US 12,344,807 B2 · Hydrocarbon gas processing

(1) first heat exchange means connected to receive said gas stream and cool said gas stream under pressure to form a cooled gas stream;

(2) first expansion means connected to said first heat exchange means to receive said cooled gas stream and expand said cooled gas stream to a first intermediate pressure to form an expanded cooled gas stream;

(3) a first distillation column connected to said first expansion means to receive said expanded cooled gas stream at a mid-column feed position;

(4) said first distillation column adapted to fractionate said expanded cooled gas stream at said first intermediate pressure to form a first overhead vapor stream comprising nitrogen and no more than 0.001 mole % carbon dioxide and a first hydrocarbon liquid stream containing a major portion of said carbon dioxide;

(5) first pumping means connected to said first distillation column to received said first hydrocarbon liquid stream and pump said first hydrocarbon liquid stream to form a pumped first hydrocarbon liquid stream;

(6) said first heat exchange means further connected to said first pumping means to receive said pumped first hydrocarbon liquid stream and heat said pumped first hydrocarbon liquid stream to form a heated first hydrocarbon liquid stream, thereby to supply at least a portion of the cooling of step (1);

(7) fractionation means connected to said first heat exchange means to receive said heated first hydrocarbon liquid stream and fractionate said heated first hydrocarbon liquid stream to form said relatively less volatile fraction containing a portion of said heavier hydrocarbon components and a first hydrocarbon vapor stream containing methane and the remaining portion of said heavier hydrocarbon components;

(8) second heat exchange means connected to said first distillation column to receive said first overhead vapor stream and cool said first overhead vapor stream sufficiently to form a partially condensed stream,

(9) a control device includes a sensor for measuring a temperature of said partially condensed stream and said device is configured to compare said temperature to a setpoint;

(10) first separating means connected to said second heat exchange means to receive said partially condensed stream and separate said partially condensed stream into a first vapor stream and a first liquid stream, said first separating means being further connected to said first distillation column to supply said first liquid stream to said first distillation column at a top feed position;

(11) said second heat exchange means further connected to said first separating means to receive said first vapor stream and cool said first vapor stream to form a cooled first vapor stream;

(12) second expansion means connected to said second heat exchange means to receive said cooled first vapor stream and expand said cooled first vapor stream to a lower pressure to form an expanded cooled stream;

(13) distillation means connected to said second expansion means to receive said expanded cooled stream to distill said expanded cooled stream to form a heated vapor stream containing a major portion of said nitrogen and a heated second hydrocarbon liquid stream;

(14) said second heat exchange means further connected to said distillation means and said first exchange means further connected to said second heat exchange means to receive said heated vapor stream and further heat said heated vapor stream to form said purge stream, thereby to supply at least a portion of the cooling of steps (1), (8), and (11);

(15) said second heat exchange means further connected to said distillation means and said first exchange means further connected to said second heat exchange means to receive said heated second hydrocarbon liquid stream and further heat and vaporize said heated second hydrocarbon liquid stream to form a second hydrocarbon vapor stream, thereby to supply at least a portion of the cooling of steps (1), (8), and (11);

(16) first compressing and cooling means connected to said first heat exchange means to receive said second hydrocarbon vapor stream and compress to a first higher pressure and cool said second hydrocarbon vapor stream to form a cooled compressed vapor stream;

(17) combining means connected to said first compressing and cooling means and to said fractionation means to receive said cooled compressed vapor stream and said first hydrocarbon vapor stream and combine said cooled compressed vapor stream and said first hydrocarbon vapor stream to form said volatile residue gas fraction;

(18) said first heat exchange means further connected to receive a refrigerant stream and further connected to said second heat exchange means to cool said refrigerant stream to form a cooled refrigerant stream, thereby to supply at least a portion of the heating of steps (6), (14), and (15);

(19) third expansion means connected to said second heat exchange means to receive said cooled refrigerant stream and expand said cooled refrigerant stream to a second intermediate pressure to form an expanded cooled refrigerant stream wherein said control device adjusts said third expansion means to control said second intermediate pressure based on the comparison of the temperature of the partially condensed stream to the setpoint;

(20) said second heat exchange means further connected to said third expansion means and said first heat exchange means further connected to said second heat exchange means to receive said expanded cooled refrigerant stream and heat said expanded cooled refrigerant stream to form a heated refrigerant stream, thereby to supply at least a portion of the cooling of steps (1), (8), (11), and (18);

(21) second compressing and cooling means connected to said first heat exchange means to receive said heated refrigerant stream and compress to a second higher pressure and cool said heated refrigerant stream to form said refrigerant stream, said second compressing and cooling means being further connected to said first heat exchange means to supply said refrigerant stream thereto;

and

(22) first control means adapted to regulate the quantities and temperatures of said expanded cooled gas stream and said first liquid stream to said first distillation column to maintain the overhead temperature of said first distillation column at a temperature whereby the major portion of said carbon dioxide is recovered in said first hydrocarbon liquid stream.

Hydrocarbon gas processing

Life of this patent

Hydrocarbon gas processing

Life of this patent

Abstract

Claims20