초록 ▼

Pressure swing adsorption separation of a gas mixture containing a more readily adsorbed component and a less readily adsorbed component is performed to concentrate one of the components as a relatively purified product, within an apparatus which includes an adsorbent bed and cyclically operated var

Pressure swing adsorption separation of a gas mixture containing a more readily adsorbed component and a less readily adsorbed component is performed to concentrate one of the components as a relatively purified product, within an apparatus which includes an adsorbent bed and cyclically operated variable volume displacement means associated with the adsorbent bed to vary the working pressure of the gas contacting the adsorbent bed. The invention provides means to generate flow over the adsorbent bed and achieve recovery of expansion energy, while enabling large exchanges of fresh feed gas for depleted feed gas during each cycle.

대표청구항 ▼

A process for concentrating a first component from a feed gas mixture containing the first component and a second component, so that the feed gas mixture is separated into a product gas enriched in the first component and a depleted gas mixture enriched in the second component and depleted in the fi

A process for concentrating a first component from a feed gas mixture containing the first component and a second component, so that the feed gas mixture is separated into a product gas enriched in the first component and a depleted gas mixture enriched in the second component and depleted in the first component; one of the first and second components being more readily adsorbed under increase of pressure relative to the other component which is less readily adsorbed under increase of pressure over an adsorbent material, such that a mixture of the first and second components contacting the adsorbent material is relatively depleted in the first component at a first pressure and is relatively enriched in the first component at a second pressure when the pressure is cycled between the first pressure and the second pressure at a cyclic frequency; providing for the process a flow path through an adsorbent bed of the adsorbent material within a working space, the flow path contacting the adsorbent material between first and second ends of the flow path; and the process including the cyclically repeated steps in some sequence of: (a) introducing the feed gas mixture to adjacent the first end of the flow path through the adsorbent bed. (b) changing the volume of the working space communicating with the flow path, so as to change the working pressure over the adsorbent material between the first pressure and the second pressure, (c) while the working pressure is substantially at the second pressure, and the gas mixture contacting the adsorbent material is thus relatively enriched in the first component, generating flow of the feed gas mixture into the flow path through the adsorbent bed from the first end of the flow path, so that the gas mixture flows along the flow path in a first direction from the first end toward the second end of the flow path; and expanding the volume of a second space communicating with the second end of the flow path so as to store within the second space some gas enriched in the first component that has flowed from the second end of the flow path, (d) withdrawing from adjacent the second end of the flow path some product gas enriched in the first component which has flowed out of the adsorbent bed at the second end of the flow path, (e) changing the volume of the working space so as to change the working pressure from substantially the second pressure to substantially the first pressure, (f) while the working pressure is substantially at the first pressure, and the gas mixture contacting the adsorbent bed is thus relatively depleted in the first component, contracting the volume of the second space so as to generate flow along the flow path in a second direction reverse to the first direction, so that gas that was enriched in the first component and stored in the second portion of the working space in step (c) flows into the adsorbent bed at the second end of the flow path to purge the adsorbent bed, while a depleted gas mixture which is depleted in the first component relative to the feed gas mixture flows out of the adsorbent bed at the first end of the flow path, (g) removing from adjacent the first end of the flow path space a fraction in the range of about 20% up to 100% of the depleted gas mixture that has flowed from the adsorbent bed at the first end of the flow path in step (f) above, so as to limit mixing of gas enriched in the second component with the feed gas mixture to be introduced in a subsequent step (a) of the next cycle, and correspondingly to limit the concentration of the second component in the first end of the flow path, (h) exhausting some gas enriched in the second component from the working space, (i) changing the volume of the working space so as to change the working pressure from substantially the second pressure to substantially the first pressure, (j) repeating the above steps cyclically at the cyclic frequency. Apparatus for concentrating a first component from a feed gas mixture containing the first component and a second component, and separating the feed gas mixture into a product gas enriched in the first component and a depleted gas mixture enriched in the second component and depleted in the first component; one of the first and second components being more readily adsorbed under increase of pressure relative to the other component which is less readily adsorbed under increase of pressure over an adsorbent material, such that a mixture of the first and second components contacting the adsorbent material is relatively depleted in the first component at a first pressure and is relatively enriched in the first component at a second pressure when the pressure is cycled between the first pressure and the second pressure at a cyclic frequency; and the apparatus including: (a) an adsorbent bed of the adsorbent material within a working space, the adsorbent bed having a flow path through the adsorbent material, and the flow path contacting the adsorbent material between first and second ends of the flow path, (b) feed supply means for introducing the feed gas mixture to adjacent the first end of the flow path, (c) product delivery means for withdrawing the product gas from adjacent the second end of the flow path, (d) exhaust means for exhausting the depleted gas mixture from the apparatus, (e) a second space within the working space communicating with the second end of the flow path, (f) cyclic volume displacement means for cyclically changing the volume of the working space at the cyclic frequency, so as to change the working pressure in the flow path cyclically between the first pressure and the second pressure, (g) means to generate flow in the flow path in a first direction from the first end to the second end of the flow path, when the working pressure is substantially the second pressure, so that gas enriched in the first component will flow out of the adsorbent bed from the second end of the flow path, (h) means to generate flow in the flow path in a second direction reverse to the first direction, when the working pressure is substantially the first pressure, so that depleted gas mixture will flow out of the adsorbent bed from the first end of the flow path, (i) means to change the volume of the second space at the cyclic frequency, so that the volume of the second space is expanding when the pressure is substantially the second pressure, and the volume of the second space is contracting when the pressure is substantially the first pressure, (j) means to exchange depleted gas mixture for feed gas mixture, so as to restrict reintroduction of the depleted gas mixture to the flow path, (k) means to restrict mixing of depleted gas mixture about to be exhausted with feed gas mixture that will be introduced to the flow path.