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US 4,230,535 AGranted
Heat-pumped fractionation process
AssigneeUop LLC
InventorLeroy J. Howard
Life of this patent
Estimating the term…
Abstract
A process for separating two close-boiling chemical compounds by fractionation wherein a vapor stream removed from the overhead receiver is superheated by indirect heat exchange and is then further heated by compression. The thus-heated high pressure stream is cooled by heat exchange against the overhead vapor and split into at least two portions. One portion of the high pressure stream is passed through a reboiler at an intermediate point in a fractionation column. Preferably, both portions of the high pressure stream are subcooled and returned to the overhead receiver except for the overhead product drawn off.
Claims14
A process for separating two chemical compounds by fractionation which comprises the steps of:
- (a) passing a feed stream comprising a first and a second chemical compound into a fractionation zone operated at fractionation conditions;
- (b) removing a net bottoms stream which is rich in the first chemical compound from the fractionation zone as a first product stream;
- (c) removing an overhead vapor stream which is rich in the second chemical compound from the fractionation zone, partially condensing the overhead vapor stream by direct heat exchange within an overhead receiver to produce an overhead liquid and a receiver vapor stream, supplying a first portion of the overhead liquid to the fractionation zone as reflux and removing a second portion of the overhead liquid from the process as a second product stream;
- (d) heating the receiver vapor stream by indirect heat exchange against a hereinafter specified high pressure working stream;
- (e) heating the receiver vapor stream by compression and thereby forming the previously specified high pressure working stream;
- (f) cooling the high pressure working stream by indirect heat exchange against the receiver vapor stream;
- (g) passing a first portion of the high pressure working stream through a first reboiler which is used to supply heat to the fractionation zone and then into the overhead receiver;
- and,
- (h) condensing a second portion of the high pressure working stream to thereby form a condensate stream and then passing the resultant condensate stream into the overhead receiver.
6 more elements
A process for separating two chemical compounds by fractionation which comprises the steps of:
- (a) passing a feed stream comprising a first and a second chemical compound into a fractionation zone operated at fractionation conditions;
- (b) removing a net bottoms stream which is rich in the first chemical compound from the fractionation zone;
- (c) removing an overhead vapor stream which is rich in the second chemical compound from the fractionation zone, partially condensing the overhead vapor stream by direct heat exchange within an overhead receiver to produce an overhead liquid and a receiver vapor stream, and supplying the overhead liquid to the fractionation zone as reflux;
- (d) heating the receiver vapor stream by indirect heat exchange against a hereinafter specified high pressure working stream;
- (e) heating the receiver vapor stream by compression and thereby forming the previously specified high pressure working stream;
- (f) cooling the high pressure working stream by indirect heat exchange against the receiver vapor stream;
- (g) passing a first portion of the high pressure working stream through a first reboiler which is used to supply heat to the fractionation zone and then into the overhead receiver;
- (h) condensing a second portion of the high pressure working stream to thereby form a condensate stream;
- and,
- (i) passing a first portion of the condensate stream into the overhead receiver and removing a second portion of the condensate stream from the process as a second product stream which is rich in the second chemical compound.
7 more elements
A process for recovering the product hydrocarbon of an isomerization reaction by fractional distillation which comprises the steps of:
- (a) passing a fractionation zone feed stream comprising two isomeric hydrocarbons and which is derived from the vaporous effluent of an isomerization zone into a fractionation zone operated at fractionation conditions at a first intermediate point;
- (b) removing a net bottoms stream which is rich in a first hydrocarbon from the fractionation zone as a first product stream;
- (c) removing an overhead vapor stream which is rich in a second hydrocarbon, which is the more volatile of two isomeric hydrocarbons present in the feed stream, from the fractionation zone and partially condensing the overhead vapor stream by direct heat exchange within an overhead receiver to produce an overhead liquid and a receiver vapor stream, and supplying a portion of the overhead liquid to the fractionation zone as reflux;
- (d) heating the receiver vapor stream by indirect heat exchange against a hereinafter specified high pressure working stream;
- (e) heating the receiver vapor stream by compression and thereby forming the previously specified high pressure working stream;
- (f) cooling the high pressure working stream by indirect heat exchange against the overhead vapor;
- (g) passing a first portion of the high pressure working stream through a first reboiler which is used to supply heat to the fractionation zone at a second intermediate point located below the first intermediate point, condensing the high pressure working stream to thereby form a liquid hydrocarbon stream, and then passing the liquid hydrocarbon stream into the overhead receiver;
- (h) condensing and subcooling a second portion of the high pressure working stream to thereby form a condensate stream, passing a first portion of the condensate stream into the overhead receiver and removing a second portion of the condensate stream as a second product stream;
- and,
- (i) supplying heat to the bottom of the fractionation zone through the use of a lower second reboiler.
7 more elements
Dependencies are inferred from the claim text.