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EP-4735167-A1 - PROCESS FOR CATALYTIC CO2 DESORPTION AND SUPPORTED CATALYST FOR SAID PROCESS

EP4735167A1EP 4735167 A1EP4735167 A1EP 4735167A1EP-4735167-A1

Abstract

The present invention relates to a process for CO 2 desorption in an overall CO 2 absorption/desorption procedure. The present invention in particular relates to a process and a system for the catalytic CO 2 desorption steps, in the presence of at least one supported Zr- based catalyst. The present invention also relates to a suitable supported Zr-based catalyst for the CO 2 desorption process, and to methods for preparing such a catalyst.

Inventors

  • KUMAR, PARVEEN
  • SELS, BERT
  • ZHOU, CHENG
  • VERMEIREN, WALTER

Assignees

  • TotalEnergies OneTech

Dates

Publication Date
20260506
Application Date
20240627

Claims (15)

  1. 1 . A method for preparing a supported Zr-based catalyst for CO2 desorption, the method comprising the steps of: providing a slurry comprising a solid catalyst support and a soluble Zr source and a solvent, thereby preparing a synthesis slurry; providing a basic precipitating agent; and, precipitating a Zr-based catalyst on the solid catalyst support, by adding the basic precipitating agent to the synthesis slurry, thereby obtaining a supported Zr-based catalyst; characterized in that the basic precipitating agent is added until the pH of the synthesis slurry is at least 4 and at most 7, for example about 5; and in that the supported Zr-based catalyst comprises Zr, O, and H, wherein the O:Zr atomic ratio is at least 2.1 ; preferably wherein the O:Zr atomic ratio is measured by the weight loss of the catalyst between 170°C to 800°C assuming the weight loss is from the loss of hydroxyl groups forming H2O, and the rest of the solids are ZrCh; wherein the weight loss is measured by Thermalgravimetric analysis (TGA) tested under N2 flow and a temperature rate of between 5 to 20°C/min, preferably 10°C/min, assuming all the weight decrement after a temperature of 180°C forms water and the final solid species above 600-800°C is considered ZrC>2.
  2. 2. The method according to claim 1 , wherein the supported Zr-based catalyst comprises ZrO(OH)2, preferably wherein the supported Zr-based catalyst comprises at least 90% by weight ZrO(OH)2 compared to the total weight of the supported Zr-based catalyst, excluding the solid catalyst support.
  3. 3. The method according any one of claims 1 or 2, wherein the solid catalyst support is a porous solid catalyst support, preferably a mesoporous solid catalyst support.
  4. 4. The method according to any one of claims 1 to 3, wherein the basic precipitating agent is a hydroxide; and/or wherein the Zr source is selected from the group comprising zirconylnitrate, zirconyl-halides, zirconyl-sulphate, zirconium-alkoxides or zirconium halides, preferably ZrO(NOa)2.
  5. 5. The method according to any one of claims 1 to 4, further comprising the step of: calcining the supported Zr-based catalyst at a calcination temperature Tc; wherein the calcination temperature Tc is at most 400°C, preferably at most 350°C, preferably at most 300°C, preferably at most 250°C, preferably at most 200°C, preferably at most 150°C, preferably at most 100°C.
  6. 6. A supported Zr-based catalyst for CO2 desorption, prepared using the method according to any one of claims 1 to 5, wherein the O:Zr atomic ratio is at least 2.1 ; preferably wherein the supported Zr-based catalyst comprises ZrO(OH)2.
  7. 7. The supported Zr-based catalyst according to claim 6, wherein the ratio of acidic OH to basic OH of the supported Zr-based catalyst is at least 0.1 and at most 1.3; preferably wherein the ratio of acidic OH to basic OH is measured by Thermogravimetric Analysis (TGA), for example as conducted on a TGA Q500 from TA Instruments; and wherein the TGA is performed under a 10 mL/min N2 atmosphere, with a temperature ramping from 50°C to 150°C for 30 min to make sure all free water is released, and then to 800°C at a temperature ramping rate of 10°C/min.
  8. 8. The supported Zr-based catalyst according to any one of claims 6 or 7, wherein the supported Zr-based catalyst has a surface charge Zeta potential of at least -25 mV, preferably at least -5 mV; preferably wherein the Zeta potential is measured on a NanoPlus HD with an Auto-Titrator from Particulate Systems, wherein 40 mg well-grinded sample powder is mixed with 40 g ultrapure water, followed by a 20 min ultrasonic treatment to obtain a finely dispersed sample solution for the testing under a pH of 9.3 ±0.2; wherein 0.1 M HCI or 0.1 M NaOH may be used for pH adjustment.
  9. 9. The supported Zr-based catalyst according to any one of claims 6 to 8, wherein the supported Zr-based catalyst comprises other metals, preferably selected from the group comprising: Hf, Ce, or Zn; preferably wherein the molar fraction of Zr compared to the other metals in the supported Zr-based catalyst is at least 90 mol%, excluding the solid catalyst support.
  10. 10. A process for CO2 desorption from an amine solvent, the process comprising the steps of: providing an CO2-containing amine solution comprising CO2 absorbed in an amine solvent; providing a supported Zr-based catalyst according to any one of claims 6 to 9; supplying to the CO2-containing amine solution to the supported Zr-based catalyst; optionally, heating the amine solution comprising the supported Zr-based catalyst to a desorption temperature Td; and, desorbing CO2 from the amine solution comprising the supported Zr-based catalyst during a contact time.
  11. 11. The process according to claim 10, wherein the amine solvent comprises an amine selected from the group comprising: monoethanolamine (MEA), 2-amino-2-methyl-1- propanol (AMP), diglycolamine (DGA), diethanolamine (DEA), diisopropanolamine (DIPA), piperazine, aminosiloxanes, and/or amino-acids; preferably monoethanolamine (MEA).
  12. 12. The process according to any one of claims 10 or 11 , wherein the amine solvent is present in the amine solution at a molar concentration of at least a 1 M to at most a 10 M, preferably of at least a 2 M to at most an 8 M, preferably of at least a 4 M to at most a 6 M, for example at about a 5 M concentration.
  13. 13. The process according to any one of claims 10 to 12, wherein the desorption is performed in a continuous manner at a weight hourly space velocity between 0.01 and 1000 h’ 1 , preferably between 1 and 100 h’ 1 .
  14. 14. A process for CO2 absorption and desorption, comprising the steps of: absorbing CO2 in an amine solvent, thereby obtaining a CCh-containing amine solution; and, desorbing CO2 from the CCh-containing amine solution using the process of any one of claims 10 to 13, thereby regenerating the amine solvent.
  15. 15. Use of a supported Zr-based catalyst according to any one of claims 6 to 9, in the process according to any one of claims 10 to 14.

Description

PROCESS FOR CATALYTIC CO2 DESORPTION AND SUPPORTED CATALYST FOR SAID PROCESS FIELD OF THE INVENTION The present invention relates to a process for CO2 desorption in an overall CO2 absorption/desorption procedure. The present invention in particular relates to a process and a system for the catalytic CO2 desorption steps, in the presence of at least one supported Zr- based catalyst. The present invention also relates to a suitable Zr-based catalyst for the CO2 desorption process, and to methods for preparing such a catalyst. BACKGROUND The rapidly increasing carbon dioxide (CO2) concentration in the atmosphere has caused great climate changes. From the latest report of the Intergovernmental Panel on Climate Change (IPCC), limiting warming to close to 1.5°C or even 2°C will be beyond reach, unless there are immediate, rapid, and large-scale reductions in CO2 emissions. However, the risks and costs of non-fossil energy alternatives such as nuclear, biomass, solar energy, etc., cannot meet current energy demands. Additionally, any rapid changes to non-fossil energy sources, even if possible, would result in large disruptions to the existing energy supply infrastructure with substantial consequences to the global economy. The fossil fuel energy is believed to remain the dominant energy source from the Energy Information Administration. Under that premise, CO2 capture and storage (CCS), and CO2 capture and utilization (CCU) become promising routes to limit the savagely increasing CO2 emission. However, for both routes, CO2 capture is always the first step. In order to meet mid-to-long-term CO2 reduction targets, it is necessary to develop a cost-effective CO2 capture technology. For the CO2 from power plants, from any other type of fossil-fired furnace to provide high temperature heat or from any other type of fossil carbon combustion into CO2 (like steel mills, cement calciners, etc.), one of the dominant CO2 emission sources, Post-Combustion Capture (PCC), using amine solvent as a CO2 absorber, is the most mature and widely used technology. Moreover, it is believed to be the most promising technology to provide an energy-efficient and timely solution for decreasing CO2 emissions from fossil power plants, fossil fired furnaces or fossil carbon combustion. A typical amine-based CO2 capture and regeneration process involves the entire absorption-desorption cycle of CO2 using amine solvents, as shown in Figure 1. The CO2-containing flue gas stream is introduced into a packed bed absorber column where it flows counter currently as it contacts lean amine, allowing for efficient absorption. After absorption, the rich amine solvent flows through a rich-lean heat exchanger before being introduced into a stripper column for thermal regeneration. In the stripper column, thermal energy such as heated steam, is supplied, for example to the reboiler, to strip out the captured CO2 by increasing the temperature. This free (lean) amine solvent then returns to the absorber column for a new cycle of absorption. Typical amine solvents for CO2 capture include primary amines like monoethanolamine (MEA), secondary amines like diethanolamine (DEA), and tertiary amines like methyldiethanolamine (MDEA). The mechanism of CO2 absorption in different amine solvents is shown as follows: Primary/ secondary amine: CO2 + 2R1R2NH 2R1R2NH2 + + R^NCOQ- Tertiary amine: co2 + R1R2R2N + H2O R1R2R3NH+ + HCO3~ MEA is the most widely used amine solvent because of the tremendous CO2 absorption rate, high capacity, high mass-transfer performance, and low-price properties. The absorption of CO2 in MEA solvent follows a Zwitterion mechanism. One CO2 is absorbed and forms one carbamate (anion) and one neutralizing protonated MEA (cation). Without willing to be bound to any theory, the desorption process consists of a series of chemical step(s) and physical transport steps: first the carbamate has to be decomposed into amine and dissolved CO2, while the protonated amine needs to deprotonated, next the dissolved CO2 moves to the liquidgas interphase and finally the dissolved CO2 escapes from the liquid solvent into the gas phase moving to the top of the stripper column while the solvent moves to the bottom of the stripper column. While the physical transport steps can be enhanced by increasing turbulence and in particular by increasing the liquid-gas interphase area, the carbamate decomposition requires a minimum activation energy to occur. Such minimum activation energy can be attained by using a catalyst that reduces the required activation energy. As shown in Figure 2, the desorption route of CO2 from MEA mainly comprises two steps: (1) proton transfer, which includes proton transferring from protonated amine to water and proton transferring from HaO+ to carbamate; (2) carbamate breakdown and release of CO2. The proton transfer steps are unfavourable at low temperatures, forcing the industry to run under a high desorption temperature for an acceptable so