Percentage of Ethane and Propane recovered in NGL recovery plant

[Phani Y]

Hi Everyone,

Can someone please explain how to calculate the Percentage recovery of Ethane and Propane in NGL Recovery Cryo plant? Process employed is Fluor TRAP. Also, please post some useful links in this aspect, if any.

 

[georgeverghese]

There is an example of this calculation in the GPSA in the chapter on hydrocarbon recovery for any given % recovery specification for that component. Note that % recovery is not directly reflected in the % composition of the residue gas, due to shrinkage of the total resid gas mass rate.
The % recovery for a given component is related to the process scheme used, the feedgas rate and the pressure / temp / composition of the feedgas. In the later years when feedgas composition may be much leaner, you cannot expect the same % recovery, unless the scheme accounts for this, and then only partially, by additional compression to offset the loss in refrigeration effect due to the leanout in feedgas composition.

Dont know about this TRAP process scheme from FLUOR.