9 replies to this topic

[Tolinorton]

Dear,

 

Why minimal and maximal values of C4 hydrocarbons are not introduced in this specification (please see attached PDF)? Is there any mistake?

 

As far as I know every LPG gas is mixture of C3 and C4 hydrocarbons. 

 

 

Attached Files

•  LPG MIX specification.pdf   89.37KB   26 downloads

[PingPong]

No mistake.

 

There is a minimum C3 given and a maximum C5+ and maximum C2, and there is a maximum vapor pressure given of 1550 kPa.

That max vapor pressure limits max C3 at actual C2.

 

C4 in the LPGmix is then the balance.

[Tolinorton]

Dear PingPong,

 

Please I'm still confuse about C4. Based on data which are given in the LPG Mix specification what would be the min. and max. values for C4. I'm really sorry if I'm bothering you.

Edited by Tolinorton, 05 November 2015 - 08:07 AM.

[shan]

C4 content is left as the degree of freedom.  It does not matter how much C4 in the LPG if all other specifications are satisfied.

[Pilesar]

C4 could theoretically be between 0% and 80% while meeting the spec. The C3 could theoretically be 100% and would meet the spec. C3 has to be at least 20%. (Note that I am ignoring the octane and vapor pressure portions of the spec which would also need to be met.)

Edited by Pilesar, 05 November 2015 - 01:36 PM.

[Tolinorton]

Dear Shan and Pilesar,

 

Could we say that C4 should be other amount to reach 100% (but MON and vapor pressure of the spec also need to be met).

Edited by Tolinorton, 05 November 2015 - 02:01 PM.

[Pilesar]

If you are trying to buy a specific composition, then you can require anything you like. The spec you posted completely defines the product. You need add nothing specific about C4 unless you want to. I do not understand what your concern is. Would your spec eliminate the material if there was a small trace of pentane in the mix? What about other trace components? Too tight a spec might greatly increase the cost. You should specify only what you require for your purposes.

[Tolinorton]

Dear Pilsar,

 

Yes, I want to add min. and max. values for C4 in the given spec in order to define product, in other words I'm trying to DRAW specification for LPG Mixture which should be identical as in attachment but it also should have min. and max. values for C4.  

 

Thank you for your understanding.

[Bobby Strain]

Why waste your time with such an exercise? If you are buying this stuff, be sure it satisfies your need. It's not likely ENI will cater to some boutique specification.

 

Bobby

Edited by Bobby Strain, 06 November 2015 - 10:40 AM.

[Tolinorton]

Dear Mr. Strain,

 

As I wrote before I need to draw LPG specification in order to propose for administrative instruction. This specification should contain all min. and max. values of all C-s, from C1 to C5. I found difficult with min. and max. values for C4, so I'm asking for help anyone who has experience with LPG-s. 

 

So please if you have any objection or any idea how to set limits for C4 I would be grateful to you.

 

best regards