Methods and configuration for retrofitting NGL plant for high ethane recovery
AssigneeFluor Technologies Corporation
InventorsJohn Mak, Sabrina Devone, James Shih, Curt Graham
Life of this patent
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Abstract
A natural gas liquid plant is retrofitted with a bolt-on unit that includes an absorber that is coupled to an existing demethanizer by refrigeration produced at least in part by compression and expansion of the residue gas, wherein ethane recovery can be increased to at least 99% and propane recovery is at least 99%, and where a lower ethane recovery of 96% is required, the bolt-on unit does not require the absorber, which could be optimum solution for revamping an existing facility. Contemplated configurations are especially advantageous to be used as bolt-on upgrades to existing plants.
Claims19
A method comprising:
- passing an overhead vapor stream from a demethanizer to an absorber;
- contacting, within the absorber, the overhead vapor stream with a cold lean residue gas to produce a liquid portion and a vapor portion within the absorber;
- passing the liquid portion back to the demethanizer as a reflux;
- and
- passing between about 10% and about 30% of the vapor portion to a reflux exchanger as a first portion of the vapor portion;
- cooling, within the reflux exchanger, at least the first portion of the vapor portion to produce a compressed cooled residue gas, wherein the compressed cooled residue gas is used to form the cold lean residue gas;
- passing between about 70% and about 90% of the vapor portion to a subcool exchanger as a second portion of the vapor portion.
Dependencies are inferred from the claim text.