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RU-2861355-C2 - SYSTEM FOR PRODUCING SOLID CARBON FROM CO2 AND CORRESPONDING METHOD

RU2861355C2RU 2861355 C2RU2861355 C2RU 2861355C2RU-2861355-C2

Abstract

FIELD: chemical industry. SUBSTANCE: invention relates to a system for producing solid carbon from CO 2 and a corresponding method. The system for producing solid carbon from gaseous carbon dioxide comprises: a methanation unit configured to receive at least gaseous carbon dioxide and carry out methanation of carbon dioxide to obtain at least gaseous methane and heat; and a pyrolysis unit configured to receive gaseous methane and heat and carry out pyrolysis of methane to obtain gaseous hydrogen and solid carbon. The methanation unit has a first inlet configured to receive gaseous hydrogen, and a second inlet configured to receive gaseous carbon dioxide from a carbon capture system. The methanation unit and the pyrolysis unit are fluidly connected so that at least gaseous hydrogen is supplied to the methanation unit, and the units are thermally connected so that heat is supplied to the pyrolysis unit. The method for producing solid carbon from gaseous carbon dioxide includes the steps of: methanation of carbon dioxide in a methanation unit to obtain gaseous methane and heat, wherein the methanation unit has a first inlet configured to receive gaseous hydrogen, and a second inlet configured to receive gaseous carbon dioxide from a carbon capture system; pyrolysis of methane in a pyrolysis unit to obtain gaseous hydrogen and solid carbon. The heat obtained by methanation is used to carry out the pyrolysis of methane, wherein the gaseous hydrogen obtained by pyrolysis is used to carry out the methanation of carbon dioxide. EFFECT: implementation of an energy-efficient system/method providing convenient transportation and storage of CO 2 after its capture. 12 cl, 5 dwg

Inventors

  • GANIGER, Mangush
  • PANDEJ, Manish

Dates

Publication Date
20260505
Application Date
20240304
Priority Date
20230308

Claims (20)

  1. 1. A system (100, 200) for producing solid carbon (C) from gaseous carbon dioxide (CO 2 ), comprising:
  2. - a methanation unit (110, 210) configured to receive at least gaseous carbon dioxide ( CO2 ) and to methanate the carbon dioxide ( CO2 ) to produce at least gaseous methane ( CH4 ) and heat (Q); and
  3. - a pyrolysis unit (120, 220) configured to receive gaseous methane (CH 4 ) and heat (Q) and to carry out pyrolysis of methane (CH 4 ) to obtain gaseous hydrogen (H 2 ) and solid carbon (C),
  4. wherein the methanation unit (110, 210) has a first inlet (113, 213) configured to receive gaseous hydrogen (H 2 ) and a second inlet (111, 211) configured to receive gaseous carbon dioxide (CO 2 ) from the carbon capture system,
  5. wherein the methanation unit (110, 210) and the pyrolysis unit (120, 220) are connected via a fluid medium in such a way that at least gaseous hydrogen (H 2 ) is supplied to the methanation unit (110, 210),
  6. wherein the methanation unit (110, 210) and the pyrolysis unit (120, 220) are thermally connected in such a way that heat (Q) is supplied to the pyrolysis unit (110, 210).
  7. 2. The system (100, 200) according to claim 1, in which the pyrolysis unit (120, 220) has a first outlet (122, 222) configured to supply hydrogen gas (H 2 ), and said first outlet (122, 222) and first inlet (113, 213) are fluidly connected.
  8. 3. The system (100, 200) according to claim 1, in which the heat (Q) produced by the methanation unit (110, 210) by methanating carbon dioxide (CO 2 ) is received by the pyrolysis unit (120, 220) and used to carry out the pyrolysis of methane (CH 4 ).
  9. 4. The system (100, 200) according to claim 1, in which the pyrolysis unit (120, 220) has a first inlet (121, 221) configured to receive gaseous methane (CH 4 ) from a methane pipeline, wherein the gaseous methane (CH 4 ) from the methane pipeline is used to carry out pyrolysis of methane (CH 4 ) and/or burned to obtain additional heat (Qi) in the pyrolysis unit (120, 220).
  10. 5. The system (200) according to claim 1, in which the methanation unit (210) has a first outlet (212) configured to supply gaseous methane (CH 4 ), and the pyrolysis unit (220) has a second inlet (223) configured to receive gaseous methane (CH 4 ), and the first outlet (212) and the second inlet (223) are connected by a fluid medium, and gaseous methane (CH 4 ) from the methanation unit (210) is used to carry out pyrolysis of methane (CH 4 ).
  11. 6. The system (200) according to claim 1, in which the methanation unit (210) has a first outlet (212) configured to supply gaseous methane (CH 4 ), and the pyrolysis unit (220) has a second inlet (223) configured to receive gaseous methane (CH 4 ), wherein the first outlet (212) and the second inlet (223) are fluidly connected, and the gaseous methane (CH 4 ) from the methanation unit (210) is burned to obtain additional heat (Qi) in the pyrolysis unit (220).
  12. 7. The system (200) according to claim 1, in which the methanation unit (210) has a first outlet (212) configured to supply gaseous methane (CH 4 ), and the pyrolysis unit (220) has a second inlet (223) configured to receive gaseous methane (CH 4 ), wherein the first outlet (212) and the second inlet (223) are connected by a fluid medium, and a portion of the gaseous methane (CH 4 ) from the methanation unit (210) is used to carry out the pyrolysis of methane (CH 4 ), and a portion of the gaseous methane (CH 4 ) from the methanation unit (210) is burned to obtain additional heat (Qi) in the pyrolysis unit (220).
  13. 8. A method (300) for producing solid carbon (C) from gaseous carbon dioxide (CO 2 ), comprising the steps of:
  14. - carrying out (320) methanation of carbon dioxide ( CO2 ) in a methanation unit (110, 210) to obtain at least gaseous methane ( CH4 ) and heat (Q), wherein the methanation unit (110, 210) has a first inlet (113, 213) configured to receive gaseous hydrogen ( H2 ) and a second inlet (111, 211) configured to receive gaseous carbon dioxide ( CO2 ) from a carbon capture system;
  15. - carrying out (310) pyrolysis of methane (CH 4 ) in a pyrolysis block (120, 220) to obtain gaseous hydrogen (H 2 ) and solid carbon (C),
  16. where the heat (Q) obtained through methanation is used to carry out the pyrolysis of methane (CH 4 ),
  17. In this case, gaseous hydrogen (H 2 ), obtained through pyrolysis, is used to carry out the methanation of carbon dioxide (CO 2 ).
  18. 9. The method (300) according to claim 8, further comprising the step of feeding (330) gaseous methane (CH 4 ), obtained by methanation of carbon dioxide (CO 2 ), to the pyrolysis unit (220).
  19. 10. The method (300) according to claim 9, in which gaseous methane (CH 4 ) supplied to the pyrolysis unit (220) is used to carry out (310) pyrolysis of methane (CH 4 ).
  20. 11. The method (300) according to claim 9, in which gaseous methane (CH 4 ) supplied to the pyrolysis unit (220) is burned to obtain additional heat (Qi) in the pyrolysis unit (220).

Description

AREA OF TECHNOLOGY [0001] The subject matter of the invention described herein relates to a system for producing solid carbon from CO 2 and a corresponding method. PREREQUISITES FOR THE CREATION OF THE INVENTION [0002] To achieve the goals of the Paris Agreement and limit future temperature increase to 1.5°C, efforts to reduce emissions and develop technologies to remove carbon dioxide ( CO2 ) from the atmosphere, known as carbon capture (CC) and carbon capture and storage (CCS), are intensifying. In general, carbon dioxide ( CO2 ) can be captured before or after combustion. Specifically, CO2 is removed during post-combustion after fossil fuel combustion ( CO2 is captured or "stripped" from waste or "flue" gases). Typically, CO2 is captured at emission sources such as power plants, natural gas processing plants, and industrial processes (however, capture from the free atmosphere is also possible). [0003] CCS involves capturing carbon dioxide ( CO2 ) at emission sources, transporting the captured CO2 , and then sequestering it in a suitable deep underground location; however, these locations are not publicly accessible. Once captured, CO2 must be transported to suitable storage locations. Pipeline CO2 transport is a well-established and reliable technology. However, pipeline safety is a critical consideration, especially in densely populated areas or areas with high seismic activity. Furthermore, pipeline CO2 transport requires compressor stations to increase the pressure of the CO2 and facilitate transport, and the interaction of CO2 with water vapor can also cause pipeline corrosion. Finally, gaseous CO2 can be used, for example, for enhanced oil recovery (EOR) , or it can be converted to a high-pressure liquid form known as supercritical CO2 and injected directly into sedimentary rocks for storage. Therefore, capturing and using/storing the captured CO2 requires significant energy inputs. [0004] It would be desirable to have a system that allows for more convenient transportation and storage of CO2 after its capture. In particular, it would be desirable to have a system equipped with a carbon capture system that does not require compression of CO2 and/or liquefaction of CO2 to store the CO2 (i.e., does not require energy-intensive CO2 conversions). SUMMARY OF THE INVENTION [0005] According to one aspect, the subject matter of the invention described herein relates to a system for producing solid carbon C from carbon dioxide CO 2 , such as CO 2 captured from power plant exhaust gases or other CO 2 sources. The system comprises a methanation unit, fluidly connected to a carbon capture system and configured to receive carbon dioxide CO2 for performing methanation of carbon dioxide CO2 with the production of at least methane CH4 and heat, and a pyrolysis unit configured to receive methane CH4 and heat and to perform pyrolysis of methane CH4 with the production of hydrogen H2 and solid carbon C, wherein the methanation unit has a first inlet configured to receive gaseous hydrogen, and a second inlet configured to receive gaseous carbon dioxide CO2 from the carbon capture system, wherein the methanation unit and the pyrolysis unit are thermally and fluidly connected in such a way that at least gaseous hydrogen H2 is supplied from the pyrolysis unit to the methanation unit, and heat is supplied from the methanation unit to the pyrolysis unit. [0006] According to another aspect, the subject matter of the invention described herein relates to a method for producing solid carbon C from carbon dioxide CO2 , comprising the steps of pyrolyzing methane CH4 in a pyrolysis unit to produce hydrogen H2 and solid carbon C and methanating carbon dioxide CO2 in a methanation unit to produce at least methane CH4 and heat. Wherein the methanation unit has a first inlet configured to receive gaseous hydrogen and a second inlet configured to receive gaseous carbon dioxide CO2 from a carbon capture system. The heat generated in the methanation process is used to pyrolyze methane CH4 , and the hydrogen H2 obtained in the pyrolysis process is used to methanate carbon dioxide CO2 . BRIEF DESCRIPTION OF GRAPHIC MATERIALS [0007] The embodiments of the invention described and many of the attendant advantages presented herein can be more fully appreciated and understood by reading the following detailed description taken in conjunction with the accompanying drawings, wherein: Fig. 1 shows a schematic diagram of the first embodiment of the innovative system for producing solid carbon C from carbon dioxide CO 2 ; Fig. 2 shows a more detailed diagram of the methanation unit shown in Fig. 1; Fig. 3 shows a more detailed diagram of the pyrolysis unit shown in Fig. 1; Fig. 4 shows a schematic diagram of a second embodiment of an innovative system for producing solid carbon C from carbon dioxide CO2 ; Fig. 5 shows a flow chart of one embodiment of a method for producing solid carbon C from carbon dioxide CO2 . DETAILED DESCRIPTION OF IMPLEMENTA