Desulfurization method for gas containing sulfur oxide and desulfurization apparatus

Patent metadata

Field	Value
Publication number	US-10099177-B2
Application number	US-201415026781-A
Country	US
Kind code	B2
Filing date	Aug 25, 2014
Priority date	Oct 3, 2013
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

Provided is a desulfurization method for sulfur oxide gas that includes: bringing a first sulfur oxide gas into contact with a humidifying liquid to obtain a second gas; separating at least part of the humidifying liquid from the second gas to obtain a third gas; contacting the third gas with an alkaline agent-containing liquid and oxygen to remove sulfur oxide from the third gas; using the alkaline agent-containing liquid as the humidifying liquid to be brought into contact with the first gas in the humidifying liquid contact step; acquiring at least part of the humidifying liquid separated from the second gas; removing gas from the humidifying liquid; and recovering a by-product, the alkaline agent-containing liquid, and oxygen from the humidifying liquid from which the gas has been removed in the gas removal step, the by-product recovery step being performed only downstream of the humidifying liquid acquisition step.

First claim

The invention claimed is:

1. A desulfurization method for a gas containing sulfur oxide, the desulfurization method comprising:
a humidifying liquid contact step of bringing a first gas containing sulfur oxide into contact with a humidifying liquid to obtain a second gas containing the humidifying liquid, where the sulfur oxide contained in the first gas is partially absorbed into the humidifying liquid;
a humidifying liquid separation step of separating at least part of the humidifying liquid from the second gas to obtain a third gas, where the third gas still contains the sulfur oxide;
a sulfur oxide removal step of bringing the third gas into contact with an alkaline agent-containing liquid and supplying oxygen into the alkaline agent-containing liquid to remove the remaining sulfur oxide from the third gas, where the sulfur oxide is absorbed into the alkaline agent-containing liquid and reacts with the alkaline agent and oxygen to generate a by-product through the reaction in the liquid;
a circulation step of circulating the alkaline agent-containing liquid brought into contact with the third gas and oxygen into the humidifying liquid contact step to use the circulated alkaline agent-containing liquid as the humidifying liquid to be brought into contact with the first gas where, any oxidizing substances in the circulated alkaline agent-containing liquid are reduced by the first gas;
a humidifying liquid acquisition step of acquiring at least part of the humidifying liquid separated from the second gas in the humidifying liquid separation step; and
a by-product recovery step of recovering the by-product from the humidifying liquid arranged downstream of the humidifying liquid acquisition step.

2. A desulfurization method for a gas containing sulfur oxide according to claim 1 , wherein the humidifying liquid acquisition step comprises adding oxygen to the humidifying liquid to generate the by-product also in the humidifying liquid.

3. A desulfurization method for a gas containing sulfur oxide according to claim 1 , wherein:
the sulfur oxide comprises SO 2 ;
the alkaline agent is calcium carbonate; and
the by-product is gypsum.

Assignees

• Chiyoda Corp

Inventors

• Yasuda Hirokazu
• Takei Noboru
• Kurosaki Naobumi

Classifications

• B01D2251/404

  of calcium · CPC title

• B01D53/504 Primary

  characterised by a specific device · CPC title

• B01D53/14

  by absorption · CPC title

• B01D53/78 Primary

  with gas-liquid contact · CPC title

• B01D53/502

  characterised by a specific solution or suspension · CPC title