Method for recovery of carbon dioxide from a gas
AssigneeUnion Engineering A/S
InventorRasmus Find
Life of this patent
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Abstract
The present invention relates to a method for recovery of carbon dioxide from a gas stream. The method is a two-step method in which carbon dioxide is compressed in the first step, while the residual carbon dioxide is recovered by an absorption process in a subsequent step. The present invention also relates to the use of the method for the recovery of carbon dioxide and a plant for recovery of carbon dioxide.
Claims18
A method for recovery of CO2 from a CO2-containing gas comprising the steps of:
- a. feeding a plant with a pressurised CO2-containing gas and/or compressing the CO2-containing gas during feeding,
- b. cooling the compressed gas obtained in step a,
- c. separating the gas obtained in step b by a condensation procedure, by which said gas is separated into a CO2-rich liquid (L1) and a CO2-containing gas (G1),
- d. absorbing the gas G1 obtained in step c with a physical liquid absorbing agent selected from the group consisting of SELEXOL, methanol, propylene carbonate and mixtures thereof, by which the gas G1 is separated into a liquid (L2) and a CO2-poor gas (G2),
- e. separating the liquid L2 obtained in step d in order to obtain a CO2-containing gas (G3) and a liquid (L3),
- f. compressing the gas G3 obtained in step e in order to obtain a CO2-containing gas (G4),
- g. distilling the liquid L1 obtained in step c in order to recover liquid CO2 (L5) and a gas (G5) substantially free of CO2, and
- h. processing gas G5 for recycle.
A method for recovery of CO2 from a CO2-containing gas comprising the steps of:
- a. feeding a plant with a pressurised CO2-containing gas and/or compressing the CO2-containing gas during feeding,
- b. cooling the compressed gas obtained in step a,
- c. separating the gas obtained in step b by use of a condensation procedure, by which said gas is separated into a CO2-rich liquid (L1) and a CO2-containing gas (G1),
- d. absorbing the gas G1 obtained in step c by means of a physical absorbing agent, by which the gas G1 is separated into a liquid (L2) and a CO2-poor gas (G2),
- e. separating the liquid L2 obtained in step d in order to obtain a CO2-containing gas (G3) and a liquid (L3),
- f. compressing the gas G3 obtained in step e in order to obtain a CO2-containing gas (G4), and
- g. distilling the liquid L1 obtained in step c in order to recover liquid CO2 (L5) and a gas (G5) substantially free of CO2;
- wherein the gas G2 obtained in step d and the gas G5 is processed for reuse or is disposed of by burning;
- and
- wherein the gases G2 and G5 are expanded prior to burning in order to recover energy.
A method for recovery of CO2 from a CO2-containing gas comprising the steps of:
- a. feeding a plant with a pressurised CO2-containing gas and/or compressing the CO2-containing gas during feeding,
- b. cooling the compressed gas obtained in step a,
- c. separating the gas obtained in step b by use of a condensation procedure, by which said gas is separated into a CO2-rich liquid (L1) and a CO2-containing gas (G1),
- d. absorbing the gas G1 obtained in step c by means of a physical absorbing agent, by which the gas G1 is separated into a liquid (L2) and a CO2-poor gas (G2),
- e. separating the liquid L2 obtained in step d in order to obtain a CO2-containing gas (G3) and a liquid (L3),
- f. compressing the gas G3 obtained in step e in order to obtain a CO2-containing gas (G4), and
- g. distilling the liquid L1 obtained in step c in order to recover liquid CO2 (L5) and a gas (G5) substantially free of CO2;
- wherein the CO2-containing gas is a waste gas from the manufacture of hydrogen and the gases G2 and G5 are recycled to the plant for manufacture of hydrogen.
A method for recovery of CO2 from a CO2-containing gas comprising the steps of:
- a. feeding a plant with a pressurised CO2-containing gas and/or compressing the CO2-containing gas during feeding,
- b. cooling the compressed gas obtained in step a,
- c. separating the gas obtained in step b by use of a condensation procedure, by which said gas is separated into a CO2-rich liquid (L1) and a CO2-containing gas (G1),
- d. absorbing the gas G1 obtained in step c by means of a physical absorbing agent, by which the gas G1 is separated into a liquid (L2) and a CO2-poor gas (G2),
- e. separating the liquid L2 obtained in step d in order to obtain a CO2-containing gas (G3) and a liquid (L3),
- f. compressing the gas G3 obtained in step e in order to obtain a CO2-containing gas (G4), and
- g. distilling the liquid L1 obtained in step c in order to recover liquid CO2 (L5) and a gas (G5) substantially free of CO2;
- wherein the gas G4 obtained in step f is recycled and mixed with the pressurised feeding stream obtained in step a, and wherein the gas G5 obtained in step g is recycled and mixed with the pressurised feeding stream obtained in step a.
A plant for recovery of CO2 from a CO2-containing gas comprising optionally a compressor (A) connected to a cooling unit (B), said cooling unit being connected to a condensation unit (C) having a gas outlet and a liquid outlet, the gas outlet of said condensation unit (C) being connected to an absorption column (D) with a gas outlet and a liquid outlet, said outlet for liquid being connected to one or more consecutive flash distillation columns (E) each having a gas outlet and a liquid outlet, the gas outlets of said flash distillation column(s) (E), being connected to one or more compressors (F), and the outlet of said compressor(s) (F) optionally being connected to one or more distillation columns (G) and the outlet of the liquid outlet from the condensation unit (C) being connected to one or more distillation columns (G′);
- further comprising an expander for expanding the gas G2 leaving the absorption column (D) and the gas G5 leaving the distillation column(s) (G) in order to recover energy.
Dependencies are inferred from the claim text.