Mixing Condensate with Crude Oil in a Storage Tank

[Amr Helaly]

Hello All;

If any one can help me it will be great, we used the flared gas to produce electricity and condensate, on another hand the normal operation of the crude oil is to be stored in a storage tanks then shipped in a 10" pipeline for about 70 km to another facility to be treated there by heating and fresh water mixing.

The condensate production quantity is 10 tons/day, and produced with pressure of 170 psi.

My question is could I ship the produced condensate into the un-pressurized storage tanks to be shipped together with the crude oil or this will lead to condensate evaporation, and if it will not evaporate in this stage, will it evaporate in the end point during treatment with heating?


Best regards,

Amr Helaly Mohamed
Treatment Department Head
Email: AHelaly@Eshpetco.com
Address: 3-D-4/4-D-4, Nasr St., New Maadi - Cairo Egypt

 

[EmmanuelTop]

If the condensate is in equilibrium with vapor phase at 170 psi, there will probably be significant evaporation at atmospheric storage conditions - the amount of evaporation could be quite substantial if condensate composition is light.

This could also be quite hazardous for the downstream storage tanks, if pressurized condensate is let down to atmospheric conditions.


Dejan IVANOVIC
Process Engineer, MSChE

 

[Amr Helaly]

First of all thank you for your quick response, but I need you to know that the condensate will not stored alone in the atmospheric tank, it will be blended with the existed crude oil as it will go into the tank from the lowest nozzle in the tank, would that help in minimizing the evaporation.

In addition to that, the quantity of the condensate is 10 ton and will go into the tank which should contain at least 1000 ton of crude oil, does it still hazard.

 

[EmmanuelTop]

You are talking about 1% of condensate in the stabilized crude oil, in the worst case. Does not seem like a huge concern but in order to give you the correct answer one would need to know the properties of condensate (vapor pressure, light ends composition = C1, C2, C3, C4's).

Dejan IVANOVIC
Process Engineer, MSChE

 

[Amr Helaly]

Dear sir;
kindly find the attached condensate composition

best regards

 

[EmmanuelTop]

What is the RVP/TVP spec (maximum vapor pressure) for stabilized Crude oil?

Dejan IVANOVIC
Process Engineer, MSChE

 

[Amr Helaly]

Unfortunately I don't have this data, but you can find crude oil analysis (attached)

 

[EmmanuelTop]

It is impossible to answer your question without knowing the product specification criteria. I'd suggest you perform a study where different scenarios will be evaluated. The problem I can anticipate is not related to blending of 1% of wild condensate into stabilized crude (you'll probably be OK with the resulting vapor pressure - calculations or lab testing to confirm), but to the possibilities (and associated hazards) of insufficient/improper mixing of condensate and crude oil in the tanks.

What is virtually impossible to predict under real conditions, is the degree of mixing inside the tank where Condensate is introduced into crude oil - this is not only a question of thermodynamic equilibrium but also of kinetics of the mixing process - depending on the incoming flowrate, mass of crude oil in the tank, process and ambient temperatures etc. - and these are all varying factors. You may encounter a "bullet" of condensate that will lift the emergency hatch off the tanks, and that can escalate to many unwanted scenarios.

Dejan IVANOVIC
Process Engineer, MSChE

 

[BigInch]

A general rule is not saFE practice to put products with appreciable vapor pressures (170 is far mOre than significant) into ATMOSPHERIC TANKS.

First: It's dangerous as hell.
Second: Maybe illegal
Third: Figure you're going to lose most of it to boiloff anyway.

 

[georgeverghese]

You say condensate is produced at 170psig, but what is its RVP or TVP ? Offhand, I wouldnt attempt to mix condensate into crude if condensate TVP at 100degF >15psia max. If it is less, then it would be worth further study.

If the condensate is very volatile (say TVP at 100degF >20psia), it could blow the roof off your crude storage tanks.

 

[Amr Helaly]

Thanks a lot for your efforts, it was very useful and will be taken into consideration.



Best regards,

Amr Helaly Mohamed
Treatment Department Head
Email: AHelaly@Eshpetco.com
Address: 3-D-4/4-D-4, Nasr St., New Maadi - Cairo Egypt

 

[EmmanuelTop]

An ounce of prevention is better than a pound of cure. Has always been.

Dejan IVANOVIC
Process Engineer, MSChE

 

[LittleInch]

With that composition, my guess is you would only have about 20 to 25% of the liquid you started with at 170 psi when it mixes with the Crude oil.

All the methane, ethane, propane and butane will turn to gas and go out of the vent of the storage tank.

Think of a can of coke. What you have at 170 psi is a warm can of coke/pepsi which has been vigourously shaken. When you open the can to mix it with something, you won't have much left.....

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