3 replies to this topic

[DANA-IF]

Hello friends ;

 

I'm wondering if anyone have a chemical composition of LPG with vapor pressure (37.8 °C ) as 300 Kpa .

 

As I do some research in internet , most of LPG composition is around 900 Kpa .

 

I really need it to input it into HYSYS 

 

Thanks a lot !

[PingPong]

There are as many LPG compositions as there are LPG producers.

So you best check with the supplier of the LPG. In any case check whether that LPG contains olefins.

 

Or you can make any mixture of C3's and C4's , plus max 2 mol% C5's, such that the mixture has the required vapor pressure, according to Hysis. But you should realise that there are different mixtures with the same vapor pressure possible, especially if the LPG also contains olefins.

 

A vapor pressure of 300 kPa at 37.8 ^oC for LPG seems low to me. Are you sure that is correct? Would be almost pure C4's.

Edited by PingPong, 23 February 2015 - 11:33 AM.

[Zauberberg]

Good advice from PingPong. You can use the Adjust operation in Hysys and blend pure C3 into a predefined mixture of iC4 and nC4, until you reach the required vapor pressure (= bubble point at 37.8 degC). Another problem - as also mentioned in PingPong's post - is whether there are C5's or other components in the mixture. Then there are virtually infinite combinations of mole fractions of C3, C4's and C5's which would give you the same result.

Edited by Zauberberg, 23 February 2015 - 02:52 PM.

[P.K.Rao]

In addition to what Zauberberg and PingPoing said, please use ASTM D 2163 for a compositional analysis of the LPG in question. This can give you your required direction.