Ethane recovery and ethane rejection methods and configurations
First Claim
Patent Images
1. A method of changing ethane recovery to ethane rejection operation in an NGL plant, comprising:
- changing a top reflux of a demethanizer from a demethanizer overhead product to a deethanizer overhead product for ethane rejection;
reducing a demethanizer pressure to a pressure that is lower than a deethanizer pressure for ethane rejection; and
increasing flow of a first portion of a feed gas relative to flow of a second portion of the feed gas for ethane rejection;
wherein the demethanizer is configured to receive a second reflux below the top reflux, wherein the second reflux is the first portion of the feed gas, wherein the second portion of the feed gas is cooled in a demethanizer side reboiler heat exchanger and then combined with a third portion of the feed gas to form a partially condensed feed stream, wherein the partially condensed feed stream is separated into a liquid stream and a vapor stream, wherein the demethanizer is configured to receive the liquid stream and the vapor stream.
1 Assignment
0 Petitions
Accused Products
Abstract
Contemplated plants for flexible ethane recovery and rejection by allowing to switch the top reflux to the demethanizer from residue gas to the deethanizer overhead product and by controlling the flow ratio of feed gas to two different feed gas exchangers. Moreover, the pressure of the demethanizer is adjusted relative to the deethanizer pressure for control of the ethane recovery and rejection.
-
Citations
20 Claims
-
1. A method of changing ethane recovery to ethane rejection operation in an NGL plant, comprising:
-
changing a top reflux of a demethanizer from a demethanizer overhead product to a deethanizer overhead product for ethane rejection; reducing a demethanizer pressure to a pressure that is lower than a deethanizer pressure for ethane rejection; and increasing flow of a first portion of a feed gas relative to flow of a second portion of the feed gas for ethane rejection; wherein the demethanizer is configured to receive a second reflux below the top reflux, wherein the second reflux is the first portion of the feed gas, wherein the second portion of the feed gas is cooled in a demethanizer side reboiler heat exchanger and then combined with a third portion of the feed gas to form a partially condensed feed stream, wherein the partially condensed feed stream is separated into a liquid stream and a vapor stream, wherein the demethanizer is configured to receive the liquid stream and the vapor stream. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
Specification