Method for operating a fired furnace and arrangement comprising such a furnace

Patent metadata

Field	Value
Publication number	US-12330979-B2
Application number	US-202017597613-A
Country	US
Kind code	B2
Filing date	Jul 8, 2020
Priority date	Jul 18, 2019
Publication date	Jun 17, 2025
Grant date	Jun 17, 2025

Abstract

The invention concerns a process for operating a fired furnace which is heated using a fuel gas stream and forming a combustion product stream, wherein heat of at least part of the combustion product stream is used in forming a steam stream. It is provided that at least a part of the steam stream is subjected to a high-temperature electrolysis to form a hydrogen-containing and an oxygen-containing material stream, and that at least a part of the hydrogen-containing material stream is used as the fuel gas stream. A corresponding arrangement is also the subject of the invention.

First claim

The invention claimed is:

1. A method for operating a fired furnace, comprising:
heating a fired furnace using a fuel gas stream and forming a combustion product stream,
forming a steam stream using heat from at least a part of the combustion product stream,
subjecting at least a part of the steam stream to a high temperature electrolysis to form a hydrogen-containing substance stream and an oxygen-containing substance stream, and
using at least a part of the hydrogen-containing substance stream as the fuel gas stream,
wherein formation of the steam stream comprises a plurality of heat exchange steps to which the combustion product stream or a part thereof is subjected, wherein water used to form the steam stream and/or steam used to form the steam stream is heated in the heat exchange steps, and
wherein the plurality of heat exchange steps comprises a first heat exchange step in which
(a) the combustion product stream or a portion thereof is cooled from a temperature level of 1400 to 1600° C. to a temperature level of 900 to 1100° C., and in which saturated steam used to form the steam stream is superheated from a temperature level of 100 to 120° C. to a temperature level of 700 to 900° C., or
(b) the combustion product stream or a portion thereof is cooled from a temperature level of 1400 to 1600° C. to a temperature level of 600 to 700° C., and in which water used to form the steam stream is evaporated to form saturated steam.

2. The method according to claim 1 , further comprising using at least a part of the oxygen-containing substance stream together with the fuel gas stream to heat the furnace.

3. The method according to claim 1 , wherein in the first heat exchange step combustion product stream or a portion thereof is cooled from a temperature level of 1400 to 1600° C. to a temperature level of 900 to 1100° C., and saturated steam used to form the steam stream is superheated from a temperature level of 100 to 120° C. to a temperature level of 700 to 900° C., and wherein the plurality of heat exchange steps comprises a second heat exchange step in which the combustion product stream or a portion thereof is cooled from a temperature level of 900 to 1100° C. to a temperature level of 100 to 200° C., and in which water used to form the steam stream is evaporated to form saturated steam.

4. The method according to claim 3 , wherein the plurality of heat exchange steps comprises a third heat exchange step in which the combustion product stream or a part thereof is cooled from a temperature level of 100 to 200° C. to a lower temperature level and is thereby partially condensed, and in which water used to form the steam stream is preheated.

5. The method according to claim 4 , wherein the combustion product stream or part thereof that is subjected to the second and third heat exchange steps is compressed between the second and third heat exchange steps or after the third heat exchange step.

6. The method according to claim 1 , wherein in the first heat exchange step the combustion product stream or a portion thereof is cooled from a temperature level of 1400 to 1600° C. to a temperature level of 600 to 700° C., and in which water used to form the steam stream is evaporated to form saturated steam.

7. The method according to claim 6 , wherein the plurality of heat exchange steps comprises a second heat exchange step in which the combustion product stream or a portion thereof is cooled from a temperature level of 600 to 700° C. to a temperature level of 100 to 200° C., and in which saturated steam used to form the steam stream is superheated from a temperature level of 100 to 120° C. to a temperature level of 700 to 900° C.

8. The method according to claim 7 , wherein the plurality of heat exchange steps comprises a third heat exchange step in which the combustion product stream or a part thereof is cooled from a temperature level of 100 to 200° C. to a lower temperature level and is thereby partially condensed, and in which water used to form the steam stream is preheated.

9. The method according to claim 8 , wherein the combustion product stream or part thereof that is subjected to the second and third heat exchange steps is compressed between the second and third heat exchange steps or after the third heat exchange step.

10. The method according to claim 6 , wherein the plurality of heat exchange steps comprises a second heat exchange step in which the combustion product stream or part thereof is cooled from a temperature level of 600 to 700° C. to a temperature level of 300 to 400° C., and in which the hydrogen-containing substance stream and/or oxygen-containing substance stream formed in the high temperature electrolysis is heated.

11. The method according to claim 10 , wherein the plurality of heat exchange steps comprises a third heat exchange step in which the combustion product stream or a part thereof is cooled from a temperature level of 100 to 200° C. to a lower temperature level and is thereby partially condensed, and in which water used to form the steam stream is preheated.

12. The method according to claim 11 , wherein the plurality of heat exchange steps comprises a further heat exchange step, between the second heat exchange step and the third heat exchange step, in which combustion product stream or a portion thereof is cooled, and in which saturated steam used to form the steam stream is superheated.

13. The method according to claim 11 , wherein the combustion product stream or part thereof that is subjected to the second and third heat exchange steps is compressed between the second and third heat exchange steps or after the third cooling step.

14. The process according to claim 1 , wherein a heater operated by a separate heat source is also used to evaporate the water.

15. The method according to claim 1 , wherein the hydrogen-containing and oxygen-containing substance streams formed in the high temperature electrolysis are cooled against steam supplied to the high temperature electrolysis.

16. The method according to claim 1 , wherein the furnace is partially electrically heated.

17. The method according to claim 1 , wherein in the first heat exchange step combustion product stream or a portion thereof is cooled from a temperature level of 1400 to 1600° C. to a temperature level of 900 to 1100° C., and in which saturated steam used to form the steam stream is superheated from a temperature level of 100 to 120° C. to a temperature level of 700 to 900° C.

18. A method for operating a fired furnace, comprising:
heating a fired furnace using a fuel gas stream and forming a combustion product stream,
forming a steam stream by preheating water, evaporating the preheated water to form saturated steam, and heating the saturated steam to form superheated steam, wherein heat from at least a part of the combustion product stream is used in forming the steam stream,
subjecting at least a part of the steam stream to a high temperature electrolysis to form a hydrogen-containing substance stream and an oxygen-containing substance stream, and
using at least a part of the hydrogen-containing substance stream as the fuel gas stream,
wherein formation of the steam stream comprises a plurality of heat exchange steps to which the combustion product stream or a part thereof is subjected, wherein water used to form the steam stream and/or steam used to form the steam stream is heated in the heat exchange steps, and
wherein the plurality of heat exchange steps comprises a first heat exchange step in which
(a) the combustion product stream or a portion there

Assignees

• Linde Gmbh

Inventors

• Adendorff Martin
• Golbach Marco
• Seys Michael
• Hentschel Benjamin
• Jarosch Maximilian

Classifications

• F27D17/13

  using regenerative heat exchangers · CPC title

• C25B1/042

  by electrolysis of steam · CPC title

• F27D17/15

  using boilers · CPC title

• Y02P40/50

  Glass production, e.g. reusing waste heat during processing or shaping · CPC title

• Y02P20/129

  Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines · CPC title