Process for preparation of one or more of monoalcohols, diols and trialcohols each having two or three carbon atoms

Abstract

The present invention relates to a method for preparing one or more of a monohydric alcohol, a diol and a trihydric alcohol each having two or three carbon atoms and, more specifically, to a method for preparing one or more of a monohydric alcohol, a diol and a trihydric alcohol using a catalyst comprising nickel, wherein 5 to 60 wt.-% of the catalyst consists of zirconium oxide, calculated as ZrO2.

Description

[0001] The present invention relates to a process for preparing one or more of mono-, di- and tri-ols each having two or three carbon atoms and more particularly to a process for preparing one or more of mono-, di- and tri-ols using a catalyst comprising nickel, wherein the catalyst comprises zirconium oxide, wherein 5 to 50 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2).

[0002] The chemical industry has recognized the need to reduce the carbon footprint of its products (i.e., the amount of CO2 equivalent emissions per unit of output). Consequently, the use of renewable feedstocks derived from biomass is gaining increasing attention. A subset of these feedstocks is sugars and common sugar derivatives, such as sugar alcohols.

[0003] It is known that sugar alcohols, such as sorbitol, can react with hydrogen (hydrogenolysis) to produce diols, triols, and polyols, alcohols, and even alkanes. Of these products, 1,2-propylene glycol (1,2-PDO, PDA, propylene glycol) and ethylene glycol (EG) have garnered the most attention due to their potential use as formulation additives in the polymer, food, feed, agriculture, personal care, and home care industries. It is also known that the selective conversion of sorbitol to these diols requires specific reaction conditions and additives. Most notably, alkali metal hydroxides and alkaline earth metal hydroxides are added to aqueous and / or alcoholic sorbitol feed mixtures.

[0004] However, in addition to the required hydrothermal conditions, the use of dissolved bases poses immediate challenges to the stability of the catalysts used. Consequently, catalyst stability was identified as a persistent challenge in a recent review of heterogeneous catalyst research for sorbitol hydrogenolysis (Journal of Environmental Chemical Engineering 2022, 10, 107229; DOI: 10.1016 / j.jece.2022.107229). Wang et al. (ChemCatChem 2019, 11, 4123–4129; DOI: 10.1002 / cctc.201900299) proposed a catalyst containing Cu and an activated carbon support. During subsequent batch reactions with an aqueous sorbitol feed (5 wt.%) and Ca(OH)2 as an additive, the catalyst activity continued to decline. This suggests a lack of catalyst stability under the tested reaction conditions (240°C, 50 bar).

[0005] Attempts to operate without base additives have also been discussed in the academic literature. For example, Xin Jin et al. (ACS Catal. 2015, 5, 6545-6558; DOI: 10.1021 / acscatal.5b01324) proposed a catalyst containing Cu, CaO, and Al2O3 and discussed its use for the hydrogenolysis of sorbitol (0.18 mol / L). Even without the addition of a hydroxide base, the catalyst was unstable at 230°C and 76 bar, resulting in a continuous decrease in substrate conversion in successive batch experiments. Chen et al. (Catalysis Communications 2013, 39, 86–89; DOI: 10.1016 / j.catcom.2013.05.012) proposed a catalyst containing Ni and MgO and tested the conversion of an aqueous sorbitol solution (20 wt.%). The applied reaction conditions lead to corrosion of the support (MgO) and reduced conversion of sorbitol.In the above-mentioned prior art, the basic oxides CaO and MgO in the catalyst formulation replace the hydroxide additive, possibly at the expense of dissolution effects that limit catalyst stability.

[0006] US 6,900,361 B2 describes a continuous three-step conversion process for lactose to diols. The third step is hydrogenolysis of the aldol intermediate obtained in the process to obtain the diols. Nickel-containing catalysts are suggested as particularly useful hydrogenation catalysts, and US 5,814,112 and US 6,152,975 are provided for reference. US 5,814,112 discloses a catalyst comprising nickel and ruthenium, wherein ruthenium is added to delay or reduce agglomeration or sintering of the nickel dispersed phase. Corresponding tests were performed using an aqueous phenol reaction mixture without an alkali additive. US 6,152,975 also discloses adding a metal other than ruthenium to the nickel-containing catalyst to delay or reduce agglomeration or sintering. Similarly, tests were performed using an aqueous phenol reaction mixture without an alkali additive. Finally, the initial lactose concentration in the aqueous feed of US 6,900,361 B2 is specified to be 5 to 20 wt.%, which is low and significantly reduces the economic efficiency of the process.

[0007] EP 2 403 818 A1 discloses a method for obtaining diols (e.g., 1,2-PDO, EG, GLY) from sorbitol. The claimed catalyst comprises a polyacid-promoted zirconium oxide support impregnated with at least one catalytically active metal (e.g., nickel). The polyacid promoter is specified to include at least one of chromium, molybdenum, tungsten, phosphorus, sulfur, or an organic polyacid. No examples of catalyst stability are provided. An average sorbitol conversion of 71% was achieved, which severely limited the overall diol yield. Therefore, the prior art lacks catalysts that are sufficiently stable under the required operating conditions for producing diols from sugar alcohols in high yields.

[0008] Although a large number of catalysts have been developed for the preparation of diols and triols each having two or three carbon atoms from sugars and sugar alcohols, there remains a need for more efficient catalysts that can be used on an industrial scale and overcome stability limitations. In particular, there remains a need for catalysts that are stable in water at high temperatures (e.g., temperatures above 100° C.) and, in particular, in the presence of acids or bases, thereby enabling efficient processes for the preparation of diols and triols each having two or three carbon atoms from sugars and sugar alcohols.

[0009] Therefore, another object of the present invention is to provide a method for preparing one or more of a diol and a triol each having two or three carbon atoms, which is not limited by a lack of catalyst stability. This includes selecting a catalyst that is mechanically and chemically stable in aqueous solutions of sugars and sugar alcohols at high temperatures (e.g., at temperatures above 100°C). Preferably, during the hydrogenolysis reaction, in the presence of an acid or base additive, the stability of the catalyst must remain high. In addition, the selected catalyst contains a hydrogenation metal (e.g., nickel and nickel and copper) to achieve high activity in the hydrogenolysis of sugars and sugar alcohols. This is necessary to achieve high levels of feedstock conversion and product yields. In addition, it was unexpectedly discovered that a selected catalyst composition containing a high concentration of a hydrogenation metal (e.g., nickel and copper), and in particular, a selected catalyst composition in which 40 to 90 wt.% of the catalyst is composed of nickel and / or nickel and copper, achieves high activity in the hydrogenolysis of sugars and sugar alcohols.

[0010] Therefore, the present invention relates to a process for preparing one or more of a monohydric alcohol, a dihydric alcohol and a trihydric alcohol each having two or three carbon atoms, the process comprising

[0011] (i) providing a liquid aqueous feed stream comprising one or more of sugars and sugar alcohols each having three, five, or six carbon atoms;

[0012] (ii) feeding the liquid aqueous feed stream provided according to (i) to a reaction zone comprising a catalyst comprising nickel, and subjecting the feed stream to reaction conditions in the reaction zone to obtain a reaction mixture comprising one or more of the monool, diol, and triol;

[0013] (iii) removing a liquid aqueous effluent stream comprising one or more of the monool, diol, and triol from the reaction zone;

[0014] wherein the catalyst comprises zirconium oxide, wherein 5 to 60 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2).

[0015] Preferably, the catalyst further comprises a metal oxide, wherein the metal of the metal oxides is preferably selected from the group consisting of Na, Mg, Al, Si, K, Ca, Ti, Mn, Co, Cu, Zn, Nb, Mo, La, Hf, and W, including combinations of two or more thereof; more preferably selected from the group consisting of Na, Mg, Al, Si, Ca, Ti, Mn, Co, Cu, La, and Hf, including combinations of two or more thereof; more preferably selected from the group consisting of Al, Si, Mn, Co and Cu, including combinations of two or more thereof; more preferably selected from the group consisting of Cu and Co, including combinations thereof; more preferably the metal of the metal oxides is Cu; wherein more preferably the catalyst further comprises a metal oxide selected from the group consisting of CuO, CoO, Co2O3 and Co3O4, including mixtures thereof; more preferably the catalyst further comprises CuO.

[0016] Preferably, the catalyst has a crystallinity in the range of 60% to 100%, preferably 80% to 100%, more preferably 90% to 100%, based on the total catalyst, as determined from the powder X-ray diffraction pattern of the catalyst, preferably as determined from the powder X-ray diffraction pattern of the catalyst according to the following formula:

[0017]

[0018] Among them A i corresponds to the signal area attributable to the crystalline sample component, and A j The area corresponding to the signal attributable to the X-ray amorphous sample component, more preferably as determined by the powder X-ray diffraction pattern of the catalyst according to example 4-1 Determined.

[0019] Preferably, the powder X-ray diffraction pattern of the catalyst shows signal peaks in the ranges of 28° to 29° and 31° to 32° 2θ angles.

[0020] The signal peaks in the ranges of 28° to 29° and 31° to 32° 2θ angles indicate that the crystalline ZrO2 is in the monoclinic phase. Preferably, the difference between the maximum signal intensity and the baseline signal intensity in the ranges of 28° to 29° and 31° to 32° 2θ angles is greater than the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles. Preferably, the difference between the maximum signal intensity and the baseline signal intensity in the range of 28° to 29° 2θ angles is at least three times the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles. Preferably, the difference between the maximum signal intensity and the baseline signal intensity in the range of 28° to 29° 2θ angles is at least six times the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles.

[0021] Preferably, the catalyst comprises a monoclinic phase comprising zirconium oxide and Optionally A tetragonal phase comprising zirconium oxide, preferably wherein the monoclinic phase comprises zirconium oxide in an amount of 5 to 100 wt.-% and the tetragonal phase comprises zirconium oxide in an amount of 0 to 20 wt.-%, based on 100 wt.-% of all crystalline phases in the catalyst, as determined by the powder X-ray diffraction pattern of the catalyst, preferably as determined by the powder X-ray diffraction pattern of the catalyst according to Example 4-1.

[0022] Preferably, the monoclinic phase contains zirconium oxide in an amount of 10 to 80 wt.-%, and the tetragonal phase contains zirconium oxide in an amount of 0 to 10 wt.-%, based on 100 wt.-% of all crystalline phases in the catalyst, as determined by the powder X-ray diffraction pattern of the catalyst, preferably as determined by the powder X-ray diffraction pattern of the catalyst according to Example 4-1. Preferably, the monoclinic phase contains zirconium oxide in an amount of 25 to 70 wt.-%, and the tetragonal phase contains zirconium oxide in an amount of 0 to 5 wt.-%, based on 100 wt.-% of all crystalline phases in the catalyst, as determined by the powder X-ray diffraction pattern of the catalyst, preferably as determined by the powder X-ray diffraction pattern of the catalyst according to Example 4-1. Preferably, the monoclinic phase contains zirconium oxide in an amount of 30 to 60 wt.-% and the tetragonal phase contains zirconium oxide in an amount of 0 to 5 wt.-%, based on 100 wt.-% of all crystalline phases in the catalyst, as determined from the powder X-ray diffraction pattern of the catalyst, preferably as determined from the powder X-ray diffraction pattern of the catalyst according to Example 4-1.

[0023] Preferably, 40 to 90 wt.-%, preferably 45 to 85 wt.-%, more preferably 50 to 80 wt.-% of the catalyst consists of nickel (calculated as NiO).

[0024] Preferably, 40 to 90 wt.-%, preferably 60 to 85 wt.-% of the catalyst consists of nickel and copper (calculated as NiO and CuO).

[0025] Preferably, the catalyst is substantially free of alumina, preferably substantially free of Al2O3.

[0026] Preferably, 40 to 60 wt.-% of the catalyst consists of nickel (calculated as NiO), 10 to 30 wt.-% of the catalyst consists of copper (calculated as CuO), and 20 to 40 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2).

[0027] Preferably, the catalyst is substantially free of CrO3 and / or Cr2O3, preferably substantially free of CrO3 and Cr2O3.

[0028] Preferably, the catalyst is in the form of a molding and / or in the form of a powder, preferably in the form of a molding, more preferably in the form of an extrudate and / or tablet, and more preferably in the form of a cylindrical tablet.

[0029] In the case where the catalyst is in the form of a cylindrical tablet, it is preferred that the cylindrical tablet has a diameter x height in the range 1 x 1 to 10 x 10 mm, preferably 1.5 x 1.5 to 7 x 7 mm, more preferably 2.0 x 2.0 to 6 x 6 mm.

[0030] Preferably, the sugar having three carbon atoms is glyceraldehyde.

[0031] Preferably, one or more of the sugars having five carbon atoms are selected from the group consisting of ribose, arabinose, xylose and lyxose, including combinations of two or more thereof.

[0032] Preferably, one or more of the sugars having six carbon atoms are preferably selected from the group consisting of glucose, galactose, maltose, lactose, sucrose, allose, altrose, mannose, gulose, idose, talose, including combinations of two or more thereof.

[0033] Preferably, the sugar alcohol having three carbon atoms is glycerol.

[0034] Preferably, one or more of the sugar alcohols having five carbon atoms are selected from the group consisting of arabitol, ribitol and xylitol, including combinations of two or more thereof; more preferably, the sugar alcohols having six carbon atoms include xylitol.

[0035] Preferably, one or more of the sugar alcohols having six carbon atoms are selected from the group consisting of mannitol, iditol, galactitol and sorbitol, including combinations of two or more thereof; more preferably, the sugar alcohols having six carbon atoms include sorbitol.

[0036] Preferably, one or more of the monohydric alcohols, dihydric alcohols and trihydric alcohols, each having two or three carbon atoms, is selected from the group consisting of 1,2-propylene glycol, ethylene glycol, 1,3-propylene glycol, glycerol, 1-propanol, 2-propanol and ethanol, including combinations of two or more thereof.

[0037] Preferably, one or more of the diols and triols each having two or three carbon atoms is selected from the group consisting of 1,2-propylene glycol, ethylene glycol and glycerol, including combinations of two or more thereof.

[0038] Preferably, the diol having two carbon atoms comprises ethylene glycol.

[0039] Preferably, the diol having three carbon atoms includes 1,2-propylene glycol.

[0040] Preferably, the triol having three carbon atoms includes glycerol.

[0041] Preferably, the liquid aqueous feed stream in (ii) comprises 20 to 99 wt.-%, preferably 25 to 60 wt.-%, more preferably 25 to 40 wt.-% of sugars or sugar alcohols each having three, five or six carbon atoms.

[0042] Preferably, the liquid aqueous feed stream provided in (i) further comprises a solvent, preferably a solvent comprising a monohydric alcohol, preferably the monohydric alcohol is selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol and 1-butanol, more preferably the monohydric alcohol is selected from the group consisting of methanol, ethanol and 1-butanol, more preferably the monohydric alcohol is ethanol.

[0043] Preferably, the process involves the preparation of one or more of diols and triols each having two or three carbon atoms.

[0044] Preferably, the liquid aqueous feed stream provided in (i) comprises one or more of sugars and sugar alcohols each having five or six carbon atoms.

[0045] Preferably, the liquid aqueous feed stream provided in (i) further comprises a compound selected from the group consisting of a base, a Lewis acid and combinations thereof, preferably the liquid aqueous feed stream provided in (i) further comprises a base.

[0046] Where the liquid aqueous feed stream provided in (i) further comprises a base, it is preferred that wherein the base is selected from the group consisting of metal hydroxides and metal carbonates, wherein the metal of the metal hydroxide and the metal carbonate is preferably selected from the group consisting of Li, Na, K, Ca and Mg, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides and metal carbonates, the one or more metal hydroxides and metal carbonates being selected from the group consisting of LiOH, NaOH, Na2CO3, KOH, K2CO3, Ca(OH)2 and Mg(OH)2, including mixtures of two or more thereof; preferably selected from the group consisting of NaOH, Na2CO3, KOH, K2CO3, Ca(OH)2 and Mg(OH)2, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides and metal carbonates being selected from the group consisting of NaOH, Na2CO3, KOH and K2CO3, including combinations of two of them; more preferably the base comprises NaOH, preferably NaOH.

[0047] In case the liquid aqueous feed stream provided in (i) further comprises a base, it is preferred that the liquid aqueous feed stream provided in (i) comprises 0.1 to 8 wt.-%, preferably 0.3 to 7 wt.-%, more preferably 4 to 6 wt.-% of base.

[0048] Where the liquid aqueous feed stream provided in (i) further comprises a Lewis acid, it is preferred that in (i), the Lewis acid is selected from the group consisting of metallic polyacids, wherein the metal of the metallic polyacid is preferably selected from the group consisting of Mo and W, including combinations of two or more thereof; wherein more preferably the Lewis acid comprises one or more metallic polyacids selected from the group consisting of H2WO4 and (NH4)2MoO2, including combinations thereof.

[0049] Preferably, the reaction conditions according to (ii) comprise a reaction pressure in the range of 40 to 250 bar, preferably 60 to 200 bar and more preferably 80 to 120 bar.

[0050] Preferably, the reaction conditions according to (ii) comprise a temperature in the range of 140 to 220°C, preferably 170 to 200°C.

[0051] Preferably, the reaction conditions according to (ii) comprise a reaction time of 0.1 to 5 h. -1 , preferably 0.2 to 5 h -1 Liquid hourly space velocity in the range of .

[0052] Preferably, the liquid aqueous feed stream provided in (i) and fed to the reaction zone in (ii) further comprises H2.

[0053] Where the liquid aqueous feed stream provided in (i) and fed to the reaction zone in (ii) further comprises H2, it is preferred that the liquid aqueous feed stream exhibits a H2:sugar or sugar alcohol molar ratio of H2 to sugar or sugar alcohol in the range of 1 to 8, preferably 1.5 to 7, more preferably 1.8 to 7.

[0054] Preferably, the liquid aqueous effluent stream removed in (iii) comprises from 10 to 95 mol% C, preferably from 30 to 95 mol% C, more preferably from 40 to 95 mol% C, more preferably from 50 to 90 mol% C of one or more of mono-, di- and tri-ols each having two or three carbon atoms, based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (I):

[0055]

[0056] (I);

[0057] Wherein the subscript n refers to the weight, molar mass, and carbon number of 1,2-propylene glycol, glycerol, and ethylene glycol, respectively. The subscript α refers to the weight, molar mass, and carbon number of one or more of the sugars and sugar alcohols.

[0058] Preferably, the liquid aqueous effluent stream removed in (iii) comprises 10 to 95 mol % C, preferably 30 to 95 mol % C, more preferably 40 to 95 mol % C, more preferably 50 to 90 mol % C of 1,2-propylene glycol, glycerol and ethylene glycol, based on 100 mol % C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol % C is defined according to equation (II):

[0059]

[0060] (II);

[0061] Wherein, subscripts 1-3 refer to the weight, molar mass, and carbon number of 1,2-propylene glycol, glycerol, and ethylene glycol, respectively. Subscript α refers to the weight, molar mass, and carbon number of one or more of sugars and sugar alcohols.

[0062] Preferably, the liquid aqueous effluent stream removed in (iii) comprises 10 to 95 mol% C, preferably 20 to 95 mol% C, more preferably 30 to 95 mol% C, more preferably 40 to 90 mol% C of 1,2-propylene glycol based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (III):

[0063]

[0064] (III);

[0065] The subscript α refers to the weight, molar mass and carbon number of one or more of the sugar and sugar alcohol.

[0066] Preferably, the process is a continuous process.

[0067] Preferably, the process is operated in a trickle bed reactor.

[0068] The present invention further relates to a process for preparing a catalyst, preferably a catalyst for the process according to the invention, comprising

[0069] (a) preparing a first mixture comprising zirconium oxide and water;

[0070] (b) preparing a second mixture comprising a nickel precursor selected from the group consisting of nickel nitrate, nickel halide, nickel acetate, nickel sulfate, and optionally a copper precursor and water, the nickel precursor selected from the group consisting of copper nitrate, copper halide, copper acetate, copper sulfate, copper amine complex, including combinations of two or more thereof;

[0071] (c) mixing the first mixture obtained in (a), the second mixture obtained in (b), and a precipitant to obtain a slurry comprising solids and water;

[0072] (d) removing water from the slurry obtained in (c) to obtain a solid;

[0073] (e) optionally, drying the solid obtained in (d) at a temperature in the range of 80°C to 150°C to obtain a dried solid;

[0074] (f) calcining the solid obtained in (d), preferably the dried solid obtained in (e), at a temperature in the range of 300° C. to 700° C., to obtain a catalyst comprising nickel oxide and zirconium oxide, wherein 5 to 60 wt.-% of the catalyst, preferably the catalyst for use in the process according to any one of embodiments 1 to 41, consists of zirconium oxide (calculated as ZrO ).

[0075] In case the present invention relates to a method for preparing a catalyst, preferably, (a) comprises

[0076] (a.1) preparing a solution comprising a zirconium precursor and water, wherein the zirconium precursor is selected from the group consisting of zirconium nitrate, zirconium halide, zirconyl halide, zirconium acetate, zirconium sulfate, and combinations of two or more thereof;

[0077] (a.2) mixing the solution prepared in (a.1) with a precipitant to obtain a suspension;

[0078] (a.3) removing water from the suspension obtained in (a.3) to obtain a solid;

[0079] (a.4) optionally, drying the solid obtained in (a.4) at a temperature in the range of 80°C to 150°C to obtain a dried solid;

[0080] (a.5) calcining the solid obtained in (a.3), preferably the dried solid obtained in (a.4), at a temperature in the range of 400° C. to 800° C. to obtain zirconium oxide.

[0081] Preferably, the zirconium oxide has a crystallinity in the range of 60% to 100%, preferably 80% to 100%, more preferably 90% to 100%, based on the total zirconium oxide, as determined from a powder X-ray diffraction pattern of the zirconium oxide, preferably as determined from a powder X-ray diffraction pattern of the zirconium oxide according to the following formula:

[0082]

[0083] Among them A i corresponds to the signal area attributable to the crystalline sample component, and A j The area corresponding to the signal attributable to the X-ray amorphous sample component, more preferably as determined from the powder X-ray diffraction pattern of zirconium oxide according to Example 1-1.

[0084] Preferably, the powder X-ray diffraction pattern of the zirconium oxide shows signal peaks in the range of 28° to 29° and 31° to 32° 2θ angles, preferably these signal peaks indicate that the crystalline zirconium oxide is in a monoclinic phase.

[0085] Preferably, the difference between the maximum signal intensity and the baseline signal intensity in the ranges of 28° to 29° and 31° to 32° 2θ angles is greater than the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles. Preferably, the difference between the maximum signal intensity and the baseline signal intensity in the range of 28° to 29° 2θ angles is at least twice the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles. Preferably, the difference between the maximum signal intensity and the baseline signal intensity in the range of 28° to 29° 2θ angles is at least four times the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles.

[0086] Preferably, the zirconium oxide comprises a monoclinic phase and Optionally Tetragonal phase, preferably wherein the zirconium oxide comprises the monoclinic phase in an amount of 50 to 100 wt.-% and the tetragonal phase in an amount of 0 to 50 wt.-%, based on 100 wt.-% of all crystalline phases in the zirconium oxide, as determined by a powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by a powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1. Preferably, the zirconium oxide comprises the monoclinic phase in an amount of 70 to 100 wt.-% and the tetragonal phase in an amount of 0 to 30 wt.-%, based on 100 wt.-% of all crystalline phases in the zirconium oxide, as determined by a powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by a powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1. Preferably, the zirconium oxide comprises a monoclinic phase in an amount of 80 to 100 wt.-% and a tetragonal phase in an amount of 0 to 20 wt.-%, based on 100 wt.-% of all crystalline phases in the zirconium oxide, as determined by a powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by a powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1. Preferably, the zirconium oxide comprises a monoclinic phase in an amount of 90 to 100 wt.-% and a tetragonal phase in an amount of 0 to 10 wt.-%, based on 100 wt.-% of all crystalline phases in the zirconium oxide, as determined by a powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by a powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1.

[0087] Preferably, in (c) and / or in (a.3), the precipitant is selected from the group consisting of sodium carbonate, sodium hydroxide, ammonia and ammonium hydroxide, including combinations of two or more thereof.

[0088] In one embodiment, the catalyst is obtained by a series of precipitation, washing, drying and annealing steps. After the annealing step, the catalyst is in its oxidized state. The oxidized state is characterized by the presence of the metal in the form of a metal oxide or a mixed metal oxide. Preferably, Ni exists as NiO, Zr exists as ZrO2, and Cu exists as CuO. The catalyst composition is determined by analyzing the elemental content of the material in its oxidized state. The molecular weight of the metal and oxide is used to convert the obtained value into oxide content.

[0089] In one embodiment, the catalyst is reduced before use or during use. Thus, the active catalyst comprises nickel in its reduced state, preferably nickel as nickel metal. In this case, the catalyst comprises nickel in an oxidation state including 0.

[0090] In one embodiment, the catalyst reduction is incomplete. Therefore, the active catalyst comprises nickel in its oxidation state, preferably as nickel oxide, preferably as NiO. In this case, the catalyst comprises nickel in an oxidation state selected from the group consisting of +I, +II, +III and +IV, including combinations of two or more thereof, more preferably the catalyst comprises nickel in an oxidation state including +II.

[0091] In one embodiment, where Cu is present in the catalyst, the catalyst is reduced prior to use or during use. Thus, the active catalyst comprises copper in its reduced state, preferably copper as copper metal. In this case, the catalyst comprises copper in an oxidation state including 0.

[0092] Another object of the present invention is to provide a method for preparing one or more of diols and triols each having two or three carbon atoms, which is not limited by a lack of catalyst stability. This involves selecting a catalyst that is mechanically and chemically stable in aqueous solutions of sugars and sugar alcohols at high temperatures. Preferably, the stability of the catalyst must remain high in the presence of an alkaline additive during the hydrogenolysis reaction. In addition, the selected catalyst contains a hydrogenation metal (such as nickel and nickel and copper) to achieve high activity in the hydrogenolysis of sugars and sugar alcohols. This is necessary to achieve high levels of feedstock conversion and product yield. In addition, it was unexpectedly discovered that a selected catalyst composition containing a high concentration of a hydrogenation metal (such as nickel and copper), and in particular, a selected catalyst composition in which 40 to 90 wt.% of the catalyst consists of nickel and / or nickel and copper, achieves high activity in the hydrogenolysis of sugars and sugar alcohols.

[0093] Therefore, the present invention further relates to a process for preparing one or more of a diol and a triol each having two or three carbon atoms, the process comprising

[0094] (i) providing a liquid aqueous feed stream comprising one or more of sugars and sugar alcohols each having five or six carbon atoms;

[0095] (ii) feeding the liquid aqueous feed stream provided according to (i) to a reaction zone comprising a catalyst comprising nickel, and subjecting the feed stream to reaction conditions in the reaction zone to obtain a reaction mixture comprising one or more of a diol and a triol;

[0096] (iii) removing a liquid aqueous effluent stream comprising one or more of a diol and a triol from the reaction zone;

[0097] wherein the catalyst comprises zirconium oxide, wherein 5 to 50 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2), and wherein 0 to 15 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3).

[0098] In one embodiment, the catalyst is obtained by a series of precipitation, washing, drying and annealing steps. After the annealing step, the catalyst is in its oxidized state. The oxidized state is characterized by the presence of the metal in the form of a metal oxide or a mixed metal oxide. Preferably, Ni is present as NiO, Zr is present as ZrO2, and Al is present as Al2O3. The catalyst composition is determined by analyzing the elemental content of the material in its oxidized state. The molecular weight of the metal and oxide is used to convert the obtained value into oxide content.

[0099] In one embodiment, the catalyst is reduced before use or during use. Thus, the active catalyst comprises nickel in its reduced state, preferably nickel as nickel metal. In this case, the catalyst comprises nickel in an oxidation state including 0.

[0100] In one embodiment, the catalyst reduction is incomplete. Therefore, the active catalyst comprises nickel in its oxidation state, preferably as nickel oxide, preferably as NiO. In this case, the catalyst comprises nickel in an oxidation state selected from the group consisting of +I, +II, +III and +IV, including combinations of two or more thereof, more preferably the catalyst comprises nickel in an oxidation state including +II.

[0101] In one embodiment, the catalyst is substantially free of aluminum oxide, preferably substantially free of Al2O3. In the case where the catalyst is substantially free of aluminum oxide, preferably substantially free of Al2O3, 0 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3). In another embodiment, the catalyst comprises aluminum oxide, wherein 0.01 to 15 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3).

[0102] Preferably, the catalyst further comprises a metal oxide, wherein the metal of the metal oxide is preferably selected from the group consisting of Na, Mg, Si, K, Ca, Ti, Mn, Co, Cu, Zn, Nb, Mo, La, Hf, and W, including combinations of two or more thereof; more preferably selected from the group consisting of Na, Mg, Si, Ca, Ti, Mn, Cu, Mo, La, Hf, and W, including combinations of two or more thereof; more preferably selected from the group consisting of Si, Ca, Cu, Mn, and Mo, including combinations of two or more thereof; more preferably selected from the group consisting of Si, and Mo, including combinations thereof; wherein more preferably the catalyst further comprises a metal oxide selected from the group consisting of SiO2, CuO, and MoO x (wherein x is 1 to 3), including mixtures thereof.

[0103] Preferably, 0 to 10 wt.-%, preferably 0 to 5.5 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3).

[0104] Preferably, 40 to 90 wt.-%, preferably 60 to 85 wt.-% of the catalyst consists of nickel (calculated as NiO).

[0105] Preferably, 0.1 to 5.5 wt.-%, preferably 2 to 5.5 wt.-%, more preferably 3 to 5 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3).

[0106] Preferably, 65 to 75 wt.-% of the catalyst consists of nickel (calculated as NiO), 5 to 7 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2), and 3 to 5 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3).

[0107] Preferably, 65 to 75 wt.-% of the catalyst consists of nickel (calculated as NiO), 5 to 7 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2), 3 to 5 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3), and 15 to 25 wt.-% of the catalyst consists of silicon oxide (calculated as SiO2).

[0108] In one embodiment, the catalyst comprises nickel and copper. In the case where the catalyst comprises nickel and copper, it is preferred that 40 to 90 wt.-%, preferably 60 to 85 wt.-% of the catalyst consists of nickel and copper (calculated as NiO and CuO).

[0109] In one embodiment, the catalyst is obtained by a series of precipitation, washing, drying and annealing steps. After the annealing step, the catalyst is in its oxidized state. The oxidized state is characterized by the presence of the metal in the form of a metal oxide or a mixed metal oxide. Preferably, Ni is present as NiO, Cu is present as CuO, Zr is present as ZrO2, and Mo is present as MoO3. The catalyst composition is determined by analyzing the elemental content of the material in its oxidized state. The molecular weight of the metal and oxide is used to convert the obtained value into oxide content.

[0110] In one embodiment, the catalyst is reduced prior to use or during use. Thus, the active catalyst comprises nickel and copper in their reduced states, preferably nickel and copper as nickel metal and copper metal. In this case, the catalyst comprises nickel and copper in an oxidation state including 0.

[0111] In one embodiment, the catalyst reduction is incomplete. Therefore, the active catalyst comprises nickel and copper in their oxidation states, preferably as nickel oxide and copper oxide, preferably as NiO and CuO. In this case, the catalyst comprises nickel and copper in an oxidation state selected from the group consisting of +I, +II, +III and +IV, including combinations of two or more thereof, more preferably the catalyst comprises nickel and copper in an oxidation state including +II.

[0112] In cases where the catalyst comprises nickel and copper, it is preferred that the catalyst is substantially free of alumina, preferably substantially free of Al2O3.

[0113] In the case where the catalyst comprises nickel and copper, it is preferred that 40 to 60 wt.-% of the catalyst consists of nickel (calculated as NiO), 10 to 30 wt.-% of the catalyst consists of copper (calculated as CuO), and 20 to 40 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2).

[0114] In the case where the catalyst comprises nickel and copper, it is preferred that 40 to 60 wt.-% of the catalyst consists of nickel (calculated as NiO), 10 to 30 wt.-% of the catalyst consists of copper (calculated as CuO), 20 to 40 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2), and 0.1 to 5 wt.-% of the catalyst consists of molybdenum oxide (calculated as MoO3).

[0115] Preferably, the zirconia comprises one or more crystalline phases and / or is amorphous, wherein the one or more crystalline phases of zirconia are selected from the group consisting of monoclinic, tetragonal, and cubic phases of zirconia, including mixtures of two or three thereof.

[0116] Preferably, the catalyst is substantially free of CrO3 and / or Cr2O3, preferably substantially free of CrO3 and Cr2O3.

[0117] Preferably, the catalyst is in the form of a molding and / or in the form of a powder, preferably in the form of a molding, more preferably in the form of an extrudate and / or tablet, and more preferably in the form of a cylindrical tablet.

[0118] In the case where the catalyst is in the form of a cylindrical tablet, it is preferred that the cylindrical tablet has a diameter x height in the range 1 x 1 to 10 x 10 mm, preferably 2 x 2 to 7 x 7 mm, more preferably 2.5 x 2.5 to 6 x 6 mm.

[0119] Preferably, one or more of the sugars having five carbon atoms are selected from the group consisting of ribose, arabinose, xylose and lyxose, including combinations of two or more thereof.

[0120] Preferably, one or more of the sugars having six carbon atoms are preferably selected from the group consisting of glucose, galactose, maltose, lactose, sucrose, allose, altrose, mannose, gulose, idose, talose, including combinations of two or more thereof.

[0121] Preferably, one or more of the sugar alcohols having five carbon atoms are selected from the group consisting of arabitol, ribitol and xylitol, including combinations of two or more thereof; more preferably, the sugar alcohols having six carbon atoms include xylitol.

[0122] Preferably, one or more of the sugar alcohols having six carbon atoms are selected from the group consisting of mannitol, iditol, galactitol and sorbitol, including combinations of two or more thereof; more preferably, the sugar alcohols having six carbon atoms include sorbitol.

[0123] Preferably, one or more of the diols and triols each having two or three carbon atoms is selected from the group consisting of 1,2-propylene glycol, ethylene glycol, 1,3-propylene glycol and glycerol, including combinations of two or more thereof; preferably one or more of the diols and triols each having two or three carbon atoms is selected from the group consisting of 1,2-propylene glycol, ethylene glycol and glycerol, including combinations of two or more thereof.

[0124] Preferably, the diol having two carbon atoms comprises ethylene glycol.

[0125] Preferably, the diol having three carbon atoms includes 1,2-propylene glycol

[0126] Preferably, the triol having three carbon atoms includes glycerol.

[0127] Preferably, the liquid aqueous feed stream prepared in (ii) comprises 20 to 60 wt.-%, preferably 25 to 50 wt.-%, more preferably 25 to 40 wt.-% of sugars or sugar alcohols each having five or six carbon atoms.

[0128] Preferably, the liquid aqueous feed stream provided in (i) further comprises a solvent, preferably a solvent comprising a monohydric alcohol, more preferably the monohydric alcohol is selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol and 1-butanol.

[0129] Preferably, the liquid aqueous feed stream provided in (i) further comprises a compound selected from the group consisting of a base, a Lewis acid and combinations thereof, preferably a base.

[0130] Where the liquid aqueous feed stream provided in (i) further comprises a base, it is preferred that the base is selected from the group consisting of metal hydroxides, wherein the metal of the metal hydroxide is preferably selected from the group consisting of Li, Na, K, Ca, and Mg, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides selected from the group consisting of LiOH, NaOH, KOH, Ca(OH)2, and Mg(OH)2, including mixtures of two or more thereof; preferably selected from the group consisting of NaOH, KOH, Ca(OH)2, and Mg(OH)2, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides selected from the group consisting of NaOH and KOH, including combinations of two of them; more preferably the base comprises NaOH.

[0131] In case the liquid aqueous feed stream provided in (i) further comprises a base, it is preferred that the liquid aqueous feed stream provided in (i) comprises 0.1 to 8 wt.-%, preferably 0.3 to 7 wt.-%, more preferably 4 to 6 wt.-% of base.

[0132] Where the liquid aqueous feed stream provided in (i) further comprises an acid, it is preferred that the acid is selected from the group consisting of phosphoric acid and sulfuric acid, including combinations thereof.

[0133] Where the liquid aqueous feed stream provided in (i) further comprises a Lewis acid, it is preferred that the Lewis acid is selected from the group consisting of metallic polyacids, wherein the metal of the metallic polyacid is preferably selected from the group consisting of Mo and W, including combinations of two or more thereof; wherein more preferably the Lewis acid comprises one or more metallic polyacids selected from the group consisting of H2WO4 and (NH4)2MoO2, including combinations thereof.

[0134] Preferably, the reaction conditions according to (ii) comprise a reaction pressure in the range of 40 to 170 bar, preferably 60 to 150 bar and more preferably 80 to 120 bar.

[0135] Preferably, the reaction conditions according to (ii) comprise a temperature in the range of 140 to 210°C, preferably 170 to 200°C.

[0136] Preferably, the reaction conditions according to (ii) comprise a reaction time of 0.1 to 5 h. -1 , preferably 0.2 to 5 h -1 Liquid hourly space velocity within the range of .

[0137] Preferably, the liquid aqueous feed stream provided in (i) and fed to the reaction zone in (ii) further comprises H2.

[0138] Where the liquid aqueous feed stream provided in (i) and fed to the reaction zone in (ii) further comprises H2, it is preferred that the liquid aqueous feed stream exhibits a H2:sugar or sugar alcohol molar ratio of H2 to sugar or sugar alcohol in the range of 1 to 8, preferably 1.5 to 7, more preferably 1.8 to 7.

[0139] Preferably, the liquid aqueous effluent stream removed in (iii) comprises from 10 to 95 mol% C, preferably from 15 to 95 mol% C, more preferably from 20 to 85 mol% C, more preferably from 25 to 80 mol% C of one or more of diols and triols each having two or three carbon atoms, based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (I):

[0140]

[0141] (I);

[0142] Wherein, the subscript n refers to the weight, molar mass and carbon number of one or more diols among diols and triols, and the subscript α refers to the weight, molar mass and carbon number of one or more sugars and sugar alcohols.

[0143] Preferably, the liquid aqueous effluent stream removed in (iii) comprises 10 to 95 mol% C, preferably 15 to 90 mol% C, more preferably 20 to 85 mol% C, more preferably 25 to 80 mol% C of 1,2-propylene glycol, glycerol and ethylene glycol, based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (II):

[0144]

[0145] (II);

[0146] Wherein, subscripts 1-3 refer to the weight, molar mass, and carbon number of 1,2-propylene glycol, glycerol, and ethylene glycol, respectively. Subscript α refers to the weight, molar mass, and carbon number of one or more of sugars and sugar alcohols.

[0147] Preferably, the liquid aqueous effluent stream removed in (iii) comprises 10 to 80 mol% C, preferably 15 to 75 mol% C, more preferably 20 to 70 mol% C, more preferably 25 to 65 mol% C of 1,2-propylene glycol based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (III):

[0148]

[0149] (III);

[0150] The subscript α refers to the weight, molar mass and carbon number of one or more of the sugar and sugar alcohol.

[0151] Preferably, the process is a continuous process.

[0152] Preferably, the process is operated in a trickle bed reactor.

[0153] The present invention is further illustrated by the following set of examples and combinations of examples derived from the dependencies and back-references shown. In particular, it should be noted that in each case where a series of examples is mentioned, for example, in the context of a phrase such as "as in any one of Examples 1 to 4...", each example in this series is intended to be clearly disclosed to the skilled person, i.e., the wording of this phrase should be understood by the skilled person as synonymous with "as in any one of Examples 1, 2, 3, and 4...". In addition, it is expressly noted that the following set of examples is not a set of claims that determines the scope of protection, but rather represents a suitable structural part of this specification relating to general and preferred aspects of the present invention.

[0154] 1. A method for preparing one or more of a monohydric alcohol, a dihydric alcohol and a trihydric alcohol each having two or three carbon atoms, the method comprising

[0155] (i) providing a liquid aqueous feed stream comprising one or more of sugars and sugar alcohols each having three, five, or six carbon atoms;

[0156] (ii) feeding the liquid aqueous feed stream provided according to (i) to a reaction zone comprising a catalyst comprising nickel, and subjecting the feed stream to reaction conditions in the reaction zone to obtain a reaction mixture comprising one or more of the monool, diol, and triol;

[0157] (iii) removing a liquid aqueous effluent stream comprising one or more of the monool, diol, and triol from the reaction zone;

[0158] wherein the catalyst comprises zirconium oxide, wherein 5 to 60 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2).

[0159] 2. The method of embodiment 1, wherein the catalyst further comprises a metal oxide, wherein the metal of the metal oxides is preferably selected from the group consisting of Na, Mg, Al, Si, K, Ca, Ti, Mn, Co, Cu, Zn, Nb, Mo, La, Hf, and W, including combinations of two or more thereof; more preferably selected from the group consisting of Na, Mg, Al, Si, Ca, Ti, Mn, Co, Cu, La, and Hf, including combinations of two or more thereof; more preferably selected from the group consisting of Al, Si, Mn, Co, and Cu, including combinations of two or more thereof; more preferably selected from the group consisting of Cu and Co, including combinations thereof; more preferably the metal of the metal oxides is Cu; wherein more preferably the catalyst further comprises a metal oxide selected from the group consisting of CuO, CoO, Co2O3, and Co3O4, including mixtures thereof; more preferably the catalyst further comprises CuO.

[0160] 3. The method of embodiment 1 or 2, wherein the catalyst has a crystallinity in the range of 60% to 100%, preferably 80% to 100%, more preferably 90% to 100%, based on the total catalyst, as determined by the powder X-ray diffraction pattern of the catalyst, preferably as determined by the powder X-ray diffraction pattern of the catalyst according to the following formula:

[0161]

[0162] Among them Ai corresponds to the signal area attributable to the crystalline sample component, and A j The area corresponding to the signal attributable to the X-ray amorphous sample component, more preferably as determined from the powder X-ray diffraction pattern of the catalyst according to Example 4-1.

[0163] 4. The method of any one of embodiments 1 to 3, wherein the powder X-ray diffraction pattern of the catalyst shows signal peaks in the ranges of 28° to 29° and 31° to 32° 2θ angles, preferably the difference between the maximum signal intensity and the baseline signal intensity in the ranges of 28° to 29° and 31° to 32° 2θ angles is greater than the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles, more preferably the difference between the maximum signal intensity and the baseline signal intensity in the range of 28° to 29° 2θ angles is at least three times the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles, more preferably the difference between the maximum signal intensity and the baseline signal intensity in the range of 28° to 29° 2θ angles is at least six times the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles.

[0164] 5. The method of any one of embodiments 1 to 4, wherein the catalyst comprises a monoclinic phase comprising zirconium oxide and OptionallyA tetragonal phase comprising zirconium oxide, preferably wherein, based on 100 wt.-% of all crystalline phases in the catalyst, the monoclinic phase comprises zirconium oxide in an amount of 5 to 100 wt.-%, and the tetragonal phase comprises zirconium oxide in an amount of 0 to 20 wt.-%, as determined by the powder X-ray diffraction pattern of the catalyst, preferably as determined according to Example 4-1 from the powder X-ray diffraction pattern of the catalyst; preferably wherein, based on 100 wt.-% of all crystalline phases in the catalyst, the monoclinic phase comprises zirconium oxide in an amount of 10 to 80 wt.-%, and the tetragonal phase comprises zirconium oxide in an amount of 0 to 10 wt.-%, as determined by the powder X-ray diffraction pattern of the catalyst, preferably as determined according to Example 4-1 from the powder X-ray diffraction pattern of the catalyst; more preferably wherein, based on 100 wt.-% of all crystalline phases in the catalyst, the monoclinic phase comprises zirconium oxide in an amount of 25 to 70 wt.-%. wt.-% of zirconium oxide, and the tetragonal phase contains zirconium oxide in an amount of 0 to 5 wt.-%, as determined by the powder X-ray diffraction pattern of the catalyst, preferably as determined by the powder X-ray diffraction pattern of the catalyst according to Example 4-1; more preferably wherein, based on 100 wt.-% of all crystalline phases in the catalyst, the monoclinic phase contains zirconium oxide in an amount of 30 to 60 wt.-%, and the tetragonal phase contains zirconium oxide in an amount of 0 to 5 wt.-%, as determined by the powder X-ray diffraction pattern of the catalyst, preferably as determined by the powder X-ray diffraction pattern of the catalyst according to Example 4-1.

[0165] 6. The process according to any one of embodiments 1 to 5, wherein 40 to 90 wt.-%, preferably 45 to 85 wt.-%, more preferably 50 to 80 wt.-% of the catalyst consists of nickel (calculated as NiO).

[0166] 7. The process according to any one of embodiments 1 to 6, wherein 40 to 90 wt.-%, preferably 60 to 85 wt.-% of the catalyst consists of nickel and copper (calculated as NiO and CuO).

[0167] 8. The method of any one of embodiments 1 to 7, wherein the catalyst is substantially free of alumina, preferably substantially free of Al2O3.

[0168] 9. The method of any one of embodiments 1 to 8, wherein 40 to 60 wt.-% of the catalyst consists of nickel (calculated as NiO), 10 to 30 wt.-% of the catalyst consists of copper (calculated as CuO), and 20 to 40 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2).

[0169] 10. The method of any one of embodiments 1 to 9, wherein the catalyst is substantially free of CrO 3 and / or Cr 2 O 3 , preferably substantially free of CrO 3 and Cr 2 O 3 .

[0170] 11. The process of any one of embodiments 1 to 10, wherein the catalyst is in the form of a molding and / or in powder form, preferably in the form of a molding, more preferably in the form of an extrudate and / or tablet, and more preferably in the form of a cylindrical tablet.

[0171] 12. The method of embodiment 11, wherein the cylindrical tablet has a diameter x height in the range of 1 x 1 to 10 x 10 mm, preferably 1.5 x 1.5 to 7 x 7 mm, more preferably 2.0 x 2.0 to 6 x 6 mm.

[0172] 13. The method of any one of embodiments 1 to 12, wherein the sugar having three carbon atoms is glyceraldehyde.

[0173] 14. The method of any one of embodiments 1 to 13, wherein one or more of the sugars having five carbon atoms is selected from the group consisting of ribose, arabinose, xylose, and lyxose, including combinations of two or more thereof.

[0174] 15. The method of any one of embodiments 1 to 14, wherein one or more of the sugars having six carbon atoms is preferably selected from the group consisting of glucose, galactose, maltose, lactose, sucrose, allose, altrose, mannose, gulose, idose, talose, including combinations of two or more thereof.

[0175] 16. The method of any one of embodiments 1 to 15, wherein the sugar alcohol having three carbon atoms is glycerol.

[0176] 17. The method of any one of embodiments 1 to 16, wherein one or more of the sugar alcohols having five carbon atoms is selected from the group consisting of arabitol, ribitol, and xylitol, including combinations of two or more thereof; more preferably, the sugar alcohols having six carbon atoms include xylitol.

[0177] 18. The method of any one of embodiments 1 to 17, wherein one or more of the sugar alcohols having six carbon atoms is selected from the group consisting of mannitol, iditol, galactitol, and sorbitol, including combinations of two or more thereof; more preferably, the sugar alcohols having six carbon atoms include sorbitol.

[0178] 19. The method of any one of embodiments 1 to 18, wherein one or more of the mono-, di-, and tri-ols, each having two or three carbon atoms, is selected from the group consisting of 1,2-propylene glycol, ethylene glycol, 1,3-propylene glycol, glycerol, 1-propanol, 2-propanol, and ethanol, including combinations of two or more thereof.

[0179] 20. The method of any one of embodiments 1 to 19, wherein one or more of the diols and triols each having two or three carbon atoms is selected from the group consisting of 1,2-propylene glycol, ethylene glycol, and glycerol, including combinations of two or more thereof.

[0180] 21. The method of any one of embodiments 1 to 20, wherein the diol having two carbon atoms comprises ethylene glycol.

[0181] 22. The method of any one of embodiments 1 to 21, wherein the diol having three carbon atoms comprises 1,2-propylene glycol.

[0182] 23. The method of any one of embodiments 1 to 22, wherein the triol having three carbon atoms comprises glycerol.

[0183] 24. The process of any one of embodiments 1 to 23, wherein the liquid aqueous feed stream in (ii) comprises 20 to 99 wt.-%, preferably 25 to 60 wt.-%, more preferably 25 to 40 wt.-% of sugars or sugar alcohols each having three, five or six carbon atoms.

[0184] 25. The process of any one of embodiments 1 to 24, wherein the liquid aqueous feed stream provided in (i) further comprises a solvent, preferably a solvent comprising a monohydric alcohol, preferably the monohydric alcohol is selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol and 1-butanol, more preferably the monohydric alcohol is selected from the group consisting of methanol, ethanol and 1-butanol, more preferably the monohydric alcohol is ethanol.

[0185] 26. The method of any one of embodiments 1 to 25, wherein the method involves preparing one or more of diols and triols each having two or three carbon atoms.

[0186] 27. The method of any one of embodiments 1 to 26, wherein the liquid aqueous feed stream provided in (i) comprises one or more of sugars and sugar alcohols each having five or six carbon atoms.

[0187] 28. The method of any one of embodiments 1 to 27, wherein the liquid aqueous feed stream provided in (i) further comprises a compound selected from the group consisting of a base, a Lewis acid, and a combination thereof, preferably the liquid aqueous feed stream provided in (i) further comprises a base.

[0188] 29. The method of embodiment 28, wherein in (i) wherein the base is selected from the group consisting of metal hydroxides and metal carbonates, wherein the metal of the metal hydroxide and the metal carbonate is preferably selected from the group consisting of Li, Na, K, Ca and Mg, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides and metal carbonates, the one or more metal hydroxides and metal carbonates being selected from the group consisting of LiOH, NaOH, Na2CO3, KOH, K2CO3, Ca(OH)2, and Mg(OH)2, including mixtures of two or more thereof; preferably selected from the group consisting of NaOH, Na2CO3, KOH, K2CO3, Ca(OH)2 and Mg(OH)2, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides and metal carbonates being selected from the group consisting of NaOH, Na2CO3, KOH and K2CO3, including combinations of two of them; more preferably the base comprises NaOH, preferably NaOH.

[0189] 30. The process of embodiment 28 or 29, wherein the liquid aqueous feed stream provided in (i) comprises 0.1 to 8 wt.-%, preferably 0.3 to 7 wt.-%, more preferably 4 to 6 wt.-% of the base.

[0190] 31. The method of embodiment 28, wherein in (i), the Lewis acid is selected from the group consisting of metallic polyacids, wherein the metal of the metallic polyacid is preferably selected from the group consisting of Mo and W, including combinations of two or more thereof; wherein more preferably the Lewis acid comprises one or more metallic polyacids selected from the group consisting of H2WO4 and (NH4)2MoO2, including combinations thereof.

[0191] 32. The process of any one of embodiments 1 to 31, wherein the reaction conditions according to (ii) comprise a reaction pressure in the range of 40 to 250 bar, preferably 60 to 200 bar, and more preferably 80 to 120 bar.

[0192] 33. The method of any one of embodiments 1 to 32, wherein the reaction conditions according to (ii) comprise a temperature in the range of 140°C to 220°C, preferably 170°C to 200°C.

[0193] 34. The method of any one of embodiments 1 to 33, wherein the reaction conditions according to (ii) comprise a reaction mixture at 0.1 to 5 h. -1 , preferably 0.2 to 5 h -1 Liquid hourly space velocity within the range of .

[0194] 35. The process of any one of embodiments 1 to 34, wherein the liquid aqueous feed stream provided in (i) and fed to the reaction zone in (ii) further comprises H2.

[0195] 36. The method of embodiment 35, wherein the liquid aqueous feed stream exhibits a H2:sugar or sugar alcohol molar ratio of H2 to sugar or sugar alcohol in the range of 1 to 8, preferably 1.5 to 7, more preferably 1.8 to 7.

[0196] 37. The method of any one of embodiments 1 to 36, wherein the liquid aqueous effluent stream removed in (iii) comprises 10 to 95 mol% C, preferably 30 to 95 mol% C, more preferably 40 to 95 mol% C, more preferably 50 to 90 mol% C of one or more of mono-, di-, and tri-ols, each having two or three carbon atoms, based on 100 mol% C of one or more of sugars and sugar alcohols, each having five or six carbon atoms, wherein mol% C is defined according to equation (I):

[0197]

[0198] (I);

[0199] Wherein the subscript n refers to the weight, molar mass, and carbon number of 1,2-propylene glycol, glycerol, and ethylene glycol, respectively. The subscript α refers to the weight, molar mass, and carbon number of one or more of the sugars and sugar alcohols.

[0200] 38. The method of any one of embodiments 1 to 37, wherein the liquid aqueous effluent stream removed in (iii) comprises 10 to 95 mol% C, preferably 30 to 95 mol% C, more preferably 40 to 95 mol% C, more preferably 50 to 90 mol% C of 1,2-propylene glycol, glycerol, and ethylene glycol, based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (II):

[0201]

[0202] (II);

[0203] Wherein, subscripts 1-3 refer to the weight, molar mass, and carbon number of 1,2-propylene glycol, glycerol, and ethylene glycol, respectively. Subscript α refers to the weight, molar mass, and carbon number of one or more of sugars and sugar alcohols.

[0204] 39. The method of any one of embodiments 1 to 38, wherein the liquid aqueous effluent stream removed in (iii) comprises 10 to 95 mol% C, preferably 20 to 95 mol% C, more preferably 30 to 95 mol% C, more preferably 40 to 90 mol% C of 1,2-propylene glycol based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (III):

[0205]

[0206] (III);

[0207] The subscript α refers to the weight, molar mass and carbon number of one or more of the sugar and sugar alcohol.

[0208] 40. The method of any one of embodiments 1 to 39, wherein the method is a continuous method.

[0209] 41. The method of any one of embodiments 1 to 40, wherein the method is operated in a trickle bed reactor.

[0210] 42. A method for preparing a catalyst, preferably a catalyst for use in the method of any one of embodiments 1 to 41, comprising

[0211] (a) preparing a first mixture comprising zirconium oxide and water;

[0212] (b) preparing a second mixture comprising a nickel precursor selected from the group consisting of nickel nitrate, nickel halide, nickel acetate, nickel sulfate, and optionally a copper precursor and water, the nickel precursor selected from the group consisting of copper nitrate, copper halide, copper acetate, copper sulfate, copper amine complex, including combinations of two or more thereof;

[0213] (c) mixing the first mixture obtained in (a), the second mixture obtained in (b), and a precipitant to obtain a slurry comprising solids and water;

[0214] (d) removing water from the slurry obtained in (c) to obtain a solid;

[0215] (e) optionally, drying the solid obtained in (d) at a temperature in the range of 80°C to 150°C to obtain a dried solid;

[0216] (f) calcining the solid obtained in (d), preferably the dried solid obtained in (e), at a temperature in the range of 300° C. to 700° C., to obtain a catalyst comprising nickel oxide and zirconium oxide, wherein 5 to 60 wt.-% of the catalyst, preferably the catalyst for use in the process according to any one of embodiments 1 to 41, consists of zirconium oxide (calculated as ZrO ).

[0217] 43. The method of embodiment 42, wherein (a) comprises

[0218] (a.1) preparing a solution comprising a zirconium precursor and water, wherein the zirconium precursor is selected from the group consisting of zirconium nitrate, zirconium halide, zirconium oxyhalide, zirconium acetate, zirconium sulfate, and combinations of two or more thereof;

[0219] (a.2) mixing the solution prepared in (a.1) with a precipitant to obtain a suspension;

[0220] (a.3) removing water from the suspension obtained in (a.3) to obtain a solid;

[0221] (a.4) optionally, drying the solid obtained in (a.4) at a temperature in the range of 80°C to 150°C to obtain a dried solid;

[0222] (a.5) calcining the solid obtained in (a.3), preferably the dried solid obtained in (a.4), at a temperature in the range of 400° C. to 800° C. to obtain zirconium oxide.

[0223] 44. The method of embodiment 42 or 43, wherein the zirconium oxide has a crystallinity in the range of 60% to 100%, preferably 80% to 100%, more preferably 90% to 100%, based on the total zirconium oxide, as determined by a powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by a powder X-ray diffraction pattern of the zirconium oxide according to the formula:

[0224]

[0225] Among them A i corresponds to the signal area attributable to the crystalline sample component, and A j The area corresponding to the signal attributable to the X-ray amorphous sample component, more preferably as determined from the powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1.

[0226] 45. The method of any one of embodiments 42 to 44, wherein the powder X-ray diffraction pattern of the zirconium oxide shows signal peaks in the ranges of 28° to 29° and 31° to 32° 2θ angles, preferably the signal peaks indicate that the crystalline zirconium oxide is in a monoclinic phase, more preferably the difference between the maximum signal intensity and the baseline signal intensity in the ranges of 28° to 29° and 31° to 32° 2θ angles is greater than the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles, more preferably the difference between the maximum signal intensity and the baseline signal intensity in the range of 28° to 29° 2θ angles is at least two times the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles, more preferably the difference between the maximum signal intensity and the baseline signal intensity in the range of 28° to 29° 2θ angles is at least four times the difference between the maximum signal intensity and the baseline signal intensity in the range of 29.5° to 31° 2θ angles.

[0227] 46. ​​The method of any one of embodiments 42 to 45, wherein the zirconium oxide comprises a monoclinic phase and optionally a tetragonal phase, preferably wherein the zirconium oxide comprises a monoclinic phase in an amount of 50 to 100 wt.-% and a tetragonal phase in an amount of 0 to 50 wt.-%, based on 100 wt.-% of all crystalline phases in the zirconium oxide, as determined by a powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by a powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1; preferably wherein the zirconium oxide comprises a monoclinic phase in an amount of 70 to 100 wt.-% and a tetragonal phase in an amount of 0 to 30 wt.-%, based on 100 wt.-% of all crystalline phases in the zirconium oxide. % of the tetragonal phase in an amount of 0 to 10 wt.-%, as determined by the powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by the powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1; more preferably wherein, based on 100 wt.-% of all crystalline phases in the zirconium oxide, the zirconium oxide comprises the monoclinic phase in an amount of 80 to 100 wt.-% and the tetragonal phase in an amount of 0 to 20 wt.-%, as determined by the powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by the powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1; more preferably wherein, based on 100 wt.-% of all crystalline phases in the zirconium oxide, the zirconium oxide comprises the monoclinic phase in an amount of 90 to 100 wt.-% and the tetragonal phase in an amount of 0 to 10 wt.-%, as determined by the powder X-ray diffraction pattern of the zirconium oxide, preferably as determined by the powder X-ray diffraction pattern of the zirconium oxide according to Example 1-1.

[0228] 47. The method of any one of embodiments 42 to 46, wherein in (c) and / or (a.3), the precipitating agent is selected from the group consisting of sodium carbonate, sodium hydroxide, ammonia, and ammonium hydroxide, including combinations of two or more thereof.

[0229] The present invention is further illustrated by the following second group of embodiments and the combination of the embodiments resulting from the dependencies and back-references as shown. The second group of embodiments can be combined with any of the first group of embodiments above and the third group of embodiments below. In particular, it should be noted that in each case where a series of embodiments is mentioned, for example in the context of a term such as "as described in any one of embodiments 1' to 4'...", each embodiment in this series is intended to be clearly disclosed to the skilled person, i.e. the wording of this term should be understood by the skilled person as being synonymous with "as described in any one of embodiments 1', 2', 3' and 4'...". In addition, it is explicitly pointed out that the following group of embodiments is not a group of claims determining the scope of protection, but rather represents an appropriate structural part of this specification relating to the general and preferred aspects of the invention.

[0230] 1 '. A method for preparing one or more of a diol and a triol each having two or three carbon atoms, the method comprising

[0231] (i) providing a liquid aqueous feed stream comprising one or more of sugars and sugar alcohols each having five or six carbon atoms;

[0232] (ii) feeding the liquid aqueous feed stream provided according to (i) to a reaction zone comprising a catalyst comprising nickel, and subjecting the feed stream to reaction conditions in the reaction zone to obtain a reaction mixture comprising one or more of a diol and a triol;

[0233] (iii) removing a liquid aqueous effluent stream comprising one or more of a diol and a triol from the reaction zone;

[0234] wherein the catalyst comprises zirconium oxide, wherein 5 to 50 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2), and wherein 0 to 15 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3).

[0235] 2'. The method of embodiment 1', wherein the catalyst further comprises a metal oxide, wherein the metal of the metal oxide is preferably selected from the group consisting of Na, Mg, Si, K, Ca, Ti, Mn, Co, Cu, Zn, Nb, Mo, La, Hf, and W, including combinations of two or more thereof; more preferably selected from the group consisting of Na, Mg, Si, Ca, Ti, Mn, Cu, Mo, La, Hf, and W, including combinations of two or more thereof; more preferably selected from the group consisting of Si, Ca, Mn, Cu, and Mo, including combinations of two or more thereof; more preferably selected from the group consisting of Si, Cu, and Mo, including combinations thereof; wherein more preferably the catalyst further comprises a metal oxide selected from the group consisting of SiO2, CuO, and MoO x (wherein x is 1 to 3), including mixtures thereof.

[0236] 3'. The method according to embodiment 1' or 2', wherein 0 to 10 wt.-%, preferably 0 to 5.5 wt.-% of the catalyst consists of alumina (calculated as Al2O3).

[0237] 4'. The method according to any one of embodiments 1' to 3', wherein 40 to 90 wt.-%, preferably 60 to 85 wt.-% of the catalyst consists of nickel (calculated as NiO).

[0238] 5'. The method according to any one of embodiments 1' to 4', wherein 0.1 to 5.5 wt.-%, preferably 2 to 5.5 wt.-%, more preferably 3 to 5 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3).

[0239] 6'. The method of any one of embodiments 1' to 5', wherein 65 to 75 wt.-% of the catalyst consists of nickel (calculated as NiO), 5 to 7 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2), and 3 to 5 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3).

[0240] 7'. The method of any one of embodiments 1' to 6', wherein 65 to 75 wt.-% of the catalyst consists of nickel (calculated as NiO), 5 to 7 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2), 3 to 5 wt.-% of the catalyst consists of aluminum oxide (calculated as Al2O3), and 15 to 25 wt.-% of the catalyst consists of silicon oxide (calculated as SiO2).

[0241] 8'. The method according to any one of embodiments 1' to 4', wherein 40 to 90 wt.-%, preferably 60 to 85 wt.-% of the catalyst consists of nickel and copper (calculated as NiO and CuO).

[0242] 9'. The method of any one of embodiments 1' to 4' or 8', wherein the catalyst is substantially free of alumina, preferably substantially free of Al2O3.

[0243] 10'. The method of any one of embodiments 1' to 4', 8' or 9', wherein 40 to 60 wt.-% of the catalyst consists of nickel (calculated as NiO), 10 to 30 wt.-% of the catalyst consists of copper (calculated as CuO), and 20 to 40 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2).

[0244] 11'. The method of any one of embodiments 1' to 4', 8', 9' or 10', wherein 40 to 60 wt.-% of the catalyst consists of nickel (calculated as NiO), 10 to 30 wt.-% of the catalyst consists of copper (calculated as CuO), 20 to 40 wt.-% of the catalyst consists of zirconium oxide (calculated as ZrO2), and 0.1 to 5 wt.-% of the catalyst consists of molybdenum oxide (calculated as MoO3).

[0245] 12'. A method as described in any one of Examples 1' to 11', wherein the zirconium oxide comprises one or more crystalline phases and / or is amorphous, wherein the one or more crystalline phases of zirconium oxide are selected from the group consisting of: monoclinic, tetragonal and cubic phases of zirconium oxide, including mixtures of two or three thereof.

[0246] 13'. The method of any one of embodiments 1' to 12', wherein the catalyst is substantially free of CrO3 and / or Cr2O3, preferably substantially free of CrO3 and Cr2O3.

[0247] 14'. The method of any one of embodiments 1' to 13', wherein the catalyst is in the form of a molding and / or in powder form, preferably in the form of a molding, more preferably in the form of an extrudate and / or tablet, and more preferably in the form of a cylindrical tablet.

[0248] 15'. The method of embodiment 14', wherein the cylindrical tablet has a diameter x height in the range of 1 x 1 to 10 x 10 mm, preferably 2 x 2 to 7 x 7 mm, more preferably 2.5 x 2.5 to 6 x 6 mm.

[0249] 16'. The method of any one of embodiments 1' to 15', wherein one or more of the sugars having five carbon atoms is selected from the group consisting of ribose, arabinose, xylose, and lyxose, including combinations of two or more thereof.

[0250] 17'. The method of any one of embodiments 1' to 16', wherein one or more of the sugars having six carbon atoms is preferably selected from the group consisting of glucose, galactose, maltose, lactose, sucrose, allose, altrose, mannose, gulose, idose, talose, and combinations of two or more thereof.

[0251] 18'. The method of any one of embodiments 1' to 17', wherein one or more of the sugar alcohols having five carbon atoms is selected from the group consisting of arabitol, ribitol, and xylitol, including combinations of two or more thereof; more preferably, the sugar alcohols having six carbon atoms include xylitol.

[0252] 19'. The method of any one of embodiments 1' to 18', wherein one or more of the sugar alcohols having six carbon atoms is selected from the group consisting of mannitol, iditol, galactitol, and sorbitol, including combinations of two or more thereof; more preferably, the sugar alcohol having six carbon atoms includes sorbitol.

[0253] 20'. A method as described in any one of Examples 1' to 19', wherein one or more of the diols and triols each having two or three carbon atoms is selected from the group consisting of 1,2-propylene glycol, ethylene glycol, 1,3-propylene glycol and glycerol, including combinations of two or more thereof; preferably, one or more of the diols and triols each having two or three carbon atoms is selected from the group consisting of 1,2-propylene glycol, ethylene glycol and glycerol, including combinations of two or more thereof.

[0254] 21'. The method of any one of embodiments 1' to 20', wherein the diol having two carbon atoms comprises ethylene glycol.

[0255] 22'. The method of any one of embodiments 1' to 21', wherein the diol having three carbon atoms comprises 1,2-propylene glycol.

[0256] 23'. The method of any one of embodiments 1' to 22', wherein the triol having three carbon atoms comprises glycerol.

[0257] 24'. The method of any one of embodiments 1' to 23', wherein the liquid aqueous feed stream prepared in (ii) comprises 20 to 60 wt.-%, preferably 25 to 50 wt.-%, more preferably 25 to 40 wt.-% of sugars or sugar alcohols each having five or six carbon atoms.

[0258] 25'. The method of any one of embodiments 1' to 24', wherein the liquid aqueous feed stream provided in (i) further comprises a solvent, preferably a solvent comprising a monohydric alcohol, more preferably the monohydric alcohol is selected from the group consisting of methanol, ethanol, 1-propanol, 2-propanol and 1-butanol.

[0259] 26'. The method of any one of embodiments 1' to 25', wherein the liquid aqueous feed stream provided in (i) further comprises a compound selected from the group consisting of a base, a Lewis acid, and a combination thereof, preferably a base.

[0260] 27'. A method as described in Example 26', wherein in (i), the base is selected from the group consisting of metal hydroxides, wherein the metal of the metal hydroxide is preferably selected from the group consisting of Li, Na, K, Ca, and Mg, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides selected from the group consisting of LiOH, NaOH, KOH, Ca(OH)2, and Mg(OH)2, including mixtures of two or more thereof; preferably selected from the group consisting of NaOH, KOH, Ca(OH)2, and Mg(OH)2, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides selected from the group consisting of NaOH and KOH, including combinations of two of them; more preferably the base comprises NaOH.

[0261] 28'. The method of embodiment 26' or 27', wherein the liquid aqueous feed stream provided in (i) comprises 0.1 to 8 wt.-%, preferably 0.3 to 7 wt.-%, more preferably 4 to 6 wt.-% of the base.

[0262] 29'. The method of embodiment 26', wherein in (i), the acid is selected from the group consisting of phosphoric acid and sulfuric acid, including combinations thereof.

[0263] 30'. A method as described in Example 26', wherein in (i), the Lewis acid is selected from the group consisting of metal polyacids, wherein the metal of the metal polyacid is preferably selected from the group consisting of Mo and W, including combinations of two or more thereof; wherein more preferably the Lewis acid includes one or more metal polyacids selected from the group consisting of H2WO4 and (NH4)2MoO2, including combinations thereof.

[0264] 31'. The method of any one of embodiments 1' to 30', wherein the reaction conditions according to (ii) comprise a reaction pressure in the range of 40 to 170 bar, preferably 60 to 150 bar and more preferably 80 to 120 bar.

[0265] 32'. The method of any one of embodiments 1' to 31', wherein the reaction conditions according to (ii) comprise a temperature in the range of 140°C to 210°C, preferably 170°C to 200°C.

[0266] 33 '. The method of any one of embodiments 1 'to 32 ', wherein the reaction conditions according to (ii) comprise 0.1 to 5 h -1 , preferably 0.2 to 5 h -1 Liquid hourly space velocity within the range of .

[0267] 34'. The method of any one of embodiments 1' to 33', wherein the liquid aqueous feed stream provided in (i) and fed to the reaction zone in (ii) further comprises H2.

[0268] 35'. A method as described in embodiment 34', wherein the liquid aqueous feed stream exhibits a H2:sugar or sugar alcohol molar ratio of H2 to sugar or sugar alcohol in the range of 1 to 8, preferably 1.5 to 7, more preferably 1.8 to 7.

[0269] 36'. The method of any one of embodiments 1' to 35', wherein the liquid aqueous effluent stream removed in (iii) comprises 10 to 95 mol% C, preferably 15 to 90 mol% C, more preferably 20 to 85 mol% C, more preferably 25 to 80 mol% C of one or more diols and triols, each having two or three carbon atoms, based on 100 mol% C of one or more sugars and sugar alcohols, each having five or six carbon atoms, wherein mol% C is defined according to equation (I):

[0270]

[0271] (I);

[0272] Wherein the subscript n refers to the weight, molar mass, and carbon number of 1,2-propylene glycol, glycerol, and ethylene glycol, respectively. The subscript α refers to the weight, molar mass, and carbon number of one or more of the sugars and sugar alcohols.

[0273] 37'. The method of any one of embodiments 1' to 36', wherein the liquid aqueous effluent stream removed in (iii) comprises 10 to 95 mol% C, preferably 15 to 90 mol% C, more preferably 20 to 85 mol% C, more preferably 25 to 80 mol% C of 1,2-propylene glycol, glycerol, and ethylene glycol, based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (II):

[0274]

[0275] (II);

[0276] Wherein, subscripts 1-3 refer to the weight, molar mass, and carbon number of 1,2-propylene glycol, glycerol, and ethylene glycol, respectively. Subscript α refers to the weight, molar mass, and carbon number of one or more of sugars and sugar alcohols.

[0277] 38'. The method of any one of embodiments 1' to 37', wherein the liquid aqueous effluent stream removed in (iii) comprises 10 to 80 mol% C, preferably 15 to 75 mol% C, more preferably 20 to 70 mol% C, more preferably 25 to 65 mol% C of 1,2-propylene glycol, based on 100 mol% C of one or more of sugars and sugar alcohols each having five or six carbon atoms, wherein mol% C is defined according to equation (III):

[0278]

[0279] (III);

[0280] The subscript α refers to the weight, molar mass and carbon number of one or more of the sugar and sugar alcohol.

[0281] 39'. The method of any one of embodiments 1' to 38', wherein the method is a continuous method.

[0282] 40'. The method of any one of embodiments 1' to 39', wherein the method is operated in a trickle bed reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0283] The term "bar" as used in the context of the present invention refers to "abs", ie bara (absolute value), sometimes also referred to as "bara".

[0284] Figure 1 Schematic representation of the X-ray diffraction pattern of the ZrO2 powder synthesized in Example 1-1. The labels in the figure indicate the locations of diffraction signals reported in database references for specific zirconium dioxide crystal phases. The references are taken from the Powder Diffraction File Database and identified by the PDF number (XX-XXX-XXXX) in the figure legend. Matching the recorded signal positions with those in the references reveals the qualitative phase composition of the zirconium dioxide powder of Example 1-1.

[0285] Figure 2 : Schematic diagram of the X-ray diffraction pattern of catalyst A-1 as synthesized in Example 2-1 before use and after operation according to Example 3-1. Figure 1 / Qualitative evaluation was performed by matching the reference pattern in the same manner as in Example 1-1.

[0286] Figure 3 : Schematic diagram of the X-ray diffraction pattern of catalyst B as synthesized in Comparative Example 1-1 before use and after use in Comparative Example 2-1. Figure 1 / Qualitative evaluation was performed by matching the reference pattern in the same manner as in Example 1-1.

[0287] Experimental part

[0288] The present invention is further illustrated by the following examples and comparative examples.

[0289] Example 1-1: Synthesis of support material for catalyst A-1

[0290] Zirconia (ZrO2) powder was prepared through a series of precipitation, washing, drying, and calcination steps. A Zr(NO3)4 solution (10.7 wt.% Zr) was used as the starting material. A 25 wt.% NH3 solution was used as the precipitant.

[0291] A mixing vessel was filled with one part (by weight) deionized water and one part 25 wt.% NH3 solution. No heating was applied, and the mixture temperature was < 40°C. Subsequently, two parts (by weight) of Zr(NO3)4 solution were added continuously to the stirred vessel over a 25-minute period. After the addition of the nitrate, the pH of the mixture was measured using a glass electrode. If necessary, the pH was adjusted to 7.5 using nitric acid. The contents of the mixing vessel were heated to 85°C and stirred for an additional 6 hours.

[0292] The resulting suspension was filtered, and the filter cake was washed with deionized water until the conductivity of the filtrate was less than 200 μS / cm, as measured using a WTW Cond 330i device equipped with a TetraCon 325 probe. The filter cake was then dried in a drying oven at 120° C. The precursor obtained in this way was calcined at 520° C. in flowing air for a period of 1 hour to obtain the final zirconium oxide powder.

[0293] The zirconium oxide powder obtained as described above was subjected to powder X-ray diffraction (PXRD) for characterization. Data were collected using a diffractometer (D8 Advance II series, Bruker AXS GmbH) equipped with a LYNXEYE detector operated at 40 kV and 40 mA using a copper anode X-ray tube. Bragg-Brentano geometry was used, and air scattering was reduced using an air scattering shield. Prior to measurement, the sample was ground using an IKA TubeMill at 20,000 rpm for 2 minutes with 30-second intervals. The sample was homogenized in a mortar and then pressed into a standard flat sample holder provided by Bruker AXS for Bragg-Brentano geometry data collection. The sample powder was compressed and flattened using a glass plate to achieve a flat sample surface. Data were collected from an angular range of 10° to 70° 2θ in steps of 0.02° 2θ, with a variable divergence slit set to a fixed angle of 0.3°.

[0294] The recorded diffraction patterns are shown in Figure 1 Comparison of the signal positions with database references and consideration of the relative signal intensities revealed the dominant contribution of the monoclinic phase to the overall diffraction pattern.

[0295] The crystallinity and crystalline phase composition (w cryst. ) and crystallite size (CS). The background intensity, the crystal structure of the identified phase, and the instrument parameters were taken into account in the regression analysis of the recorded PXRD patterns. The background was simulated using first-order Chebychev coefficients. The degree of crystallinity was defined as the percentage of the signal area occupied by the crystalline phase after background subtraction:

[0296]

[0297] Among them, A i corresponds to the signal area attributable to the crystalline sample component, and A jCorresponds to the signal area attributable to the X-ray amorphous sample component.

[0298] According to the evaluation, the ZrO2 powder of original state after synthesis shows 100% total crystallinity.Do not need amorphous phase to represent experimental PXRD pattern.Find that 91 wt.% crystallization ZrO2 in the sample has been crystallized with monoclinic phase, and 9 wt.% is present in tetragonal phase.Therefore, this sample illustrates the crystallization ZrO2 mainly by monoclinic phase composition.

[0299] Example 2-1: Synthesis of Catalyst A-1

[0300] A catalyst powder nominally containing 52 wt.% NiO, 17 wt.% CuO, and 31 wt.% ZrO2 was prepared through a series of precipitation, washing, drying, and calcination steps. Nickel nitrate (Ni(NO3)2), copper nitrate (Cu(NO3)2), and zirconium oxide (ZrO2) powders from Example 1-1 were used as starting materials. Sodium carbonate (Na2CO3) was used as a precipitant. Nitrates and carbonates were used as aqueous solutions with predefined concentrations. The amounts consumed were based on the above catalyst composition and the amount of ZrO2.

[0301] Nickel nitrate (14.2 wt.% Ni) and copper nitrate (15.6 wt.% Cu) solutions were mixed to form a metal precursor solution. A mixing vessel was filled with 1.5 L of deionized water and 156 g of the zirconium oxide powder from Example 1-1 was added. The vessel was heated to 65°C. Subsequently, the metal precursor solution was continuously added to the mixing vessel over a period of 1 hour. 20 wt.% sodium carbonate solution was co-added in such a manner that the pH measured with a glass electrode was maintained at 6.2. After the addition of the metal precursor solution was complete, the pH was adjusted to 7.7 using sodium carbonate solution. The vessel contents were stirred at a constant temperature for an additional 1.5 hours.

[0302] The resulting suspension was filtered and the filter cake was washed with deionized water until the conductivity of the filtrate was less than 200 μS / cm, as measured using a WTW Cond 330i device equipped with a TetraCon 325 probe. The filter cake was then dried in a drying cabinet at a temperature of 120° C. The hydroxide-carbonate mixture obtained in this way was calcined at a temperature of 520° C. in flowing air over a period of 1 hour to obtain the stated oxide composition.

[0303] The catalyst powder was mixed with 3% by weight of graphite and formed into cylindrical tablets measuring 3 x 3 mm (diameter x height) by compression. The tablets were calcined at 500°C in flowing air for 1 hour. Prior to use, the catalyst tablets were reduced at 280°C in a flowing gas mixture containing 50 vol.% H2 and 50 vol.% N2 for 2 hours, followed by air cooling and passivation at ambient temperature.

[0304] Example 3-1: Hydrogenolysis of Sorbitol Using Catalyst A-1

[0305] The conversion using Catalyst A was carried out in a fixed-bed reactor (10 mL). After loading the catalyst, a standard reduction procedure was employed. To this end, the reactor containing the catalyst was heated to 120°C under an N2 atmosphere (120 nL / h). After reaching this temperature, the N2 feed was stopped and H2 (50 nL / h) was added for one hour. The temperature was then raised to 200°C and maintained for an additional four hours. Following this procedure, the reactor was cooled to room temperature under N2.

[0306] After catalyst reduction, a feed consisting of 40 wt.-% sorbitol and 5 wt.-% NaOH was heated at 110 bar and 200 °C with LHSV = 2.9 h -1 Pumped through the reactor. Details are presented in Table 1-1.

[0307] The yield of diols is plotted as mol% C, which describes the molar conversion of the C atoms of the starting material (e.g., sorbitol) to the desired diols (1,2-propylene glycol (1,2-PDO), ethylene glycol (EG), and glycerol (GLY). The yield is calculated according to the general equation (IV):

[0308]

[0309] The following equation gives an example of the mol% C of 1,2-PDO in Experiment 7 in Table 1-1.

[0310]

[0311] Table 1-1: Conversion test of sorbitol using catalyst A-1.

[0312]

[0313] Example 4-1: Analysis of original catalyst and spent catalyst A-1

[0314] Catalyst A-1 was analyzed before use (as synthesized according to Example 2-1) and after operation (sorbitol hydrogenolysis according to Example 3-1).

[0315] The radial side crushing strength (SCS) of individual tablets was used as a descriptor of mechanical stability. Analysis was performed on a commercial Sotax ST50 system operated in "constant velocity" mode. For each measurement, a cylindrical catalyst tablet was positioned between a fixed support and a moving piston (approaching at 0.35 mm / s). The force required to press the piston forward until the catalyst tablet broke was monitored, and the maximum force in Newtons was recorded as the tablet's SCS value. This measurement was repeated for 20 individual tablets per catalyst type, and the resulting values ​​were calculated as the arithmetic mean.

[0316]

[0317] Chemical stability was tested by elemental analysis. The metal content of an aliquot of the ground catalyst was determined by ICP-OES (inductively coupled plasma optical emission spectrometry). A mixture of H2SO4, HNO3, and HClO4 was used for sample digestion. After evaporating the digested solution to dryness, the solid residue was redissolved in dilute HCl (10 vol.%). The resulting solution was analyzed on an Agilent 5100 spectrometer. Results were quantified after blank subtraction and using external calibration. Results are given as element ratios. This is to exclude the influence of absolute mass changes from catalyst reduction and organic adsorption.

[0318] Table 2-1: Analysis results of the mechanical and chemical stability of catalyst A-1 synthesized in Example 2-1.

[0319]

[0320] Overall, no significant changes were observed in the mechanical properties of the catalyst tablets, demonstrating the high mechanical stability of the catalyst material described herein. Furthermore, the results of the chemical analysis indicated that there was no or very limited dissolution of the catalyst components, which would have altered the determined metal ratios. Thus, the proposed material possesses high chemical stability, making it suitable for use in hydrothermal operating conditions and with alkaline additives in the feed mixture.

[0321] Table 3-1: Analysis results of the phase composition of the catalyst A-1 synthesized in Example 2-1 determined by powder X-ray diffraction.

[0322]

[0323] *While a NiCu alloy was used for the representative fit of the recorded diffraction patterns, contributions from metallic Ni and Cu will also be applicable to describe the sample.

[0324] Catalyst A-1 as synthesized and after use in Example 3-1 were characterized by PXRD according to the method described in Example 1-1. Figure 2 The corresponding powder X-ray diffraction patterns are given in Figure 2. Qualitative analysis of the signal positions and intensities, compared to the reference, shows that the monoclinic phase of zirconium oxide is dominant in both samples. The contributions from amorphous material and tetragonal ZrO2 are negligible. Quantitative evaluation of the diffraction patterns does not show the crystalline phase composition (w cryst. ) or crystallite size (CS), highlighting the discussed favorable stability characteristics of Catalyst A-1 (Table 3-1).

[0325] Comparative Example 1-1: Synthesis of Catalyst B-1

[0326] Catalyst powders nominally containing 51 wt.% NiO, 17 wt.% CuO, 1.5 wt.% MoO3, and 30.5 wt.% ZrO2 were prepared by a series of precipitation, washing, drying, and calcination steps. Nickel nitrate (Ni(NO3)2), ammonium heptamolybdate ((NH4)6Mo7O 24 ), copper nitrate (Cu(NO₃)₂), and zirconium acetate (Zr(C₂H₃O₂)₄) as starting materials. Sodium carbonate (Na₂CO₃) was used as a precipitant. The corresponding amounts used were derived from the catalyst composition and concentration levels given above.

[0327] Nickel nitrate, copper nitrate, and zirconium acetate solutions were mixed with deionized water to obtain a solution having the following metal contents: 7.0 wt.% Ni, 2.4 wt.% Cu, and 4.1 wt.% Zr. The mixed solution was continuously added to a mixing vessel over a 2-hour period. 20 wt.% sodium carbonate solution was co-added such that the pH measured with a glass electrode remained at 6.2. The temperature of the vessel was controlled at 65°C. After the addition of the metal precursor solutions was complete, the pH was adjusted to 7.7 using sodium carbonate solution. The vessel contents were stirred at a constant temperature for an additional 1.5 hours.

[0328] The resulting suspension was filtered and the filter cake washed with deionized water until the conductivity of the filtrate was below 200 μS / cm, as measured using a WTW Cond 330i device equipped with a TetraCon 325 probe. The still moist filter cake was mixed with solid ammonium heptamolybdate. The filter cake was then dried in a drying oven at a temperature of 120° C. The hydroxide-carbonate mixture obtained in this way was calcined at a temperature of 520° C. in flowing air over a period of 1 hour to obtain the stated oxide composition.

[0329] The catalyst powder was mixed with 3% by weight of graphite and compressed into cylindrical tablets measuring 3 x 3 mm (diameter x height). The tablets were calcined at 500°C in flowing air for 1 hour. Prior to use, the catalyst tablets were reduced at 280°C in a flowing gas mixture containing 50 vol.% H2 and 50 vol.% N2 for 2 hours, followed by air cooling and passivation at ambient temperature.

[0330] Comparative Example 2-1: Hydrogenolysis of Sorbitol Using Catalyst B-1

[0331] The conversion using catalyst B-1 was carried out in a fixed-bed reactor (10 mL). After loading the catalyst, a standard reduction procedure was employed. To this end, the reactor containing the catalyst was heated to 120°C under an N2 atmosphere (120 nL / h). After reaching this temperature, the N2 feed was stopped and H2 (50 nL / h) was added for one hour. The temperature was then raised to 200°C and maintained for an additional four hours. Following this procedure, the reactor was cooled to room temperature under N2.

[0332] After catalyst reduction, a feed consisting of 40 wt.-% sorbitol and 5 wt.-% NaOH was heated at 110 bar and 200 °C with LHSV = 2.9 h -1 Pumped through the reactor. Details are presented in Table 3-1.

[0333] The yield of diols is plotted as mol% C, which describes the molar conversion of the C atoms of the starting material (e.g., sorbitol) to the desired diols (1,2-propylene glycol (1,2-PDO), ethylene glycol (EG), and glycerol (GLY). The yield is calculated according to the general equation (IV):

[0334]

[0335] The following equation gives an example of the mol% C of 1,2-PDO in Experiment 4 in Table 3-1.

[0336]

[0337] Table 4-1: Conversion test of sorbitol using catalyst B-1.

[0338]

[0339] Comparative Example 3-1: Analysis of Original Catalyst and Spent Catalyst B-1

[0340] Catalyst B-1 was analyzed before use (as synthesized according to Comparative Example 1-1) and after operation (sorbitol hydrogenolysis according to Comparative Example 2-1). The methods used were the same as those used in Example 4-1. The only exception was that the contribution of tetragonal ZrO2 to the diffraction pattern of Catalyst B-1 could not be modeled using a defined crystalline phase. Therefore, regression analysis accounted for the contribution from the amorphous ZrO2 that replaced it. The ZrO2 in Catalyst B-1 could not be modeled as a crystalline phase, likely due to the presence of small crystallites with insufficient long-range order.

[0341] Table 5-1: Analysis results of the mechanical and chemical stability of the catalyst B-1 synthesized according to Comparative Example 1-1.

[0342]

[0343] Compared to Example 4-1, the results show evidence of Catalyst B's lack of mechanical and chemical catalyst stability. The mechanical stability of the catalyst tablets was severely reduced after testing, which could lead to fines formation, increased pressure drop, or even reactor plugging in commercial operations. Elemental analysis showed a clear decrease in the Zr / Ni weight ratio of the spent catalyst. Therefore, the zirconium oxide support included in Catalyst B-1 may be chemically unstable and leaching may occur. This material is unsuitable for use under the reaction conditions tested.

[0344] Table 6-1: Analysis results of the phase composition of the comparative catalyst B-1 synthesized in Comparative Example 1-1 determined by X-ray diffraction.

[0345]

[0346]

[0347] The X-ray diffraction patterns of the catalyst B-1 as synthesized and the catalyst B-1 used in Comparative Example 2-1 are Figure 3 . It is noteworthy that no crystalline monoclinic ZrO2 was observed in these experiments, as can be inferred from the lack of corresponding signal peaks in the recorded PXRD patterns. Instead, the zirconia support was amorphous before use. After use, a defined tetragonal zirconia phase formed, demonstrating a strong change in the material that may be responsible for the unfavorable stability characteristics of catalyst B-1.

[0348] The PXRD pattern of Catalyst B-1 after use in Comparative Example 2-1 also showed evidence of SiC inert material, which could not be completely separated from the catalyst due to the decomposition of most of the tablets in the catalyst bed. Therefore, a quantitative evaluation is only given for Catalyst B-1 in its as-synthesized state. The crystallinity of the as-synthesized samples of Catalyst B-1 was generally lower than that of Catalyst A-1, highlighting the presence of X-ray amorphous material in Catalyst B-1. In addition, the contribution of ZrO2 to the crystalline phase composition of Catalyst B-1 was negligible. The grain size determined for Catalyst B-1 was lower than that determined for Catalyst A-1.

[0349] Overall, the low crystallinity and the absence of crystalline ZrO2 in the monoclinic phase indicate that Catalyst B-1 lacks stability.

[0350] Example 1: Synthesis of Catalyst A

[0351] A catalyst powder containing 71.0 wt.% NiO, 6.0 wt.% ZrO2, 4.3 wt.% Al2O3, and 18.7 wt.% SiO2 was prepared through a series of precipitation, washing, drying, and annealing steps. Nickel nitrate (Ni(NO3)2), zirconium nitrate (Zr(NO3)4), sodium aluminate (NaAlO2), and diatomaceous earth (amorphous SiO2) were used as starting materials. Sodium carbonate (Na2CO3) was used as a precipitant. The corresponding amounts used were derived from the catalyst composition and concentration levels given above.

[0352] First, a 1.8 wt.% sodium aluminate solution was prepared in a mixing vessel. Then, one weight equivalent of a 20 wt.% sodium carbonate solution was added. The mixture was heated to 95°C, followed by the addition of diatomaceous earth. A second amount of 20 wt.% sodium carbonate solution, equivalent to the first addition, was added to the mixing vessel. Then, a zirconium nitrate solution (10.8 wt.% Zr content) was added over a period of 0.5 hours. The pH measured with a glass electrode was 9.7. Precipitation was completed by continuously adding a nickel nitrate solution (13.5 wt.% Ni content) over a period of 1.5 hours, resulting in a decrease in the pH. After the additions were completed, the pH measured with a glass electrode was 8.3.

[0353] The resulting suspension was filtered and the filter cake was washed with deionized water until the conductivity of the filtrate was less than 200 μS / cm, as measured using a WTW Cond 330i device equipped with a TetraCon 325 probe. The filter cake was then dried at 100° C. in a drying oven or spray dryer. The hydroxide-carbonate mixture obtained in this way was annealed at 500° C. in flowing air for a period of 4 hours to give the stated oxide composition.

[0354] The catalyst powder was mixed with 4% by weight of graphite and formed into 3 × 3 mm (diameter × height) cylindrical tablets by compression. Prior to use, the catalyst tablets were dried at 350°C in flowing nitrogen for 2 hours and reduced at 450°C in a flowing gas mixture containing 50 vol.% H2 and 50 vol.% N2 for 12 hours, followed by air cooling and passivation at ambient temperature.

[0355] Example 2: Synthesis of Catalyst B

[0356] The catalyst powder containing 51 wt.% NiO, 17 wt.% CuO, 1.5 wt.% MoO3 and 30.5 wt.% ZrO2 was prepared by a series of precipitation, washing, drying and annealing steps. Nickel nitrate (Ni(NO3)2), ammonium heptamolybdate ((NH4)6Mo7O 24 ), copper nitrate (Cu(NO₃)₂), and zirconium acetate (Zr(C₂H₃O₂)₄) as starting materials. Sodium carbonate (Na₂CO₃) was used as a precipitant. The corresponding amounts used were derived from the catalyst composition and concentration levels given above.

[0357] Nickel nitrate, copper nitrate, and zirconium acetate solutions were mixed with deionized water to obtain a solution having the following metal contents: 7.0 wt.% Ni, 2.4 wt.% Cu, and 4.1 wt.% Zr. The mixed solution was continuously added to a mixing vessel over a period of 2 hours. 20 wt.% sodium carbonate solution was co-added such that the pH, measured with a glass electrode, was maintained at 6.2. The temperature of the vessel was controlled at 65°C.

[0358] The resulting suspension is filtered and the filter cake is washed with deionized water until the conductivity of the filtrate is less than 200 μS / cm, as measured using a WTW Cond 330i device equipped with a TetraCon 325 probe. The still moist filter cake is mixed with solid ammonium heptamolybdate. The filter cake is then dried at 100° C. in a drying oven or spray dryer. The hydroxide-carbonate mixture obtained in this way is annealed at 500° C. in flowing air over a period of 4 hours to give the stated oxide composition.

[0359] The catalyst powder was mixed with 3% by weight of graphite and formed into cylindrical tablets measuring 6 x 3 mm (diameter x height) by compression. The tablets were annealed at 500°C in flowing air for 4 hours. Prior to use, the catalyst tablets were reduced at 240°C in a flowing gas mixture containing 50 vol.% H2 and 50 vol.% N2 for 2 hours, followed by air cooling and passivation at ambient temperature.

[0360] Examples 3 and 4: Mechanical and chemical testing of the catalysts of Examples 1 and 2

[0361] The catalysts from Examples 1 and 2 were subjected to a catalyst stability test. For this purpose, 15 g of the reduced, air-stabilized catalyst was placed in the coaxial collector screen of a 300 mL stainless steel autoclave. The autoclave was filled with 180 g of an aqueous feed solution containing 25 wt.% sorbitol and 2 wt.% sodium hydroxide (NaOH). The sealed autoclave was heated to 200°C. H₂ gas was introduced with continuous stirring to a pressure of 110 bar. After 12 hours, the reaction was stopped, the reactor cooled, and the pressure was reduced. A sample of the spent catalyst was collected and dried.

[0362] The radial side crushing strength (SCS) of individual tablets was used as a descriptor of mechanical stability. Analysis was performed on a commercial Sotax ST50 system operated in "constant velocity" mode. For each measurement, a cylindrical catalyst tablet was positioned between a fixed support and a moving piston (approaching at 0.35 mm / s). The force required to press the piston forward until the catalyst tablet broke was monitored, and the maximum force in Newtons was recorded as the tablet's SCS value.

[0363] The measurement was repeated with 20 individual tablets per catalyst type, and the arithmetic mean of the values ​​obtained was formed.

[0364]

[0365] Wherein the subscript "spent catalyst" refers to the tablets that were subjected to the reaction conditions, recovered and dried. i indicates a counter variable (counter) for consecutive measurements of 20 individual tablets.

[0366] The same procedure and evaluation were performed on 20 catalyst tablets before use.

[0367]

[0368] Here, "fresh catalyst" refers to the reduced, air-stabilized tablets prior to being subjected to the reaction conditions.

[0369] The remaining mechanical stability after subjecting the catalyst to the reaction conditions was expressed as a percentage of the value of the fresh catalyst according to the following equation:

[0370]

[0371] The metal content of the solid-free reaction solutions from the above tests was measured by ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy). A mixture of H2SO4, HNO3, and HClO4 was used for sample digestion. After evaporating the digested solution to dryness, the solid residue was redissolved in dilute HCl (10 vol.%). The resulting solution was analyzed on an Agilent 5100 spectrometer. The results were quantified after subtracting the blank value and using an external calibration. All measurement results related to Examples 3 and 4 are given in Table 1.

[0372] Table 1: Mechanical and chemical stability of the catalysts of Examples 1 to 2.

[0373]

[0374]

[0375] The results of the test for dissolved nickel in the reaction solution indicate that the catalysts described in Examples 1 and 2 exhibit low chemical corrosion. The catalysts of Examples 1 and 2 also retained their tablet shape after being subjected to the test conditions. The relative decrease in SCS observed for the catalyst of Example 1 was offset by the high absolute SCS value of the spent catalyst. For the catalyst of Example 2, SCS was almost completely retained after the described tests. Thus, the catalysts of Examples 1 and 2 exhibit high stability with respect to corrosion and mechanical degradation under the conditions relevant to the present invention.

[0376] Comparative Example 1: Synthesis of Catalyst C

[0377] A catalyst powder containing 72.3 wt.% NiO, 8 wt.% ZrO2, 19.5 wt.% Al2O3, and 0.2 wt.% Na2O was prepared through a series of precipitation, washing, drying, and annealing steps. Nickel nitrate (Ni(NO3)2), zirconium oxide (ZrO2), and aluminum nitrate (Al(NO3)3)3) were used as starting materials. Sodium carbonate (Na2CO3) was used as the precipitant. The corresponding amounts used were derived from the catalyst composition and concentration levels given above.

[0378] First, deionized water and zirconium oxide powder were added to a mixing vessel to form a slurry containing 1.8 wt.% solids. In a separate vessel, nickel nitrate and aluminum nitrate solutions were mixed with deionized water to obtain a solution with the following concentrations, calculated based on the following metals: 7.0 wt.% Ni and 1.3 wt.% Al. The mixed solution was continuously added to the mixing vessel containing the zirconium oxide suspension over a period of 0.25 hours. 20 wt.% sodium carbonate solution was co-added in such a manner that the pH measured with a glass electrode was maintained at 8.1. The temperature of the vessel was controlled at 50°C.

[0379] The resulting suspension was filtered and the filter cake was washed with deionized water until the conductivity of the filtrate was less than 200 μS / cm, as measured using a WTW Cond 330i device equipped with a TetraCon 325 probe. The filter cake was then dried at 100° C. in a drying oven or spray dryer. The hydroxide-carbonate mixture obtained in this way was annealed at 500° C. in flowing air for a period of 4 hours to give the stated oxide composition.

[0380] The catalyst powder was mixed with 3% by weight of graphite and formed into cylindrical tablets measuring 5 x 3 mm (diameter x height) by compression. Prior to use, the catalyst tablets were annealed at 460°C in flowing air for 4 hours. Subsequent reduction was performed at 400°C in a flowing gas mixture containing 50 vol.% H2 and 50 vol.% N2 for 5 hours, followed by air cooling and passivation at ambient temperature.

[0381] Comparative Example 2: Synthesis of Catalyst D

[0382] A catalyst powder containing 58 wt.% CuO, 30 wt.% Al2O3, and 12 wt.% MnO2 was prepared through a series of precipitation, washing, drying, and annealing steps. Copper nitrate (Cu(NO3)2), sodium aluminate (NaAlO2), and manganese nitrate (Mn(NO3)2) were used as starting materials. Sodium carbonate (Na2CO3) was used as the precipitant. The corresponding amounts were derived from the catalyst composition and concentration levels given above.

[0383] Copper nitrate (15.5 wt.% Cu content), manganese nitrate (15 wt.% Mn content), and sodium aluminate solution (12.5 wt.% Al) were prepared according to the target catalyst composition. These solutions were continuously added to a mixing vessel containing deionized water equivalent to one-quarter the volume of the copper nitrate solution. A 20 wt.% sodium carbonate solution was co-added in such a manner that the pH measured with a glass electrode was maintained at 7.0. The vessel temperature was controlled at 25°C.

[0384] The resulting suspension was filtered and the filter cake was washed with deionized water until the conductivity of the filtrate was less than 200 μS / cm, as measured using a WTW Cond 330i device equipped with a TetraCon 325 probe. The filter cake was then dried at 100° C. in a drying oven or spray dryer. The hydroxide-carbonate mixture obtained in this way was annealed at 600° C. in flowing air for a period of 4 hours to give the stated oxide composition.

[0385] The catalyst powder was mixed with 3% by weight of graphite and compressed into granules in such a way as to achieve a specific bulk density equivalent to 40%-50% of the value of the corresponding tablet product. The granules were then compressed to form 3.2 x 3.2 mm (diameter x height) cylindrical tablets. The catalyst tablets were annealed at 750°C in flowing air for a period of 4 hours, resulting in a specific bulk density of 1.1 g / mL. Subsequent reduction was carried out at 220°C for 2 hours in a flowing gas mixture containing 50 vol.% H2 and 50 vol.% N2, followed by air cooling and passivation at ambient temperature.

[0386] Comparative Example 3: Synthesis of Catalyst E

[0387] The catalyst was prepared in the form of extrudates according to the procedure disclosed in Example 1 of WO 2020 / 117532 A1. The calcination temperature was selected to be 600°C. The resulting material contained 76.2 wt.% CuO, 13.6 wt.% SiO2, 5.9 wt.% CaO, 0.9 wt.% MnO2, and 3.4 wt.% Na2O. Prior to use, the catalyst tablets were reduced at 220°C in a flowing gas mixture containing 50 vol.% H2 and 50 vol.% N2 for 2 hours, then air-cooled and passivated at ambient temperature.

[0388] Comparative Examples 4 to 6: Mechanical and Chemical Testing of the Catalysts of Comparative Examples 1 to 3

[0389] The catalysts of Comparative Examples 1 to 3 were subjected to the catalyst stability test as described for Examples 3 and 4. For the catalysts of Comparative Examples 1 and 2, the radial side crushing strength (SCS) of a single tablet was used as a descriptor of mechanical stability. The measurement was performed as described in Examples 3 and 4.

[0390] The cut hardness (CH) of a single extrudate strand was used as a descriptor of the mechanical stability of the catalyst of Comparative Example 3. The analysis was performed on a Zwick BZ2.5 / TS1S system. For each single strand measurement, the catalyst extrudate was positioned between a fixed support and a 0.3 mm wide moving blade, which approached at a constant speed of 0.027 mm / s. The force required to push the blade forward was monitored until the strand broke, and the maximum force in Newtons was recorded as the SH value for that strand. Breakage was detected when the measured force was less than 30% of the maximum force currently tested.

[0391] The measurement was repeated with 20 individual batches for each catalyst type, and the arithmetic mean of the values ​​obtained was formed.

[0392]

[0393] wherein the subscript "spent catalyst" refers to the extrudate strand that was subjected to reaction conditions, recovered, and dried. i indicates a count variable where consecutive measurements were made on 20 individual strands.

[0394] The same procedure and evaluation were performed on 20 catalyst stocks before use.

[0395]

[0396] Here, "fresh catalyst" refers to the reduced, air-stabilized tablets prior to being subjected to the reaction conditions.

[0397] The remaining mechanical stability after subjecting the catalyst to the reaction conditions was expressed as a percentage of the value of the fresh catalyst according to the following equation:

[0398]

[0399] The metal content of the solid-free reaction solution from the above test was measured by ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy). The measurement details were the same as in Examples 3 and 4. The results of all measurements related to Comparative Examples 5 and 6 are given in Table 2.

[0400] Table 2: Mechanical and chemical stability of the catalysts of Comparative Examples 3 and 4.

[0401]

[0402]

[0403] a Measurements were not possible due to loss of tablet integrity

[0404] b not applicable

[0405] The results of the test for dissolved metals in the reaction solution showed that the catalyst described in Comparative Example 2 underwent chemical corrosion, but the catalysts of Comparative Examples 1 and 3 did not. However, the catalyst of Comparative Example 1 suffered a loss of tablet integrity under the test conditions. The catalysts of Comparative Examples 2 and 3 retained their shape after being subjected to the test conditions. However, the relative decrease in SCS or SH of the catalysts of Comparative Examples 2 and 3 was high compared to the catalysts of Examples 1 and 2. The remaining absolute SCS or SH values ​​of the spent catalysts of Comparative Examples 2 and 3 were also low. Therefore, Comparative Examples 3 to 6 demonstrate that the catalysts of Comparative Examples 1 to 3 have low stability with respect to corrosion and mechanical degradation under the conditions associated with the process of the present invention.

[0406] Example 5: Conversion test of sorbitol using the catalyst of Example 1

[0407] The conversion using the catalyst of Example 1 was carried out in a fixed bed reactor (200 mL). After loading the catalyst, no additional reduction procedure was performed. The reaction mixture was heated at 110 bar and 200 ° C with a LHSV of 0.3 h. -1 A feed consisting of 10 to 40 wt.-% sorbitol and 0.0 to 0.45 wt.-% NaOH was pumped through the reactor. Details are presented in Table 3.

[0408] The yield of diols is plotted as mol% C, which describes the molar conversion of the C atoms of the starting material (e.g., sorbitol) to the desired diols (1,2-propylene glycol (1,2-PDO), ethylene glycol (EG), and glycerol (GLY). The yield is calculated according to the general equation (IV):

[0409]

[0410] The following equation gives an example of the mol% C of 1,2-PDO in Experiment 4 in Table 3.

[0411]

[0412] Table 3: Conversion test of sorbitol using the catalyst of Example 1.

[0413]

[0414] Table 5 shows complete conversion of sorbitol under all applied reaction conditions. Selectivities of up to 40.5 mol% C for 1,2-propylene glycol (1,2 PDO), up to 22.5 mol% C for glycerol (GLY), and up to 16.0 mol% C for ethylene glycol (EG) were achieved. The yields of 1,2-PDO, GLY, and EG are shown in mol% C as calculated according to Equation (I).

[0415] Example 6: Conversion test of sorbitol using the catalyst of Example 1

[0416] The conversion using the catalyst of Example 1 was carried out in a fixed bed reactor (200 mL). After loading the catalyst, no additional reduction procedure was employed. The reaction mixture was heated at 110 to 150 bar, 200°C and LHSV = 0.15 - 1.2 h. -1 A feed consisting of 40 wt.-% sorbitol and 0.45 wt.-% NaOH was pumped through the reactor at 4°C. Details are presented in Table 4.

[0417] Table 4: Conversion test of sorbitol using the catalyst of Example 1.

[0418]

[0419] Table 4 shows complete conversion of sorbitol under all applied reaction conditions. Selectivities of up to 30.7 mol% C for 1,2-propylene glycol (1,2-PDO), up to 23.5 mol% C for glycerol (GLY), and up to 15.4 mol% C for ethylene glycol (EG) were achieved. The yields of 1,2-PDO, GLY, and EG are shown in mol% C as calculated according to Equation (I).

[0420] Examples 7 and 8 and Comparative Example 7: High Throughput Screening

[0421] The catalysts of Examples 1 and 2 and Comparative Example 1 were tested in a high-throughput reactor system that can include up to 16 fixed-bed reactors in parallel. The reactors were loaded with either 0.6 mL or 2.4 mL of catalyst to establish different LHSVs in the particle size range of 250-315 µm. All reactors were connected to the same liquid feed and the same evolved gas and could be heated to the reaction temperature individually. The product was condensed in a liquid condenser while the gas continued to enter a multiport valve and was analyzed by an online gas chromatograph. The condensed liquid samples were analyzed offline by offline gas chromatography and HPLC. Figure 1 A flux reactor system is shown in .

[0422] Example 7: High-throughput screening of sorbitol using the catalyst of Example 1

[0423] For each experiment, the reaction was run for 48 hours in a fixed-bed reactor (0.6 mL). After catalyst loading, no additional reduction procedures were employed. A feed consisting of 40 wt.% sorbitol and 0.72 to 4.88 wt.% NaOH was pumped through the reactor at 110 bar. The temperature and space velocity were adjusted throughout the experimental series. Details are presented in Table 5.

[0424] Table 5: Results of high-throughput screening of sorbitol using the catalyst of Example 1.

[0425]

[0426] Table 5 shows the conversion of sorbitol up to 100 mol% C under all applied reaction conditions. Selectivities for 1,2-propylene glycol (1,2 PDO) up to 43.83 mol% C, selectivities for glycerol (GLY) up to 26.4 mol% C, and selectivities for ethylene glycol (EG) up to 15.00 mol% C were achieved. The yields of 1,2-PDO, GLY, and EG are depicted in mol% C as calculated according to Equation (I).

[0427] Example 8: High-throughput screening of sorbitol using the catalyst of Example 2

[0428] For each experiment, conversion using the catalyst from Example 2 was carried out in a fixed-bed reactor (0.6 mL) for 48 hours. After catalyst loading, no additional reduction procedures were employed. A feed consisting of 40 wt.% sorbitol and 0.72 to 4.88 wt.% NaOH was pumped through the reactor at 110 bar. Temperature and space velocity were adjusted throughout the experimental series. Details are presented in Table 6.

[0429] Table 6: Results of high-throughput screening of sorbitol using the catalyst of Example 2.

[0430]

[0431] Table 6 shows the conversion of sorbitol up to 100 mol% C under all applied reaction conditions. Selectivities for 1,2-propylene glycol (1,2 PDO) up to 45.31 mol% C, selectivities for glycerol (GLY) up to 23.99 mol% C, and selectivities for ethylene glycol (EG) up to 16.13 mol% C were achieved. The yields of 1,2-PDO, GLY, and EG are depicted in mol% C as calculated according to Equation (I).

[0432] Comparative Example 7: High-throughput screening of sorbitol using the catalyst of Comparative Example 1

[0433] For each experiment, the reaction using the catalyst from Comparative Example 1 was carried out in a fixed-bed reactor (0.6 mL) for 48 hours. After catalyst loading, no additional reduction procedure was employed. A feed consisting of 40 wt.% sorbitol and 0.72 to 4.88 wt.% NaOH was pumped through the reactor at 110 bar. The temperature and space velocity were adjusted throughout the experimental series. Details are presented in Table 7.

[0434] Table 7: Results of high-throughput screening of sorbitol using the catalyst of Comparative Example 1.

[0435]

[0436] Table 7 shows the conversion of sorbitol up to 100 mol% C under all applied reaction conditions. Selectivities of up to 44.89 mol% C were achieved for 1,2-propylene glycol (1,2-PDO), 22.7 mol% C for glycerol (GLY), and 15.29 mol% C for ethylene glycol (EG). The yields of 1,2-PDO, GLY, and EG are plotted as mol% C as calculated according to Equation (1). However, Comparative Example 4 reveals insufficient mechanical stability of the catalyst of Comparative Example 1. Therefore, the conversion and selectivity results presented in Table 7 cannot be sustainably achieved in an industrial process using the catalyst of Comparative Example 1.

[0437] Comparative Example 8: High-throughput screening of sorbitol using the catalyst of Comparative Example 2

[0438] For each experiment, the reaction using the catalyst from Comparative Example 2 was carried out in a fixed-bed reactor (0.6 mL) for 48 hours. After catalyst loading, no additional reduction procedure was employed. A feed consisting of 40 wt.% sorbitol and 0.72 to 4.88 wt.% NaOH was pumped through the reactor at 110 bar. The temperature and space velocity were adjusted throughout the experimental series. Details are presented in Table 8.

[0439] Table 8: Results of high-throughput screening of sorbitol using the catalyst of Comparative Example 2.

[0440]

[0441] Table 8 shows the conversion of sorbitol up to 100 mol% C under all applied reaction conditions. Selectivities of up to 42.71 mol% C were achieved for 1,2-propylene glycol (1,2-PDO), 7.15 mol% C for glycerol (GLY), and 9.76 mol% C for ethylene glycol (EG). The yields of 1,2-PDO, GLY, and EG are plotted as mol% C as calculated according to Equation (1). After Experiment 4, the test had to be terminated due to an increase in the reactor pressure drop caused by a loss of catalyst stability. Therefore, the conversion and selectivity results presented in Table 8 cannot be sustainably achieved in an industrial process using the catalyst of Comparative Example 2.

[0442] Comparative Example 9: High-throughput screening of sorbitol using the catalyst of Comparative Example 3

[0443] For each experiment, the reaction using the catalyst from Comparative Example 3 was carried out in a fixed-bed reactor (0.6 mL) for 48 hours. After catalyst loading, no additional reduction procedure was employed. A feed consisting of 40 wt.% sorbitol and 0.72 to 4.88 wt.% NaOH was pumped through the reactor at 110 bar. The temperature and space velocity were adjusted throughout the experimental series. Details are presented in Table 9.

[0444] Table 9: Results of high-throughput screening of sorbitol using the catalyst of Comparative Example 3.

[0445]

[0446] Table 9 shows the conversion of sorbitol up to 100 mol% C under all applied reaction conditions. Selectivities of up to 41.98 mol% C were achieved for 1,2-propylene glycol (1,2-PDO), 11.51 mol% C for glycerol (GLY), and 10.37 mol% C for ethylene glycol (EG). The yields of 1,2-PDO, GLY, and EG are plotted as mol% C as calculated according to Equation (1). In Table 9, Experiments 1 and 7 show the results obtained under identical operating conditions at the beginning and end of the catalyst testing program. In Experiment 7, the sorbitol conversion was significantly lower than the value in Experiment 1, indicating a loss of catalyst activity and, therefore, a lack of catalyst stability. Therefore, the conversion and selectivity results presented in Table 9 cannot be sustainably achieved in an industrial process using the catalyst of Comparative Example 3.

[0447] Prior art cited:

[0448] -US 6,900,361 B2

[0449] -EP 2 403 818 A1

[0450] -US 5,814,112 A

[0451] -US 6,152,975 A

[0452] -Journal of Environmental Chemical Engineering 2022, 10, 107229

[0453] -Wang et al. (ChemCatChem 2019, 11, 4123–4129

[0454] -Xin Jin et al. (ACS Catal. 2015, 5, 6545-6558

[0455] -Chen et al. (Catalysis Communications 2013, 39, 86–89

Claims

1. A method for preparing one or more of a monohydric alcohol, a dihydric alcohol and a trihydric alcohol each having two or three carbon atoms, the method comprising (i) providing a liquid aqueous feed stream comprising one or more of sugars and sugar alcohols each having three, five, or six carbon atoms; (ii) feeding the liquid aqueous feed stream provided according to (i) to a reaction zone comprising a catalyst comprising nickel, and subjecting the feed stream to reaction conditions in the reaction zone to obtain a reaction mixture comprising one or more of the monool, diol, and triol; (iii) removing a liquid aqueous effluent stream comprising one or more of the monool, diol, and triol from the reaction zone; The catalyst comprises zirconium oxide, wherein 5 to 60 wt.-% of the catalyst consists of zirconium oxide, calculated as ZrO2.

2. The method according to claim 1, wherein The catalyst further comprises a metal oxide, wherein the metal of the metal oxides is preferably selected from the group consisting of Na, Mg, Al, Si, K, Ca, Ti, Mn, Co, Cu, Zn, Nb, Mo, La, Hf, and W, including combinations of two or more thereof; more preferably selected from the group consisting of Na, Mg, Al, Si, Ca, Ti, Mn, Co, Cu, La, and Hf, including combinations of two or more thereof; more preferably selected from the group consisting of Al, Si, Mn, Co and Cu, including combinations of two or more thereof; more preferably selected from the group consisting of Cu and Co, including combinations thereof; more preferably the metal of the metal oxides is Cu; wherein more preferably the catalyst further comprises a metal oxide selected from the group consisting of CuO, CoO, Co2O3 and Co3O4, including mixtures thereof; more preferably the catalyst further comprises CuO.

3. The method according to claim 1 or 2, wherein The catalyst has a crystallinity ranging from 60% to 100% based on the total catalyst, as determined from a powder X-ray diffraction pattern of the catalyst.

4. The method according to any one of claims 1 to 3, wherein The powder X-ray diffraction pattern of the catalyst showed signal peaks in the ranges of 28° to 29° and 31° to 32° 2θ angles.

5. The method according to any one of claims 1 to 4, wherein The catalyst comprises a monoclinic phase comprising zirconium oxide and optionally a tetragonal phase comprising zirconium oxide, preferably wherein, The monoclinic phase contains zirconium oxide in an amount of 5 to 100 wt.-% and the tetragonal phase contains zirconium oxide in an amount of 0 to 20 wt.-%, based on 100 wt.-% of all crystalline phases in the catalyst, as determined from the powder X-ray diffraction pattern of the catalyst.

6. The method according to any one of claims 1 to 5, wherein 40 to 90 wt.-%, preferably 45 to 85 wt.-%, more preferably 50 to 80 wt.-% of the catalyst consists of nickel, calculated as NiO.

7. The method according to any one of claims 1 to 6, wherein 40 to 90 wt.-%, preferably 60 to 85 wt.-% of the catalyst consists of nickel and copper, calculated as NiO and CuO.

8. The method according to any one of claims 1 to 7, wherein One or more of the sugars having six carbon atoms are preferably selected from the group consisting of glucose, galactose, maltose, lactose, sucrose, allose, altrose, mannose, gulose, idose, talose, including combinations of two or more thereof.

9. The method according to any one of claims 1 to 8, wherein The one or more of the monohydric alcohols, dihydric alcohols and trihydric alcohols each having two or three carbon atoms is selected from the group consisting of 1,2-propylene glycol, ethylene glycol, 1,3-propylene glycol, glycerol, 1-propanol, 2-propanol and ethanol, including combinations of two or more thereof.

10. The method of claim 9, wherein: The one or more of the diols and triols each having two or three carbon atoms is selected from the group consisting of 1,2-propylene glycol, ethylene glycol, and glycerol, including combinations of two or more thereof.

11. The method according to any one of claims 1 to 10, wherein The liquid aqueous feed stream in (ii) comprises 20 to 99 wt.-%, preferably 25 to 60 wt.-%, more preferably 25 to 40 wt.-% of sugars or sugar alcohols each having three, five or six carbon atoms.

12. The method according to any one of claims 1 to 11, wherein The liquid aqueous feed stream provided in (i) further comprises a compound selected from the group consisting of a base, a Lewis acid and a combination thereof, preferably the liquid aqueous feed stream provided in (i) further comprises a base, wherein preferably the base is selected from the group consisting of a metal hydroxide and a metal carbonate, wherein the metal of the metal hydroxide and the metal carbonate is preferably selected from the group consisting of Li, Na, K, Ca, and Mg, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides and metal carbonates, wherein the one or more metal hydroxides and metal carbonates are selected from the group consisting of LiOH, NaOH, Na2CO3, KOH, K2CO3, C a(OH)2, and Mg(OH)2, including mixtures of two or more thereof; preferably selected from the group consisting of NaOH, Na2CO3, KOH, K2CO3, Ca(OH)2 and Mg(OH)2, including combinations of two or more thereof; wherein more preferably the base comprises one or more metal hydroxides and metal carbonates selected from the group consisting of NaOH, Na2CO3, KOH and K2CO3, including combinations of two thereof; more preferably the base comprises NaOH, preferably NaOH.

13. The method according to any one of claims 1 to 12, wherein The reaction conditions according to (ii) include a reaction pressure in the range of 40 to 250 bar, preferably 60 to 200 bar and more preferably 80 to 120 bar.

14. The method according to any one of claims 1 to 13, wherein The reaction conditions according to (ii) include temperatures in the range of 140 to 220°C, preferably 170 to 200°C.

15. The method according to any one of claims 1 to 14, wherein The liquid aqueous feed stream provided in (i) and fed to the reaction zone in (ii) further comprises H2.

16. A method for preparing a catalyst, preferably a catalyst for use in the method according to any one of claims 1 to 15, comprising (a) preparing a first mixture comprising zirconium oxide and water; (b) preparing a second mixture comprising a nickel precursor selected from the group consisting of nickel nitrate, nickel halide, nickel acetate, nickel sulfate and, optionally, a copper precursor and water; and Copper nitrate, copper halide, copper acetate, copper sulfate, copper amine complex, including combinations of two or more thereof; (c) mixing the first mixture obtained in (a), the second mixture obtained in (b), and a precipitant to obtain a slurry comprising solids and water; (d) removing water from the slurry obtained in (c) to obtain a solid; (e) optionally, drying the solid obtained in (d) at a temperature in the range of 80°C to 150°C to obtain a dried solid; (f) calcining the solid obtained in (d), preferably the dried solid obtained in (e), at a temperature in the range of 300 to 700 ° C. to obtain a catalyst comprising nickel oxide and zirconium oxide, wherein 5 to 60 wt.-% of the catalyst, preferably the catalyst for use in the process as claimed in any one of claims 1 to 15, consists of zirconium oxide, calculated as ZrO2.

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