Convert hydrocarbon vapor stream to equivalent liquid barrels

[AlanH79]

So I'm new to the oil and gas field, having been in more of a non-technical and unrelated industry for the past 20+ years. So, I'm pretty rusty!

I have a M&E balance for hydrocarbon stream where I'm trying to confirm the calculations to convert a vapor stream to nominal liquid barrels/day. The reason is I'm trying to do a mass balance on a spill back line off the vapor line and my partial output is in barrels after condensing the vapor stream.

The mixture is mostly isobutane, so will just assume 100% to simplify.
Vapor phase:
T = 151.8°F
P = 99 psia
Mol Wt. = 56.23 g/mol
Mass flow = 146,262 lb/hr

Is this as simple as saying that the density of isobutane at 60°F is 563 kg/m3 -> 563 kg/m3 * 2.2 lb/kg / 264.17 gal/m3 * 42 gal/barrel -> 196.92 lb/barrel

Then 146,262 lb/hr * 24 hr/day / 196.92 lb/barrel --> 17,826 barrel/day

Am I missing anything?

 

[pierreick]

Hi,
I got 17787 barrel/day .. same.
563 kg/m3 is the density at 15 C for isobutane (boiling liquid)
Pierre

 

[LittleInch]

I did it in reverse, but got about 17,500 barrels/day of liquid butane, noting that it is only liquid above about 50 psi at 20C.

If in doubt stick to mass - you can't go wrong then.

Actual volume at a higher temp might be higher as density changes quite a bit, but always say at what temp and pressure some of these things are to avoid confusion.

 

[georgeverghese]

At 151degF, sat vap pressure of iC4 is about 148psia > 99psia, so your condensor is a partial condensor, not a total condensor. So the liquid phase volumetric flow will not be 17.8kbd. Otherwise, your simplification that this is only iC4 is too approximate.

 

[shvet]

1. Why asking oil barrels at chem forum?
2. You are trying to convert this stream to a particular oil, correct? Not a hypotetical oil? The ultimate goal is to reference money, not a volume, correct?
There are so many oils, they have a wide range of densities and light ends content.
Why not to find out iC4 content in the reference oil and combine that with the mass flow?

The volume is easy to measure by primitive means, e.g. a rope, so the historically it has been picking for fiscal calcs. The volume is horrible for eng issues, as yours is.

 

[LittleInch]

Barrels of liquid in O&G world is very common or even BOE, just making it similar.

As such this is a simple volume conversion calculation.

 

[shvet]

@lI
I didn't catch the idea.
Do you mean that 1m3 of iC4 @15°C is equal to 1m3 of crude oil @15°C? Or oil storing temp (e.g. -15°C), or unloading temp (e.g. 30°C), or adjusted survey temp (e.g. 20°C)?
We all know what I am talking about.

My idea is - there are so many hidden issues in the volume conversion (besides those have been mentioned above) that the core idea to convert a light end to a crude oil should be reconsidered from the the point of an ultimate goal.

@Alan
Can you share where you have 1'600 TPD of vaporized pure isobutane?
1600 TPD is 600 KTA which is far above the market limit. This would be a new step in petrochem industry evolution. Where do you have such?

 

[LittleInch]

@lI
I didn't catch the idea.
Do you mean that 1m3 of iC4 @15°C is equal to 1m3 of crude oil @15°C? Or oil storing temp (e.g. -15°C), or unloading temp (e.g. 30°C), or adjusted survey temp (e.g. 20°C)?
We all know what I am talking about.

My idea is - there are so many hidden issues in the volume conversion (besides those have been mentioned above) that the core idea to convert a light end to a crude oil should be reconsidered from the the point of an ultimate goal.

@Alan
Can you share where you have 1'600 TPD of vaporized pure isobutane?
1600 TPD is 600 KTA which is far above the market limit. This would be a new step in petrochem industry evolution. Where do you have such?

No. Barrels is simply a volume. There's nothing about making it equivalent to volumes of oil, it's just a different volume measurement at a set temperature.