Gas treatment system and gas treatment method

• US 10,449,495 B2
• Filed: 08/18/2016
• Issued: 10/22/2019
• Est. Priority Date: 08/21/2015
• Status: Active Grant

• Current Assignee: Klaus Schmidt
• Original Assignee: Kobe Steel Limited
• Inventors: Kishimoto, Akira, Matsuoka, Akira, Maeda, Norihide, Nishimura, Makoto
• Primary Examiner(s): Lawrence, Jr., Frank M
• Application Number:
  US15/742,467
• Publication Number:
  US 20180193798A1
• Time in Patent Office: 1,160 Days
• Field of Search: 95178-180, 95183, 95206, 95236, 96243, 423220, 423228, 423229
• CPC Class Codes: B01D 2252/202 Alcohols or their derivatives
• CPC Class Codes: B01D 2252/204 Amines
• CPC Class Codes: B01D 2252/20478 Alkanolamines
• CPC Class Codes: B01D 2257/304 Hydrogen sulfide
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2258/0283 Flue gases
• CPC Class Codes: B01D 53/1468 Removing hydrogen sulfide
• CPC Class Codes: B01D 53/1475 Removing carbon dioxide
• CPC Class Codes: B01D 53/1481 Removing sulfur dioxide or sulfur trioxide
• CPC Class Codes: B01D 53/18 Absorbing units; Liquid distributors therefor B01D3/16, B01D3/26, B01D3/30 take precedence; packing elements B01J19/30, B01J19/32
• CPC Class Codes: B01D 53/507 by treating the gases with other liquids
• CPC Class Codes: B01D 53/52 Hydrogen sulfide
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 53/78 with gas-liquid contact
• CPC Class Codes: B01D 53/96 Regeneration, reactivation or recycling of reactants
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

A gas treatment system includes an absorber, a liquid separator, a regenerator, a circulation mechanism and a heat transfer apparatus. The absorber contacts the gas with the treatment liquid. The liquid separator separates the treatment liquid having been in contact with the gas into a first phase portion having a high content of the acidic compound and a second phase portion having a low content of the acidic compound. The regenerator heats the first phase portion to eliminate the acidic compound from the first phase portion. The circulation mechanism recycles the second phase portion and the treatment liquid from which the acidic compound has been eliminated by the regenerator, in the absorber as a treatment liquid with which the gas is to be contacted. The heat transfer apparatus transfers heat from the treatment liquid discharged by the absorber and from the gas having undergone separation of the acidic compound, to the treatment liquid in the regenerator.

Claims

1. A gas treatment system for separating an acidic compound which generates an acid by dissolution in water from a gas containing the acidic compound, by using a treatment liquid capable of absorbing the acidic compound to undergo a phase separation, the gas treatment system comprising:

an absorber for contacting the gas with the treatment liquid;

a liquid separator for separating the treatment liquid having been in contact with the gas into a first phase portion having a high content of the acidic compound and a second phase portion having a low content of the acidic compound;

a regenerator for heating the first phase portion separated by the liquid separator to eliminate the acidic compound from the first phase portion;

a circulation mechanism for recycling the second phase portion separated by the liquid separator and the treatment liquid from which the acidic compound has been eliminated by the regenerator, in the absorber as a treatment liquid with which the gas is to be contacted; and

a heat transfer apparatus for transferring heat from the treatment liquid discharged by the absorber and from the gas having undergone separation of the acidic compound, to the treatment liquid in the regenerator.

2. The gas treatment system according to claim 1, further comprising a water reflux mechanism which comprises:

a water vapor separator for separating a gaseous matter generated by the heating in the regenerator, into water vapor and an acidic compound gas;

a water vapor compressor for compressing the water vapor separated by the water vapor separator; and

a condenser for exchanging heat between the water vapor compressed by the water vapor compressor and the treatment liquid in the regenerator,

wherein the water reflux mechanism allows the water condensed by the condenser to reflux into the regenerator.

3. The gas treatment system according to claim 1, wherein the circulation mechanism comprises a heat exchanger for exchanging heat between the first phase portion separated by the liquid separator and the treatment liquid from which the acidic compound has been eliminated in the regenerator.

4. The gas treatment system according to claim 2, wherein the circulation mechanism comprises a heat exchanger for exchanging heat between the first phase portion separated by the liquid separator and the treatment liquid from which the acidic compound has been eliminated in the regenerator.

5. The gas treatment system according to claim 3, further comprising a gas compressor for compressing the acidic compound gas emitted by the regenerator,

wherein the heat exchanger is a three-fluid heat exchanger for exchanging heat between the acidic compound gas compressed by the gas compressor, and both the treatment liquid discharged by the absorber and the first phase portion separated by the liquid separator.

6. The gas treatment system according to claim 1, wherein the heat transfer apparatus transfers heat from the absorption liquid before the absorption liquid is separated by the liquid separator.

7. The gas treatment system according to claim 1, wherein the heat transfer apparatus transfers heat from the first phase portion and the second phase portion separated by the liquid separator.

8. A gas treatment method comprising:

contacting a gas comprising an acidic compound which generates an acid by dissolution in water, with a treatment liquid capable of absorbing the acidic compound to undergo a phase separation;

separating the treatment liquid having been in contact with the gas into a first phase portion having a high content of the acidic compound and a second phase portion having a low content of the acidic compound;

heating the first phase portion to eliminate the acidic compound from the first phase portion;

recycling the second phase portion and the treatment liquid from which the acidic compound has been eliminated, as a treatment liquid with which the gas is to be contacted in the contacting; and

transferring by a heat transfer apparatus heat recovered from the treatment liquid having been in contact with the gas, and heat recovered from the gas having undergone separation of the acidic compound, in order to heat the first phase portion.