----- Forwarded by Melanie King/RTP/USEPA/US on 08/09/2010 11:58 AM

-----

|------------>

| From: |

|------------>

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

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

|Melanie King/RTP/USEPA/US

|

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

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

|------------>

| To: |

|------------>

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

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

|Cortney_Higgins@omb.eop.gov

|

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

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

|------------>

| Cc: |

|------------>

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

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

|Fred Talcott/DC/USEPA/US@EPA, RobertJ Wayland/RTP/USEPA/US@EPA, Michael

Horowitz/DC/USEPA/US@EPA |

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

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

|------------>

| Date: |

|------------>

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

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

|08/06/2010 10:59 PM

|

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

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

|------------>

| Subject: |

|------------>

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

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

|Fw: Catalyst windows

|

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

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

Hi Cortney,

I am forwarding the email below in response to SBA's claim that NOx reductions

would not be achieved through the use of NSCR on 4SRB engines. This is

information from Miratech who is a large supplier of catalyst technology.

See also their catalyst manual which is attached, which discusses the

potential to over-oxygenate the catalyst if you run it at too high of an O2.

See at the top of p. 11. According to Miratech, saturating it with too much

O2 would result in the catalyst losing the ability to reduce any pollutants.

I would also reference the information on p. 5-6 in the attached report from

MECA. It says "NOx conversion efficiency drops dramatically when the engine

is run in the lean regime, while NMHC and CO conversion efficiency also

declines somewhat." and shows in Figure 2 that the NMHC reductions will

decrease as you lean out the engine.

(See attached file: icengine.pdf)(See attached file: Catalyst Operating Manual

- 012909B.PDF)

Melanie King

Energy Strategies Group

Sector Policies and Programs Division

Office of Air Quality Planning and Standards U.S. Environmental Protection

Agency

Mail Code D243-01

RTP, NC 27711

Phone: (919) 541-2469

Fax: (919) 541-5450

king.melanie@epa.gov

----- Forwarded by Melanie King/RTP/USEPA/US on 08/06/2010 10:38 PM
-----

|------------>

| From: |

|------------>

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

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

|"Kevin O'Sullivan (MIRATECH)" <kosullivan@miratechcorp.com>

|

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

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

|------------>

| To: |

|------------>

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

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

|Melanie King/RTP/USEPA/US@EPA

|

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

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

|------------>

| Cc: |

|------------>

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

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

|"David Zenthoefer" <dzenthoefer@miratechcorp.com>

|

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

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

|------------>

| Date: |

|------------>

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

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

|08/06/2010 06:04 PM

|

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

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

|------------>

| Subject: |

|------------>

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

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

|FW: Catalyst windows

|

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

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

Melanie –

We haven’t met – and David was tied up so I reached out to one of our experts

and his abridged response is below. As you can see, we believe the original

investigator is dealing with dated and limited material.

I’m not much on sugar coating – so my simple synopsis is if you’re designing

rules on the information provided us to respond to, there is a lot more work

to be done and more technology to understand than what we were presented.

I’d be pleased to discuss this in more detail with you or the investigator.

My best -

Kevin

Kevin R. O'Sullivan, President and Chief Operating Officer, MIRATECH

Corporation

Primary: 918.628.6110 (Office Direct), Alternate: 918.630.1658 (Cell)

Emission Solutions for Industrial Engines: kosullivan@miratechcorp.com or

www.miratechcorp.com

Fax: 918.933.6220, 420 South 145th East Avenue, Mail Drop A Tulsa, OK

74108 - 1305

From our consultant:

I've looked over this BS and it looks to me like whoever submitted this to the

EPA is banking everything off of data that they have collected years back or

with catalyst that were manufactured years ago. Looking at what he is saying,

he has a catalyst that is using the older loadings and designs that only give

90% reduction. The current 0.5 gram catalyst is achieving 96 to 97% reduction.
The next thing that he is basing his information on is a very narrow operating

window (lambda window). Most catalyst manufactures today have opened the size

of the operating window allowing a greater deviation in the AFR control and

still be within the desired emissions levels.

He is defining a Rich Burn engine as an engine with a Lambda setting of 1.10.

I believe the EPA defines any engine running with 2 percent of oxygen or less

to be a rich burn. A few years back they defined it as 4% or less. Everyone in

the free world that has ever seen a catalytic converter knows that it must

operate at 0.5% or less.

The chart that the guy provided, in my opinion, is not accurate. Of course you

can get these readings with as large of a swing that they are inducing on the

AFR and catalyst. This chart should be zoomed into a realistic area somewhere

between 0.96 lambda (1.040 phi) and 0.99 lambda (1.010 phi). This is an area

where the AFR will be operating. The ammonia levels that he is showing is

higher than anyone would expect.

Typically you start smelling ammonia at about 30 ppm. They are saying that

this level is showing up at about 0.985 lambda.

Lastly, the AFR issue. If they are testing with a low end system, yes they

will have problems maintaining the operational window. The better the

controller, the tighter the hold on the operational window.

The bottom line is, these guys are throwing both the AFR and catalyst under

the bus with data from only one source. Modern AFR technology and modern

catalyst technologies are far more superior that the older stuff.

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

From: David Zenthoefer

Sent: Friday, August 06, 2010 9:19 AM

To: John Sartain; Kevin O'Sullivan (MIRATECH)

Subject: FW: Catalyst windows

Kevin,

Can you take a pass at this for the EPA, this is helping to finalize the

NESHAP rule due out next Tuesday.

David

David Zenthoefer, Vice President - Sales and Service MIRATECH Corporation

Primary: 918.640.1140 (Cell)

Emissions Solutions for industrial engines: dzenthoefer@miratechcorp.com or

www.miratechcorp.com

Fax: 918.933.6236, 420 South 145th East Ave, Tulsa, OK 74145-4712

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

From: King.Melanie@epamail.epa.gov [mailto:King.Melanie@epamail.epa.gov]

Sent: Friday, August 06, 2010 9:01 AM

To: David Zenthoefer

Subject: Re: Catalyst windows

Hi David,

Thanks so much to you and John for speaking with me this morning. The issue I

am trying to resolve is whether you will get NOx reductions from a 3-way

catalyst that is installed on a rich burn engine to meet CO or VOC emission

standards. The argument that is being made is that they will set the engine

up specifically to get the CO/VOC reductions and not achieve any NOx

reductions since they aren't trying to meet a NO limit as well. Below I have

copied the information that was sent to us by one of the interagency

stakeholders who is suggesting that little to no NOx reductions will be

achieved. From speaking with you this morning, my understanding is that

running the engine too lean will saturate/poison the catalyst and the

reductions of all 3 pollutants will be decreased.

Below is the information that was sent to me by the interagency reviewer to

support the claim that little to no NOx reductions will occur:

If you get NOx reduction with NSCR it is usually relatively high – e.g., 90%

or more. The problem is that the NOx performance is very sensitive to the air

to fuel ratio (AFR) and the stream needs to be “more rich” (i.e., more fuel

rich or air deficient). A lesser NOx reduction (e.g., 20 – 60% NOx reduction)

with NSCR is typically not seen, because the performance curve (versus AFR) is

very steep – meaning that you go from no NOx reduction to relatively high NOx

reduction (e.g., 80% or

more) with very small changes to AFR. Similarly, if set for “richer”

operation with NOx reduction, relatively small changes in AFR can move the AFR
more lean and significantly impact NOx performance. Thus, if an operator

installs NSCR to meet a NOx limit, the set to provide a better assurance of

emission performance is often accomplished by establishing a “richer” set

point (which can result in significant ammonia emissions). In this scenario,

there is more of an operating window before minor AFR changes can move “too

lean” and significantly compromise NOx performance. Those richer set point

also result in lower efficiency / higher fuel use, more hydrocarbon (HC)

emissions, and hotter operation – and these conditions affect maintenance

requirements because the HC and higher temps impact performance and increase

maintenance frequency (and related costs).

An example of NOx (post NSCR catalyst) versus AFR for a RB with NSCR is

provided here. Note the “stoichiometric ratio” (SR) is the theoretical amount

of air relative to the amount required to burn all of the fuel – i.e., at 1.00

there is just enough air to burn all the fuel. From the scale on the x-axis,

a change in the amount of air by 1 or 2% dramatically changes the NOx

emissions (and ammonia and CO emissions).

This level of AFR control is difficult to maintain on a continuous basis. It’s

also not reasonable to operate in a region of the “NOx curve” that provides

intermediate levels of NOx reduction so in general NOx reduction with NSCR

close to an all or nothing proposition. Also – as a reminder, the definition

of “rich burn” is an engine with a stoichiometric ratio up to 1.10 (beyond the

scale of this graph). As you can see from the graph, the NOx emissions on the

right side of the graph (from SR of about 0.99 or higher) have high NOx

indicative of very little or no NOx reduction. This relates to our discussion

that NOx reductions cannot be presumed with NSCR – and operators can achieve

better efficiency, lower fuel use, and lower greenhouse gas emissions by

running leaner where NSCR will not reduce NOx.

Also for the NOx data – the marginal relative change in the 3 data points to

the right (from about 2100 to about 2650 ppmv) is due to changes in the inlet

NOx and not from NSCR reduction – i.e., the inlet NOx versus AFR is also

dependent on AFR at this operating threshold where you cross from “rich” to

“lean”, and the NOx reduction across the catalyst is insignificant. Note that

the one NOx point at about 850 ppmv is 58% reduction and the three low NOx

points on the left are about 98% reduction for these tests.

(Embedded image moved to file: pic10264.gif) Since facilities will be

attempting to meet an air toxics standard, the preferred operation will use a

stoichiometric ratio of 0.99 or more, which would be on the “fuel lean” side

(right hand side) of the graph.

However, the NOx reductions will only occur on the rich side (left hand

side) of the graph – in this case approximately 0.98 or less. In addition to

good HCHO emissions performance, there are additional reasons for being on the

lean side of the curve – reduced fuel consumption, associated reductions in

greenhouse gas emissions (i.e., lower CO2 and methane), reduced maintenance,

and avoidance of ammonia and CO emissions. The NOx reductions go very quickly

from roughly 98% to 0% once you move from richer settings to leaner operation

above about

0.98. Also, the air to fuel ratio differences are very small and given

some instability of the settings of these engines, maintaining a precise

setpoint is difficult and you will need to set an even leaner setting optimize

engine operability and effieciency – or, conversely, set a

richer setting to ensure NOx reductions. The above graph is from a

rich burn engine tested by Colorado State University. Unless EPA is also

setting a NOx limit with the HCHO limit, these desired NOx reductions are

unlikely to occur.

EPA may wish to review additional data to see how under what AFR ratios, both

the HCHO number and the desired NOx reductions can occur (by how much and

whether these overlap), although I don’t know how this result can be achieved

under the current standard.

Melanie King

Energy Strategies Group

Sector Policies and Programs Division

Office of Air Quality Planning and Standards U.S. Environmental Protection

Agency

Mail Code D243-01

RTP, NC 27711

Phone: (919) 541-2469

Fax: (919) 541-5450

king.melanie@epa.gov

|------------>

| From: |

|------------>

>-----------------------------------------------------------------------------
-------------------------------------------------------------|

|"David Zenthoefer"

<dzenthoefer@miratechcorp.com>

|

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

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

|------------>

| To: |

|------------>

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

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

|Melanie

King/RTP/USEPA/US@EPA

|

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

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

|------------>

| Date: |

|------------>

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

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

|08/06/2010 09:39

AM

|

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

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

|------------>

| Subject: |

|------------>

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

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

|Catalyst

windows |

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

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

David

David Zenthoefer, Vice President - Sales and Service MIRATECH Corporation

Primary: 918.640.1140 (Cell)

Emissions Solutions for industrial engines: dzenthoefer@miratechcorp.com or

www.miratechcorp.com

Fax: 918.933.6236, 420 South 145th East Ave, Tulsa, OK 74145-4712 [attachment

"Catalyst Operating Manual - 012909B.PDF" deleted by Melanie

King/RTP/USEPA/US]

“This message and any attachments may contain FW Murphy information that is

highly confidential, privileged, and exempt from disclosure. Any recipient

other than the intended recipient is advised that dissemination, distribution,

copying, or other use of this message is strictly prohibited. If you have

received this message in error, please notify the sender immediately, plus

delete the message and any backups.”