Jerry Davis [JDavis@lsb-okc.com] Sent: Friday, October 08, 2010 3:17 PM To: Neuffer.Bill@epamail.epa.gov Cc: Icenhour, Melissa K.; Laney, Michael N. Subject: RE: NSPS Nitric Acid - Monitoring Question

Bill,

Methods for reporting an official daily production rate may vary from plant to plant. In our case we have our "official daily production" as an accounting function. If we did not do this then we would end up with two figures, because no two meters or mea suring systems will be in perfect agreement. For sure we only get credit (financially) for what we sell. If we used a meter on the acid from out plant, then at the end of the day/ month/ year there would be two numbers.

Some plants may have some type o f production indication system/meter on their plant, but to measure production is very difficult because production is reported as 100% nitric acid when in reality there will be 30 to 50% water in the stream. So, to "measure" instantaneous " production, i t is required to have instrumentation that can measure total wet flow, some analyzer or instrumentation that can determine what percent of the flowing stream is nitric acid and then multiply the two (wet flow x % acid). There are a lot of inaccuracies in both the wet flow meter and any "analyzer"; when you multiply them, it multiplies the inaccuracy. Thus, you see why we and I think almost all plants, strive to get an accounting production number (acid sold + inventory adjustment) ; that number, whether right or wrong, is the number that goes on the financial books and provides the financial backing for the operation.

Another issue comes up on any attempt to measure acid flow directly from the plant during startup, shutdowns and malfunctions. During the se periods, the acid can be very low concentration where any analyzer used would be out of range and give very incorrect results. Any plant that may have some type of metering system for production indication can just ignore these times as the flow indica tion is only to assist plant operations and has no "official" status. An additional, but similar issue comes about when the plant is in a maintenance shutdown and is being flushed with water to clear/ clean the equipment for personnel entry. This flush

wa ter would go through the meter and register as a flow while the plant was not in operation. Again, when it is not official, it can be ignored without issue.

During startup, the product is below the acid percent specification. During this time, the acid may flow through a plant meter that would register as "production", but go to a startup tank. Later, after the plant is lined out making on spec acid, this "startup acid" would be worked off slowly by recycling it to the plant absorber tower. As it come s out of the plant a second time, any flow indication system from the plant would pick it up double measuring the same acid. Again, this is not a problem for any plant that has an operations flow/ production indication meter, because it is not official an d can be ignored as a true indication of plant production during this time. I hope this helps you understand why I think our plant is typical and uses the accounting daily production as the official reported number for the plant production. This one numbe r is used for all stakeholders, including regulatory.

A last thought is what if the regulations attempt to regulate NOx per measured production ton on an hourly basis, what is the definition of when the nitric acid is produced? In the absorber column, th ere are large levels of acid on each tray where the NOx is actually reacting with the water. After the plant us "shutdown", which we usually define as when the ammonia flow to the AOR is stopped, then the compressor is shutdown and the absorber begins2 to drain. There is a large amount of nitric that comes out of the "plant" at that time which may take a few hours. In the regulations, which NOx emission will be associated with that nitric acid when calculating a NOx emission per measured ton of nitric ac id? Could be a tough question if left to each plant to define. During startup, if the absorber starts with only water on the trays, acid will be made on the trays, but not discharged to storage until the strength is in specification; acid is being "made" and NOx is being emitted from the plant, but no measured product is going to storage

- the regulations would have to address this if a NOx emission per measured ton on an hourly basis is the permit limit.

Many plant approximate production based on the amo unt of ammonia flow to the AOR. If someway the regs used this approach, it may be easier to calculate and more meaningful in the long run on a short time (hourly) basis.

I hope your final rules will clearly address nitric plant, startups, shutdowns and

u pset/malfunctions. This will be interesting to see what your group ends up with. Good luck.

Hope all this helps,

Jerry

----- Original Message

----- From: Neuffer.Bill@epamail.epa.gov [mailto:Neuffer.Bill@epamail.epa.gov] Sent: Wednesday, October 06, 2010 9:39 AM To: Jerry Davis Cc: Icenhour, Melissa K.; Laney, Michael N. Subject: RE: NSPS Nitric Acid

- Monitoring Question

The air flow monitoring would be done at the stack. With this measurement and the NOx CEM one would know lb/hr of NOx emitted.

Another question

- the present NSPS requires daily production rate. How is this usually determined? Is measuring of hourly production rate usually done? If so, by what methods? Is hourly production difficult to measure?

Thanks as always.

Bill Neuffer M etals and Minerals Group Office of Air Quality Planning and Standards (D 243

- 02) US Environmental Protection Agency Research Triangle Park, NC 27711

Phone

- 919

- 541

- 5435 Fax

- 919

- 541

- 3207 E

- mail

- neuffer.bill@epa.gov Office Location: 109 TW Alexander Drive RTP, NC (D 231C)

Overnight mail address: US EPA Mail Code D243

- 02 109 TW Alexander Drive RTP, NC 27709

|

------------ > | From: | |

------------ >3

>

------------------------------------------------------------------------------------------

----- --------------------------------------- | |Jerry Davis <JDavis@lsb

- okc.com> |

>

------------------------------------------------------------------------------------------

-------------------------------------------- | |

------------ > | To: | |

------------ >

>

--------------------------------------------------------------------- ---------------------

-------------------------------------------- | |Bill Neuffer/RTP/USEPA/US@EPA |

>

----------------------------------------------- -------------------------------------------

-------------------------------------------- | |

------------ > | Cc: | |

------------ >

>

------------------------------------------------------------------------------------------

----------------------------- --------------- | |"Icenhour, Melissa K." <mkicenhour@rti.org>, "Neulicht, Roy" <rmneulicht@rti.org> |

>

------------------------------------------------------------------------------------------

------- ------------------------------------- | |

------------ > | Date: | |

------------ >

>

------------------------------------------------------------------------------------------

-------------------------------------------- | |09/20/2010 09:00 AM |

>

------------------------------------------------------------------------------------------

-------------------------------------------- | |

---------- -- > | Subject: | |

------------ >

>

------------------------------------------------------------------------------------------

-------------------------------------------- | |RE: NSPS Nitric Acid

- Monitoring Question |

>

------------------------------------------------------------------------------------------

-------------------------------------------- |

Bill,

Good to hear from you. My thoughts on the points you raise follow:

Opacity: I do not feel opacity is of any value when we are achieving low NOx levels. The analyzer monitoring NOx is all that makes sense. If industry is meeting the PPM limits, there wil l be no opacity.

Air monitoring: I am not sure what the consideration/ justification/ environmental benefit for monitoring air flow (I assume to the reactor) would be. During startup an shutdown, we4 have air flow when we are not burning ammonia. Any cor relation to emissions from air flow may not be correct. It should not be a problem for any company as all companies monitor this flow for operational reasons. I would need more information on your justification/ thinking to give you any thoughts that coul d help.

Regards,

Jerry

----- Original Message

----- From: Neuffer.Bill@epamail.epa.gov [mailto:Neuffer.Bill@epamail.epa.gov] Sent: Wednesday, September 15, 2010 8:14 AM To: Jerry Davis Cc: Icenhour, Melissa K.; Neulicht, Roy Subject: NSPS Nitric Acid

- Mo nitoring Question

Jerry, Hope you are doing well.

We are considering adding to this NSPS a monitoring requirement to continually monitor air flow rate. We are also thinking of deleting the requirement for opacity monitors.

Any tho ughts? Thanks

Bill Neuffer Metals and Minerals Group Office of Air Quality Planning and Standards (D 243

- 02) US Environmental Protection Agency Research Triangle Park, NC 27711

Phone

- 919

- 541

- 5435 Fax

- 919

- 541

- 3207 E

- mail

- neuffer.bill@epa.gov Office Location: 109 TW Alexander Drive RTP, NC (D 231C)

Overnight mail address: US EPA Mail Code D243

- 02 109 TW Alexander Drive RTP, NC 27709