ethane compression from 21 to 120 bar 5

[mamed]

Is it possible to compress ethane from 21 bar to 120 bar in one compression stage??

More overall, in your thoughts it is better to transport ethane in gas phase or dense phase? which one is more practical and common?
What are the operating pressure and temperature??

Thank you for your time

 

[apetri]

dcasto,
I woonder why there is that large difference in results, about 12% (203-150)/(150+273) or 50 C in calculated temperatures,
where 150 C has been calculated with Peng Robinson and Huntigton method,
are you using the simplified GPSA equation ?

Tout = Tin*(Pout / Pin)**(k-1)/k

that may give those values.

 

[dcasto]

No I'm using a process simulator with a variable efficiency gossip has an ideal efficiency . The value you calculate more closely matches a water cool reciprocating compressor with very low ratios.

 

[apetri]

dcasto,
since you do not explain how you calculate that temperature I can only presume that you utilize some custom procedure and that result should, in my opinion, be validated,

actually 50 C difference can have a large impact on selection,

in these cases I prefer as first step use a standard procedure (rigorous polytropic stage with 75-80% efficiency) and then ask the manufacturer to include all the specific operating parameters (which may show large differences in different compressors)

 

[dcasto]

apereti, I am not using a custom equation, you are using a custom equation from the GPA. That formula closely matches in real life a water cooled cylinder.

In real life, I'd guess that the screw compressor discharge temperature will be exactly 180 F. Trust me on that one.

When you use the GPA equation, which K do you use, there are 10 million different K's.

 

[apetri]

your previous value was "At 15 C the discharge temp will be 203 C at 75% polytropic eff."
in the last post temperature has been reduced to 82 C (180 F),
I would call this a big change.

 

[dcasto]

oil flooded screws have internal cooling of the process.

 

[rotw]

Now I really do not understand anything to this discussion.

 

[apetri]

>Now I really do not understand anything to this discussion.

I think dcasto likes to create a bit of confusion
but don't care for that,
the correct answer was given in previous posts.

 

[dcasto]

Now I'm confused. Is this a engineering forum or a theoretical class discussion. The OP was all over the place on composition and not clear on what is the exact compressor in use or proposed. So how can anyone answer 100%? I'm not here to give free engineering, I'm here to make others think and learn so leading people to an answer is how this is suppose to work IMHO.