6 replies to this topic

[sheiko]

Hi,

It has been suggested, in my refinery, to use part of the gas of the flare network, as a fuel gas for the furnaces. This is to decrease flare losses and valorize the flare gas as a combustible.

This would assume connect a new line to the flare header. The location has not been discussed yet.

My first guess is that it may be risky to modify the flare network.
What if a major relieving scenario occur (including rapid depressurization for example)?

Of course, a prerequisite for this kind of modification will be to make an HAZOP, but I would like to have your opinion on this idea?

Edited by sheiko, 19 August 2011 - 07:28 PM.

[DB Shah]

Yes you are right, such type of flare connections should not be carried out.

Do you have a gas stream/streams vented on continues basis(off gases) which have fuel value? If that is the case you can tap the gas from the source (ie upstream of vent valve) and use it as a fuel. This is the most common way.

From process----------------------Vent valve------->Flare
l
l
l-----Fuel valve------> Use for fuel (modification)

[breizh]

Hi Sheiko ,

Consider this resource :
http://www.mtrinc.co...s_recovery.html

Breizh

[fallah]

Sheiko,

Flare gas may not having the characteristics (sulfur level,....) and heat value such that to be consumed as fuel gas and it should be investigated.

In our refinery the off gas (originally fuel gas) from regeneration section of LPG treatment, instead of conducting to flare network, at first has been treated by caustic for sulfur component removal, and then to be conducted to steam boilers as fuel gas.

Thus, variety in flare gas composition due to various relief scenarios causes the flare gas not to be used as fuel gas and if the composition/characteristics of a gas are close to fuel gas it should be used (of course after adequate treatment) before connecting to flare network.

Fallah

[ankur2061]

Sheiko,

The concept of zero flaring has already caught up in oil & gas production facilities specially in the offshore installations in the North Sea. For the purpose of achieving zero-flaring, Flare Gas Recovery Systems (FGRS) have become quite popular with various types of configurations. The concept of FGRS can also be implemented in refinery service and the refinery of Reliance Industries in Jamnagar has one such system in place. The basic concept of FGRS is very well described in API STD 521 and can be configured to adapt specific flare gas recovery needs for any O&G, refinery or petrochemical installation.

The links provided below give the brief description of the FGRS implemented at the refinery of Reliance Inustries Ltd. in Jamnagar.

http://www.pcra.org/...al/flaregas.htm

http://www.emt-india...E JAMNAGAR).pdf

Hope this helps.

Regards,
Ankur.

[sheiko]

Thanks!

[GSaikrishn]

sir,

the concept of off gas recovery unit is catching up very quickly. the flare network at our refinery is designed to accomodate the off gas recovery compressor systems. flare network usually has a pressure of around 1000-2000mmwc. fuel gas systems operate at 4 kg. please check what ur flare gas analysis is, like is it more of sulfur rich gases, why this is critical is because sulfur rich fuel gas has environmental regulations. also fuel is mostly consumed in fired heaters (acid dew point is very critical in fired heaters). a stream from the flare network is at all times drawn from the flare system and compressod in ogru compressor. flaring is done only if the compressor is found to be limiting. what quality o fuel gas do u have.


regards