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EP-4735404-A1 - CONVERSION OF CARBON DIOXIDE TO VALUE-ADDED CHEMICALS USING ZEOLITE-BASED CATALYSTS

EP4735404A1EP 4735404 A1EP4735404 A1EP 4735404A1EP-4735404-A1

Abstract

The present invention relates to the field of carbon dioxide (CO 2 ) utilization and more specifically the conversion of CO 2 into value-added chemicals through hydrogenation. The present invention thus provides methods and catalysts for efficient and selective conversion of CO 2 into value-added chemicals through hydrogenation, as well as systems implementing both of these.

Inventors

  • KEGNÆS, Søren
  • MIELBY, Jerrik
  • ILTSIOU, Dimitra
  • PETERSEN, Christian Sander

Assignees

  • Danmarks Tekniske Universitet

Dates

Publication Date
20260506
Application Date
20240416

Claims (20)

  1. 1 . A method for the catalytic hydrogenation of CO2 into at least one value-added chemical selected from the group consisting of ethanol, methanol, methane, methanal, and ethanal, the method comprising contacting in a reaction chamber, a feed stream containing CO2 and H 2 with a solid gmelinite (GME) based heterogeneous catalyst comprising 0.8 wt% to 2.2 wt% Cu, wherein the H2/CO2 volume ratio in the feed stream is from 4:1 to 6:1 and wherein the catalytic hydrogenation is carried out at a pressure at or above 1 .8 MPa, further wherein the method comprises a step of introducing water into the reaction chamber, wherein the water provides a H2O/CO2 molar ratio between 0.4 and 0.5.
  2. 2. The method according to the preceding claim, wherein the H2/CO2 volume ratio in the feed stream is from 4.5:1 to 5.5:1 , such as 5:1 .
  3. 3. The method according to any one of the preceding claims, wherein the reaction chamber is selected from the group consisting of plug-flow reactor, multi-tubular reaction, fluidised bed reactor and void reactor.
  4. 4. The method according to any one of the preceding claims, wherein the value- added chemical is ethanol.
  5. 5. The method according to any one of the preceding claims, wherein the catalyst is selected from the group consisting of gmelinite sodium (Na-GME), gmelinite potassium (K-GME) and gmelinite calcium (Ca-GME) or a mixture thereof.
  6. 6. The method according to any one of the preceding claims, wherein the catalyst unit cell comprises a repeating unit selected from the group consisting of Na4(SisAl4)O24- 11 H2O, K 4 (Si 8 Al4)O24-11 H2O, and Ca2(Si8Al4)O24‘1 1 H2O or a mixture thereof.
  7. 7. The method according to any one of the preceding claims, wherein the catalyst is a mixed gmelinite potassium/calcium catalyst ((K-Ca)-GME).
  8. 8. The method according to claim 7, wherein the catalyst comprise potassium and calcium in a K/Ca ratio ranging from 0.4 to 4, more preferably ranging from 0.5 to 2.0, more preferably from 1 .0 to 1 .5.
  9. 9. The method according to any one of the preceding claims, wherein the Cu is in the form of zero-valent Cu.
  10. 10. The method according to any one of the preceding claims, wherein the catalyst comprises a hydrophobic layer, such as a hydrophobic layer obtained by silylation of zeolite OH-groups using a silylating agent.
  11. 11 . The method according to any one of the preceding claims, wherein the catalyst is a silylated heterogenous catalyst such as a silylated zeolite-based catalyst, or is a catalyst having been subjected to a step of silylation using a silylating agent.
  12. 12. The method according to claim 11 , wherein the silylated zeolite-based catalyst comprise and/or is obtained from the reaction with a silylating agent selected from the group consisting of trichloromethylsilane (hi), trimethylchlorosilane (h 2 ), trimethoxymethylsilane (h 3 ) and hexadecyltrimethoxysilane (h 4 ).
  13. 13. The method according to any one of claims 10 to 12, wherein the silylating agent is selected from the group consisting of trichloromethylsilane (hi), trimethylchlorosilane (h 2 ), trimethoxymethylsilane (h 3 ) and hexadecyltrimethoxysilane (h 4 ).
  14. 14. The method according to any one of claims 10 to 13, wherein the silylating agent is trichloromethylsilane (hi).
  15. 15. The method according to any one of claims 10 to 13, wherein the silylating agent is trimethylchlorosilane (h 2 ).
  16. 16. The method according to any one of claims 10 to 13, wherein the silylating agent is trimethoxymethylsilane (h 3 ).
  17. 17. The method according to any one of claims 10 to 13, wherein the silylating agent is hexadecyltrimethoxysilane (h 4 ).
  18. 18. The method according to any one of claims 10 to 17, wherein the silylated catalyst comprise and/or is obtained by reaction with 0.1 mmol to 20 mmol silylating agent per gram of zeolite.
  19. 19. The method according to any one of claims 10 to 18, wherein the silylated catalyst comprise and/or is obtained by reaction with 0.5 mmol to 10 mmol silylating agent per gram of zeolite, such as 0.5 mmol silylating agent per gram of zeolite, such as 1 .0 mmol silylating agent per gram of zeolite, such as 2.5 mmol silylating agent per gram of zeolite, such as 5.0 mmol silylating agent per gram of zeolite, such as 7.5 mmol silylating agent per gram of zeolite, such as 10.0 mmol silylating agent per gram of zeolite.
  20. 20. The method according to any one of claims 10 to 19, wherein the silylated catalyst comprise and/or is obtained by reaction with 0.4 mmol to 0.6 mmol silylating agent per gram of zeolite, such as 0.5 mmol silylating agent per gram of zeolite.

Description

Conversion of carbon dioxide to value-added chemicals using zeolite-based catalysts Technical field The present invention relates to the field of carbon dioxide (CO2) utilization and more specifically the conversion of CO2 into value-added chemicals through hydrogenation. The present invention thus provides methods and catalysts for efficient and selective conversion of CO2 into value-added chemicals through hydrogenation, as well as systems implementing both of these. Background The accumulation of carbon dioxide (CO2) in the Earth's atmosphere has reached alarming levels, leading to severe environmental consequences such as climate change and global warming. To address this pressing issue, there is an urgent need for innovative approaches that can effectively reduce CO2 emissions and mitigate its impact on the planet. Additionally, the utilization of CO2 plays a crucial role in carbon cycling for the advancement of the circular economy and has gathered significant research attention worldwide due to its potential to mitigate greenhouse gas emissions and contribute to sustainable development. In this context, zeolites have emerged as highly promising candidates for addressing the challenges associated with CO2 capture and conversion. Zeolites are crystalline, macro-/meso-/ and microporous materials with well-defined structures, characterized by a network of interconnected channels and cages. These unique structures provide an ideal platform for catalytic processes, making zeolites exceptionally versatile in a wide range of applications. In recent years, there has been substantial research focused on the conversion of CO2 into methanol (CH3OH), which is considered the primary product of interest. However, the synthesis of ethanol or higher-value C2+OH compounds through CO2 hydrogenation has received comparatively limited attention. Ethanol is an attractive target product due to its non-toxic nature and its versatility for further conversion into valuable chemicals, such as ethylene, which has numerous industrial applications. Thus there is a need in the field for further developments of evermore stable and efficient catalysts suitable for CO2 conversion to value-added chemicals and the implementation of such catalysts in catalytic systems which are industrially scalable. For the practical application of CO2 hydrogenation to ethanol, several challenges have hindered its widespread adoption, such as low selectivity, slow reaction kinetics, undesirable reaction intermediates and poor cost-effectiveness. Thus there remains as need in the field for the development of new catalyst- and/or process designs that can achieve high ethanol selectivity as well as a high CO2 conversion. Summary The present invention aims to address at least some of the aforementioned limitations and challenges associated with synthesis of ethanol from CO2 in catalytic hydrogenation reactions. It is thus a first aspect of the present invention to provide a method for the catalytic hydrogenation of CO2 into ethanol, the method comprising contacting a feed stream containing CO2 and H2 with a solid heterogeneous catalyst in a reaction chamber, wherein the H2/CO2 volume ratio in the feed stream is from 1 :1 to 10:1. A second aspect of the present invention is to provide a system for the catalytic conversion of CO2 into ethanol in a hydrogenation reaction, the system comprising: a. a reaction chamber equipped with a zeolite catalyst; b. a reaction chamber inlet for CO2, H2 and optionally H2O provided together or separately; c. a heating source; and d. a product outlet; wherein the reaction chamber is a plug-flow reactor and wherein the zeolite catalyst is a gmelinite (GME) based catalyst. A third aspect of the present invention is to provide a solid zeolite catalyst selected from the group consisting of gmelinite potassium (K-GME), gmelinite sodium (Na- GME), and gmelinite calcium (Ca-GME), characterized in comprising 1-2 wt% (based on total catalyst weight) of at least one auxiliary non-noble transition metal. The present inventors have surprisingly found that all of the above mentioned aspects can aid in providing solutions to the challenge of converting harmful greenhouse gas CO2 into value-added chemicals such as ethanol. Definitions As used herein the term “GME” refers to a crystalline synthetic form of the mineral compound gmelinite. Gmelinite is a zeolite with an aluminosilicate framework comprising the repeating unit {(SisAI4)O24- 11 H2O}4-. The structure of the interconnected tetrahedra results in channels and pores within the framework with exposed active sites that can be targeted either for the purpose of catalysis, or for adsorbing a chemical entity such as a metal ion into the channel structure. The negative charge of the aluminosilicate framework may be in principle be balanced by any cationic material or metal. Within the present disclosure, in particular potassium, calcium and sodium forms of GME are highlighted, and refer