Process for separating and recovering carbonic acid gas from gas mixture by adsorption

• US 4,986,835 A
• Filed: 08/23/1989
• Issued: 01/22/1991
• Est. Priority Date: 12/26/1987
• Status: Expired due to Term

• Current Assignee: Seitetsu Kagaku Company Limited (Sumitomo Chemical Company Limited)
• Original Assignee: Seitetsu Kagaku Company Limited (Sumitomo Chemical Company Limited)
• Inventors: Inoue, Masahiro, Kaji, Shinichi, Uno, Masaru, Ueda, Kanji
• Primary Examiner(s): Spitzer, Robert
• Application Number:
  US07/397,469
• Time in Patent Office: 517 Days
• Field of Search: 55/25, 55/26, 55/31, 55/33, 55/58, 55/62, 55/68, 55/74, 55/75
• US Class Current: 95/99
• CPC Class Codes: B01D 2253/102 Carbon
• CPC Class Codes: B01D 2253/104 Alumina
• CPC Class Codes: B01D 2253/108 Zeolites
• CPC Class Codes: B01D 2256/22 Carbon dioxide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2257/80 Water
• CPC Class Codes: B01D 2259/4003 with two sub-steps
• CPC Class Codes: B01D 2259/40064 Five
• CPC Class Codes: B01D 2259/403 using three beds
• CPC Class Codes: B01D 2259/404 using four beds
• CPC Class Codes: B01D 2259/4145 arranged in series
• CPC Class Codes: B01D 53/02 by adsorption, e.g. preparative gas chromatography solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01
• CPC Class Codes: B01D 53/0476 Vacuum pressure swing adsorption
• CPC Class Codes: B01D 53/261 by adsorption
• CPC Class Codes: C01B 32/50 Carbon dioxide
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

The present invention relates to a process for separating and recovering a high purity carbonic acid gas from a wet mixed gas containing carbonic acid gas which comprises using a pressure swing adsorption and separation apparatus composed of an adsorber packed with alumina gel and zeolite and carrying out the steps of adsorption, washing, desorption and pressurization.

Claims

1. A process for separating and recovering a high purity carbonic acid gas from a wet mixed gas containing carbonic acid gas according to a pressure swing adsorption and separation method which comprises using a pressure swing adsorption and separation apparatus having at least three adsorbers, each of which is paced with alumina gel and zeolite, comprising the steps of:

providing the amount of carbonic acid gas in a feeding raw material gas at least 8% by volume;

providing the alumina gel at a composition of 20 to 50% by weight of Al₂ O₃ and 80 to 50% by weight of SiO₂, and packed at a feeding gas inlet side of the adsorber;

providing a 10A type zeolite packed at the downstream side of the adsorber;

providing a packing volume ratio of the alumina gel to zeolite of between 1;

10 and 1;

2; and

carrying out the steps of adsorption, washing, desorption and pressurization in each adsorber in one operation sequence.

2. The process according to claim 1, wherein water in the feeding raw material gas is such that the dew point thereof, at atmospheric pressure, is -50°

C. or higher and a temperature thereof is in the range between 10°

C. and 50°

C.

3. The process according to claim 1, wherein the steps for adsorption, washing and desorption are carried out by using an apparatus composed of three adsorbers and, when the desorption step is completed, a feeding raw material gas is introduced into the adsorber from a raw material inlet side and an adsorption waste gas is introduced into it from an outlet side to carry out the pressurization step.

4. A process according to claim 1, wherein four steps of adsorption, washing, desorption and pressurization is carried out by using an apparatus composed of four adsorbers and the pressurization step is carried out by utilizing only an adsorption waste gas.

5. A process according to claim 1, wherein dehumidification is carried out so that the dew point of water in a high purity carbonic acid gas becomes not higher than 35°

C. and the resulting gas is utilized for the washing step.

6. The process according to claim 1, wherein the adsorption waste gas heated to a temperature in the range between normal temperature and 100°

C. just before completion of the desorption step is introduced into an adsorber from an opposite side of a desorption gas outlet to carry out desorption and rinse.