Abstract: A process for removal of sour species from a dehydrated natural gas feed stream is provided. The dehydrated natural gas feed stream is cooled to conditions where a slurry of solid sour species and hydrocarbon liquids is formed together with a gaseous stream containing gaseous sour species. The gaseous stream containing gaseous sour species is then separated from the slurry and treated with a liquid solvent, thereby forming a liquid solution of the sour species and a dehydrated sweetened natural gas product stream. An apparatus for removing sour species from a dehydrated natural gas feed stream is also provided. The apparatus has a vessel with a solids formation zone in fluid communication with a gas solvation zone. The solids formation zone is configured to facilitate formation of a slurry of solid sour species and hydrocarbon liquids and a gaseous stream containing gaseous sour species. The gas solvation zone is configured to facilitate formation of a liquid solution of sour species.
Abstract: Novel processes and devices for the removal of freezable species such as carbon dioxide, water and heavy hydrocarbons from a natural gas feed stream during liquefaction to produce LNG are disclosed. The freezable species are able to be removed as a solid, avoiding the costly step of pretreatment to remove the freezable species from the natural gas feed stream prior to the liquefaction stage. The freezable species may be removed on a continuous basis being separated as solids following liquefaction of the natural gas feed stream with subsequent separation of the solids. The solid freezable species may then be liquefied on a continuous basis if required with natural gas recycled to the process. Continuous removal of the freezable species from the natural gas feed stream is achievable by maintaining cooling and separation apparatus at the same working pressure.
Type:
Grant
Filed:
January 17, 2003
Date of Patent:
February 5, 2008
Assignee:
Cool Energy Limited
Inventors:
Robert Amin, Anthony Frederick Kennaird