Separation of gases

Claim 1

A METHOD OF SEPARATING A FEED GAS MIXTURE OBTAINED BY THE STEAM REFORMING OF NATURAL GAS FOLLOWED BY THE REMOVAL OF A SUBSTANTIAL PORTION OF THE CARBON DIOXIDE BY AN ABSORPTION PROCESS AND THE WATER VAPOR BY CONDENSATION WHICH MIXTURE CONTAINS HYDROGEN, CARBON MONOXIDE, NOT MORE THAN 1 MOL. % CARBON DIOXIDE, NOT MORE THAN 1 MOL. % WATER VAPOR AND SMALL QUANTITIES OF NITROGEN AND METHANE FOR THE PRODUCTION OF CARBON MONOXIDE WHICH COMPRISES: A. PASSING SAID FEED MIXTURE THROUGH AND COOLING SAID MIXTURE IN A FIRST SET OF PASSAGES IN A HEAT EXCHANGER CONTAINING AT LEAST TWO SETS OF PASSAGES TO DEPOSIT SAID CARBON DIOXIDE AND WATER VAPOR IN SOLID FORM ON THE INNER SURFACE THEREOF; B. COUNTERCURRENTLY PASSING A HYDROGEN-RICH STREAM AT A PRESSURE LOWER THAN THAT OF SAID GAS MIXTURE THROUGH AND WARMING SAID STREAM IN A SECOND, ADJACENT SET OF PASSAGES IN SAID HEAT EXCHANGER; C. PERIODICALLY PASSING SAID FEED GAS MIXTURE THROUGH AND COOLING SAID MIXTURE IN SAID SECOND SET OF PASSAGES TO DEPOSIT SAID CARBON DIOXIDE AND WATER VAPOR ON THE INNER SURFACE THEREOF AND COUNTERCURRENTLY PASSING SAID HYDROGEN-RICH STREAM THROUGH AND WARMING SAID STREAM IN SAID FIRST SET OF PASSAGES TO RE-EVAPORATE SUBSTANTIALLY ALL OF THE SOLID CARBON DIOXIDE AND ICE DEPOSITED ON THE INNER SURFACE THEREOF; D. PASSING THE COOLED FEED GAS MIXTURE FROM SAID HEAT EXCHANGER INTO THE BOTTOM OF A METHANE WASH COLUMN;

Claim 2

A METHOD OF SEPARATING A FEED GAS MIXTURE OBTAINED BY THE STEAM REFORMING OF NATURAL GAS FOLLOWED BY THE REMOVAL OF A SUBSTANTIAL PORTION OF THE CARBON DIOXIDE BY AN ABSORPTION PROCESS AND THE WATER VAPOR BY CONDENSATION WHICH MIXTURE CONTAINS HYDROGEN, CARBON MONOXIDE, NOT MORE THAN 1 MOL. % CARBON DIOXIDE, NOT MORE THAN 1 MOL. % WATER VAPOR AND SMALL QUANTITIES OF NITROGEN AND METHANE FOR THE PRODUCTION OF CARBON MONOXIDE WHICH COMPRISES: A. PASSING SAID FEED MIXTURE THROUGH AND COOLING SAID MIXTURE IN A FIRST SET OF PASSAGES IN A HEAT EXCHANGER CONTAINING AT LEAST TWO SETS OF PASSAGES TO DEPOSIT SAID CARBON DIOXIDE AND WATER VAPOR IN SOLID FORM ON THE INNER SURFACE THEREOF; B. COUNTERCURRENTLY PASSING A HYDROGEN-RICH STREAM AT A PRESSURE LOWER THAN THAT OF SAID GAS MIXTURE THROUGH AND WARMING SAID STREAM IN A SECOND, ADJACENT SET OF PASSAGES IN SAID HEAT EXCHANGER; C. PERIODICALLY PASSING SAID FEED GAS MIXTURE THROUGH AND COOLING SAID MIXTURE IN SAID SECOND SET OF PASSAGES TO DEPOSIT SAID CARBON DIOXIDE AND WATER VAPOR ON THE INNER SURFACE THEREOF AND COUNTERCURRENTLY PASSING SAID HYDROGEN-RICH STREAM THROUGH AND WARMING SAID STREAM IN SAID FIRST SET OF PASSAGES TO RE-EVAPORATE SUBSTANTIALLY ALL OF THE SOLID CARBON DIOXIDE AND ICE DEPOSITED ON THE INNER SURFACE THEREOF; D. PASSING THE COOLED FEED GAS MIXTURE FROM SAID HEAT EXCHANGER INTO THE BOTTOM OF A METHANE WASH COLUMN;

Claim 3

A method of separating a feed gas mixture obtained by the steam reforming of natural gas followed by the removal of a substantial portion of the carbon dioxide by an absorption process and the water vapor by condensation which mixture contains hydrogen, carbon monoxide, not more than 1 mol. % carbon dioxide, not more than 1 mol. % water vapor and small quantities of nitrogen and methane for the production of carbon monoxide which comprises: a. passing said feed mixture through and cooling said mixture in a first set of passages in a heat exchanger containing at least two sets of passages to deposit said carbon dioxide and water vapor in solid form on the inner surface thereof; b. countercurrently passing a hydrogen-rich stream at a pressure lower than that of said feed gas mixture through and warming said stream in a second, adjacent set of passages in said heat exchanger; c. periodically passing said feed gas mixture through and cooling said mixture in said second set of passages to deposit said carbon dioxide and water vapor on the inNer surface thereof and countercurrently passing said hydrogen-rich stream through and warming said stream in said first set of passages to re-evaporate substantially all of the solid carbon dioxide and ice deposited on the inner surface thereof; d. passing the cooled feed gas mixture from said heat exchanger into the bottom of a methane wash column; e. expanding the hydrogen stream recovered from the top of said column and recycling at least a part of said hydrogen to said heat exchanger as said hydrogen-rich stream; f. letting down the pressure of the liquid withdrawn from the bottom of said wash column to effect further hydrogen removal; g. partially vaporizing said liquid from step (f) and passing the resulting stream into a distillation column to separate carbon monoxide product from the methane; and h. recovering said carbon monoxide product.

Claim 4

A method of separating a feed gas mixture obtained by the steam reforming of natural gas followed by the removal of a substantial portion of the carbon dioxide by an absorption process and the water vapor by condensation which mixture contains hydrogen, carbon monoxide, not more than 1 mol. % carbon dioxide, not more than 1 mol. % water vapor and small quantities of nitrogen and methane for the production of carbon monoxide which comprises: a. passing said feed mixture through and cooling said mixture in a first set of passages in a heat exchanger containing at least two sets of passages to deposit said carbon dioxide and water vapor in solid form on the inner surface thereof; b. countercurrently passing a hydrogen-rich stream at a pressure lower than that of said feed gas mixture through and warming said stream in a second, adjacent set of passages in said heat exchanger; c. periodically passing said feed gas mixture through and cooling said mixture in said second set of passages to deposit said carbon dioxide and water vapor on the inNer surface thereof and countercurrently passing said hydrogen-rich stream through and warming said stream in said first set of passages to re-evaporate substantially all of the solid carbon dioxide and ice deposited on the inner surface thereof; d. passing the cooled feed gas mixture from said heat exchanger into the bottom of a methane wash column; e. expanding the hydrogen stream recovered from the top of said column and recycling at least a part of said hydrogen to said heat exchanger as said hydrogen-rich stream; f. letting down the pressure of the liquid withdrawn from the bottom of said wash column to effect further hydrogen removal; g. partially vaporizing said liquid from step (f) and passing the resulting stream into a distillation column to separate carbon monoxide product from the methane; and h. recovering said carbon monoxide product.

Claim 7

A method of separating a feed gas mixture obtained by the steam reforming of natural gas followed by the removal of a substantial portion of the carbon dioxide by an absorption process and the water vapor by condensation which mixture contains hydrogen, carbon monoxide, not more than 1 mol. % carbon dioxide, not more than 1 mol. % water vapor and small quantities of nitrogen and methane for the production of carbon monoxide which comprises: a. passing said feed mixture through and cooling said mixture in a first set of passages in a heat exchanger containing at least two sets of passages to deposit said carbon dioxide and water vapor in solid form on the inner surface thereof; b. countercurrently passing a hydrogen-rich stream at a pressure lower than that of said feed gas mixture through and warming said stream in a second, adjacent set of passages in said heat exchanger; c. periodically passing said feed gas mixture through and cooling said mixture in said second set of passages to deposit said carbon dioxide and water vapor on the inner surface thereof and countercurrently passing said hydrogen-rich stream through and warming said stream in said first set of passages to re-evaporate substantially all of the solid carbon dioxide and ice deposited on the inner surface thereof; d. passing the cooled feed gas mixture from said heat exchanger into the bottom of a methane wash column; e. expanding the hydrogen stream recovered from the top of said column and recycling at least a part of said hydrogen to said heat exchanger as said hydrogen-rich stream; f. letting down the pressure of the liquid withdrawn from the bottom of said wash column to effect further hydrogen removal; g. partially vaporizing said liquid from step (f) and passing the resulting stream into a distillation column to separate carbon monoxide product from the methane; h. pumping to a higher pressure, cooling and returning to the top of said wash column said liquid methane from the bottom of said distillation column; i. passing said carbon monoxide stream leaving the top of said distillation column through a carbon monoxide heat-pump circuit to provide cooling for said heat exchanger and internal refrigeration to said methane wash column; j. warming said carbon monoxide stream from the top of said distillation column by passing a part thereof through said heat exchanger and another part to a second, separate heat exchanger; k. compressing the recombined, warmed stream from the first and second heat exchangers to a high pressure; l. withdrawing a portion of said compressed stream as the carbon monoxide product; m. cOoling the remaining portion of said compressed stream by returning it to said second heat exchanger; n. withdrawing the remaining portion of said compressed stream being cooled in said second separate heat exchanger at an intermediate point, condensing it in the reboiler of said distillation column, and returning the condensed stream to continue passage to the cold end of said second heat exchanger; o. expanding the cooled, compressed stream on leaving said second heat exchanger to provide reflux for said distillation column; and p. expanding and employing the remaining part of said cooled, compressed stream to provide refrigeration for said methane wash column.

Claim 8

A method of separating a feed gas mixture obtained by the steam reforming of natural gas followed by the removal of a substantial portion of the carbon dioxide by an absorption process and the water vapor by condensation which mixture contains hydrogen, carbon monoxide, not more than 1 mol. % carbon dioxide, not more than 1 mol. % water vapor and small quantities of nitrogen and methane for the production of carbon monoxide which comprises: a. passing said feed mixture through and cooling said mixture in a first set of passages in a heat exchanger containing at least two sets of passages to deposit said carbon dioxide and water vapor in solid form on the inner surface thereof; b. countercurrently passing a hydrogen-rich stream at a pressure lower than that of said feed gas mixture through and warming said stream in a second, adjacent set of passages in said heat exchanger; c. periodically passing said feed gas mixture through and cooling said mixture in said second set of passages to deposit said carbon dioxide and water vapor on the inner surface thereof and countercurrently passing said hydrogen-rich stream through and warming said stream in said first set of passages to re-evaporate substantially all of the solid carbon dioxide and ice deposited on the inner surface thereof; d. passing the cooled feed gas mixture from said heat exchanger into the bottom of a methane wash column; e. expanding the hydrogen stream recovered from the top of said column and recycling at least a part of said hydrogen to said heat exchanger as said hydrogen-rich stream; f. letting down the pressure of the liquid withdrawn from the bottom of said wash column to effect further hydrogen removal; g. partially vaporizing said liquid from step (f) and passing the resulting stream into a distillation column to separate carbon monoxide product from the methane; h. pumping to a higher pressure, cooling and returning to the top of said wash column said liquid methane from the bottom of said distillation column; i. passing said carbon monoxide stream leaving the top of said distillation column through a carbon monoxide heat-pump circuit to provide cooling for said heat exchanger and internal refrigeration to said methane wash column; j. warming said carbon monoxide stream from the top of said distillation column by passing a part thereof through said heat exchanger and another part to a second, separate heat exchanger; k. compressing the recombined, warmed stream from the first and second heat exchangers to a high pressure; l. withdrawing a portion of said compressed stream as the carbon monoxide product; m. cOoling the remaining portion of said compressed stream by returning it to said second heat exchanger; n. withdrawing the remaining portion of said compressed stream being cooled in said second separate heat exchanger at an intermediate point, condensing it in the reboiler of said distillation column, and returning the condensed stream to continue passage to the cold end of said second heat exchanger; o. expanding the cooled, compressed stream on leaving said second heat exchanger to provide reflux for said distillation column; and p. expanding and employing the remaining part of said cooled, compressed stream to provide refrigeration for said methane wash column.