Process for operating a blast furnace installation with top gas recycling

Patent metadata

Field	Value
Publication number	US-10054366-B2
Application number	US-201113996869-A
Country	US
Kind code	B2
Filing date	Dec 20, 2011
Priority date	Dec 21, 2010
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

Blast furnace installation having top gas recycling and process for operating same, in which the oxygen concentration of the oxidizing gas injected into the blast furnace is regulated as a function of the flow rate of the recycled top gas.

First claim

What is claimed is:

1. A process for the operation of a blast furnace plant, comprising: an air plant comprising, a compression unit and an air separation unit, a blast furnace, and a gas treatment plant,
the process comprising:
generating compressed air in the compression unit,
introducing the compressed air into the air separation unit thereby generating at least an oxygen-rich air gas and a nitrogen-rich air gas,
injecting a blast comprising an oxidizing gas into the blast furnace, said oxidizing gas having an oxygen concentration Cvox≥21.0 vol % and a flow rate Dvox,
generating a top gas in the blast furnace,
introducing the top gas into the gas treatment unit generating at least a top gas enriched in CO 2 and a top gas enriched in CO,

recovering at least a portion of the top gas enriched in CO, and injecting the top gas enriched in CO into the blast furnace as reducing gas with a flow rate Drco,
wherein the oxidizing gas is selected from the group consisting of:
(a) compressed air generated by the air compression unit,
(b) oxygen-rich air gas,
(c) a mixture of said compressed air with said oxygen-rich air gas,
(d) a mixture of said oxygen-rich air gas with the nitrogen-rich air gas, or
(e) a mixture of said compressed air with said oxygen-rich air gas and with said nitrogen-rich air gas, and

further comprising a control unit for regulating the flow rate Drco of the recovered top gas enriched in CO and the oxygen concentration Cvox of the air gas supplied to the blast furnace by means of an air gas feed network, said control unit being connected to the gas treatment plant and controlling the oxygen concentration Cvox of the air gas thus supplied as a function of the flow rate Drco of the recovered to gas enriched in CO.

2. The process of claim 1 , wherein the concentration Cvox of the oxidizing gas is increased when the flow rate Drco of the recovered top gas enriched in CO increases and the concentration Cvox of the oxidizing gas is lowered when the flow rate Drco of the recovered top gas enriched in CO falls.

3. The process of claim 1 , wherein the flow rate Dvox of the oxidizing gas is also regulated as a function of the flow rate Drco of the recovered top gas enriched in CO.

4. The process of claim 1 , wherein the top gas enriched in CO 2 exhibits a CO 2 concentration of at least 50 vol %.

5. The process of claim 1 , wherein at least a portion of the top gas enriched in CO 2 is captured and/or enhanced in value and/or sequestered.

6. The process of claim 1 , wherein the recovered top gas enriched in CO exhibits a CO concentration between 50 vol % and 100 vol %.

7. The process of claim 1 , wherein the recovered top gas enriched in CO exhibits an H 2 concentration of greater than 4 vol %.

8. The process of claim 1 , wherein the oxidizing gas of the blast is selected from the group consisting of:
(a) compressed air generated by the air compression unit,
(b) oxygen-rich air gas generated by the air separation unit, and
(c) a mixture of said compressed air with said oxygen-rich air gas.

9. The process of claim 1 , wherein, when the flow rate Drco of the recovered top gas enriched in CO is zero, the oxidizing gas is compressed air.

10. The process of claim 1 , wherein the oxidizing gas of the blast is selected from the group consisting of:
(a) oxygen-rich air gas generated by the air separation unit, and
(b) a mixture of said oxygen-rich air gas with compressed air generated by the air compression unit.

11. The process of claim 10 , wherein, when the flow rate Drco of the recovered top gas enriched in CO is zero, the oxidizing gas is a mixture of said oxygen-rich air gas with compressed air.

12. The process of claim 1 , wherein the oxidizing gas of the blast is selected from the group consisting of:
(a) oxygen-rich air gas generated by the air separation unit, and
(b) a mixture of said oxygen-rich air gas with nitrogen-rich air gas generated by the air separation unit.

13. The process of claim 12 , wherein, when the flow rate Drco of the recovered top gas enriched in CO is zero, the oxidizing gas is said oxygen-rich air gas.

14. The process of claim 1 , wherein, when the flow rate Drco of the recovered top gas enriched in CO reaches its maximum, the oxidizing gas is oxygen-rich air gas generated by the air separation unit.

Assignees

• Blostein Philippe
• Devaux Michel
• Dubettier Grenier Richard
• Air Liquide

Inventors

• Blostein Philippe
• Devaux Michel
• Dubettier-Grenier Richard

Classifications

• C21B2100/64

  Controlling the physical properties of the gas, e.g. pressure or temperature · CPC title

• C21B5/006

  Automatically controlling the process · CPC title

• C21B2100/26

  by adding additional fuel in recirculation pipes · CPC title

• C21B2100/28

  by separation · CPC title

• C21B2100/282

  of carbon dioxide · CPC title