6 replies to this topic

[SenOil]

Dear members; does anyone know a shortcut to convert 1000 m3 of LNG to Nm3 of gas. many thanks for all.

[Bobby Strain]

If you google my name you will find my site that has such a conversion among the applications. But you must then convert from scf to nm3, the conversion factor being readily available, or derived by you.

 

Bobby

Edited by Bobby Strain, 18 November 2013 - 08:43 PM.

[SenOil]

than you Bobby for your reply I visited site and found conversions tables but I would like exactly to see the differents steps of the conversion.

 

many thanks

[ankur2061]

Senoil,

 

NG when condensed to liquid (LNG) occupies 1/600th the volume of the same volume of natural gas at atmospheric pressure (101.325 kPaa) and a temperature of -161 deg C.

 

LNG is normally traded and transported in tons (mass basis) or more specifically in millions of metric tons.

 

I do not know the specifics of the conversion of LNG conversion to NG conversion but the LNG mass conversion to NG volume conversion is expressed as follows:

 

1 metric ton of LNG or 1000 kg of LNG = 1379 Sm3 of NG

 

If we assume that the density of LNG is 550 kg/m3 then:

 

1000 / 550 m3 of LNG = 1379 Sm3 of NG

i.e.

1.818 m3 of LNG = 1379 Sm3 of NG

so, 1000 m3 of LNG = 1000*1379 / 1.818 = 758,450 Sm3 of NG for a LNG density of 550 kg/m3

 

Hope this helps.

 

Regards,

Ankur

[SenOil]

Thank you very much Ankur for your reply, my difficult was to find the real density of LNG, in what conditions of Temperature, and pressure .... 550kg/m3 correspond to the density of LNG?

 

again many thanks for your reply.

[SenOil]

Thank you very much Ankur for your reply, my difficult was to find the real density of LNG, in what conditions of Temperature, and pressure .... 550kg/m3 correspond to the density of LNG?

 

again many thanks for your reply.

[ankur2061]

SenOil,

 

The figure of 550 kg/m3 is an assumed figure. For your case, you need to find out the actual density of the LNG product you are handling at the operating temperature.

 

"Engineering Toolbox" reports a range for LNG density as 410 to 500 kg/m3. Refer:

 

http://www.engineeri...lng-d_1092.html

 

There is also an online calculator for LNG density given the operating temperature and the composition of the LNG at:

 

http://www.unitrove....ral-gas-density

 

I don't know its reliability.

 

Actual measurement of liquid specific gravity can be done using an instrument called hydrometer which provides the specific gravity or in modern terminology the relative density of a liquid in comparison to water. The liquid specific gravity or relative density as measured by the hydrometer when multiplied with 1000 will give the density of the liquid.

 

Hope this helps.

 

Regards,

Ankur.