Process for removing a nitrogen gas from mixture comprising N.sub.2 and CO or N.sub.2 ' CO.sub.2 and CO

• US 4,468,238 A
• Filed: 07/26/1983
• Issued: 08/28/1984
• Est. Priority Date: 07/27/1982
• Status: Expired due to Term

• Current Assignee: Kawasaki Steel Corporation (JFE Holdings Incorporated), Osaka Oxygen Industries Limited
• Original Assignee: Kawasaki Steel Corporation (JFE Holdings Incorporated), Osaka Oxygen Industries Limited
• Inventors: Hayashi, Shigeki, Kumagai, Masahiko, Matsui, Sigeo, Tukahara, Yogo
• Primary Examiner(s): Spitzer, Robert H.
• Application Number:
  US06/517,272
• Time in Patent Office: 399 Days
• Field of Search: 55/25, 55/26, 55/58, 55/62, 55/68, 55/75
• US Class Current: 95/102
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2253/116 Molecular sieves other than zeolites
• CPC Class Codes: B01D 2256/10 Nitrogen
• CPC Class Codes: B01D 2256/20 Carbon monoxide
• CPC Class Codes: B01D 2256/22 Carbon dioxide
• CPC Class Codes: B01D 2257/502 Carbon monoxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2259/40015 with two sub-steps
• CPC Class Codes: B01D 2259/4003 with two sub-steps
• CPC Class Codes: B01D 2259/40037 with two sub-steps
• CPC Class Codes: B01D 2259/40052 Recycled product or process gas
• CPC Class Codes: B01D 2259/40062 Four
• CPC Class Codes: B01D 2259/40064 Five
• CPC Class Codes: B01D 2259/40066 Six
• CPC Class Codes: B01D 2259/402 using two beds
• CPC Class Codes: B01D 2259/404 using four beds
• CPC Class Codes: B01D 53/0476 Vacuum pressure swing adsorption
• CPC Class Codes: C10K 1/32 with selectively adsorptive solids, e.g. active carbon
• CPC Class Codes: C21B 2100/282 of carbon dioxide
• CPC Class Codes: C21B 2100/284 : of nitrogen
• CPC Class Codes: C21B 7/002 : Evacuating and treating of exhaust gases
• CPC Class Codes: Y02C 20/40 : of CO2
• CPC Class Codes: Y02P 10/122 : by capturing or storing CO2
• CPC Class Codes: Y02P 20/151 : Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

Processes for removing N₂ from a feed gas comprising CO+N₂ or CO, CO₂ +N₂ through PSA by using at least two adsorption columns containing an adsorbent exhibiting selective adsorb property to carbon monoxide which comprises:

(i) a step of pressurizing an adsorption column by the feed gas;

(ii) a step of introducing the feed gas into the adsorption column, in which step (i) was previously completed, so as to adsorb CO, or CO+CO₂ on or in the adsorbent;

(iii) a step of connecting the adsorption column, in which step (ii) was previously completed, to the other adsorption column in which step (v) was previously completed, to reduce the pressure in the former adsorption column to one atmosphere or a pressure close to it;

(iv) a step of purging nitrogen by passing product gas through the adsorption column;

(v) a step of desorbing carbon monoxide adsorbed on or in the adsorbent of the adsorption column, by vacuum pump to recover a product gas; and

(vi) a step of a connecting the adsorption column, in which step (v) was previously completed, to the other adsorption column in which step (ii) was previously completed to increase pressure in the former column,

periodically switching the flow between or among said adsorption columns so as to repeat the above steps in all the adsorption columns.

Claims

1. A process for separating carbon monoxide from a feed gas comprising carbon monoxide and nitrogen through pressure swing adsorption by using at least two adsorption columns containing an adsorbent exhibiting selective adsorb property to carbon monoxide which comprises:

(i) a step of pressurizing an adsorption column by the feed gas, in which the step (vi) was previously completed;

(ii) a step of introducing the feed gas into the adsorption column, in which step (i) was previously completed, so as to adsorb carbon monoxide on or in the adsorbent until the breakthrough point is reached or until just before that point is reached;

(iii) a step of connecting the adsorption column, in which step (ii) was previously completed, to the other adsorption column in which step (v) was previously completed, to reduce the pressure in the former adsorption column to one atmosphere or a pressure close to it, and to increase pressure in the latter adsorption column;

(iv) a step of purging nitrogen by passing product gas through the adsorption column, in which step (iii) was previously completed;

(v) a step of desorbing carbon monoxide adsorbed on or in the adsorbent of the adsorption column, in which step (iv) was previously completed, by vacuum pump to recover a product gas, and

(vi) a step of connecting the adsorption column, in which step (v) was previously completed, to the other adsorption column in which step (ii) was previously completed to increase pressure in the former column,

periodically switching the flow between or among said adsorption columns so as to repeat the above steps in all the adsorption columns.

2. The process according to claim 1 wherein the adsorption pressure is in the range of 0.1-3.0 Kg/cm² ·

G.

3. The process according to claim 1 wherein depressurization by pressure equalization is countercurrently carried out.

4. The process according to claim 1 wherein purge by product gas is concurrently carried out.

5. The process according to claim 1 wherein the evacuation is countercurrently carried out.

6. The process according to claim 1 wherein pressurization by pressure equalization is concurrently carried out.

7. A process for separating carbon monoxide and carbon dioxide from a feed gas comprising carbon monoxide, carbon dioxide and nitrogen through pressure swing adsorption by using at least two adsorption columns containing an adsorbent exhibiting selective adsorb property to carbon monoxide and carbon dioxide which comprises:

(i) a step of pressurizing an adsorption column by the feed gas, in which the step (vi) was previously completed;

(ii) a step of introducing the feed gas into the adsorption column, in which step (i) was previously completed, so as to adsorb carbon monoxide and carbon dioxide adsorbed on or in the adsorbent until the breakthrough point is reached or until just before that point is reached;

(iii) a step of connecting the adsorption column, in which step (ii) was previously completed, to the other adsorption column in which step (v) was previously completed, to reduce the pressure in the former adsorption column to one atmosphere or a pressure close to it, and to increase pressure in the latter column;

(iv) a step of purging nitrogen by passing product gas through the adsorption column, in which step (iii) was previously completed;

(v) a step of desorbing carbon monoxide and carbon dioxide on the adsorbent of the adsorption column, in which step (iv) was previously completed, by vacuum pump to recover a product gas, and

(vi) a step of connecting the adsorption column, in which step (v) was previously completed, to the other adsorption column in which step (ii) was previously completed to increase pressure in the former column,

periodically switching the flow between or among said adsorption columns so as to repeat the above steps in all the adsorption columns.

8. The process according to claim 7 wherein the adsorption pressure is in the range of 0.1-3.0 Kg/cm² ·

G.

9. The process according to claim 7 wherein depressurization by pressure equalization is countercurrently carried out.

10. The process according to claim 7 wherein purge by product gas is concurrently carried out.

11. The process according to claim 7 wherein the evacuation is countercurrently carried out.

12. The process according to claim 7 wherein pressurization by pressure equalization is concurrently carried out.