Method for sub-cooling a normally gaseous hydrocarbon mixture
AssigneeThe M. W. Kellogg Company
InventorCharles A. Durr
Life of this patent
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Abstract
A method for sub-cooling normally gaseous hydrocarbon mixtures produced in a cryogenic process unit wherein the mixture is introduced to a gas/liquid separator, which may be a storage vessel, and vapor containing at least two components of the mixture is recovered as refrigerant, employed in an open cycle refrigeration system to sub-cool the hydrocarbon mixture, and returned to the separator. The system is particularly useful for sub-cooling a hydrocarbon product stream while, at the same time, recovering boil-off vapor from a cryogenic storage vessel.
Claims9
A method for sub-cooling a normally gaseous hydrocarbon product stream which comprises:
- (a) expanding a liquid phase, sub-cooled, multi-component, normally gaseous, hydrocarbon stream into a low-pressure, adiabatic gas/liquid separation zone;
- (b) recovering a gaseous refrigerant stream containing portions of at least two of the lightest components of the multi-component, normally gaseous, hydrocarbon stream from the low-pressure, adiabatic gas/liquid separation zone;
- (c) compressing the gaseous refrigerant stream to an elevated pressure and then condensing the stream to form a high-pressure refrigerant liquid;
- (d) sub-cooling at least a portion of the high-pressure refrigerant liquid to form a first, cold refrigerant liquid;
- (e) expanding at least a portion of the first, cold refrigerant liquid to form a first, low-pressure refrigerant;
- (f) vaporizing the first low-pressure refrigerant to form a first low-pressure revaporized refrigerant;
- (g) introducing the first low-pressure revaporized refrigerant to the low-pressure, adiabatic gas/liquid separation zone;
- (h) sub-cooling a multi-component, normally gaseous, hydrocarbon process stream by indirect heat exchange with the first low-pressure refrigerant to form the liquid phase, sub-cooled, multi-component, normally gaseous, hydrocarbon stream that is expanded into the low-pressure, adiabatic gas/liquid separation zone;
- and
- (i) recovering a normally gaseous, liquid phase, hydrocarbon product stream from the low-pressure, adiabatic gas/liquid separation zone.
Dependencies are inferred from the claim text.