7 replies to this topic

[A.Shatla]

i am working in an LPG plant and i am making a study to retrofit it to produce ethane but i have some questions:

 

1- does ethane produces in gaseous phase or in liquid phase, and if it is in liquid how it is stored in a cryogenic Tanks or what???

 

2- what is most common ethane product specification??

 

3- where can i get an up-to-date prices of ethane??

 

[fallah]

A.Shatla,

 

The ethane is produced either in gaseous or in liquid phase, stored in liquid phase and is normally transported in liquid phase through the pipeline under pressure

[Art Montemayor]

To add to Fallah's valuable comments and to address the possible storage conditions available for liquid ethane, please refer to the attached workbook.

 

Liquid ethane is stored as a pure, saturated liquid and consequently the storage conditions are the characteristic thermodynamic conditions of the saturated liquid.  These are clearly seen in the tables I have furnished you.

 

Note that you can store the liquid at either ambient or cryogenic temperature - all depending on the design pressure of the storage tank.

 

 Saturated Ethane Thermodynamic Properties.xlsx   42.37KB   24 downloads

[PingPong]

2- what is most common ethane product specification??

minimum 95 LV % ethane

maximum 3 LV % methane

maximum 1 LV % ethylene

maximum 1 LV % propylene

maximum 3.5 LV % heavier than ethane

maximum 1000 ppw wt CO2

maximum  30 ppm wt S

Copper strip test ASTM D1838, maximum No. 1

3- where can i get an up-to-date prices of ethane??

There is no such thing as an "up-to-date" price of ethane (or any other hydrocarbon product for that matter).

It is a free market price that changes every day, and varies in a broad range through the years.

[A.Shatla]

thank you very much 

 

There is no such thing as an "up-to-date" price of ethane (or any other hydrocarbon product for that matter).

It is a free market price that changes every day, and varies in a broad range through the years.

  yes i understand but i need to make a feasibility study so i need a recent price in my area or even the average for last month or  year 

[PingPong]

For a feasibility study for a new unit you would need the ethane price for the coming 20 years, which nobody knows.

 

You can assume something based on ... (whatever) but when your project goes ahead, outside financing of the new unit is usually required. Banks, and investors, then want to have economic calculations based on future price predictions done by "experts". Some consulting firms pretend they can predict future prices, and banks accept their reports for financing a new unit. It is all nonsens of course, but that is how it works.

 

Anyway, ethane price in the US fluctuated a lot in the past years and dropped to about 30 dollar cents per gallon, due to oversupply of ethane.

See Figure #1a below:

 

[PingPong]

Just to be clear: with gallon is meant a US gallon (3.785 liter) and moreover at 15 ^oC (60 ^oF).

 

Ethane liquid density at 15 ^oC is 355 kg/m³ or 2.96 lb/gal, so an ethane price of say 23 cents/gal = 7.8 cents/lb = 17 cents/kg.

 

 

In case anybody wondered: Figure #1b gives the Ratio of Ethane price versus Natural Gas (HH = Henry Hub), both expressed in $/MMBtu.

 

Ethane price was 23 cents/gal on July 22 at Mont Belvieu (Texas) and even lower at other places.

HHV (Higher Heating Value) of ethane is 22300 Btu/lb, so an ethane price of 23 cents/gal corresponds to 3.5 $/MMBtu.

Natural gas price (Nymex spot market) closed at 3.78 $/MMBtu this Friday July 25.

So at 23 cents/gal a few days ago the Ratio Ethane/NaturalGas was less than 1.

 

As can be seen from Figure #1b the ethane heating value price has been only slightly higher than that of natural gas for more than a year, so the economics are presently rather poor to justify separating ethane from natural gas.

 

What the Ratio, and thus the economics of ethane recovery, will be in future is anybody's guess.

Edited by PingPong, 27 July 2014 - 07:24 AM.

[Ali_gholamalian]

Ethane can storage in spherical storage tank in ambient temp and under its vapor pressure.

for up-to-date price, check FOB price of your own area markets; first find where will buy your product in you neighbors. (Specially check petrochemical companies.)