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EP-4739647-A1 - PROCESS FOR PRODUCING METHANOL

EP4739647A1EP 4739647 A1EP4739647 A1EP 4739647A1EP-4739647-A1

Abstract

The invention is directed to process for catalyzing a production of methanol from hydrogen and carbon monoxide. The reaction takes place in the presence of at least one nucleophilic promoter, whereby a complex is used which comprises a transition metal (M) and at least one ligand. The lligand is designed as a chelating agent that binds tightly to three or more sites with two donor atoms which are connected via a ligand backbone with at least one Lewis base centrum (LB). One of the donor atoms is a phosphor atom being a chiral center with two different substituents R ' and R '' and/or both donor atoms are phosphor atoms whereby each donor atom has two identical substituents R ' or R '' each and whereby the substituents R ' and R '' differ from each other.

Inventors

  • CHECINSKI, Marek Pawel
  • Clauss, Reike
  • Akash, Kaithal
  • Suntrup, Lisa

Assignees

  • C1 Green Chemicals AG

Dates

Publication Date
20260513
Application Date
20240704

Claims (13)

  1. 1 . Process for catalyzing a production of methanol from hydrogen and carbon monoxide taking place in the presence of at least one nucleophilic promoter, whereby a complex is used which comprises a transition metal (M) and at least one ligand designed as a chelating agent that binds tightly to three or more sites with two donor atoms which are connected via a ligand backbone with at least one Lewis base centrum (LB), characterized in that either at least one donor atom is a phosphor atom being a chiral center with two different substituents R' and R" and/or that both donor atoms are phosphor atoms whereby each donor atom has two identical substituents R' or R" and the substituents R' and R" differ from each other, that the process takes place in presence of a base and that the promoter contains nitrogen and/or oxygen.
  2. 2. Process according to claim 1 , characterized in that the transition metal (M) is selected of the group comprising Mn, Re, Cr, Mo, W, Fe, Ru, Co, Rh, lr and Pd and/or the Lewis base centrum (LB) is an N atom of an amid or an NH-group.
  3. 3. Process according to claim 1 or 2, characterized in that the complex is described as
  4. 4. Process according to claim 1 or 2, characterized in that the complex is described as whereby Y is defined as a P, N, S or C atom being bound to the Lewis base centrum (LB) and featuring further substituents such that P is specified as PR”’R”” with R’” and/or R”” as Et, nPr, iPr, nBu, iBu, tBu, Ph, Ph* [substituted], Naph or Naph* [substituted], N is specified as NH2, NEt2, N(nBu)2, pyridine, pyrrole, indole, isoindole, imidazol, benzimidazol or aniline, S is specified as SMe, SEt, SPh, SPh* [substituted], SNaph or SNaph [substituted], and C is specified an N-heterocyclic carbene, aryl cyclopentadienyl or a derivate of cyclopentadienyl.
  5. 5. Process according to any of the previous claims, characterized in that R' and R" an alkyl or an aryl group, preferably are selected from a group comprising ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, phenyl, cyclohexyl, naphtyl as well as substituted phenyls, naphthyls and cyclohexyls and whereby R' and R" are two different substituents.
  6. 6. Process according to any of the previous claims, characterized in that the complex is selected from a group comprising with X as F, Cl, Br, OH or an alcoholate.
  7. 7. Process according to any of the previous claims, characterized in that the base is a hydroxide and/or an alkoxide and/or that the base is a methoxide salt, te/Y-butoxide salt or alcoholate of the utilized solvent and/or that the cation of the base is at least one of Li, Na, K, Rb, Mg, Ca, Sr or B, Al, Ti, Zr, Fe, Mn, Co or Mo.
  8. 8. Process according to any of the previous claims, characterized in that the process takes place in a non-polar or polar solvent or solvent mixtures, particularly decaline, 1 -octanol and/or 2-ethyl-1 -hexanol.
  9. 9. Process according to any of the previous claims, characterized in that the solvent a primary or secondary alcohol and/or that the solvent acts also as the promoter.
  10. 10. Process according to any of claims 6 to 9, characterized in that the ratio r1 between base and catalyst is between 1 : 1 and 100: 1 and/or that the ratio
  11. 11 . Process according to any of the previous claims, characterized in that the process is run at a temperature below between 50 and 200 °C and/or that hydrogen as well as carbon monoxide are introduced with a partial pressure between 0.1 and 50 bar.
  12. 12. Process according to any of the previous claims, characterized in that the reaction setup runs as a semi-batch or continuous process.
  13. 13. Process according to any of the previous claims, characterized in that the process is run at total pressures between 10 and 100 bar, preferably 10 to 40 bar, and at a temperature between 80 and 150 °C, that the complex has the structural formula , in particular that the base is KOMe and/or K-(2-ethyl-1 -hexanoate) and that the solvent and the promotor is 1 -octanol and/or 2-ethyl-1 -hexanol.

Description

Process for producing methanol The invention is directed to process for catalyzing a production of methanol from hydrogen and carbon monoxide taking place in the presence of at least one nucleophilic promoter, whereby a complex is used which comprises a transition metal (M) and at least one ligand designed as a chelating agent that binds tightly to three or more sites with two donor atoms which are connected via a ligand backbone with at least one Lewis base centrum (LB). Methanol, also known as CH3OH or MeOH (a methyl group linked to a hydroxyl group), is a chemical compound that plays a crucial role in the chemical industry. It serves not only as a fuel component but also as a fundamental building block in various chemical processes. In 2018, its production volume exceeded 100 million metric tons. However, a drawback of all known reaction mechanisms is that they require harsh conditions, particularly temperatures above 250 °C and high pressures exceeding 100 bar. This results in energy-intensive processes, which pose challenges from both economic and environmental perspectives. To address this, reducing energy consumption can lead to cost savings and enhance the sustainability of the process by reducing operational expenses (opex) and capital expenses (capex). The invention aims to provide a process for producing methanol with significantly lower energy requirements compared to the processes known from the state of the art. This is important from both an economic and environmental perspective, as it can reduce costs and improve the sustainability of the process. By reducing energy consumption, the process can lower opex and capex, resulting in cost savings. Additionally, the reduced energy requirements contribute to a more sustainable and environmentally friendly production of methanol. From document WO 2020/136003 A1 it is already known to use pincer type complexes as a catalyst. However, only homogeneous ligand structures are used which means that in cases a pincer type ligand is used, each type of donor atoms of the pincer type ligand features only one type of substitute. This holds particularly true for P atoms as donor atoms which are complete substituted with either isopropyl or phenyl rests. The use of at least two different substituents for one type of donor atoms and the correlation between these types and the donor atoms is not described. However, the invention aims to optimize the production of methanol by developing a process that is more energy-efficient, cost-effective, and environmentally sustainable compared to existing methods. Surprisingly, it has been found that in contrast to the teaching of WO 2020/136003 A1 at least one phosphor donor atom and the use of at least two different substituents for phosphor donor atoms leads to increased yields which can be proved by new computational simulations and confirmed by experiment, the inventors observed an increase of the turnover rate by a factor of three through the newly designed asymmetric ligand structure for the (pre-) catalysts presented herein. This enables lower reaction temperatures, which leads to lower energy consumption and higher catalyst stability. In addition, at lower temperatures, the reactions are suppressed, so that the selectivity of the reaction is increased. This could be achieved through the specific ligand design, which lowers the activation barrier and/or increases the stability significantly compared to other known catalysts. Summing up, the invention discloses a process according to the features of claim 1. In detail, 1 the process takes place in the presence of at least one nucleophilic promoter. Moreover, a complex is used as the basic component for the catalyzed conversion of hydrogen and carbon monoxide. Said complex comprises a transition metal and at least one Lewis basic ligand, preferably one Lewis base ligand designed as a chelating agent that binds tightly to three or more sites including two donor atoms. The three or more sites binds preferably in adjacent coplanar site, which are most preferably in a meridional configuration. In particularly preferred embodiments, three or four sites are bound. Most preferably, three sides are bound which leads to a pincer type complex. A pincer type complex, including an N atom as the only Lewis base centrum is most preferred as it shows particularly good performance. Coming back to the two donor atoms, these two donor atoms are connected via a ligand backbone with at least one Lewis base centrum, preferably one or two Lewis base centrum. Both donor atoms can feature substituents each. For the idea underlying the invention two cases 1 and 2 are possible. In case 1 both donor atoms are phosphor atoms whereby each donor atom has two identical substituents R' or R" each and whereby the substituents R' and R" differ from each other. In case 2 at least one donor atom is a phosphor atome and each phosphor atom features a chiral center with two different substituents R' and