Back to results
US 4,466,946 AGranted
CO.sub.2 Removal from high CO.sub.2 content hydrocarbon containing streams
AssigneeStandard Oil Company (Indiana)
InventorsClifton S. Goddin, Jr., Edward A. Turek, Boyd A. George
Life of this patent
Estimating the term…
Abstract
Carbon dioxide is removed from CO.sub.2 and hydrocarbon containing gaseous streams. In the instance where the hydrocarbons and CO.sub.2 are such that hydrocarbons would condense out during CO.sub.2 removal, the gas stream is treated in one or more stages to accomplish hydrocarbon composition control.
Claims39
Process for treating a gaseous stream comprising hydrocarbons and CO.sub.2 comprising
- (a) separating a portion of hydrocarbons from the gaseous stream to produce a first stream;
- (b) separating CO.sub.2 from the first stream in a first CO.sub.2 absorption zone by absorption in a first solution effective for CO.sub.2 removal to produce a hydrocarbon enriched second stream;
- (c) further separating CO.sub.2 from the second stream in at least a second CO.sub.2 absorption zone by absorption in a second solution effective for CO.sub.2 removal to produce a further hydrocarbon enriched third stream,
- wherein the gaseous stream comprises CO.sub.2 and hydrocarbons such that in the absence of step (a) hydrocarbon condensation due to hydrocarbon dewpoint temperature increase occurs as CO.sub.2 is removed in at least one of steps (b) and (c), and
- wherein the first solution comprises an aqueous tertiary alkanolamine solution;
- and
- the second solution comprises an aqueous alkanolamine solution selected from the group consisting of aqueous secondary alkanolamine solutions and aqueous primary alkanolamine solutions.
4 more elements
Process for treating a gaseous stream comprising
- (a) separating at least a first portion of hydrocarbons from the gaseous stream to produce a first stream having a reduced hydrocarbon content;
- (b) separating CO.sub.2 from the first stream in a first CO.sub.2 absorption zone by absorption in a first solution effective for CO.sub.2 removal to produce a hydrocarbon enriched second stream;
- (c) subsequently separating a second portion of hydrocarbons from the second stream to produce a third stream having a further reduced hydrocarbon content;
- and
- (d) further separating CO.sub.2 from the third stream in at least a second CO.sub.2 absorption zone by absorption in a second solution effective for CO.sub.2 removal to produce a further hydrocarbon enriched fourth stream;
- and wherein
- the separation of step (a) is effective for preventing hydrocarbon condensation due to hydrocarbon dewpoint temperature increase during CO.sub.2 removal in at least the first CO.sub.2 absorption zone, and
- the separation of step (c) is effective for preventing hydrocarbon condensation due to hydrocarbon dewpoint temperature increase during CO.sub.2 removal in said at least a second CO.sub.2 absorption zone, and wherein
- the gaseous stream comprises CO.sub.2 and hydrocarbons such that in the absence of steps (a) and (c) hydrocarbon condensation due to hydrocarbon dewpoint increase occurs as CO.sub.2 is removed, and wherein
- the first solution comprises an aqueous tertiary alkanolamine solution;
- and
- the second solution comprises an aqueous alkanolamine solution selected from the group consisting of aqueous secondary alkanolamine solutions and aqueous primary alkanolamine solutions.
9 more elements
Process for treating a gaseous stream comprising hydrocarbons and CO.sub.2, the process comprising:
- (a) separating a first portion of CO.sub.2 from the gaseous stream in a permeation zone by selective permeation of CO.sub.2 across a differentially permeable membrane to produce a CO.sub.2 permeate and a hydrocarbon enriched first stream;
- and
- (b) further separating CO.sub.2 from the hydrocarbon enriched first stream in at least one CO.sub.2 absorption zone by absorption utilizing an aqueous alkanolamine solution effective for CO.sub.2 removal to produce a further hydrocarbon enriched process stream, and wherein
- the gaseous stream comprises hydrocarbons including C.sub.3 and heavier hydrocarbons such that hydrocarbon condensation occurs during separation of CO.sub.2 unless the gaseous stream is treated to remove at least a portion of the hydrocarbons, the process thus further comprising:
- separating a portion of hydrocarbons from the gaseous stream such that hydrocarbon condensation does not occur due to hydrocarbon dewpoint increase as CO.sub.2 is removed during step (a);
- and
- subsequently separating a further portion of hydrocarbons from the hydrocarbon enriched first stream such that hydrocarbon condensation does not occur due to hydrocarbon dewpoint increase as CO.sub.2 is removed during step (b).
4 more elements
Dependencies are inferred from the claim text.