EP-4735409-A1 - CO2-NEGATIVE METHANOL SYNTHESIS

Abstract

The invention relates to a method for CO 2 -negative methanol synthesis, comprising: - at least one electrodialysis, and - at least one methanol synthesis, the at least one electrodialysis comprising at least one CO 2 -containing absorber solution. The invention further relates to an installation for CO 2 -negative methanol synthesis, and to the use of the method and the installation.

Inventors

• SCHUETZ, Christine
• MAAS, CHRISTIAN
• LANGE, Enrica
• GROTE, ANDREAS

Assignees

• Volkswagen Aktiengesellschaft

Dates

Publication Date

20260506

Application Date

20240626

Claims (15)

1. 1. A process for CCh-negative methanol synthesis comprising: - at least one electrodialysis, and - at least one methanol synthesis, wherein the at least one electrodialysis comprises at least one CCh-containing absorber solution.
2. 2. The method according to claim 1, wherein the at least one CC>2-containing absorber solution is an amine-containing CO2-containing absorber solution.
3. 3. A process according to claim 1 or claim 2, wherein the methanol synthesis is a direct methanol synthesis.
4. 4. The process according to at least one of claims 1 to 3, wherein the methanol synthesis comprises a reverse water gas shift reaction.
5. 5. The method according to at least one of claims 1 to 4, wherein the at least one electrodialysis comprises at least one CCh wash.
6. 6. The method according to at least one of claims 1 to 5, wherein the electrodialysis comprises at least one membrane contactor.
7. 7. The method according to at least one of claims 1 to 6, wherein the method further comprises a direct air capture method.
8. 8. The method according to at least one of claims 1 to 7, wherein the CO2 comes from the atmosphere.
9. 9. Plant for CCh-negative methanol synthesis comprising: - at least one electrodialysis cell, - at least one methanol synthesis reactor, wherein the at least one electrodialysis comprises at least one CCh-containing absorber solution.
10. 10. Plant according to claim 9, wherein the at least one CCh-containing absorber solution is an amine-containing CCh-containing absorber solution.
11. 11. Plant according to claim 9 or claim 10, wherein the at least one electrodialysis comprises at least one CO2 scrubber.
12. 12. Plant according to at least one of claims 9 to 11, wherein the at least one electrodialysis comprises at least one membrane contactor.
13. 13. System according to at least one of claims 9 to 12, wherein the system further comprises a direct air capture unit.
14. 14. Plant according to at least one of claims 9 to 13, wherein the CO2 comes from the atmosphere.
15. 15. Use of a process according to at least one of claims 1 to 8, or of a plant according to at least one of claims 9 to 14 for producing methanol for fuel production.

Description

Description “CC>2-negative methanol synthesis” The invention relates to a process for CCh-negative methanol synthesis, a plant for CO2-negative methanol synthesis and a use of a process and a plant as described herein. The emission of carbon dioxide into the atmosphere is currently considered a major driver of climate change. Carbon capture and storage (CCS) technologies are efficient and effective methods for reducing carbon dioxide emissions into the atmosphere. To reduce CCh emissions, CCh-negative emission technologies can be used, as well as technologies for reducing CCh in the atmosphere or exhaust gases. The demand for such technologies is constantly increasing. CO2 can be used as a starting material for various chemical reactions, in particular for the production of basic chemicals and fuels (e.g. e-fuels). By using CO2 from the atmosphere or from exhaust gases, basic chemicals and fuels with a CCh-neutral or CC>2-negative footprint can be provided. Eisaman et al, Clean Technol. 2009, 175-178 describes the energy-efficient electrochemical capture of CO2 from the atmosphere. The conversion of CO2 takes place by means of electrodialysis. Voskian et al, Energy Environ. Sci., 2019,12, 3530-3547 discloses an electrochemical device for CC>2 deposition based on quinones. The object of the present invention is to provide a process for CCh-negative methanol synthesis, a plant for CCh-negative methanol synthesis and the use of the process or the plant which at least partially overcome the above-mentioned disadvantages. This object is achieved by the inventive method according to claim 1, the system according to claim 9 or the use according to claim 15. The present invention relates to a process for CCh-negative methanol synthesis comprising: - at least one electrodialysis, and - at least one methanol synthesis, wherein the at least one electrodialysis comprises at least one CCh-containing absorber solution. A CCh-negative process is a process in which more CO2 is generated than is consumed. A CCh-negative methanol synthesis is a process for producing methanol in which more CO2 is produced than is consumed. In a method according to the invention, the at least one electrodialysis comprises a CO2-containing absorber solution. An absorber solution is a liquid medium in which certain substances, such as gases (e.g. CO2), are absorbed and, ideally, can also be desorbed again. As explained, the present process involves an absorber solution containing CO2. The absorber solution used in the process can therefore absorb CO2 and, preferably, also desorb it again. The CO2-containing absorber solution can absorb CO2 in an amount in the range of 0.1 M to 2.5 M, preferably in the range of 0.15 M to 2 M, more preferably in the range of 0.15 M to 1.2 M, based on the total amount of the absorber solution. In one embodiment, the at least one CO2-containing absorber solution is an amine-containing CO2-containing absorber solution. An amine-containing CO2-containing absorber solution thus comprises at least one amine. The amine preferably comprises at least one amino group (primary amino group -NH2, secondary amino group -NHR, tertiary amino group -NR2) and/or at least one guanidino group ([CH(NH 2 )3] + ). The absorber solution may contain one amine or a combination of at least two amines. Amines can have the advantage that they can increase the absorption capacity of gases (e.g. CO2) in absorber solutions. Amines can increase the reaction of gases (e.g. CO2) with water to form water-soluble compounds, since the amine or guanidino groups of the amines can promote a rapid and increased absorption of gases (e.g. CO2) in solvents such as water. Examples of amine-containing absorber solutions are solutions of amino acids. The amino acid can be selected from the group consisting of arginine, alanine, asparagine, tyrosine, isoleucine, phenylalanine, cysteine, glycine, glutamine, proline, histidine, serine, leucine, lysine, tryptophan, valine, methionine and threonine. The absorber solution has a pH in the range of 8 to 14. Preferably, the absorber solution has a pH in the range of 10 to 14. More preferably, the absorber solution has a pH in the range of 13 to 14. The absorber solution may alternatively have a pH in the range 8 to 13, preferably in the range 9 to 12, more preferably in the range 10 to 11. The amine-containing CO2-containing absorber solution may comprise CO2 in an amount in the range of 0.5 M to 2.5 M, preferably in the range of 0.8 M to 2 M, more preferably in the range of 1 M to 1.8 M, based on the total amount of the absorber solution. A method according to the invention comprises the step of at least one methanol synthesis. The methanol synthesis can be a direct methanol synthesis. In the direct methanol synthesis, CO2 is converted with H2, preferably metal-catalyzed, to methanol (equation 1). CO 2 + 3 H 2 — CH3OH + H 2 O (Equation 1) The methanol synthesis of a process according to the invention can comprise a r