MIXED-REFLUX FOR HEAVIES REMOVAL IN LNG PROCESSING

摘要

Systems and methods for removing heavy hydrocarbons are provided. Methods for liquefying a natural gas stream include: (a) cooling at least a portion of the natural gas stream in an upstream refrigeration cycle of a liquefaction process to produce a cooled natural gas stream; (b) separating via a first distillation column the cooled natural gas stream into a first top fraction and a first bottom fraction, wherein the first fraction does not freeze in a subsequent downstream step of the liquefaction process; (c) separating via a second distillation column the first bottom fraction into a second top fraction and a second bottom fraction, wherein the second top fraction at least a portion of a reflux stream; (d) optionally separating via a third distillation column the second bottom fraction into a third top fraction and a third bottom fraction, wherein the third top fraction forms a portion of the reflux stream; and (e) introducing the reflux stream into the first distillation column.

主权项

1. A method of liquefying a natural gas stream, comprising:
(a) cooling at least a portion of the natural gas stream in an upstream refrigeration cycle of a liquefaction process to produce a cooled natural gas stream; (b) separating via a first distillation column the cooled natural gas stream into a first top fraction and a first bottom fraction, wherein the first distillation column is a heavies removal column; (c) separating via a second distillation column the first bottom fraction into a second top fraction and a second bottom fraction; (d) separating via a third distillation column the second bottom fraction into a third top fraction and a third bottom fraction; (e) combining at least a portion of the second top fraction and a portion of the third top fraction to form a mixed-reflux stream; and (f) introducing the mixed-reflux stream into the first distillation column.