Melanie – See the e‐mail below from Emitec, a MECA  member, per your request for info on retrofitting C3

marine engines with DOCs.  (FYI, I’ve edited Sri’s response a bit.)

Sorry for the delay in getting this to you.

Hope this helps.

Antonio

From: Srikanth.Reddy@EMITEC.COM [mailto:Srikanth.Reddy@EMITEC.COM] 

Sent: Thursday, June 07, 2012 9:59 AM 

To: Antonio Santos 

Cc: Ulrich Pfahl 

Subject: Experience retrofitting large marine engines with DOCs

FW: Experience retrofitting large marine engines with DOCs

Antonio Santos 

to: 

Melanie King 

06/15/2012 03:34 PM 

Hide Details 

From: Antonio Santos <asantos@meca.org> 

To: Melanie King/RTP/USEPA/US@EPA 

History: This message has been replied to. 

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Hello Mr. Santos,

1) Does Emitec have any experience with retrofitting Category 3 marine diesel engines with DOCs? 

I'm not aware of any activities which Emitec was directly involved in with Category 3 marine diesel engines for 

retrofit applications. I have put the question out to my colleagues in Europe. If I find out something different. I will 

inform you. Typically, DOC's will work with fuels with lower sulfur levels. Typically, the large ships burn distillate 

fuels which are high in sulfur. The use of a DOC in a high sulfur in fuel environment can increase Particulate 

matter by Sulfate formation.

2) If so, "if the engines typically only operated at lower loads (25-50%), would you expect there to be problems 

with catalyst fouling due to additional partially unburned hydrocarbon’s passing into the exhaust stream?" 

The issue of face plugging (unburned hydrocarbons) has been one of Emitec's strengths. Face plugging is a 

concern for ceramic substrates. Face plugging is mitigated by having a low cell density substrate. Ceramic 

substrates require thick walls to have low cell densities to maintain structural integrity. However, with metallic 

substrates, you are able to get both low cell density and low cell wall thickness. This is a real advantage for 

Emitec which several of the large engine manufacturers are taking advantage of. Locomotive manufacturers 

have gone with Emitec substrates for this reason, among others. However, with the distillate fuel being used, 

I'm not sure if face plugging is an issue especially at the operating conditions which you describe. With 

ULSD these problems are likely not to occur above than 200°C.

3) Are you aware of other companies (MECA members or non-MECA members) who have retrofitted DOCs on 

these types of engines?

I'm not aware of any companies which have done DOC retrofit of Category 3 marine engines. I have asked this 

question to our colleagues in Germany. Again, if I get a response back regarding this I will let you know. 

However, there is some retrofitting going on for NOx reduction using Vandia based SCR technology. It is an 

SCR only system, no DOC. Again the high sulfur distillate fuel is the primary issue. 

 

Sincerely, 

Sri

 

 

Dr. Srikanth Reddy 

Senior Application Engineer 

Emitec Inc. 

3943 Hamlin Rd. 

Rochester Hills, MI 48309

(248) 276-6440 (work) 

(309) 585-5533 (cell)

Srikanth.Reddy@emitec.com

Web address: http://emitec.com

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This e-mail may contain confidential information. If you have received this e-mail in error, you are hereby 

notified that any use or circulation of it is strictly prohibited. Please inform us immediately at +49 (0)2246-109-0 

and destroy the original transmittal. 

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