Carbon dioxide absorption methanol process
OwnerFred P. Apffelinventor
Life of this patent
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Abstract
A process is disclosed for the separation of hydrocarbon feed gas mixture containing methane and carbon dioxide, as well as other components such as ethane propane-and-heavier hydrocarbon, hydrogen sulfide, nitrogen, or other lighter inert gases, into various components. The steps of separation include distillation and absorption. These separations operate at temperatures and pressures such that the freezing or formation of solid carbon dioxide will not occur. The process utilizes four distillation units and one absorption unit.
Claims34
A process for removing carbon dioxide from a feed stream of natural gas, having at least methane, ethane and heavier hydrocarbon, comprising:
- A. First, separating the feed stream in a first separator to form a first stream, having substantially all of the propane and heavier hydrocarbons and carbon dioxide and ethane, and a second stream, having methane, carbon dioxide and ethane;
- B. Mixing the second stream with a polar compound to form a third stream;
- C. Separating the vapor and liquid of the third stream in the bottom portion of an absorber;
- D. Absorbing carbon dioxide and ethane from the separated vapor of Step C in a lean portion of the polar compound in the absorber, the absorbed carbon dioxide and ethane forming a fourth stream;
- E. Separating the ethane from the polar compound and carbon dioxide in a separator;
- F. Separating the first stream in a third separator to separate the propane and heavier hydrocarbons from the carbon dioxide and ethane, which carbon dioxide and ethane forms a fifth stream;
- and
- G. Separating the polar compound/carbon dioxide effluent of the second separator in a fourth separator, to separate the carbon dioxide from the polar compound, the polar compound forming a sixth stream.
A process for removing carbon dioxide from a feed stream of natural gas, having at least methane, ethane, and heavier hydrocarbons, comprising:
- A. Separating the feed stream into a Stream 1 including substantially all of the propane and heavier hydrocarbons components and into a Stream 2 including substantially all the methane and lighter gases, both Streams 1 and 2 having other components including ethane;
- B. Absorbing the other components from Stream 2 in a lean polar compound, the other components forming Stream 3;
- C. Separating the other components from Stream 1, the other components forming Stream 4;
- D. Separating the ethane from Streams 3 and 4, the remainder forming Stream 5;
- and
- E. Separating the polar compound from the rest of Stream 5.
Apparatus for the removal of carbon dioxide from a feed stream of natural gas, having at least methane, ethane and heavier hydrocarbons, comprising:
- First means for separating the feed stream into a Stream 1 having substantially all of the propane and heavier hydrocarbons and a Stream 2 having substantially all the methane and lighter gases, both of said Streams 1 and 2 having other components including ethane;
- Second means including a polar compound for absorbing said other components from said Stream 2 to form Stream 3;
- Third means for separating said other components of said Stream 1 to form Stream 4;
- Fourth means for separating ethane from said Streams 3 and 4, the remainder of said Streams 3 and 4 forming Stream 5;
- Fifth means for separating said polar compound from the rest of said Stream 5;
- and
- Sixth means for recycling said polar compound to said Second means.
Dependencies are inferred from the claim text.