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.
Claims8
A natural gas liquid plant bolt-on unit, comprising:
- an absorber configured to condense an ethane content from an overhead gas stream from a demethanizer using a cold lean residue gas to produce a liquid portion and a vapor portion, wherein the demethanizer is configured to receive the liquid portion as a first reflux;
- a reflux exchanger configured to receive at least a portion of the vapor portion and use the portion of the vapor portion to provide cooling within the reflux exchanger;
- and
- a flow control valve configured to direct between about 70% to 90% of the vapor portion to a subcool exchanger to provide cooling to a portion of a feed stream that is directed to the demethanizer and configured to direct about 10% to about 30% of the vapor portion to the reflux exchanger to provide the cooling within the reflux exchanger to cool a residue gas stream that is directed to the absorber.
Dependencies are inferred from the claim text.