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EP-4735154-A1 - ENHANCING SEPARATION OF ACID GASES FROM A PROCESS STREAM OR A FLUE GAS

EP4735154A1EP 4735154 A1EP4735154 A1EP 4735154A1EP-4735154-A1

Abstract

The present description relates to processes for the desorption of an acid gas, such as carbon dioxide, from an acid gas loaded carbonate solution generated by absorption of the acid gas from an acid gas containing stream into an absorption solution based on carbonates such as potassium carbonate. The process can include: contacting the acid gas loaded carbonate solution with desorption enhancement structures that comprise acid surfaces at desorption conditions such that the acid surfaces cause a shift in equilibrium to promote release of the acid gas from the gas loaded carbonate solution; and producing an acid gas depleted solution and an acid gas stream. The acid surfaces can provide enhancements that can facilitate reduced energy requirements for desorption in carbonate based systems. Systems and uses where acid surfaces are implemented to enhance desorption in carbonate based solutions are also described herein.

Inventors

  • MINVILLE, Francois
  • FRADETTE, LOUIS

Assignees

  • Cyclecarbone Inc.

Dates

Publication Date
20260506
Application Date
20240627

Claims (20)

  1. 1 . A process for desorption of an acid gas from an acid gas loaded carbonate solution generated by absorption of the acid gas from an acid gas containing stream into an absorption solution based on carbonates formed with an element of the first and second groups of the periodic table of elements, the process comprising: contacting the acid gas loaded carbonate solution with desorption enhancement structures that comprise a non-soluble supports and acid surfaces supported by the non-soluble supports at desorption conditions such that the acid surfaces cause a shift in equilibrium to promote release of the acid gas from the gas loaded carbonate solution; and producing an acid gas depleted solution and an acid gas stream.
  2. 2. The process of claim 1 , wherein the acid gas comprises CO2.
  3. 3. The process of claim 1 or 2, wherein the carbonates comprise potassium carbonate.
  4. 4. The process of any one of claims 1 to 3, wherein the acid gas containing stream comprises flue gas.
  5. 5. The process of any one of claims 1 to 3, wherein the acid gas containing stream comprises an industrial gas stream.
  6. 6. The process of any one of claims 1 to 5, wherein the absorption solution has a concentration between
  7. 7. The process of any one of claims 1 to 6, wherein the acid surfaces comprises a protondonating surface.
  8. 8. The process of claim 7, wherein the acid surfaces comprise one or more of the following: FeC., SbFs and AICIs Supported on graphite, AI2O, SiO, Zeolites, & clays (e.g. AICI/AI2O, ZnCh/Acid treated clays, FeCI/graphite, SbFs/graphite, AlCI/graphite, Vanadium phosphates and aluminophosphates, CaO ZrC>2; SimO ZrO, YbO ZrO, aluminum chlorofluoride, ACF. (AICIF, Xs().O5 0.25), aluminum bromofluoride, ABF. (AIBrF, X-0.05 0.25)); heteropoly acids (HPAs) such as HPWO and HPMo.O.; silica- supported Nation (SAC-13); alumina, amorphous silica-alumina, amorphous silica- alumina molecular sieves such as microporous aluminosilicates or Zeolites (e.g. HZSM-5, H. Y. H X) and mesoporous aluminosilicates such as M41S (e.g. MCM-41. SBA-15, MCF); silica-magnesia, Silica-Zirconia, alumina-boria, titania-boria, tungstate-alumina, and tungstate Zirconia; AlCI/mesoporous silica, CrO/ZrO., Sulfated Zirconia, pillared clays (PILC) and acidic porous clay heterostructures (PCH). Any suitable Bronsted acid surface may be used herein. For example, amorphous silica- alumina molecular sieves such as microporous aluminosilicates or Zeolites (e.g. HZSM-5, H. Y. H X) and mesoporous aluminosilicates such as M41S (e.g. MCM-41 , SBA-15, MCF); heteropoly acids (HPAs) such as HPWO and HPMo.O.; silica supported Nation (SAC-13), and combinations thereof.
  9. 9. The process of any one of claims 1 to 8, wherein the acid surfaces comprise an electron-acceptor surface.
  10. 10. The process of claim 9, wherein the electron-acceptor surface comprises one or more of the following: FeCI., SbF and AICIs Supported on graphite, AI2O, SiO, Zeolites, & clays (e.g. AICI/AI2O, ZnCI2/Acid treated clays, FeCI/graphite, SbF5/graphite, AlCI/graphite, Vanadium phosphates and aluminophosphates, CaO ZrO. SmO-ZrO: YbO, ZrO, aluminum chlorofluoride, ACF. (AICIF, Xs(0.05-0.25), aluminum bromofluoride, ABF (AIBr, F. X-0.05-0.25), and combinations thereof.
  11. 11. The process of any one of claims 1 to 8, wherein the acid surfaces comprise a combination of electron-acceptor surface and proton-donor surface.
  12. 12. The process of claim 11 , wherein the acid surfaces comprise alumina, amorphous silica-alumina, amorphous silica-alumina molecular sieves, silica-magnesia, silica- Zirconia, alumina-boria, titania-boria, tungstate-alumina, and tungstate Zirconia; AlCI/mesoporous silica, CrO/ZrO., sulfated zirconia, pillared clays (PILC) and acidic porous clay heterostructures (PCH).
  13. 13. The process of any one of claims 1 to 12, wherein the non-soluble supports comprise graphite, polymer material, metal material, ceramic material, or a combination thereof.
  14. 14. The process of any one of claims 1 to 13, wherein the contacting of the acid gas loaded carbonate solution with the acids surfaces is performed at a temperature between 20°C and 120°C.
  15. 15. The process of any one of claims 1 to 14, wherein the contacting of the acid gas loaded carbonate solution with the acids surfaces is performed at a pressure between 20 000 Pa and 100 000 Pa.
  16. 16. The process of any one of claims 1 to 15, wherein the concentration of the carbonates in the absorption solution is 0.5 to 2.5 mol/liter.
  17. 17. The process of any one of claims 1 to 16, wherein the contacting of the acid gas loaded carbonate solution with the acids surfaces is performed in a stripping unit that receives the acid gas loaded carbonate solution directly from an absorption unit.
  18. 18. The process of any one of claims 1 to 16, wherein the contacting of the acid gas loaded carbonate solution with the acids surfaces is performed in a pretreatment desorption unit that receives the acid gas loaded carbonate solution directly from an absorption unit and produces a pretreated solution that is supplied to a stripping unit for further removal of the acid gas.
  19. 19. The process of any one of claims 1 to 16, wherein the acid gas loaded carbonate solution is supplied to a stripping unit to produce a partially stripped solution that is then supplied to a desorption unit for further removal of the acid gas to produce the acid gas depleted solution.
  20. 20. The process of any one of claims 1 to 19, wherein the non-soluble support and the acid surfaces are composed of the same material.

Description

ENHANCING SEPARATION OF ACID GASES FROM A PROCESS STREAM OR A FLUE GAS TECHNICAL FIELD The technical field generally relates to acid gas capture and more specifically to enhanced desorption of acid gases, such as CO2, from a loaded carbonate solution using acid surfaces. BACKGROUND Removing acid gas from a gas fluid can include an absorption stage where the acid gas is absorbed into a liquid, followed by a desorption stage where the liquid loaded in acid gas is treated to promote release of the acid gas. In certain systems, such as those that employ carbonate solutions as the absorption liquid, the energy required in the desorption stage to heat the liquid to promote acid gas release is significant to the point that such systems may not be feasible or practical in many contexts. There is a need for a technology that overcomes at least some of the challenges in this field. SUMMARY In some implementations, there is provided a process for desorption of an acid gas from an acid gas loaded carbonate solution generated by absorption of the acid gas from an acid gas containing stream into an absorption solution based on carbonates formed with an element of the first and second groups of the periodic table of elements, the process comprising: contacting the acid gas loaded carbonate solution with desorption enhancement structures that comprise a non-soluble supports and acid surfaces supported by the non-soluble supports at desorption conditions such that the acid surfaces cause a shift in equilibrium to promote release of the acid gas from the gas loaded carbonate solution; and producing an acid gas depleted solution and an acid gas stream. In some implementations, the acid gas comprises CO2. In some implementations, the carbonates comprise potassium carbonate. In some implementations, the acid gas containing stream comprises flue gas. In some implementations, the acid gas containing stream comprises an industrial gas stream. In some implementations, the absorption solution has a concentration below a precipitation concentration in the overall capture system. In some implementations, the acid surfaces comprise a proton-donating surface. In some implementations, the acid surfaces comprise one or more of the following: FeC., SbFs and AICIs Supported on graphite, AhO, SiO, Zeolites, & clays (e.g. AICI/AI2O, ZnCh/Acid treated clays, FeCI/graphite, SbFs/graphite, AlCI/graphite, Vanadium phosphates and aluminophosphates, CaO ZrCh; SimO ZrO, YbO ZrO, aluminum chlorofluoride, ACF. (AICIF, Xs().O5 0.25), aluminum bromofluoride, ABF. (AIBrF, X-0.05 0.25)); heteropoly acids (HPAs) such as HPWO and HPMo.O.; silica-supported Nation (SAC-13); alumina, amorphous silica-alumina, amorphous silica-alumina molecular sieves such as microporous aluminosilicates or Zeolites (e.g. HZSM-5, H. Y. H X) and mesoporous aluminosilicates such as M41S (e.g. MCM-41 . SBA-15, MCF); silica- magnesia, Silica-Zirconia, alumina-boria, titania-boria, tungstate-alumina, and tungstate Zirconia; AlCI/mesoporous silica, CrO/ZrO., Sulfated Zirconia, pillared clays (PILC) and acidic porous clay heterostructures (PCH). Any suitable Bronsted acid surface may be used herein. For example, amorphous silica-alumina molecular sieves such as microporous aluminosilicates or Zeolites (e.g. HZSM-5, H. Y. H X) and mesoporous aluminosilicates such as M41S (e.g. MCM-41 , SBA-15, MCF); heteropoly acids (HPAs) such as HPWO and HPMo.O.; silica supported Nation (SAC-13), and combinations thereof. In some implementations, the acid surfaces comprise an electron-acceptor surface. In some implementations, the electron-acceptor surface comprises one or more of the following: FeCI., SbF and AICIs Supported on graphite, AI2O, SiO, Zeolites, & clays (e.g. AICI/AI2O, ZnCI2/Acid treated clays, FeCI/graphite, SbF5/graphite, AlCI/graphite, Vanadium phosphates and aluminophosphates, CaO ZrO. SmO-ZrO: YbO, ZrO, aluminum chlorofluoride, ACF. (AICIF, Xs(0.05-0.25), aluminum bromofluoride, ABF (AIBr, F. X-0.05-0.25), and combinations thereof. In some implementations, the acid surfaces comprise a combination of electron-acceptor surface and proton-donor surface. In some implementations, the acid surfaces comprise alumina, amorphous silica-alumina, amorphous silica-alumina molecular sieves, silica-magnesia, silica-Zirconia, alumina- boria, titania-boria, tungstate-alumina, and tungstate Zirconia; AlCI/mesoporous silica, CrO/ZrO., sulfated zirconia, pillared clays (PILC) and acidic porous clay heterostructures (PCH). In some implementations, the non-soluble supports comprise graphite, polymer material, metal material, ceramic material, or a combination thereof. In some implementations, the contacting of the acid gas loaded carbonate solution with the acids surfaces is performed at a temperature between 20°C and 120°C. In some implementations, the contacting of the acid gas loaded carbonate solution with the acids surfaces is performed at a pressure between 20 000 Pa and 100 000 Pa. In some