5 replies to this topic

[Hafiz Zakaria]

Greetings,

I am doing front end engineering design for a crude storage terminal. For this terminal, we need to generate about 90 MT/hr steam using fired tube boiler. Initially we want to use fuel gas as fuel for the boiler. But the client said that fuel gas may not be available in that area. So one of the solution is to design a diesel fuel system for the boiler.

1. Is there any reference or specific code in designing the system?

2. Is the diesel should be preheated before being fed into boiler? If yes, to what temperature it should be heated? what is the standard practice?

3. Combustion of diesel may produce black smoke and the flue gas might be dirty, is there any pollution control system required to be installed?

Thank you in advance for your help.

Regards,

Hafiz

[Rahimzadeh]

Dear hafiz i attached a file that i hope help you effectively .

Attached Files

•  e-pr-340.txt   38.71KB   86 downloads

[Art Montemayor]

Hafiz:

I have burned a lot of fuels in my time – from solids to gases – most for the purpose of generating steam power.

There are a lot of engineering books that can be referenced and studied if you have never done this type of design before – specifically in the stoichiometry area. If you don’t know how to do a combustion calculation, you should start first with a complete study of how this is done.

You should also have sufficient knowledge of Steam Thermodynamics before you venture into such calculations.

I have never had to pre-heat diesel fuel in a boiler. I’ve used both air and steam atomized burners. Although I don’t know what you call “diesel”, I strongly suspect you won’t have to preheat it. You should a FULL and DETAILED diesel fuel analysis and specification in your hands and should freely distribute it to possible boiler and/or burner manufacturers that you will have to deal with.

Why do you state that burning diesel may produce black smoke? I have burned #6 Bunker Fuel oil for many years and never produced any smoke. You may produce smoke because of inexperience or poor operations, but I certainly would not accept any smoke to be produced from diesel combustion in a steam boiler. If you have sulfur or other contaminants in your diesel, you may certainly expect to meet contamination limits – and that is why I emphasize that you must have all your fuel specifications and analysis done and ready.

[kkala]

Some additional notes, probably useful.
1. Some codes that could be adopted
- API 650 for a diesel oil tank that might be installed.
Assuming min flash point of 55 oC for diesel (common case for several countries), a cone roof tank can be considered.
- Certified Burning Management and Emergency Shutdown System (BMS/ESD) per NFPA 8502.
- Performance guarantee test run per ASME Power test code PTC 4 - 2008
- ASME codes for the boiler drums and rest pieces of equipment.
Alternatively local codes can be adopted or other (e.g. DIN).
Diesel oil does not need hot or cold return (a heavy fuel oil system does).
These are probably most significant codes. I am not familiar with all of them, since local Process Dept does not deal with codes.
2. Diesel oil should not be preheated. See http://www.cheresou...iesel-oil-tank
3. As explained in post No 3, burning of diesel will be smokeless. But will environmental emissions be acceptable without flue gas treatment?
In a recently ordered refinery boiler (burning fuel oil), an electrostatic precipitator was installed to lower particulates in flow gases to 30 mg / Nm3 (*). Low NOx burners could result in 400 mg / Nm3 (*) of NOx (as NO2). Provision for an NH3 Selective Catalytic Reduction System (SCRS) would reduce NOx to 200 mg / Nm3 (*) as NO2.
Diesel will result in lower emissions before treatment. Clarify local legal requirements concerning emissions, so that the boiler supplier can specify the necessary gas treatment facilities. For NOx emissions of 200 mg / Nm3 (*) a SCRS is deemed necessary.
(*) Note: Guaranteed values based on 3% O2 in flue gases, considered dry.
Note: http://www.cheresour...-utility-boiler '> http://www.cheresour...-utility-boiler may be useful to read.

Edited by kkala, 11 February 2012 - 03:48 PM.

[Hafiz Zakaria]

Dear Mr m.r.rahimzadeh & kkala,

Thank you very much for your reply, I will see through your suggestion and opinion. It'll really help alot. Thanks

Dear Art Montemayor,

Having the opinion from an experienced engineer like you is really appreciated, especially for young engineer like me. Thanks a lot for your opinion and comment.

By the way the pollution control/ flue gas treatment is something that we have debated over and over in our team. Some of our experienced engineer said that usually no black smoke will be produced during diesel combustion. But our team leader want to be conservative and really sure about this matter.

Anyway your comment is really appreciated and i will bring this matter to the team.

Thanks,

Hafiz

[Zubair Exclaim]

i have sized, installed and operated heaters with fuel oil and .......smokeLESS ... 

 

like ART said if you give your boiler / burner manufacture the right fuel analysis ... select burner with proper turn up and turn down capability and right firing mechanism, no question of smoke... Although your team leader is concerned about it .. but many times in consultancies a team leader is experienced in one area and is working on another ... take the expert engineer advice on it .

Edited by Exclamation, 07 July 2013 - 12:19 PM.