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A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds to produce a hydrogen-rich product gas from a low hydrogen concentration feed with a high recovery rate. Each of the plurality of adsorption beds subjected to a repeti

A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds to produce a hydrogen-rich product gas from a low hydrogen concentration feed with a high recovery rate. Each of the plurality of adsorption beds subjected to a repetitive cycle. The process comprises an adsorption step for producing the hydrogen-rich product from a feed gas mixture comprising 5% to 50% hydrogen, at least two pressure equalization by void space gas withdrawal steps, a provide purge step resulting in a first pressure decrease, a blowdown step resulting in a second pressure decrease, a purge step, at least two pressure equalization by void space gas introduction steps, and a repressurization step. The second pressure decrease is at least 2 times greater than the first pressure decrease.

대표청구항 ▼

The invention claimed is: 1. A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds each containing an adsorbent selective for the at least one more strongly adsorbable component to produce a hydrogen-rich product gas, ea

The invention claimed is: 1. A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds each containing an adsorbent selective for the at least one more strongly adsorbable component to produce a hydrogen-rich product gas, each of the plurality of adsorption beds subjected to a repetitive cycle, the process comprising: (a) an adsorption step for producing the hydrogen-rich product from a feed gas mixture comprising 5% to 50% hydrogen; (b) at least two pressure equalization by void space gas withdrawal steps; (c) a provide purge step resulting in a first pressure decrease ΔP1; (d) a blowdown step resulting in a second pressure decrease ΔP2; (e) a purge step; (f) at least two pressure equalization by void space gas introduction steps; and (g) a repressurization step; wherein Δ ⁢ ⁢ P 2 Δ ⁢ ⁢ P 1 ≥ 2.0 . 2. The process of claim 1 wherein the feed gas mixture comprises 5% to 40% hydrogen. 3. The process of claim 1 wherein the feed gas mixture comprises 5% to 30% hydrogen. 4. The process of claim 1 wherein Δ ⁢ ⁢ P 2 Δ ⁢ ⁢ P 1 ≥ 3.0 . 5. The process of claim 1 wherein the blowdown step is to a blowdown pressure wherein the blowdown pressure is 108 kPa to 170 kPa. 6. The process of claim 1 wherein at least one of the at least two pressure equalization by void space gas introduction steps is a pressure equalization by void space gas introduction step with hydrogen-rich product gas assistance. 7. The process of claim 1 wherein the process comprises at least three pressure equalization by void space gas withdrawal steps and at least three pressure equalization by void space gas introduction steps. 8. The process of claim 7 wherein Δ ⁢ ⁢ P 2 Δ ⁢ ⁢ P 1 ≥ 4.0 . 9. A process for selectively separating hydrogen from at least one more strongly adsorbable component in a plurality of adsorption beds each containing an adsorbent selective for the at least one more strongly adsorbable component to produce a hydrogen-rich product gas, each of the plurality of adsorption beds subjected to a repetitive cycle, the process comprising: (a) introducing a feed gas mixture comprising 5% to 50% hydrogen at an elevated pressure into a first adsorption bed of the plurality of adsorption beds and adsorbing the at least one more strongly adsorbable component on the adsorbent in the first adsorption bed while withdrawing the hydrogen-rich product gas from the first adsorption bed, thereafter leaving a first void space gas in the first adsorption bed substantially at the elevated pressure; (b) co-currently withdrawing a first portion of the first void space gas from the first adsorption bed and passing the first portion of the first void space gas to a second adsorption bed of the plurality of adsorption beds for pressure equalization; (c) co-currently withdrawing a second portion of the first void space gas from the first adsorption bed and passing the second portion of the first void space gas to a third adsorption bed of the plurality of adsorption beds to purge the third adsorption bed with the second portion of the first void space gas resulting in a first pressure decrease in the first adsorption bed from a first pressure P1 to a second pressure P2; (d) co-currently withdrawing a third portion of the first void space gas from the first adsorption bed and passing the third portion of the first void space gas to one of the third adsorption bed and a fourth adsorption bed of the plurality of adsorption beds for pressure equalization; (e) counter-currently withdrawing a fourth portion of the first void space gas from the first adsorption bed resulting in a second pressure decrease in the first adsorption bed from the second pressure P2 or a third pressure P3 to a blowdown pressure P4; wherein ( P 2 - P 4 ) ( P 1 - P 2 ) ≥ 2.0  when the second pressure decrease in the first adsorption bed is from the second pressure P2 to the blowdown pressure P4, and ( P 3 - P 4 ) ( P 1 - P 2 ) ≥ 2.0  when the second pressure decrease in the first adsorption bed is from the third pressure P3 to the blowdown pressure P4; (f) counter-currently introducing a first portion of a second void space gas into the first adsorption bed for purging the first adsorption bed, the second void space gas from one of a fifth adsorption bed of the plurality of adsorption beds, the second adsorption bed, the third adsorption bed, and the fourth adsorption bed; (g) counter-currently introducing a second portion of the second void space gas or a portion of a third void space gas into the first adsorption bed from one of a sixth adsorption bed of the plurality of adsorption beds, the second adsorption bed, the third adsorption bed, the fourth adsorption bed and the fifth adsorption bed for pressure equalization; (h) counter-currently introducing a portion of a fourth void space gas into the first adsorption bed, the fourth void space gas from one of a seventh adsorption bed of the plurality of adsorption beds, the second adsorption bed, the third adsorption bed, the fourth adsorption bed, the fifth adsorption bed and the sixth adsorption bed for pressure equalization; and (i) at least one of co-currently introducing the feed gas mixture and counter-currently introducing the hydrogen-rich product gas from at least one of a hydrogen-rich product gas storage vessel, an eighth adsorption bed of the plurality of adsorption beds, the second adsorption bed, the third adsorption bed, the fourth adsorption bed, the fifth adsorption bed and the sixth adsorption bed into the first adsorption bed until the first adsorption bed is substantially at the elevated pressure. 10. The process of claim 9 wherein the feed gas mixture comprises 5% to 40% hydrogen. 11. The process of claim 9 wherein the feed gas mixture comprises 5% to 30% hydrogen. 12. The process of claim 9 wherein withdrawing the second portion of the void space gas is prior to withdrawing the third portion of the void space gas. 13. The process of claim 9 wherein withdrawing the third portion of the void space gas is prior to withdrawing the second portion of the void space gas. 14. The process of claim 9 wherein P4 is 108 kPa to 170 kPa. 15. The process of claim 9 wherein ( P 2 - P 4 ) ( P 1 - P 2 ) ≥ 3.0 when the second pressure decrease in the first adsorption bed is from the second pressure P2 to the blowdown pressure P4 and ( P 3 - P 4 ) ( P 1 - P 2 ) ≥ 3.0 when the second pressure decrease in the first adsorption bed is from the third pressure P3 to the blowdown pressure P4. 16. The process of claim 9 further comprising counter-currently introducing the hydrogen-rich product gas from at least one of the second adsorption bed, the third adsorption bed, the fourth adsorption bed, the fifth adsorption bed, the sixth adsorption bed and the eighth adsorption bed into the first adsorption bed simultaneously with the counter-current introducing of the second portion of the second void space gas or the portion of the third void space gas into the first adsorption bed for pressure equalization with hydrogen-rich product gas assistance. 17. The process of claim 16 wherein the hydrogen-rich gas for pressure equalization with hydrogen-rich product gas assistance is from at least one of the third adsorption bed and the fourth adsorption bed. 18. The process of claim 9 wherein the second void space gas is from one of the fourth adsorption bed and the fifth adsorption bed. 19. The process of claim 9 wherein the third void space gas is from one of the second adsorption bed, the fourth adsorption bed, and the sixth adsorption bed. 20. The process of claim 9 wherein the fourth void space gas is from one of the second adsorption bed, the fourth adsorption bed and the sixth adsorption bed. 21. The process of claim 9 wherein the hydrogen-rich product gas introduced into the first adsorption bed is from at least one of the third adsorption bed and the fourth adsorption bed. 22. The process of claim 9 wherein the second void space gas is from one of the fourth adsorption bed and the fifth adsorption bed, wherein the third void space gas is from one of the second adsorption bed, the fourth adsorption bed, and the sixth adsorption bed, wherein the fourth void space gas is from one of the second adsorption bed, the fourth adsorption bed and the sixth adsorption bed, and wherein the hydrogen-rich product gas introduced into the first adsorption bed is from at least one of the third adsorption bed and the fourth adsorption bed. 23. The process of claim 9 further comprising: (j) co-currently withdrawing a fifth portion of the first void space gas from the first adsorption bed and passing the fifth portion of the first void space gas to one of the third adsorption bed and the sixth adsorption bed for pressure equalization; and (k) counter-currently introducing a portion of a fifth void space gas into the first adsorption bed, the fifth void space gas from one of a ninth adsorption bed of the plurality of adsorption beds, the second adsorption bed, the third adsorption bed, the fourth adsorption bed, the fifth adsorption bed, the sixth adsorption bed, the seventh adsorption bed and the eighth adsorption bed for pressure equalization. 24. The process of claim 23 wherein the fifth void space gas is from one of the second adsorption bed and the third adsorption bed. 25. The process of claim 23 wherein ( P 2 - P 4 ) ( P 1 - P 2 ) ≥ 4.0 when the second pressure decrease in the first adsorption bed is from the second pressure P2 to the blowdown pressure P4 and ( P 3 - P 4 ) ( P 1 - P 2 ) ≥ 4.0 when the second pressure decrease in the first adsorption bed is from the third pressure P3 to the blowdown pressure P4.