Hydrocarbon gas processing

Claim 2

In a process for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, wherein said gas under pressure is cooled sufficiently to form a liquid portion under pressure and a vapor portion under pressure, and (i) said vapor portion under pressure is expanded to a lower pressure, whereby it partially condenses, (ii) said liquid portion under pressure is expanded to said lower pressure, whereby a part of said liquid portion vaporizes to cool the expanded liquid portion; and (iii) at least the liquid formed upon partial condensation of said expanded vapor, and the remaining liquid portion of said expanded liquid stream are supplied to a fractionation column wherein said relatively less volatile fraction is separated, the improvement wherein (a) at least some of said liquid portion under pressure is subcooled to a temperature below its bubble point prior to expansion thereof, (b) at least a part of said subcooled liquid portion is expanded to said lower pressure, whereby a portion of the expanded subcooled stream is partially vaporized to further cool said expanded subcooled stream, and (c) at least a portion of the liquid remaining in the expanded subcooled stream is supplied to said distillation column as a top liquid feed thereto.

Claim 3

The improvement according to claim 1, wherein the liquid obtained by partial condensation in step (i) is supplied to said fractionation column as an additional top column feed.

Claim 4

The improvement according to claim 1, wherein the liquid obtained from partial condensation of said vapor portion in step (i) is combined with the liquid remaining from expansion of said subcooled liquid in step (b) to form a combined liquid stream; said combined liquid stream is divided into a first part and a remaining part, the first part of said combined liquid stream is directed into heat exchange relation with at least some of said liquid portion under pressure, whereby said subcooled liquid portion is obtained and said combined stream is partially vaporized, said partially vaporized first part is supplied to said fractionation column at a mid column feed position, and the remaining part of said combined liquid stream is supplied to said fractionation column as the top liquid feed.

Claim 5

The improvement according to claim 1, wherein the liquid remaining from expansion of said subcooled liquid portion in step (b) is divided into a first part and a remaining part, and said first part is directed into heat exchange relation with at least some of said liquid portion under pressure, whereby said subcooled liquid portion is obtained and said first part is at least partially vaporized, said first part is thereafter supplied to said fractionation column at a mid column feed position, and said remaining part is supplied to said fractionation column as a top column liquid feed.

Claim 6

The improvement according to claim 1, wherein said subcooled liquid portion from step (a) is divided into a first part and a remaining part, said first part is expanded to said lower pressure and directed into heat exchange relationship with at least some of said liquid portion under pressure, whereby said subcooled liquid portion is obtained, said expanded first part leaving said heat exchange relation is thereafter supplied to said fractionation column at a mid column feed position, and said remaining part of said subcooled liquid is expanded and supplied to said fractionation column as a top column liquid feed.

Claim 7

The improvement according to claim 1, wherein the expanded vapor portion obtained in step (i) is supplied to said fractionation column at a mid column feed position.

Claim 8

The improvement according to claim 1, wherein at least some of said liquid portion under pressure is subcooled by extracting heat therefrom, and said heat is supplied to said fractionation column at a mid column position in said fractionation column, whereby said subcooled liquid portion under pressure is obtained.

Claim 9

The improvement according to claim 7, wherein a liquid side stream is withdrawn from said fractionation column at a mid column position and directed into heat exchange relation with at least some of said liquid portion under pressure.

Claim 10

The improvement according to claim 1, wherein at least some of said liquid portion under pressure is directed into heat exchange relation with cold volatile residue gas, whereby said subcooled liquid portion is obtained, and said cold volatile residue gas is warmed.

Claim 11

The improvement according to claim 1, wherein at least some of said expanded vapor portion obtained in step (i) is directed into heat exchange relation with at least some of said liquid portion under pressure, whereby said subcooled liquid portion is obtained.

Claim 12

In a process for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, wherein said gas under pressure is cooled sufficiently to form a liquid portion under pressure and a vapor portion under pressure, and (i) said vapor portion under pressure is expanded to a lower pressure, whereby it partially condenses; (ii) said liquid portion under pressure is expanded to said lower pressure, whereby a part of said liquid portion vaporizes to cool the expanded liquid portion; and (iii) at least the liquid formed upon partial condensation after expansion of the vapor portion in step (i) and the liquid remaining after expansion of the liquid portion in step (ii) are supplied to a fractionation column, wherein said relatively less volatile fraction is separated, the improvement wherein (a) at least some of said liquid portion under pressure is subcooled to a temperature below its bubble point prior to expansion thereof, (b) at least a part of said subcooled liquid portion is expanded to said lower pressure, whereby it is partially vaporized to further cool said expanded subcooled liquid portion, (c) at least a part of the liquid remaining in the expanded subcooled liquid portion is supplied to said distilla-tion column at a first feed position, and (d) at least part of the stream resulting from expansion of said vapor in step (i) is supplied to said fractionation column at a second feed position, said second feed position being in a lower column position than said first feed position.

Claim 13

In a process for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, wherein said gas under pressure is cooled sufficiently to form a liquid portion under pressure and a vapor portion under pressure, and (i) said vapor portion under pressure is expanded to a lower pressure, whereby it partially condenses; (ii) said liquid portion under pressure is expanded to said lower pressure, whereby a part of said liquid portion vaporizes to cool the expanded liquid portion; and (iii) at least the liquid formed upon partial condensation after expansion of the vapor portion in step (i) and the liquid remaining after expansion of the liquid portion in step (ii) are supplied to a fractionation column, wherein said relatively less volatile fraction is separated, the improvement wherein (a) at least some of said liquid portion under pressure is subcooled to a temperature below its bubble point prior to expansion thereof, (b) at least a part of said subcooled liquid portion is expanded to said lower pressure, whereby it is partially vaporized to further cool said expanded subcooled liquid portion, (c) at least a part of the liquid remaining in the expanded subcooled liquid portion is supplied to said distilla-tion column at a first feed position, and (d) at least part of the stream resulting from expansion of said vapor in step (i) is supplied to said fractionation column at a second feed position, said second feed position being in a lower column position than said first feed position.

Claim 14

In a process for separation of a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, wherein said feed gas is cooled sufficiently under pressure to condense it to a liquid, and (1) at least some of said liquid under pressure is expanded to a lower pressure and resulting in an expanded stream, whereby part of the liquid vaporizes to cool the expanded stream, and (2) at least some of the liquid remaining in said expanded stream is supplied to a fractionation column wherein said relatively less volatile fraction is separated, the improvement wherein said liquid under pressure is subcooled to a temperature below its bubble point prior to expansion thereof by extracting heat therefrom, and (a) at least a portion of said subcooled liquid under pressure is expanded to said lower pressure and at least a part of the expanded liquid is supplied to said frac-tionation column as the top column liquid feed, and (b) the heat extracted from said liquid under pressure is supplied to said column at a mid column position.

Claim 15

In a process for separation of a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, wherein said feed gas is cooled sufficiently under pressure to condense it to a liquid, and (1) at least some of said liquid under pressure is expanded to a lower pressure and resulting in an expanded stream, whereby part of the liquid vaporizes to cool the expanded stream, and (2) at least some of the liquid remaining in said expanded stream is supplied to a fractionation column wherein said relatively less volatile fraction is separated, the improvement wherein said liquid under pressure is subcooled to a temperature below its bubble point prior to expansion thereof by extracting heat therefrom, and (a) at least a portion of said subcooled liquid under pressure is expanded to said lower pressure and at least a part of the expanded liquid is supplied to said frac-tionation column as the top column liquid feed, and (b) the heat extracted from said liquid under pressure is supplied to said column at a mid column position.

Claim 16

The improvement according to claim 12, wherein said subcooled liquid is divided into a first part and a second part prior to expansion thereof; said first part is expanded to said lower pressure and directed into heat exchange relation with at least some of said liquid under pressure, whereby said first part extracts heat therefrom; and is thereafter supplied to said fractionation column at said mid column position; and said second part is expanded to said lower pressure and supplied to said fractionation column at the top column feed position.

Claim 17

The improvement according to claim 12, wherein said subcooled liquid stream is expanded to said lower pressure and the expanded stream is thereafter divided into at least a first and second portion; and (a) said first portion is directed into a heat exchange relation with said liquid under pressure, whereby said liquid under pressure is subcooled and said portion extracts heat therefrom, and said first portion is thereafter supplied to said fractionation column at said mid column position; and (b) said second part is supplied to said fractionation column at the top column feed position.

Claim 18

The improvement according to claim 12, wherein a liquid side stream is withdrawn from said fractionation column and directed into heat exchange relation with said liquid under pressure, whereby said liquid under pressure is subcooled and said side stream extracts heat therefrom, said side stream being thereafter returned to said fractionation column at said mid column position.

Claim 19

In an apparatus for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, said apparatus including (i) a first cooling means to receive said feed gas under pressure and to cool it sufficiently to form a liquid portion and a vapor portion, (ii) a separation means connected to said first cooling means to separate said liquid portion under pressure and said vapor portion under pressure, (iii) first expansion means connected to the separation means to receive said vapor portion under pressure and expand it to a lower pressure, thereby partially condensing said expanded vapor stream, (iv) a second expansion means connected to receive said liquid portion under pressure and to expand said liquid portion to said lower pressure, thereby to vaporize a portion of said liquid and to cool the expanded liquid portion, and (v) a fractionation means connected to said first and second expansion means to receive at least the liquid formed from partial condensation of said expanded vapor and the liquid remaining from expansion of said liquid stream, to separate said relatively less volatile fraction, the improvement comprising (a) a subcooling means connected intermediate said separation means and said second expansion means to cool said liquid portion under pressure to a temperature below its bubble point prior to expansion thereof, said subcooling means being connected to supply at least a portion of said subcooled liquid to said second expansion means, and (b) said second expansion means is connected to supply at least part of the liquid remaining in the expanded subcooled liquid portion to said distillation column as a top liquid feed thereto.

Claim 20

In an apparatus for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, said apparatus including (i) a first cooling means to receive said feed gas under pressure and to cool it sufficiently to form a liquid portion and a vapor portion, (ii) a separation means connected to said first cooling means to separate said liquid portion under pressure and said vapor portion under pressure, (iii) first expansion means connected to the separation means to receive said vapor portion under pressure and expand it to a lower pressure, thereby partially condensing said expanded vapor stream, (iv) a second expansion means connected to receive said liquid portion under pressure and to expand said liquid portion to said lower pressure, thereby to vaporize a portion of said liquid and to cool the expanded liquid portion, and (v) a fractionation means connected to said first and second expansion means to receive at least the liquid formed from partial condensation of said expanded vapor and the liquid remaining from expansion of said liquid stream, to separate said relatively less volatile fraction, the improvement comprising (a) a subcooling means connected intermediate said separation means and said second expansion means to cool said liquid portion under pressure to a temperature below its bubble point prior to expansion thereof, said subcooling means being connected to supply at least a portion of said subcooled liquid to said second expansion means, and (b) said second expansion means is connected to supply at least part of the liquid remaining in the expanded subcooled liquid portion to said distillation column as a top liquid feed thereto.

Claim 21

The improvement according to claim 16, wherein there are provided connection means connected to said first expansion means to supply expanded stream produced by said first expansion means to said fractionation column as an additional top column feed.

Claim 22

The improvement according to claim 16, wherein there is provided (1) a second separation means connected intermediate said second expansion means and said distillation column to receive the expanded subcooled liquid portion from said second expansion means, said second separation means further being connected to receive the expanded vapor portion from said first expansion means, said second separation means providing thereby a combined liquid stream, (2) means connecting said second separation means to said subcooling means to receive a portion of the combined liquid stream from said second separation means and to direct a portion of said combined liquid to said subcooling means for indirect heat exchange with said liquid portion under pressure, whereby said subcooling means cools said liquid portion under pressure to a temperature below its bubble point prior to expansion thereof, and said portion of the combined liquid stream is warmed, (3) means connecting said subcooling means to said fractionation column at a mid column feed position to supply said portion of the combined liquid stream to said fractionation column as a mid column feed, and (4) further connecting means connected between said second separation means and said fractionation column to supply the remaining part of said combined liquid stream to said fractionation column as the top liquid feed thereto.

Claim 23

The improvement according to claim 16, wherein there are provided (1) a dividing means connected intermediate said second expansion means and said distillation column to receive the liquid remaining in the expanded liquid portion produced in said second expansion means, (2) means connecting said dividing means to said subcooling means to direct a first part of the expanded sub-cooled liquid portion to said second cooling means, therein said expanded subcooled liquid portion is directed into heat exchange relation with said liquid portion under pressure to subcool said liquid portion under pressure and warm the first part of said expanded subcooled liquid portion, (3) means connecting said subcooling means to said fractionation column to receive warmed first part from said second cooling means and direct it to said fractionation column at a mid column feed position, and (4) means connected to said dividing means to receive the remaining part of said expanded subcooled liquid portion and supply it to said fractionation column as a top column liquid feed.

Claim 24

The improvement according to claim 16, wherein there are provided (1) dividing means connected intermediate said subcooling means and said second expansion means to receive subcooled liquid portion from said second cooling means and to divide it into a first part and a second part, (2) a third expansion means connected to said dividing means to receive said first part of said subcooled liquid portion and to expand it to said lower pressure, said third expansion means further being connected to supply said expanded first part to said subcooling means wherein said expanded first part passes into heat exchange relation with said liquid portion under pressure to subcool said liquid portion, (3) means connected between said second cooling means to receive said expanded first part therefrom and to supply it to said fractionation column at a mid column feed position, and (4) means connected to said dividing means to receive said second part of said subcooled liquid portion and supply it to said second expansion means, whereby said remaining part is expanded to said lower pressure and supplied to said distillation column as a top liquid feed thereto.

Claim 25

The improvement according to claim 16, including means connected to said first expansion means (iii) to receive said expanded vapor portion and to supply said expanded vapor portion to said fractionation column at a mid column feed position.

Claim 26

The improvement according to claim 16, wherein said subcooling means comprises means to extract heat from said liquid portion under pressure and to supply said heat to said fractionation column at a mid column position.

Claim 27

The improvement according to claim 22, wherein said means to extract heat comprise means to withdraw a side stream from said fractionation column at a mid column position and direct said side stream into heat exchange relation with said liquid portion under pressure in said subcooling means, and means to return said side stream from said subcooling means to said fractionation column.

Claim 28

The improvement according to claim 16, wherein there are provided means to direct cold volatile residue gas to said subcooling means, and into heat exchange relation with said liquid portion under pressure in said second cooling means, whereby said liquid portion under pressure is subcooled and said cold volatile residue gas is warmed.

Claim 29

The improvement according to claim 16, wherein there are provided means connected between said first expansion means and said subcooling means to receive said expanded vapor portion and direct it into heat exchange relation with said liquid portion under pressure, whereby said liquid portion under pressure is subcooled.

Claim 30

An an apparatus for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, said apparatus including (i) a first cooling means to receive said feed gas under pressure and to cool it sufficiently to form a liquid portion and a vapor portion, (ii) separation means connected to said cooling means to separate said liquid portion under pressure and said vapor portion under pressure, (iii) a first expansion means connected to said separation means to receive said vapor portion under pressure and expand it to a lower pressure, thereby partially condensing said expanded vapor portion, (iv) a second expansion means connected to receive said liquid portion under pressure and to expand said liquid portion to said lower pressure, thereby to vaporize a portion of said liquid and to cool the expanded liquid portion, and (v) a fractionation means connected to said first and second expansion means to receive at least the liquid formed from partial condensation of said expanded vapor and the liquid remaining from expansion of said liquid stream to separate said relatively less volatile fraction, the improvement comprising (a) a subcooling means connected intermediate said separation means and said second expansion means to cool said liquid portion under pressure to a temperature below its bubble point prior to expansion thereof, said second cooling means being connected to supply at least a portion of said subcooled liquid to said second expansion means, (b) said second expansion means being connected to supply at least a part of the liquid remaining in the expanded subcooled liquid portion to said distillation column at a first column feed position, and (c) said first expansion means being connected to provide at least a part of the expanded vapor stream to said fractionation column at a second feed position, said second feed position being in a lower column position than said first feed position.

Claim 31

An an apparatus for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, said apparatus including (i) a first cooling means to receive said feed gas under pressure and to cool it sufficiently to form a liquid portion and a vapor portion, (ii) separation means connected to said cooling means to separate said liquid portion under pressure and said vapor portion under pressure, (iii) a first expansion means connected to said separation means to receive said vapor portion under pressure and expand it to a lower pressure, thereby partially condensing said expanded vapor portion, (iv) a second expansion means connected to receive said liquid portion under pressure and to expand said liquid portion to said lower pressure, thereby to vaporize a portion of said liquid and to cool the expanded liquid portion, and (v) a fractionation means connected to said first and second expansion means to receive at least the liquid formed from partial condensation of said expanded vapor and the liquid remaining from expansion of said liquid stream to separate said relatively less volatile fraction, the improvement comprising (a) a subcooling means connected intermediate said separation means and said second expansion means to cool said liquid portion under pressure to a temperature below its bubble point prior to expansion thereof, said second cooling means being connected to supply at least a portion of said subcooled liquid to said second expansion means, (b) said second expansion means being connected to supply at least a part of the liquid remaining in the expanded subcooled liquid portion to said distillation column at a first column feed position, and (c) said first expansion means being connected to provide at least a part of the expanded vapor stream to said fractionation column at a second feed position, said second feed position being in a lower column position than said first feed position.

Claim 32

In an apparatus for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising a major portion of said feed gas, said apparatus including (i) a first cooling means to receive said feed gas under pressure and to cool it sufficiently to condense it to a liquid; (ii) an expansion means connected to said cooling means to receive at least a portion of said condensed feed gas and to expand it to a lower pressure, whereby a portion of the expanded stream is vaporized to further cool the expanded stream; and (iii) fractionation means connected to said expansion means to receive at least the liquid remaining in said expanded stream to separate said relatively less volatile fraction, the improvement comprising (a) subcooling means connected intermediate said first cooling means and said expansion means to receive at least a portion of said condensed gas and to subcool it to a temperature below its bubble point prior to expansion thereof by extracting heat therefrom, (b) means to supply the heat extracted in said subcooling means to said fractionation column at a mid column position, and (c) said expansion means (ii) being connected to supply at least a portion of the expanded stream to said fractionation column as the top feed thereto.

Claim 33

In an apparatus for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising a major portion of said feed gas, said apparatus including (i) a first cooling means to receive said feed gas under pressure and to cool it sufficiently to condense it to a liquid; (ii) an expansion means connected to said cooling means to receive at least a portion of said condensed feed gas and to expand it to a lower pressure, whereby a portion of the expanded stream is vaporized to further cool the expanded stream; and (iii) fractionation means connected to said expansion means to receive at least the liquid remaining in said expanded stream to separate said relatively less volatile fraction, the improvement comprising (a) subcooling means connected intermediate said first cooling means and said expansion means to receive at least a portion of said condensed gas and to subcool it to a temperature below its bubble point prior to expansion thereof by extracting heat therefrom, (b) means to supply the heat extracted in said subcooling means to said fractionation column at a mid column position, and (c) said expansion means (ii) being connected to supply at least a portion of the expanded stream to said fractionation column as the top feed thereto.

Claim 34

The improvement according to claim 27, wherein (a) dividing means are connected intermediate said subcooling means and said expansion means (ii) to divide the subcooled liquid from said subcooling means into a first part and a remaining part; (b) a second expansion means is connected to said dividing means to receive the first part of said subcooled liquid, to expand it and to supply said expanded first part to said subcooling means and direct it into heat exchange relation with said condensed feed gas, thereby to extract heat therefrom; (c) means connecting said subcooling means to said fractionation column to receive said expanded first part containing heat extracted from the condensed feed gas, and to supply it to said fractionation column at said mid column position; and (d) said dividing means being further connected to supply the remaining part of said subcooled condensed feed gas to said expansion means (ii).

Claim 35

The improvement according to claim 27, wherein (a) dividing means are connected intermediate said expansion means (ii) and said fractionation column to divide the expanded stream into at least a first liquid part and a remaining part; (b) means connecting said dividing means to said subcooling means to supply said first liquid part to said subcooling means and direct it into heat exchange relation with said condensed feed gas to extract heat therefrom; (c) means connecting said subcooling means to said fractionation column to receive said first part containing heat extracted from the condensed feed gas and to supply it to said fractionation column at said mid column position; and (d) said dividing means being further connected to supply at least a portion of the remaining part of said subcooled expanded feed gas to said fractionation column as the top column liquid feed.

Claim 36

The improvement according to claim 27, wherein there are provided (a) means connected to said fractionation column to withdraw a liquid side stream therefrom, to supply said liquid side stream to said subcooling means, and to direct it into heat exchange relation with the condensed feed gas whereby said liquid side stream extracts heat therefrom; and (b) further means connecting said subcooling means to said fractionation column to receive said side stream containing heat extracted from said condensed feed gas and to return it to said fractionation column at said mid column position.

Claim 37

In a process for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, wherein said gas is cooled sufficiently under pressure so as to convert at least some of said gas to liquid, and, (i) any vapor portion under pressure is expanded to a lower pressure, whereby it partially condenses, (ii) said liquid portion under pressure is expanded to said lower pressure, whereby a part of said liquid portion vaporizes to cool the expanded liquid portion; and (iii) at least the liquid formed upon partial condensation of said expanded vapor, and the remaining liquid portion of said expanded liquid portion are supplied to a fractionation column wherein said relatively less volatile fraction is separated, the improvement wherein (a) at least some of said liquid portion under pressure is subcooled to a temperature below its bubble point prior to expansion thereof; (b) at least a part of said subcooled liquid portion under pressure is expanded to said lower pressure; and (c) at least a portion of the liquid remaining in the expanded subcooled liquid portion is supplied to said distilla-tion column as a top liquid feed thereto.

Claim 38

In a process for separating a feed gas into a volatile residue gas and a relatively less volatile fraction, said feed gas containing hydrocarbons, methane and ethane together comprising the major portion of said feed gas, wherein said gas is cooled sufficiently under pressure so as to convert at least some of said gas to liquid, and, (i) any vapor portion under pressure is expanded to a lower pressure, whereby it partially condenses, (ii) said liquid portion under pressure is expanded to said lower pressure, whereby a part of said liquid portion vaporizes to cool the expanded liquid portion; and (iii) at least the liquid formed upon partial condensation of said expanded vapor, and the remaining liquid portion of said expanded liquid portion are supplied to a fractionation column wherein said relatively less volatile fraction is separated, the improvement wherein (a) at least some of said liquid portion under pressure is subcooled to a temperature below its bubble point prior to expansion thereof; (b) at least a part of said subcooled liquid portion under pressure is expanded to said lower pressure; and (c) at least a portion of the liquid remaining in the expanded subcooled liquid portion is supplied to said distilla-tion column as a top liquid feed thereto.