초록 ▼

A sweet natural gas stream is stripped of water and hydrocarbon components heavier than methane to substantially any selected degree by countercurrent extraction with polyethylene glycol dimethyl ether while at pipeline pressures. The stripped natural gas meets pipeline specifications. The rich poly

A sweet natural gas stream is stripped of water and hydrocarbon components heavier than methane to substantially any selected degree by countercurrent extraction with polyethylene glycol dimethyl ether while at pipeline pressures. The stripped natural gas meets pipeline specifications. The rich polyethylene glycol dimethyl ether is let down in pressure through selected successive stages which respectively isolate fractions that are rich in ethane, propane, butanes, and hydrocarbons heavier than butane. Lastly, waste water is removed from the solvent to regenerate the polyethylene glycol dimethyl ether. The separated gas streams of ethane, propane, butanes, and hydrocarbons heavier than butanes are individually compressed, combined, condensed and cooled to form a natural gas liquid stream, suitable for pipeline shipment. A sour natural gas stream may also be treated in the same equipment if adequate solvent quantities are employed to remove water and acidic components from the sour gas and if a sweetening unit is added to remove the acidic components from the combined liquid hydrocarbon stream.

대표청구항 ▼

A continuous process for separating water and hydrocarbonns heavier than methane from a natural gas stream at pipeline pressures, comprising removing said water and said hydrocarbons heavier than methane as a C1+mixture to substantially any selected degree, including the following steps: A. extracti

A continuous process for separating water and hydrocarbonns heavier than methane from a natural gas stream at pipeline pressures, comprising removing said water and said hydrocarbons heavier than methane as a C1+mixture to substantially any selected degree, including the following steps: A. extracting said natural gas by flowing countercurrently to the natural gas stream a solvent consisting essentially of polyalkylene glycol dialkyl ethers at said pipeline pressures and at a rate sufficient to produce rich solvent containing water, methane, ethane, and hydrocarbons heavier than ethane, and residue natural gas of pipeline quality; B. returning said residue natural gas to a pipeline and flashing said rich solvent at a medium pressure to produce a C1-rich gas fraction and a medium-pressure liquid mixture of said water, said solvent, and a C1+mixture of hydrocarbons; C. flashing said medium-pressure liquid mixture at low pressure to produce a C1-rich gas fraction having a lower methane content than said gas fraction of step B and a low-pressure liquid mixture of said water, said solvent, and a C2+mixture of hydrocarbons containing minor amounts of methane; D. flashing said low-pressure liquid mixture at a pressure of up to approximately atmospheric pressure to produce a gas mixture of essentially all C1+hydrocarbons, and an atmospheric-pressure liquid mixture of said water, said solvent, and minor amounts of hydrocarbons; E. regenerating said solvent solely by removing said water and said minor amounts of hydrocarbons from said atmospheric pressure liquid mixture and returning the regenerated solvent to said extracting and returning said minor amounts of hydrocarbons to step D; F. compressing and cooling said C1-rich gas fractions produced in step B and step C and returning said cooled gas fractions to said extracting in step A; and G. compressing, condensing, and cooling said gas mixture from step D to produce a liquid product.