11 replies to this topic

[Arsal]

Compressor NO .1 (Positive displacement) as shown in attached sketch is obsolete and need to replace with new one. We have two options here:

 

1.      Purchase a new compressor and used these gasses to fuel gas system as in existing system.

2.      Install a FLARE GAS RECOVERY COMPRESSOR at flare.

 

In option 1 , we only use off gasses of refinery –I While in option -2 we recover all the gasses at flare KOD (Refinery-I and Refinery –II) These gases Obtained from different sources, like

1.      Any PSV passes and could not reset properly,

2.      Malfunctioning of any control of reflux/storage vessel.

3.      Any Upset conditions

4.      Any other.

 

My Question is that which options is suitable for refinery. Experts Opinion is required.(Sketch is attached for better understanding).

 

Attached Files

•  Sketch.pdf   200.1KB   37 downloads

Edited by rao arsalan, 27 October 2015 - 06:51 AM.

[Bobby Strain]

No expert opinion is required. It's simply a matter of economics and risk.

 

Bobby

Edited by Bobby Strain, 27 October 2015 - 09:04 AM.

[Arsal]

Thankyou bobby.so which option is looking better??
What is the risk in these options?
Furthermore i am asking about technical issues.if technically ok then we will proceed further.

Edited by rao arsalan, 27 October 2015 - 11:20 AM.

[PingPong]

Usually the gas from the Receiver is compressed and recontacted in an aircooler (or watercooler) with the naphtha from the Receiver in order to recover as much LPG as possible before sending the gas to the fuel gas system.

[Arsal]

Thanks ping pong.in your point of view which one is better?

[Arsal]

In all that scenario, my opinion is that there is no need to purchase a compressor no 1.  I should just install a skid- mounted flare gas recovery compressor that compresses this gas - and other flare gasses as well.

[Arsal]

In our refinery, the gas composition is 70 % Propane + butane.  Should we also consider the recovery option of this 70% composition?

[PingPong]

I don't understand your last question.

 

As Bobby already stated: it's a matter of economics. The purpose of a refinery is to make money. Processing crude and producing LPG, gasoline, diesel, et cetera, is really just an unavoidable hassle.

[Arsal]

Let me rephrase the previous post: If the refinery gas, used as a fuel gas, contains 70% (mol) propane and butane, then is it suitable to use as fuel?  Or should we recover the LPG from it first, and then send it to the fuel gas system.?

[PingPong]

Yes, you can burn fuel gas with 70 % LPG in it, but it is usually more economical to recover as much as possible of that LPG, and import natural gas to compensate for that in the fuel gas.

 

It is much easier to recover LPG from the crude unit Receiver than from the flare gas because the flare gas will contain H2 + C1 + C2 from the various hydrotreaters, the reformer, catcracker, thermal cracker, or whatever conversion units the refinery has.

[Bobby Strain]

You should look at what is referred to as a "Sat Gas Plant" for LPG recovery. This will show you how LPG is recovered in refinery offgasses.

 

Bobby

[Arunkannan]

Hi,

         i have some doubt in the Natural gas plant (Methane).If is used in diesel Generator,

           

          1)In what ratio or composition the CH4 is Burns in Diesel Generator(DG) and how to find out the efficiency of DG.

 

          2)In What Pressure CH4 burns in DG and how to Regulator

 

 

Kindly Reply,

             

Regards    

 

ARUN.A