COMBINED REMOVAL OF HEAVIES AND LIGHTS FROM NATURAL GAS
First Claim
1. A process for removing heavies and lights from a hydrocarbon-rich feed fraction, preferably from natural gas, said process comprising:
- a) partially condensing (E1, E2) said feed fraction (1),b) rectificatorily removing a heavies-rich liquid fraction (8) in a 1st removal stage (T1),c) partially condensing (E4) the resultant, heavies-depleted gas fraction (10), andd) rectificatorily separating said heavies-depleted gas fraction (10) into a methane-rich liquid fraction (11) and a lights-rich gas fraction (12) in a 2nd removal stage (T2),e) wherein the 1st removal stage (T1) is operated at a pressure of at least 25 bar,f) wherein said heavies-depleted gas fraction (10) does not undergo pressure elevation before being fed into the 2nd removal stage (T2),g) wherein reflux for the 2nd removal stage (T2) is produced via an open loop refrigeration cycle,h) wherein the refrigerant circulating in said open loop refrigeration cycle is vaporized to two different temperature levels against reflux streams (14, 15) in head condenser (E7) and a side condenser (E8) of the 2nd removal stage (T2), andi) wherein the pressure of the refrigerant (25) vaporized in said side condenser (E8) is at least three times the pressure of the refrigerant (22) vaporized in said head condenser (E7).
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Accused Products
Abstract
A process is described for removing heavies and lights from a hydrocarbon-rich feed fraction. A heavies-rich liquid is rectificatorily removed (1st removal stage) from a partially condensed feed fraction. Heavies-depleted gas is partially condensed and rectificatorily separated into a methane-rich liquid fraction and a lights-rich gas fraction (2nd removal stage). The 1st removal stage is operated at a pressure of at least 25 bar. The heavies-depleted gas fraction does not undergo pressure elevation before being fed into the 2nd removal stage. Reflux for the 2nd removal stage is produced via an open loop refrigeration cycle. Refrigerant circulating in the open loop refrigeration cycle is vaporized to two different temperature levels against the reflux streams in a head condenser and a side condenser of the 2nd removal stage. The pressure of refrigerant vaporized in the side condenser is at least three times the pressure of refrigerant vaporized in the head condenser.
14 Citations
19 Claims
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1. A process for removing heavies and lights from a hydrocarbon-rich feed fraction, preferably from natural gas, said process comprising:
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a) partially condensing (E1, E2) said feed fraction (1), b) rectificatorily removing a heavies-rich liquid fraction (8) in a 1st removal stage (T1), c) partially condensing (E4) the resultant, heavies-depleted gas fraction (10), and d) rectificatorily separating said heavies-depleted gas fraction (10) into a methane-rich liquid fraction (11) and a lights-rich gas fraction (12) in a 2nd removal stage (T2), e) wherein the 1st removal stage (T1) is operated at a pressure of at least 25 bar, f) wherein said heavies-depleted gas fraction (10) does not undergo pressure elevation before being fed into the 2nd removal stage (T2), g) wherein reflux for the 2nd removal stage (T2) is produced via an open loop refrigeration cycle, h) wherein the refrigerant circulating in said open loop refrigeration cycle is vaporized to two different temperature levels against reflux streams (14, 15) in head condenser (E7) and a side condenser (E8) of the 2nd removal stage (T2), and i) wherein the pressure of the refrigerant (25) vaporized in said side condenser (E8) is at least three times the pressure of the refrigerant (22) vaporized in said head condenser (E7). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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Specification