Direct reduced iron manufacturing system

Patent metadata

Field	Value
Publication number	US-9557113-B2
Application number	US-201214352922-A
Country	US
Kind code	B2
Filing date	Nov 16, 2012
Priority date	Nov 17, 2011
Publication date	Jan 31, 2017
Grant date	Jan 31, 2017

Abstract

Included are: a direct reduction furnace for reducing iron ore directly into reduced iron using a high-temperature reducing gas including hydrogen and carbon monoxide, an acid gas removal unit having an acid gas component absorber for removing, with an absorbent such as an amine-based solvent, acid gas components (CO 2 , H 2 S) in a reduction furnace flue gas discharged from the direct reduction furnace, and a regenerator for releasing the acid gas, and a degradation product removal unit for separating and removing a degradation product in the absorbent used by circulating through the absorber and the regenerator.

First claim

The invention claimed is:

1. A direct reduced iron manufacturing system comprising:
a gas heater for heating a gas to produce a reducing gas;
a direct reduction furnace for reducing iron ore directly into reduced iron using a high-temperature reducing gas comprising hydrogen and carbon monoxide;
an acid gas removal unit including
an acid gas component absorber for removing, with an absorbent, an acid gas component in a reduction furnace flue gas discharged from the direct reduction furnace, and
a regenerator for releasing the acid gas; and

a degradation product removal unit for separating and removing a degradation product in the absorbent used by circulating between the acid gas component absorber and the regenerator,
a purified gas supply line for joining a purifying gas purified in the absorber and comprising hydrogen and carbon monoxide to the gas, and
a recovery gas supply line for supplying a recovery gas released from the regenerator and comprising CO 2 and H 2 S into the gas heater.

2. The direct reduced iron manufacturing system according to claim 1 , further comprising:
a bypass circuit for bypassing a part of a lean solvent to be returned from the regenerator to the absorber; and
a filter interposed in the bypass circuit.

3. The direct reduced iron manufacturing system according to claim 1 , further comprising:
an introduction line for introducing the reduction furnace flue gas into the acid gas removal unit;
a heat exchanger, interposed on the introduction line, for heat exchanging the reduction furnace flue gas;
a bag filter provided upstream of the heat exchanger; and
a scrubber provided downstream of the heat exchanger.

4. The direct iron manufacturing system according to claim 3 , further comprising a reduction furnace flue gas supply line for supplying a part of the reduction furnace flue gas emitted from the scrubber and comprising CH 4 and N 2 to the gas heater.

5. The direct iron manufacturing system comprising:
a gas heater for heating a gas to produce a reducing gas;
a direct reduction furnace for reducing iron ore directly into reduced iron using a high-temperature reducing gas comprising hydrogen and carbon monoxide;
an acid gas removal unit including
an acid gas component absorber for removing, with an absorbent, an acid gas component in a reduction furnace flue gas discharged from the direct reduction furnace, and
a regenerator for releasing the acid gas;

an introduction line for introducing the reduction furnace flue gas into the acid gas removal unit;
a heat exchanger, interposed on the introduction line, for heat exchanging the reduction furnace flue gas;
a bag filter provided upstream of the heat exchanger;
a scrubber provided downstream of the heat exchanger; and
a reduction furnace flue gas supply line for supplying a part of the reduction furnace flue gas emitted from the scrubber and comprising CH 4 and N 2 to the gas heater.

6. The direct iron manufacturing system according to claim 5 , further comprising:
a bypass circuit for bypassing a part of a lean solvent to be returned from the regenerator to the absorber; and
a filter interposed in the bypass circuit.

7. The direct iron manufacturing system according to claim 1 , wherein the direct reduction furnace is configured to intake reducing gas produced from natural gas, coal gasification gas or coke over gas.

8. The direct iron manufacturing system according to claim 5 , wherein the direct reduction furnace is configured to intake reducing gas produced from natural gas, coal gasification gas or coke over gas.

Assignees

• Mitsubishi Heavy Ind Ltd

Inventors

• Sakaguchi Masakazu
• Hirayama Haruaki
• Susaki Makoto
• Ishida Kazuo

Classifications

• B01D53/1418 Primary

  Recovery of products · CPC title

• Y02P10/212

  Cross-Sectional Technologies · mapped topic

• C21B13/0073

  Selection or treatment of the reducing gases · CPC title

• B01D53/1462

  Removing mixtures of hydrogen sulfide and carbon dioxide · CPC title

• B01D2252/204

  Amines · CPC title