Recovering natural gas liquids from LNG using vacuum distillation
AssigneeChevron U.S.A. Inc.
InventorMichael McCoy
Life of this patent
Estimating the term…
Abstract
A process for recovering liquefied C3 compounds from a natural gas stream containing C3 compounds which comprises (a) chilling the natural gas stream under conditions sufficient to liquefy the natural gas, whereby a mixture comprising liquid natural gas (LNG) and liquid C3 compounds is formed; (b) fractionating the mixture comprising liquid natural gas (LNG) and liquid C3 compounds in a separation zone under sub-atmospheric pressure and under conditions predetermined to vaporize a significant portion of the natural gas present while retaining the C3 compounds as a liquid fraction; and (c) recovering separately from the separation zone natural gas and liquid C3 compounds.
Claims21
A process for recovering liquefied C3 compounds from a natural gas stream containing C3 compounds which comprises:
- (a) chilling the natural gas stream under conditions sufficient to liquefy the natural gas, whereby a mixture comprising liquid natural gas (LNG) and liquid C3 compounds is formed;
- (b) fractionating the mixture comprising liquid natural gas (LNG) and liquid C3 compounds in a separation zone under sub-atmospheric pressure and under conditions predetermined to vaporize a significant portion of the natural gas present while retaining the C3 compounds as a liquid fraction;
- and
- (c) recovering separately from the separation zone natural gas and liquid C3 compounds.
A process for recovering liquefied C3+ compounds from a natural gas stream containing C3, C4, and C5+ compounds which comprises:
- (a) chilling the natural gas stream under conditions sufficient to liquefy the natural gas, whereby a mixture comprising liquid natural gas (LNG) and liquid C3+ compounds is formed;
- (b) fractionating the mixture comprising liquid natural gas (LNG) and liquid C3+ compounds in a separation zone under sub-atmospheric pressure and under conditions predetermined to vaporize a significant portion of the natural gas present while retaining the C3+ compounds as a liquid fraction;
- (c) recovering separately from the separation zone natural gas and a mixture comprising liquid C3+ compounds;
- (d) introducing the mixture comprising liquid C3+ compounds into a second separation zone under sub-atmospheric pressure and under conditions predetermined to vaporize a significant portion of the C3 and C4 compounds present while retaining the C5+ compounds as a liquid fraction;
- (e) recovering separately from the second separation zone liquid C5+ compounds and a mixture comprising C3-C4 compounds.
A process for producing liquefied C3 product and liquefied C4 product comprising fractionating a liquid comprising C3 compounds and C4 compounds in a separation zone at pressures maintained at sub-atmospheric pressure and separately recovering at least liquefied C3 product and liquefied C4 product.
Dependencies are inferred from the claim text.