2 replies to this topic

[JOAN93]

Hello everyone!  

I'm doing a project about propane dehydrogenation into propylene. I've seen in bibliography that storage of propylene is usually made with propylene liquified under pressure. 

 

In my process i have to store about 200m^3 of propylene each vessel (about 28ºC in its satured pressure (12,6 bara)). 
I think the expansion due to tank embowel, can produce a strong dicrease on temperature due to liquified gas evaporation. 

 

So here is my question, what material should i use?

 

What could be the temperature reached due evaporation? 

 

I was wondering if  carbon steel was a good choice , and if so, I need to know wich kind in order to find out the stress allowance of the material.  

 

Thanks ahead,

 

Joan

[Art Montemayor]

Joan:

 

The term “embowel” is a British term which means to bury or to disembowel.  Since I’m a native U.S. speaker, I don’t understand what it is that you mean to state about the storage tank in question.  Perhaps if you explain it in Spanish, it will explain better.

 

As I understand it, you propose to store liquefied Propylene (Propene) at a storage temperature of 28 ^oC.  This means that the saturated pressure inside the tank will be 12.6 bara.  200 m³ (53,000 gallons) is a reasonable size for what could be multiple “bullet” type storage tanks (horizontal, cylindrical with ellipsoidal heads) or one spherical tank.  Your material of construction normally is selected according to the substance and its corrosivity as well as the storage temperature.  I presume you selected 28 ^oC as the design, taking into consideration any high temperature in the Spanish site you propose.  This temperature is well within the normal carbon steels available and Propene is a benign substance.  Therefore, from what you give as data, I would consider a steel such as ASTM 516 Grade 70 as being OK for the application.  As I recall, this popular steel has a design stress value of approximately 19 - 20,000 psi.

[JOAN93]

I'm sorry for that word, I meant to describe emptying the vessel but i didn't know how to say it, so i looked it up in Google and found that word in one of the translations.

 

Thanks for your help, really appreciated. Very useful answer!